linux/drivers/hv/hv_balloon.c

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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2012, Microsoft Corporation.
*
* Author:
* K. Y. Srinivasan <kys@microsoft.com>
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/kernel.h>
#include <linux/jiffies.h>
#include <linux/mman.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/kthread.h>
#include <linux/completion.h>
#include <linux/count_zeros.h>
#include <linux/memory_hotplug.h>
#include <linux/memory.h>
#include <linux/notifier.h>
#include <linux/percpu_counter.h>
#include <linux/page_reporting.h>
#include <linux/hyperv.h>
#include <asm/hyperv-tlfs.h>
#include <asm/mshyperv.h>
#define CREATE_TRACE_POINTS
#include "hv_trace_balloon.h"
/*
* We begin with definitions supporting the Dynamic Memory protocol
* with the host.
*
* Begin protocol definitions.
*/
/*
* Protocol versions. The low word is the minor version, the high word the major
* version.
*
* History:
* Initial version 1.0
* Changed to 0.1 on 2009/03/25
* Changes to 0.2 on 2009/05/14
* Changes to 0.3 on 2009/12/03
* Changed to 1.0 on 2011/04/05
*/
#define DYNMEM_MAKE_VERSION(Major, Minor) ((__u32)(((Major) << 16) | (Minor)))
#define DYNMEM_MAJOR_VERSION(Version) ((__u32)(Version) >> 16)
#define DYNMEM_MINOR_VERSION(Version) ((__u32)(Version) & 0xff)
enum {
DYNMEM_PROTOCOL_VERSION_1 = DYNMEM_MAKE_VERSION(0, 3),
DYNMEM_PROTOCOL_VERSION_2 = DYNMEM_MAKE_VERSION(1, 0),
DYNMEM_PROTOCOL_VERSION_3 = DYNMEM_MAKE_VERSION(2, 0),
DYNMEM_PROTOCOL_VERSION_WIN7 = DYNMEM_PROTOCOL_VERSION_1,
DYNMEM_PROTOCOL_VERSION_WIN8 = DYNMEM_PROTOCOL_VERSION_2,
DYNMEM_PROTOCOL_VERSION_WIN10 = DYNMEM_PROTOCOL_VERSION_3,
DYNMEM_PROTOCOL_VERSION_CURRENT = DYNMEM_PROTOCOL_VERSION_WIN10
};
/*
* Message Types
*/
enum dm_message_type {
/*
* Version 0.3
*/
DM_ERROR = 0,
DM_VERSION_REQUEST = 1,
DM_VERSION_RESPONSE = 2,
DM_CAPABILITIES_REPORT = 3,
DM_CAPABILITIES_RESPONSE = 4,
DM_STATUS_REPORT = 5,
DM_BALLOON_REQUEST = 6,
DM_BALLOON_RESPONSE = 7,
DM_UNBALLOON_REQUEST = 8,
DM_UNBALLOON_RESPONSE = 9,
DM_MEM_HOT_ADD_REQUEST = 10,
DM_MEM_HOT_ADD_RESPONSE = 11,
DM_VERSION_03_MAX = 11,
/*
* Version 1.0.
*/
DM_INFO_MESSAGE = 12,
DM_VERSION_1_MAX = 12
};
/*
* Structures defining the dynamic memory management
* protocol.
*/
union dm_version {
struct {
__u16 minor_version;
__u16 major_version;
};
__u32 version;
} __packed;
union dm_caps {
struct {
__u64 balloon:1;
__u64 hot_add:1;
/*
* To support guests that may have alignment
* limitations on hot-add, the guest can specify
* its alignment requirements; a value of n
* represents an alignment of 2^n in mega bytes.
*/
__u64 hot_add_alignment:4;
__u64 reservedz:58;
} cap_bits;
__u64 caps;
} __packed;
union dm_mem_page_range {
struct {
/*
* The PFN number of the first page in the range.
* 40 bits is the architectural limit of a PFN
* number for AMD64.
*/
__u64 start_page:40;
/*
* The number of pages in the range.
*/
__u64 page_cnt:24;
} finfo;
__u64 page_range;
} __packed;
/*
* The header for all dynamic memory messages:
*
* type: Type of the message.
* size: Size of the message in bytes; including the header.
* trans_id: The guest is responsible for manufacturing this ID.
*/
struct dm_header {
__u16 type;
__u16 size;
__u32 trans_id;
} __packed;
/*
* A generic message format for dynamic memory.
* Specific message formats are defined later in the file.
*/
struct dm_message {
struct dm_header hdr;
__u8 data[]; /* enclosed message */
} __packed;
/*
* Specific message types supporting the dynamic memory protocol.
*/
/*
* Version negotiation message. Sent from the guest to the host.
* The guest is free to try different versions until the host
* accepts the version.
*
* dm_version: The protocol version requested.
* is_last_attempt: If TRUE, this is the last version guest will request.
* reservedz: Reserved field, set to zero.
*/
struct dm_version_request {
struct dm_header hdr;
union dm_version version;
__u32 is_last_attempt:1;
__u32 reservedz:31;
} __packed;
/*
* Version response message; Host to Guest and indicates
* if the host has accepted the version sent by the guest.
*
* is_accepted: If TRUE, host has accepted the version and the guest
* should proceed to the next stage of the protocol. FALSE indicates that
* guest should re-try with a different version.
*
* reservedz: Reserved field, set to zero.
*/
struct dm_version_response {
struct dm_header hdr;
__u64 is_accepted:1;
__u64 reservedz:63;
} __packed;
/*
* Message reporting capabilities. This is sent from the guest to the
* host.
*/
struct dm_capabilities {
struct dm_header hdr;
union dm_caps caps;
__u64 min_page_cnt;
__u64 max_page_number;
} __packed;
/*
* Response to the capabilities message. This is sent from the host to the
* guest. This message notifies if the host has accepted the guest's
* capabilities. If the host has not accepted, the guest must shutdown
* the service.
*
* is_accepted: Indicates if the host has accepted guest's capabilities.
* reservedz: Must be 0.
*/
struct dm_capabilities_resp_msg {
struct dm_header hdr;
__u64 is_accepted:1;
__u64 reservedz:63;
} __packed;
/*
* This message is used to report memory pressure from the guest.
* This message is not part of any transaction and there is no
* response to this message.
*
* num_avail: Available memory in pages.
* num_committed: Committed memory in pages.
* page_file_size: The accumulated size of all page files
* in the system in pages.
* zero_free: The nunber of zero and free pages.
* page_file_writes: The writes to the page file in pages.
* io_diff: An indicator of file cache efficiency or page file activity,
* calculated as File Cache Page Fault Count - Page Read Count.
* This value is in pages.
*
* Some of these metrics are Windows specific and fortunately
* the algorithm on the host side that computes the guest memory
* pressure only uses num_committed value.
*/
struct dm_status {
struct dm_header hdr;
__u64 num_avail;
__u64 num_committed;
__u64 page_file_size;
__u64 zero_free;
__u32 page_file_writes;
__u32 io_diff;
} __packed;
/*
* Message to ask the guest to allocate memory - balloon up message.
* This message is sent from the host to the guest. The guest may not be
* able to allocate as much memory as requested.
*
* num_pages: number of pages to allocate.
*/
struct dm_balloon {
struct dm_header hdr;
__u32 num_pages;
__u32 reservedz;
} __packed;
/*
* Balloon response message; this message is sent from the guest
* to the host in response to the balloon message.
*
* reservedz: Reserved; must be set to zero.
* more_pages: If FALSE, this is the last message of the transaction.
* if TRUE there will atleast one more message from the guest.
*
* range_count: The number of ranges in the range array.
*
* range_array: An array of page ranges returned to the host.
*
*/
struct dm_balloon_response {
struct dm_header hdr;
__u32 reservedz;
__u32 more_pages:1;
__u32 range_count:31;
union dm_mem_page_range range_array[];
} __packed;
/*
* Un-balloon message; this message is sent from the host
* to the guest to give guest more memory.
*
* more_pages: If FALSE, this is the last message of the transaction.
* if TRUE there will atleast one more message from the guest.
*
* reservedz: Reserved; must be set to zero.
*
* range_count: The number of ranges in the range array.
*
* range_array: An array of page ranges returned to the host.
*
*/
struct dm_unballoon_request {
struct dm_header hdr;
__u32 more_pages:1;
__u32 reservedz:31;
__u32 range_count;
union dm_mem_page_range range_array[];
} __packed;
/*
* Un-balloon response message; this message is sent from the guest
* to the host in response to an unballoon request.
*
*/
struct dm_unballoon_response {
struct dm_header hdr;
} __packed;
/*
* Hot add request message. Message sent from the host to the guest.
*
* mem_range: Memory range to hot add.
*
*/
struct dm_hot_add {
struct dm_header hdr;
union dm_mem_page_range range;
} __packed;
/*
* Hot add response message.
* This message is sent by the guest to report the status of a hot add request.
* If page_count is less than the requested page count, then the host should
* assume all further hot add requests will fail, since this indicates that
* the guest has hit an upper physical memory barrier.
*
* Hot adds may also fail due to low resources; in this case, the guest must
* not complete this message until the hot add can succeed, and the host must
* not send a new hot add request until the response is sent.
* If VSC fails to hot add memory DYNMEM_NUMBER_OF_UNSUCCESSFUL_HOTADD_ATTEMPTS
* times it fails the request.
*
*
* page_count: number of pages that were successfully hot added.
*
* result: result of the operation 1: success, 0: failure.
*
*/
struct dm_hot_add_response {
struct dm_header hdr;
__u32 page_count;
__u32 result;
} __packed;
/*
* Types of information sent from host to the guest.
*/
enum dm_info_type {
INFO_TYPE_MAX_PAGE_CNT = 0,
MAX_INFO_TYPE
};
/*
* Header for the information message.
*/
struct dm_info_header {
enum dm_info_type type;
__u32 data_size;
} __packed;
/*
* This message is sent from the host to the guest to pass
* some relevant information (win8 addition).
*
* reserved: no used.
* info_size: size of the information blob.
* info: information blob.
*/
struct dm_info_msg {
struct dm_header hdr;
__u32 reserved;
__u32 info_size;
__u8 info[];
};
/*
* End protocol definitions.
*/
/*
* State to manage hot adding memory into the guest.
* The range start_pfn : end_pfn specifies the range
* that the host has asked us to hot add. The range
* start_pfn : ha_end_pfn specifies the range that we have
* currently hot added. We hot add in multiples of 128M
* chunks; it is possible that we may not be able to bring
* online all the pages in the region. The range
* covered_start_pfn:covered_end_pfn defines the pages that can
* be brough online.
*/
struct hv_hotadd_state {
struct list_head list;
unsigned long start_pfn;
unsigned long covered_start_pfn;
unsigned long covered_end_pfn;
unsigned long ha_end_pfn;
unsigned long end_pfn;
Drivers: hv: balloon: account for gaps in hot add regions I'm observing the following hot add requests from the WS2012 host: hot_add_req: start_pfn = 0x108200 count = 330752 hot_add_req: start_pfn = 0x158e00 count = 193536 hot_add_req: start_pfn = 0x188400 count = 239616 As the host doesn't specify hot add regions we're trying to create 128Mb-aligned region covering the first request, we create the 0x108000 - 0x160000 region and we add 0x108000 - 0x158e00 memory. The second request passes the pfn_covered() check, we enlarge the region to 0x108000 - 0x190000 and add 0x158e00 - 0x188200 memory. The problem emerges with the third request as it starts at 0x188400 so there is a 0x200 gap which is not covered. As the end of our region is 0x190000 now it again passes the pfn_covered() check were we just adjust the covered_end_pfn and make it 0x188400 instead of 0x188200 which means that we'll try to online 0x188200-0x188400 pages but these pages were never assigned to us and we crash. We can't react to such requests by creating new hot add regions as it may happen that the whole suggested range falls into the previously identified 128Mb-aligned area so we'll end up adding nothing or create intersecting regions and our current logic doesn't allow that. Instead, create a list of such 'gaps' and check for them in the page online callback. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-25 07:23:10 +08:00
/*
* A list of gaps.
*/
struct list_head gap_list;
};
struct hv_hotadd_gap {
struct list_head list;
unsigned long start_pfn;
unsigned long end_pfn;
};
struct balloon_state {
__u32 num_pages;
struct work_struct wrk;
};
struct hot_add_wrk {
union dm_mem_page_range ha_page_range;
union dm_mem_page_range ha_region_range;
struct work_struct wrk;
};
static bool allow_hibernation;
static bool hot_add = true;
static bool do_hot_add;
/*
* Delay reporting memory pressure by
* the specified number of seconds.
*/
static uint pressure_report_delay = 45;
/*
* The last time we posted a pressure report to host.
*/
static unsigned long last_post_time;
module_param(hot_add, bool, (S_IRUGO | S_IWUSR));
MODULE_PARM_DESC(hot_add, "If set attempt memory hot_add");
module_param(pressure_report_delay, uint, (S_IRUGO | S_IWUSR));
MODULE_PARM_DESC(pressure_report_delay, "Delay in secs in reporting pressure");
static atomic_t trans_id = ATOMIC_INIT(0);
static int dm_ring_size = VMBUS_RING_SIZE(16 * 1024);
/*
* Driver specific state.
*/
enum hv_dm_state {
DM_INITIALIZING = 0,
DM_INITIALIZED,
DM_BALLOON_UP,
DM_BALLOON_DOWN,
DM_HOT_ADD,
DM_INIT_ERROR
};
static __u8 recv_buffer[HV_HYP_PAGE_SIZE];
static __u8 balloon_up_send_buffer[HV_HYP_PAGE_SIZE];
#define PAGES_IN_2M (2 * 1024 * 1024 / PAGE_SIZE)
#define HA_CHUNK (128 * 1024 * 1024 / PAGE_SIZE)
struct hv_dynmem_device {
struct hv_device *dev;
enum hv_dm_state state;
struct completion host_event;
struct completion config_event;
/*
* Number of pages we have currently ballooned out.
*/
unsigned int num_pages_ballooned;
unsigned int num_pages_onlined;
unsigned int num_pages_added;
/*
* State to manage the ballooning (up) operation.
*/
struct balloon_state balloon_wrk;
/*
* State to execute the "hot-add" operation.
*/
struct hot_add_wrk ha_wrk;
/*
* This state tracks if the host has specified a hot-add
* region.
*/
bool host_specified_ha_region;
/*
* State to synchronize hot-add.
*/
struct completion ol_waitevent;
/*
* This thread handles hot-add
* requests from the host as well as notifying
* the host with regards to memory pressure in
* the guest.
*/
struct task_struct *thread;
/*
* Protects ha_region_list, num_pages_onlined counter and individual
* regions from ha_region_list.
*/
spinlock_t ha_lock;
/*
* A list of hot-add regions.
*/
struct list_head ha_region_list;
/*
* We start with the highest version we can support
* and downgrade based on the host; we save here the
* next version to try.
*/
__u32 next_version;
/*
* The negotiated version agreed by host.
*/
__u32 version;
struct page_reporting_dev_info pr_dev_info;
};
static struct hv_dynmem_device dm_device;
static void post_status(struct hv_dynmem_device *dm);
#ifdef CONFIG_MEMORY_HOTPLUG
static inline bool has_pfn_is_backed(struct hv_hotadd_state *has,
unsigned long pfn)
{
struct hv_hotadd_gap *gap;
/* The page is not backed. */
if ((pfn < has->covered_start_pfn) || (pfn >= has->covered_end_pfn))
return false;
/* Check for gaps. */
list_for_each_entry(gap, &has->gap_list, list) {
if ((pfn >= gap->start_pfn) && (pfn < gap->end_pfn))
return false;
}
return true;
}
static unsigned long hv_page_offline_check(unsigned long start_pfn,
unsigned long nr_pages)
{
unsigned long pfn = start_pfn, count = 0;
struct hv_hotadd_state *has;
bool found;
while (pfn < start_pfn + nr_pages) {
/*
* Search for HAS which covers the pfn and when we find one
* count how many consequitive PFNs are covered.
*/
found = false;
list_for_each_entry(has, &dm_device.ha_region_list, list) {
while ((pfn >= has->start_pfn) &&
(pfn < has->end_pfn) &&
(pfn < start_pfn + nr_pages)) {
found = true;
if (has_pfn_is_backed(has, pfn))
count++;
pfn++;
}
}
/*
* This PFN is not in any HAS (e.g. we're offlining a region
* which was present at boot), no need to account for it. Go
* to the next one.
*/
if (!found)
pfn++;
}
return count;
}
static int hv_memory_notifier(struct notifier_block *nb, unsigned long val,
void *v)
{
struct memory_notify *mem = (struct memory_notify *)v;
unsigned long flags, pfn_count;
switch (val) {
case MEM_ONLINE:
case MEM_CANCEL_ONLINE:
hv_balloon: don't check for memhp_auto_online manually We get the MEM_ONLINE notifier call if memory is added right from the kernel via add_memory() or later from user space. Let's get rid of the "ha_waiting" flag - the wait event has an inbuilt mechanism (->done) for that. Initialize the wait event only once and reinitialize before adding memory. Unconditionally call complete() and wait_for_completion_timeout(). If there are no waiters, complete() will only increment ->done - which will be reset by reinit_completion(). If complete() has already been called, wait_for_completion_timeout() will not wait. There is still the chance for a small race between concurrent reinit_completion() and complete(). If complete() wins, we would not wait - which is tolerable (and the race exists in current code as well). Note: We only wait for "some" memory to get onlined, which seems to be good enough for now. [akpm@linux-foundation.org: register_memory_notifier() after init_completion(), per David] Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Baoquan He <bhe@redhat.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Wei Liu <wei.liu@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Eduardo Habkost <ehabkost@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Igor Mammedov <imammedo@redhat.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Yumei Huang <yuhuang@redhat.com> Link: http://lkml.kernel.org/r/20200317104942.11178-6-david@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-07 11:07:32 +08:00
complete(&dm_device.ol_waitevent);
break;
case MEM_OFFLINE:
spin_lock_irqsave(&dm_device.ha_lock, flags);
pfn_count = hv_page_offline_check(mem->start_pfn,
mem->nr_pages);
if (pfn_count <= dm_device.num_pages_onlined) {
dm_device.num_pages_onlined -= pfn_count;
} else {
/*
* We're offlining more pages than we managed to online.
* This is unexpected. In any case don't let
* num_pages_onlined wrap around zero.
*/
WARN_ON_ONCE(1);
dm_device.num_pages_onlined = 0;
}
spin_unlock_irqrestore(&dm_device.ha_lock, flags);
break;
case MEM_GOING_ONLINE:
case MEM_GOING_OFFLINE:
case MEM_CANCEL_OFFLINE:
break;
}
return NOTIFY_OK;
}
static struct notifier_block hv_memory_nb = {
.notifier_call = hv_memory_notifier,
.priority = 0
};
Drivers: hv: balloon: account for gaps in hot add regions I'm observing the following hot add requests from the WS2012 host: hot_add_req: start_pfn = 0x108200 count = 330752 hot_add_req: start_pfn = 0x158e00 count = 193536 hot_add_req: start_pfn = 0x188400 count = 239616 As the host doesn't specify hot add regions we're trying to create 128Mb-aligned region covering the first request, we create the 0x108000 - 0x160000 region and we add 0x108000 - 0x158e00 memory. The second request passes the pfn_covered() check, we enlarge the region to 0x108000 - 0x190000 and add 0x158e00 - 0x188200 memory. The problem emerges with the third request as it starts at 0x188400 so there is a 0x200 gap which is not covered. As the end of our region is 0x190000 now it again passes the pfn_covered() check were we just adjust the covered_end_pfn and make it 0x188400 instead of 0x188200 which means that we'll try to online 0x188200-0x188400 pages but these pages were never assigned to us and we crash. We can't react to such requests by creating new hot add regions as it may happen that the whole suggested range falls into the previously identified 128Mb-aligned area so we'll end up adding nothing or create intersecting regions and our current logic doesn't allow that. Instead, create a list of such 'gaps' and check for them in the page online callback. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-25 07:23:10 +08:00
/* Check if the particular page is backed and can be onlined and online it. */
static void hv_page_online_one(struct hv_hotadd_state *has, struct page *pg)
{
hv_balloon: mark inflated pages PG_offline Mark inflated and never onlined pages PG_offline, to tell the world that the content is stale and should not be dumped. Link: http://lkml.kernel.org/r/20181119101616.8901-6-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Pankaj gupta <pagupta@redhat.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Kairui Song <kasong@redhat.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Christian Hansen <chansen3@cisco.com> Cc: Dave Young <dyoung@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Juergen Gross <jgross@suse.com> Cc: Julien Freche <jfreche@vmware.com> Cc: Kazuhito Hagio <k-hagio@ab.jp.nec.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Len Brown <len.brown@intel.com> Cc: Lianbo Jiang <lijiang@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Miles Chen <miles.chen@mediatek.com> Cc: Nadav Amit <namit@vmware.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Omar Sandoval <osandov@fb.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Pavel Tatashin <pasha.tatashin@oracle.com> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xavier Deguillard <xdeguillard@vmware.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-06 07:42:36 +08:00
if (!has_pfn_is_backed(has, page_to_pfn(pg))) {
if (!PageOffline(pg))
__SetPageOffline(pg);
Drivers: hv: balloon: account for gaps in hot add regions I'm observing the following hot add requests from the WS2012 host: hot_add_req: start_pfn = 0x108200 count = 330752 hot_add_req: start_pfn = 0x158e00 count = 193536 hot_add_req: start_pfn = 0x188400 count = 239616 As the host doesn't specify hot add regions we're trying to create 128Mb-aligned region covering the first request, we create the 0x108000 - 0x160000 region and we add 0x108000 - 0x158e00 memory. The second request passes the pfn_covered() check, we enlarge the region to 0x108000 - 0x190000 and add 0x158e00 - 0x188200 memory. The problem emerges with the third request as it starts at 0x188400 so there is a 0x200 gap which is not covered. As the end of our region is 0x190000 now it again passes the pfn_covered() check were we just adjust the covered_end_pfn and make it 0x188400 instead of 0x188200 which means that we'll try to online 0x188200-0x188400 pages but these pages were never assigned to us and we crash. We can't react to such requests by creating new hot add regions as it may happen that the whole suggested range falls into the previously identified 128Mb-aligned area so we'll end up adding nothing or create intersecting regions and our current logic doesn't allow that. Instead, create a list of such 'gaps' and check for them in the page online callback. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-25 07:23:10 +08:00
return;
hv_balloon: mark inflated pages PG_offline Mark inflated and never onlined pages PG_offline, to tell the world that the content is stale and should not be dumped. Link: http://lkml.kernel.org/r/20181119101616.8901-6-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Pankaj gupta <pagupta@redhat.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Kairui Song <kasong@redhat.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Christian Hansen <chansen3@cisco.com> Cc: Dave Young <dyoung@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Juergen Gross <jgross@suse.com> Cc: Julien Freche <jfreche@vmware.com> Cc: Kazuhito Hagio <k-hagio@ab.jp.nec.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Len Brown <len.brown@intel.com> Cc: Lianbo Jiang <lijiang@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Miles Chen <miles.chen@mediatek.com> Cc: Nadav Amit <namit@vmware.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Omar Sandoval <osandov@fb.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Pavel Tatashin <pasha.tatashin@oracle.com> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xavier Deguillard <xdeguillard@vmware.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-06 07:42:36 +08:00
}
if (PageOffline(pg))
__ClearPageOffline(pg);
Drivers: hv: balloon: account for gaps in hot add regions I'm observing the following hot add requests from the WS2012 host: hot_add_req: start_pfn = 0x108200 count = 330752 hot_add_req: start_pfn = 0x158e00 count = 193536 hot_add_req: start_pfn = 0x188400 count = 239616 As the host doesn't specify hot add regions we're trying to create 128Mb-aligned region covering the first request, we create the 0x108000 - 0x160000 region and we add 0x108000 - 0x158e00 memory. The second request passes the pfn_covered() check, we enlarge the region to 0x108000 - 0x190000 and add 0x158e00 - 0x188200 memory. The problem emerges with the third request as it starts at 0x188400 so there is a 0x200 gap which is not covered. As the end of our region is 0x190000 now it again passes the pfn_covered() check were we just adjust the covered_end_pfn and make it 0x188400 instead of 0x188200 which means that we'll try to online 0x188200-0x188400 pages but these pages were never assigned to us and we crash. We can't react to such requests by creating new hot add regions as it may happen that the whole suggested range falls into the previously identified 128Mb-aligned area so we'll end up adding nothing or create intersecting regions and our current logic doesn't allow that. Instead, create a list of such 'gaps' and check for them in the page online callback. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-25 07:23:10 +08:00
/* This frame is currently backed; online the page. */
generic_online_page(pg, 0);
lockdep_assert_held(&dm_device.ha_lock);
dm_device.num_pages_onlined++;
Drivers: hv: balloon: account for gaps in hot add regions I'm observing the following hot add requests from the WS2012 host: hot_add_req: start_pfn = 0x108200 count = 330752 hot_add_req: start_pfn = 0x158e00 count = 193536 hot_add_req: start_pfn = 0x188400 count = 239616 As the host doesn't specify hot add regions we're trying to create 128Mb-aligned region covering the first request, we create the 0x108000 - 0x160000 region and we add 0x108000 - 0x158e00 memory. The second request passes the pfn_covered() check, we enlarge the region to 0x108000 - 0x190000 and add 0x158e00 - 0x188200 memory. The problem emerges with the third request as it starts at 0x188400 so there is a 0x200 gap which is not covered. As the end of our region is 0x190000 now it again passes the pfn_covered() check were we just adjust the covered_end_pfn and make it 0x188400 instead of 0x188200 which means that we'll try to online 0x188200-0x188400 pages but these pages were never assigned to us and we crash. We can't react to such requests by creating new hot add regions as it may happen that the whole suggested range falls into the previously identified 128Mb-aligned area so we'll end up adding nothing or create intersecting regions and our current logic doesn't allow that. Instead, create a list of such 'gaps' and check for them in the page online callback. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-25 07:23:10 +08:00
}
static void hv_bring_pgs_online(struct hv_hotadd_state *has,
unsigned long start_pfn, unsigned long size)
{
int i;
pr_debug("Online %lu pages starting at pfn 0x%lx\n", size, start_pfn);
Drivers: hv: balloon: account for gaps in hot add regions I'm observing the following hot add requests from the WS2012 host: hot_add_req: start_pfn = 0x108200 count = 330752 hot_add_req: start_pfn = 0x158e00 count = 193536 hot_add_req: start_pfn = 0x188400 count = 239616 As the host doesn't specify hot add regions we're trying to create 128Mb-aligned region covering the first request, we create the 0x108000 - 0x160000 region and we add 0x108000 - 0x158e00 memory. The second request passes the pfn_covered() check, we enlarge the region to 0x108000 - 0x190000 and add 0x158e00 - 0x188200 memory. The problem emerges with the third request as it starts at 0x188400 so there is a 0x200 gap which is not covered. As the end of our region is 0x190000 now it again passes the pfn_covered() check were we just adjust the covered_end_pfn and make it 0x188400 instead of 0x188200 which means that we'll try to online 0x188200-0x188400 pages but these pages were never assigned to us and we crash. We can't react to such requests by creating new hot add regions as it may happen that the whole suggested range falls into the previously identified 128Mb-aligned area so we'll end up adding nothing or create intersecting regions and our current logic doesn't allow that. Instead, create a list of such 'gaps' and check for them in the page online callback. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-25 07:23:10 +08:00
for (i = 0; i < size; i++)
hv_page_online_one(has, pfn_to_page(start_pfn + i));
}
static void hv_mem_hot_add(unsigned long start, unsigned long size,
unsigned long pfn_count,
struct hv_hotadd_state *has)
{
int ret = 0;
int i, nid;
unsigned long start_pfn;
unsigned long processed_pfn;
unsigned long total_pfn = pfn_count;
unsigned long flags;
for (i = 0; i < (size/HA_CHUNK); i++) {
start_pfn = start + (i * HA_CHUNK);
spin_lock_irqsave(&dm_device.ha_lock, flags);
has->ha_end_pfn += HA_CHUNK;
if (total_pfn > HA_CHUNK) {
processed_pfn = HA_CHUNK;
total_pfn -= HA_CHUNK;
} else {
processed_pfn = total_pfn;
total_pfn = 0;
}
has->covered_end_pfn += processed_pfn;
spin_unlock_irqrestore(&dm_device.ha_lock, flags);
hv_balloon: don't check for memhp_auto_online manually We get the MEM_ONLINE notifier call if memory is added right from the kernel via add_memory() or later from user space. Let's get rid of the "ha_waiting" flag - the wait event has an inbuilt mechanism (->done) for that. Initialize the wait event only once and reinitialize before adding memory. Unconditionally call complete() and wait_for_completion_timeout(). If there are no waiters, complete() will only increment ->done - which will be reset by reinit_completion(). If complete() has already been called, wait_for_completion_timeout() will not wait. There is still the chance for a small race between concurrent reinit_completion() and complete(). If complete() wins, we would not wait - which is tolerable (and the race exists in current code as well). Note: We only wait for "some" memory to get onlined, which seems to be good enough for now. [akpm@linux-foundation.org: register_memory_notifier() after init_completion(), per David] Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Baoquan He <bhe@redhat.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Wei Liu <wei.liu@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Eduardo Habkost <ehabkost@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Igor Mammedov <imammedo@redhat.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Yumei Huang <yuhuang@redhat.com> Link: http://lkml.kernel.org/r/20200317104942.11178-6-david@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-07 11:07:32 +08:00
reinit_completion(&dm_device.ol_waitevent);
nid = memory_add_physaddr_to_nid(PFN_PHYS(start_pfn));
ret = add_memory(nid, PFN_PHYS((start_pfn)),
(HA_CHUNK << PAGE_SHIFT), MHP_MERGE_RESOURCE);
if (ret) {
pr_err("hot_add memory failed error is %d\n", ret);
if (ret == -EEXIST) {
/*
* This error indicates that the error
* is not a transient failure. This is the
* case where the guest's physical address map
* precludes hot adding memory. Stop all further
* memory hot-add.
*/
do_hot_add = false;
}
spin_lock_irqsave(&dm_device.ha_lock, flags);
has->ha_end_pfn -= HA_CHUNK;
has->covered_end_pfn -= processed_pfn;
spin_unlock_irqrestore(&dm_device.ha_lock, flags);
break;
}
/*
hv_balloon: don't check for memhp_auto_online manually We get the MEM_ONLINE notifier call if memory is added right from the kernel via add_memory() or later from user space. Let's get rid of the "ha_waiting" flag - the wait event has an inbuilt mechanism (->done) for that. Initialize the wait event only once and reinitialize before adding memory. Unconditionally call complete() and wait_for_completion_timeout(). If there are no waiters, complete() will only increment ->done - which will be reset by reinit_completion(). If complete() has already been called, wait_for_completion_timeout() will not wait. There is still the chance for a small race between concurrent reinit_completion() and complete(). If complete() wins, we would not wait - which is tolerable (and the race exists in current code as well). Note: We only wait for "some" memory to get onlined, which seems to be good enough for now. [akpm@linux-foundation.org: register_memory_notifier() after init_completion(), per David] Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Baoquan He <bhe@redhat.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Wei Liu <wei.liu@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Eduardo Habkost <ehabkost@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Igor Mammedov <imammedo@redhat.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Yumei Huang <yuhuang@redhat.com> Link: http://lkml.kernel.org/r/20200317104942.11178-6-david@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-07 11:07:32 +08:00
* Wait for memory to get onlined. If the kernel onlined the
* memory when adding it, this will return directly. Otherwise,
* it will wait for user space to online the memory. This helps
* to avoid adding memory faster than it is getting onlined. As
* adding succeeded, it is ok to proceed even if the memory was
* not onlined in time.
*/
hv_balloon: don't check for memhp_auto_online manually We get the MEM_ONLINE notifier call if memory is added right from the kernel via add_memory() or later from user space. Let's get rid of the "ha_waiting" flag - the wait event has an inbuilt mechanism (->done) for that. Initialize the wait event only once and reinitialize before adding memory. Unconditionally call complete() and wait_for_completion_timeout(). If there are no waiters, complete() will only increment ->done - which will be reset by reinit_completion(). If complete() has already been called, wait_for_completion_timeout() will not wait. There is still the chance for a small race between concurrent reinit_completion() and complete(). If complete() wins, we would not wait - which is tolerable (and the race exists in current code as well). Note: We only wait for "some" memory to get onlined, which seems to be good enough for now. [akpm@linux-foundation.org: register_memory_notifier() after init_completion(), per David] Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Baoquan He <bhe@redhat.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Wei Liu <wei.liu@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Eduardo Habkost <ehabkost@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Igor Mammedov <imammedo@redhat.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Yumei Huang <yuhuang@redhat.com> Link: http://lkml.kernel.org/r/20200317104942.11178-6-david@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-07 11:07:32 +08:00
wait_for_completion_timeout(&dm_device.ol_waitevent, 5 * HZ);
post_status(&dm_device);
}
}
mm/page_alloc.c: memory hotplug: free pages as higher order When freeing pages are done with higher order, time spent on coalescing pages by buddy allocator can be reduced. With section size of 256MB, hot add latency of a single section shows improvement from 50-60 ms to less than 1 ms, hence improving the hot add latency by 60 times. Modify external providers of online callback to align with the change. [arunks@codeaurora.org: v11] Link: http://lkml.kernel.org/r/1547792588-18032-1-git-send-email-arunks@codeaurora.org [akpm@linux-foundation.org: remove unused local, per Arun] [akpm@linux-foundation.org: avoid return of void-returning __free_pages_core(), per Oscar] [akpm@linux-foundation.org: fix it for mm-convert-totalram_pages-and-totalhigh_pages-variables-to-atomic.patch] [arunks@codeaurora.org: v8] Link: http://lkml.kernel.org/r/1547032395-24582-1-git-send-email-arunks@codeaurora.org [arunks@codeaurora.org: v9] Link: http://lkml.kernel.org/r/1547098543-26452-1-git-send-email-arunks@codeaurora.org Link: http://lkml.kernel.org/r/1538727006-5727-1-git-send-email-arunks@codeaurora.org Signed-off-by: Arun KS <arunks@codeaurora.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Mathieu Malaterre <malat@debian.org> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Souptick Joarder <jrdr.linux@gmail.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Aaron Lu <aaron.lu@intel.com> Cc: Srivatsa Vaddagiri <vatsa@codeaurora.org> Cc: Vinayak Menon <vinmenon@codeaurora.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-06 07:42:14 +08:00
static void hv_online_page(struct page *pg, unsigned int order)
{
struct hv_hotadd_state *has;
unsigned long flags;
unsigned long pfn = page_to_pfn(pg);
spin_lock_irqsave(&dm_device.ha_lock, flags);
list_for_each_entry(has, &dm_device.ha_region_list, list) {
Drivers: hv: balloon: account for gaps in hot add regions I'm observing the following hot add requests from the WS2012 host: hot_add_req: start_pfn = 0x108200 count = 330752 hot_add_req: start_pfn = 0x158e00 count = 193536 hot_add_req: start_pfn = 0x188400 count = 239616 As the host doesn't specify hot add regions we're trying to create 128Mb-aligned region covering the first request, we create the 0x108000 - 0x160000 region and we add 0x108000 - 0x158e00 memory. The second request passes the pfn_covered() check, we enlarge the region to 0x108000 - 0x190000 and add 0x158e00 - 0x188200 memory. The problem emerges with the third request as it starts at 0x188400 so there is a 0x200 gap which is not covered. As the end of our region is 0x190000 now it again passes the pfn_covered() check were we just adjust the covered_end_pfn and make it 0x188400 instead of 0x188200 which means that we'll try to online 0x188200-0x188400 pages but these pages were never assigned to us and we crash. We can't react to such requests by creating new hot add regions as it may happen that the whole suggested range falls into the previously identified 128Mb-aligned area so we'll end up adding nothing or create intersecting regions and our current logic doesn't allow that. Instead, create a list of such 'gaps' and check for them in the page online callback. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-25 07:23:10 +08:00
/* The page belongs to a different HAS. */
mm/page_alloc.c: memory hotplug: free pages as higher order When freeing pages are done with higher order, time spent on coalescing pages by buddy allocator can be reduced. With section size of 256MB, hot add latency of a single section shows improvement from 50-60 ms to less than 1 ms, hence improving the hot add latency by 60 times. Modify external providers of online callback to align with the change. [arunks@codeaurora.org: v11] Link: http://lkml.kernel.org/r/1547792588-18032-1-git-send-email-arunks@codeaurora.org [akpm@linux-foundation.org: remove unused local, per Arun] [akpm@linux-foundation.org: avoid return of void-returning __free_pages_core(), per Oscar] [akpm@linux-foundation.org: fix it for mm-convert-totalram_pages-and-totalhigh_pages-variables-to-atomic.patch] [arunks@codeaurora.org: v8] Link: http://lkml.kernel.org/r/1547032395-24582-1-git-send-email-arunks@codeaurora.org [arunks@codeaurora.org: v9] Link: http://lkml.kernel.org/r/1547098543-26452-1-git-send-email-arunks@codeaurora.org Link: http://lkml.kernel.org/r/1538727006-5727-1-git-send-email-arunks@codeaurora.org Signed-off-by: Arun KS <arunks@codeaurora.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Mathieu Malaterre <malat@debian.org> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Souptick Joarder <jrdr.linux@gmail.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Aaron Lu <aaron.lu@intel.com> Cc: Srivatsa Vaddagiri <vatsa@codeaurora.org> Cc: Vinayak Menon <vinmenon@codeaurora.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-06 07:42:14 +08:00
if ((pfn < has->start_pfn) ||
(pfn + (1UL << order) > has->end_pfn))
Drivers: hv: balloon: account for gaps in hot add regions I'm observing the following hot add requests from the WS2012 host: hot_add_req: start_pfn = 0x108200 count = 330752 hot_add_req: start_pfn = 0x158e00 count = 193536 hot_add_req: start_pfn = 0x188400 count = 239616 As the host doesn't specify hot add regions we're trying to create 128Mb-aligned region covering the first request, we create the 0x108000 - 0x160000 region and we add 0x108000 - 0x158e00 memory. The second request passes the pfn_covered() check, we enlarge the region to 0x108000 - 0x190000 and add 0x158e00 - 0x188200 memory. The problem emerges with the third request as it starts at 0x188400 so there is a 0x200 gap which is not covered. As the end of our region is 0x190000 now it again passes the pfn_covered() check were we just adjust the covered_end_pfn and make it 0x188400 instead of 0x188200 which means that we'll try to online 0x188200-0x188400 pages but these pages were never assigned to us and we crash. We can't react to such requests by creating new hot add regions as it may happen that the whole suggested range falls into the previously identified 128Mb-aligned area so we'll end up adding nothing or create intersecting regions and our current logic doesn't allow that. Instead, create a list of such 'gaps' and check for them in the page online callback. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-25 07:23:10 +08:00
continue;
mm/page_alloc.c: memory hotplug: free pages as higher order When freeing pages are done with higher order, time spent on coalescing pages by buddy allocator can be reduced. With section size of 256MB, hot add latency of a single section shows improvement from 50-60 ms to less than 1 ms, hence improving the hot add latency by 60 times. Modify external providers of online callback to align with the change. [arunks@codeaurora.org: v11] Link: http://lkml.kernel.org/r/1547792588-18032-1-git-send-email-arunks@codeaurora.org [akpm@linux-foundation.org: remove unused local, per Arun] [akpm@linux-foundation.org: avoid return of void-returning __free_pages_core(), per Oscar] [akpm@linux-foundation.org: fix it for mm-convert-totalram_pages-and-totalhigh_pages-variables-to-atomic.patch] [arunks@codeaurora.org: v8] Link: http://lkml.kernel.org/r/1547032395-24582-1-git-send-email-arunks@codeaurora.org [arunks@codeaurora.org: v9] Link: http://lkml.kernel.org/r/1547098543-26452-1-git-send-email-arunks@codeaurora.org Link: http://lkml.kernel.org/r/1538727006-5727-1-git-send-email-arunks@codeaurora.org Signed-off-by: Arun KS <arunks@codeaurora.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Mathieu Malaterre <malat@debian.org> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Souptick Joarder <jrdr.linux@gmail.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Aaron Lu <aaron.lu@intel.com> Cc: Srivatsa Vaddagiri <vatsa@codeaurora.org> Cc: Vinayak Menon <vinmenon@codeaurora.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-06 07:42:14 +08:00
hv_bring_pgs_online(has, pfn, 1UL << order);
Drivers: hv: balloon: account for gaps in hot add regions I'm observing the following hot add requests from the WS2012 host: hot_add_req: start_pfn = 0x108200 count = 330752 hot_add_req: start_pfn = 0x158e00 count = 193536 hot_add_req: start_pfn = 0x188400 count = 239616 As the host doesn't specify hot add regions we're trying to create 128Mb-aligned region covering the first request, we create the 0x108000 - 0x160000 region and we add 0x108000 - 0x158e00 memory. The second request passes the pfn_covered() check, we enlarge the region to 0x108000 - 0x190000 and add 0x158e00 - 0x188200 memory. The problem emerges with the third request as it starts at 0x188400 so there is a 0x200 gap which is not covered. As the end of our region is 0x190000 now it again passes the pfn_covered() check were we just adjust the covered_end_pfn and make it 0x188400 instead of 0x188200 which means that we'll try to online 0x188200-0x188400 pages but these pages were never assigned to us and we crash. We can't react to such requests by creating new hot add regions as it may happen that the whole suggested range falls into the previously identified 128Mb-aligned area so we'll end up adding nothing or create intersecting regions and our current logic doesn't allow that. Instead, create a list of such 'gaps' and check for them in the page online callback. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-25 07:23:10 +08:00
break;
}
spin_unlock_irqrestore(&dm_device.ha_lock, flags);
}
Drivers: hv: balloon: account for gaps in hot add regions I'm observing the following hot add requests from the WS2012 host: hot_add_req: start_pfn = 0x108200 count = 330752 hot_add_req: start_pfn = 0x158e00 count = 193536 hot_add_req: start_pfn = 0x188400 count = 239616 As the host doesn't specify hot add regions we're trying to create 128Mb-aligned region covering the first request, we create the 0x108000 - 0x160000 region and we add 0x108000 - 0x158e00 memory. The second request passes the pfn_covered() check, we enlarge the region to 0x108000 - 0x190000 and add 0x158e00 - 0x188200 memory. The problem emerges with the third request as it starts at 0x188400 so there is a 0x200 gap which is not covered. As the end of our region is 0x190000 now it again passes the pfn_covered() check were we just adjust the covered_end_pfn and make it 0x188400 instead of 0x188200 which means that we'll try to online 0x188200-0x188400 pages but these pages were never assigned to us and we crash. We can't react to such requests by creating new hot add regions as it may happen that the whole suggested range falls into the previously identified 128Mb-aligned area so we'll end up adding nothing or create intersecting regions and our current logic doesn't allow that. Instead, create a list of such 'gaps' and check for them in the page online callback. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-25 07:23:10 +08:00
static int pfn_covered(unsigned long start_pfn, unsigned long pfn_cnt)
{
struct hv_hotadd_state *has;
Drivers: hv: balloon: account for gaps in hot add regions I'm observing the following hot add requests from the WS2012 host: hot_add_req: start_pfn = 0x108200 count = 330752 hot_add_req: start_pfn = 0x158e00 count = 193536 hot_add_req: start_pfn = 0x188400 count = 239616 As the host doesn't specify hot add regions we're trying to create 128Mb-aligned region covering the first request, we create the 0x108000 - 0x160000 region and we add 0x108000 - 0x158e00 memory. The second request passes the pfn_covered() check, we enlarge the region to 0x108000 - 0x190000 and add 0x158e00 - 0x188200 memory. The problem emerges with the third request as it starts at 0x188400 so there is a 0x200 gap which is not covered. As the end of our region is 0x190000 now it again passes the pfn_covered() check were we just adjust the covered_end_pfn and make it 0x188400 instead of 0x188200 which means that we'll try to online 0x188200-0x188400 pages but these pages were never assigned to us and we crash. We can't react to such requests by creating new hot add regions as it may happen that the whole suggested range falls into the previously identified 128Mb-aligned area so we'll end up adding nothing or create intersecting regions and our current logic doesn't allow that. Instead, create a list of such 'gaps' and check for them in the page online callback. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-25 07:23:10 +08:00
struct hv_hotadd_gap *gap;
unsigned long residual, new_inc;
int ret = 0;
unsigned long flags;
spin_lock_irqsave(&dm_device.ha_lock, flags);
list_for_each_entry(has, &dm_device.ha_region_list, list) {
/*
* If the pfn range we are dealing with is not in the current
* "hot add block", move on.
*/
if (start_pfn < has->start_pfn || start_pfn >= has->end_pfn)
continue;
Drivers: hv: balloon: account for gaps in hot add regions I'm observing the following hot add requests from the WS2012 host: hot_add_req: start_pfn = 0x108200 count = 330752 hot_add_req: start_pfn = 0x158e00 count = 193536 hot_add_req: start_pfn = 0x188400 count = 239616 As the host doesn't specify hot add regions we're trying to create 128Mb-aligned region covering the first request, we create the 0x108000 - 0x160000 region and we add 0x108000 - 0x158e00 memory. The second request passes the pfn_covered() check, we enlarge the region to 0x108000 - 0x190000 and add 0x158e00 - 0x188200 memory. The problem emerges with the third request as it starts at 0x188400 so there is a 0x200 gap which is not covered. As the end of our region is 0x190000 now it again passes the pfn_covered() check were we just adjust the covered_end_pfn and make it 0x188400 instead of 0x188200 which means that we'll try to online 0x188200-0x188400 pages but these pages were never assigned to us and we crash. We can't react to such requests by creating new hot add regions as it may happen that the whole suggested range falls into the previously identified 128Mb-aligned area so we'll end up adding nothing or create intersecting regions and our current logic doesn't allow that. Instead, create a list of such 'gaps' and check for them in the page online callback. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-25 07:23:10 +08:00
/*
* If the current start pfn is not where the covered_end
* is, create a gap and update covered_end_pfn.
*/
if (has->covered_end_pfn != start_pfn) {
gap = kzalloc(sizeof(struct hv_hotadd_gap), GFP_ATOMIC);
if (!gap) {
ret = -ENOMEM;
break;
}
Drivers: hv: balloon: account for gaps in hot add regions I'm observing the following hot add requests from the WS2012 host: hot_add_req: start_pfn = 0x108200 count = 330752 hot_add_req: start_pfn = 0x158e00 count = 193536 hot_add_req: start_pfn = 0x188400 count = 239616 As the host doesn't specify hot add regions we're trying to create 128Mb-aligned region covering the first request, we create the 0x108000 - 0x160000 region and we add 0x108000 - 0x158e00 memory. The second request passes the pfn_covered() check, we enlarge the region to 0x108000 - 0x190000 and add 0x158e00 - 0x188200 memory. The problem emerges with the third request as it starts at 0x188400 so there is a 0x200 gap which is not covered. As the end of our region is 0x190000 now it again passes the pfn_covered() check were we just adjust the covered_end_pfn and make it 0x188400 instead of 0x188200 which means that we'll try to online 0x188200-0x188400 pages but these pages were never assigned to us and we crash. We can't react to such requests by creating new hot add regions as it may happen that the whole suggested range falls into the previously identified 128Mb-aligned area so we'll end up adding nothing or create intersecting regions and our current logic doesn't allow that. Instead, create a list of such 'gaps' and check for them in the page online callback. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-25 07:23:10 +08:00
INIT_LIST_HEAD(&gap->list);
gap->start_pfn = has->covered_end_pfn;
gap->end_pfn = start_pfn;
list_add_tail(&gap->list, &has->gap_list);
has->covered_end_pfn = start_pfn;
}
/*
* If the current hot add-request extends beyond
* our current limit; extend it.
*/
if ((start_pfn + pfn_cnt) > has->end_pfn) {
residual = (start_pfn + pfn_cnt - has->end_pfn);
/*
* Extend the region by multiples of HA_CHUNK.
*/
new_inc = (residual / HA_CHUNK) * HA_CHUNK;
if (residual % HA_CHUNK)
new_inc += HA_CHUNK;
has->end_pfn += new_inc;
}
ret = 1;
break;
}
spin_unlock_irqrestore(&dm_device.ha_lock, flags);
return ret;
}
static unsigned long handle_pg_range(unsigned long pg_start,
unsigned long pg_count)
{
unsigned long start_pfn = pg_start;
unsigned long pfn_cnt = pg_count;
unsigned long size;
struct hv_hotadd_state *has;
unsigned long pgs_ol = 0;
unsigned long old_covered_state;
unsigned long res = 0, flags;
pr_debug("Hot adding %lu pages starting at pfn 0x%lx.\n", pg_count,
pg_start);
spin_lock_irqsave(&dm_device.ha_lock, flags);
list_for_each_entry(has, &dm_device.ha_region_list, list) {
/*
* If the pfn range we are dealing with is not in the current
* "hot add block", move on.
*/
if (start_pfn < has->start_pfn || start_pfn >= has->end_pfn)
continue;
old_covered_state = has->covered_end_pfn;
if (start_pfn < has->ha_end_pfn) {
/*
* This is the case where we are backing pages
* in an already hot added region. Bring
* these pages online first.
*/
pgs_ol = has->ha_end_pfn - start_pfn;
if (pgs_ol > pfn_cnt)
pgs_ol = pfn_cnt;
Drivers: hv: balloon: account for gaps in hot add regions I'm observing the following hot add requests from the WS2012 host: hot_add_req: start_pfn = 0x108200 count = 330752 hot_add_req: start_pfn = 0x158e00 count = 193536 hot_add_req: start_pfn = 0x188400 count = 239616 As the host doesn't specify hot add regions we're trying to create 128Mb-aligned region covering the first request, we create the 0x108000 - 0x160000 region and we add 0x108000 - 0x158e00 memory. The second request passes the pfn_covered() check, we enlarge the region to 0x108000 - 0x190000 and add 0x158e00 - 0x188200 memory. The problem emerges with the third request as it starts at 0x188400 so there is a 0x200 gap which is not covered. As the end of our region is 0x190000 now it again passes the pfn_covered() check were we just adjust the covered_end_pfn and make it 0x188400 instead of 0x188200 which means that we'll try to online 0x188200-0x188400 pages but these pages were never assigned to us and we crash. We can't react to such requests by creating new hot add regions as it may happen that the whole suggested range falls into the previously identified 128Mb-aligned area so we'll end up adding nothing or create intersecting regions and our current logic doesn't allow that. Instead, create a list of such 'gaps' and check for them in the page online callback. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-25 07:23:10 +08:00
has->covered_end_pfn += pgs_ol;
pfn_cnt -= pgs_ol;
/*
* Check if the corresponding memory block is already
hv_balloon: avoid touching uninitialized struct page during tail onlining Hyper-V memory hotplug protocol has 2M granularity and in Linux x86 we use 128M. To deal with it we implement partial section onlining by registering custom page onlining callback (hv_online_page()). Later, when more memory arrives we try to online the 'tail' (see hv_bring_pgs_online()). It was found that in some cases this 'tail' onlining causes issues: BUG: Bad page state in process kworker/0:2 pfn:109e3a page:ffffe08344278e80 count:0 mapcount:1 mapping:0000000000000000 index:0x0 flags: 0xfffff80000000() raw: 000fffff80000000 dead000000000100 dead000000000200 0000000000000000 raw: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 page dumped because: nonzero mapcount ... Workqueue: events hot_add_req [hv_balloon] Call Trace: dump_stack+0x5c/0x80 bad_page.cold.112+0x7f/0xb2 free_pcppages_bulk+0x4b8/0x690 free_unref_page+0x54/0x70 hv_page_online_one+0x5c/0x80 [hv_balloon] hot_add_req.cold.24+0x182/0x835 [hv_balloon] ... Turns out that we now have deferred struct page initialization for memory hotplug so e.g. memory_block_action() in drivers/base/memory.c does pages_correctly_probed() check and in that check it avoids inspecting struct pages and checks sections instead. But in Hyper-V balloon driver we do PageReserved(pfn_to_page()) check and this is now wrong. Switch to checking online_section_nr() instead. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: stable@kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-01-04 22:19:42 +08:00
* online. It is possible to observe struct pages still
* being uninitialized here so check section instead.
* In case the section is online we need to bring the
* rest of pfns (which were not backed previously)
* online too.
*/
if (start_pfn > has->start_pfn &&
hv_balloon: avoid touching uninitialized struct page during tail onlining Hyper-V memory hotplug protocol has 2M granularity and in Linux x86 we use 128M. To deal with it we implement partial section onlining by registering custom page onlining callback (hv_online_page()). Later, when more memory arrives we try to online the 'tail' (see hv_bring_pgs_online()). It was found that in some cases this 'tail' onlining causes issues: BUG: Bad page state in process kworker/0:2 pfn:109e3a page:ffffe08344278e80 count:0 mapcount:1 mapping:0000000000000000 index:0x0 flags: 0xfffff80000000() raw: 000fffff80000000 dead000000000100 dead000000000200 0000000000000000 raw: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 page dumped because: nonzero mapcount ... Workqueue: events hot_add_req [hv_balloon] Call Trace: dump_stack+0x5c/0x80 bad_page.cold.112+0x7f/0xb2 free_pcppages_bulk+0x4b8/0x690 free_unref_page+0x54/0x70 hv_page_online_one+0x5c/0x80 [hv_balloon] hot_add_req.cold.24+0x182/0x835 [hv_balloon] ... Turns out that we now have deferred struct page initialization for memory hotplug so e.g. memory_block_action() in drivers/base/memory.c does pages_correctly_probed() check and in that check it avoids inspecting struct pages and checks sections instead. But in Hyper-V balloon driver we do PageReserved(pfn_to_page()) check and this is now wrong. Switch to checking online_section_nr() instead. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: stable@kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-01-04 22:19:42 +08:00
online_section_nr(pfn_to_section_nr(start_pfn)))
Drivers: hv: balloon: account for gaps in hot add regions I'm observing the following hot add requests from the WS2012 host: hot_add_req: start_pfn = 0x108200 count = 330752 hot_add_req: start_pfn = 0x158e00 count = 193536 hot_add_req: start_pfn = 0x188400 count = 239616 As the host doesn't specify hot add regions we're trying to create 128Mb-aligned region covering the first request, we create the 0x108000 - 0x160000 region and we add 0x108000 - 0x158e00 memory. The second request passes the pfn_covered() check, we enlarge the region to 0x108000 - 0x190000 and add 0x158e00 - 0x188200 memory. The problem emerges with the third request as it starts at 0x188400 so there is a 0x200 gap which is not covered. As the end of our region is 0x190000 now it again passes the pfn_covered() check were we just adjust the covered_end_pfn and make it 0x188400 instead of 0x188200 which means that we'll try to online 0x188200-0x188400 pages but these pages were never assigned to us and we crash. We can't react to such requests by creating new hot add regions as it may happen that the whole suggested range falls into the previously identified 128Mb-aligned area so we'll end up adding nothing or create intersecting regions and our current logic doesn't allow that. Instead, create a list of such 'gaps' and check for them in the page online callback. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-25 07:23:10 +08:00
hv_bring_pgs_online(has, start_pfn, pgs_ol);
}
if ((has->ha_end_pfn < has->end_pfn) && (pfn_cnt > 0)) {
/*
* We have some residual hot add range
* that needs to be hot added; hot add
* it now. Hot add a multiple of
* of HA_CHUNK that fully covers the pages
* we have.
*/
size = (has->end_pfn - has->ha_end_pfn);
if (pfn_cnt <= size) {
size = ((pfn_cnt / HA_CHUNK) * HA_CHUNK);
if (pfn_cnt % HA_CHUNK)
size += HA_CHUNK;
} else {
pfn_cnt = size;
}
spin_unlock_irqrestore(&dm_device.ha_lock, flags);
hv_mem_hot_add(has->ha_end_pfn, size, pfn_cnt, has);
spin_lock_irqsave(&dm_device.ha_lock, flags);
}
/*
* If we managed to online any pages that were given to us,
* we declare success.
*/
res = has->covered_end_pfn - old_covered_state;
break;
}
spin_unlock_irqrestore(&dm_device.ha_lock, flags);
return res;
}
static unsigned long process_hot_add(unsigned long pg_start,
unsigned long pfn_cnt,
unsigned long rg_start,
unsigned long rg_size)
{
struct hv_hotadd_state *ha_region = NULL;
Drivers: hv: balloon: account for gaps in hot add regions I'm observing the following hot add requests from the WS2012 host: hot_add_req: start_pfn = 0x108200 count = 330752 hot_add_req: start_pfn = 0x158e00 count = 193536 hot_add_req: start_pfn = 0x188400 count = 239616 As the host doesn't specify hot add regions we're trying to create 128Mb-aligned region covering the first request, we create the 0x108000 - 0x160000 region and we add 0x108000 - 0x158e00 memory. The second request passes the pfn_covered() check, we enlarge the region to 0x108000 - 0x190000 and add 0x158e00 - 0x188200 memory. The problem emerges with the third request as it starts at 0x188400 so there is a 0x200 gap which is not covered. As the end of our region is 0x190000 now it again passes the pfn_covered() check were we just adjust the covered_end_pfn and make it 0x188400 instead of 0x188200 which means that we'll try to online 0x188200-0x188400 pages but these pages were never assigned to us and we crash. We can't react to such requests by creating new hot add regions as it may happen that the whole suggested range falls into the previously identified 128Mb-aligned area so we'll end up adding nothing or create intersecting regions and our current logic doesn't allow that. Instead, create a list of such 'gaps' and check for them in the page online callback. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-25 07:23:10 +08:00
int covered;
unsigned long flags;
if (pfn_cnt == 0)
return 0;
Drivers: hv: balloon: account for gaps in hot add regions I'm observing the following hot add requests from the WS2012 host: hot_add_req: start_pfn = 0x108200 count = 330752 hot_add_req: start_pfn = 0x158e00 count = 193536 hot_add_req: start_pfn = 0x188400 count = 239616 As the host doesn't specify hot add regions we're trying to create 128Mb-aligned region covering the first request, we create the 0x108000 - 0x160000 region and we add 0x108000 - 0x158e00 memory. The second request passes the pfn_covered() check, we enlarge the region to 0x108000 - 0x190000 and add 0x158e00 - 0x188200 memory. The problem emerges with the third request as it starts at 0x188400 so there is a 0x200 gap which is not covered. As the end of our region is 0x190000 now it again passes the pfn_covered() check were we just adjust the covered_end_pfn and make it 0x188400 instead of 0x188200 which means that we'll try to online 0x188200-0x188400 pages but these pages were never assigned to us and we crash. We can't react to such requests by creating new hot add regions as it may happen that the whole suggested range falls into the previously identified 128Mb-aligned area so we'll end up adding nothing or create intersecting regions and our current logic doesn't allow that. Instead, create a list of such 'gaps' and check for them in the page online callback. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-25 07:23:10 +08:00
if (!dm_device.host_specified_ha_region) {
covered = pfn_covered(pg_start, pfn_cnt);
if (covered < 0)
return 0;
if (covered)
goto do_pg_range;
Drivers: hv: balloon: account for gaps in hot add regions I'm observing the following hot add requests from the WS2012 host: hot_add_req: start_pfn = 0x108200 count = 330752 hot_add_req: start_pfn = 0x158e00 count = 193536 hot_add_req: start_pfn = 0x188400 count = 239616 As the host doesn't specify hot add regions we're trying to create 128Mb-aligned region covering the first request, we create the 0x108000 - 0x160000 region and we add 0x108000 - 0x158e00 memory. The second request passes the pfn_covered() check, we enlarge the region to 0x108000 - 0x190000 and add 0x158e00 - 0x188200 memory. The problem emerges with the third request as it starts at 0x188400 so there is a 0x200 gap which is not covered. As the end of our region is 0x190000 now it again passes the pfn_covered() check were we just adjust the covered_end_pfn and make it 0x188400 instead of 0x188200 which means that we'll try to online 0x188200-0x188400 pages but these pages were never assigned to us and we crash. We can't react to such requests by creating new hot add regions as it may happen that the whole suggested range falls into the previously identified 128Mb-aligned area so we'll end up adding nothing or create intersecting regions and our current logic doesn't allow that. Instead, create a list of such 'gaps' and check for them in the page online callback. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-25 07:23:10 +08:00
}
/*
* If the host has specified a hot-add range; deal with it first.
*/
if (rg_size != 0) {
ha_region = kzalloc(sizeof(struct hv_hotadd_state), GFP_KERNEL);
if (!ha_region)
return 0;
INIT_LIST_HEAD(&ha_region->list);
Drivers: hv: balloon: account for gaps in hot add regions I'm observing the following hot add requests from the WS2012 host: hot_add_req: start_pfn = 0x108200 count = 330752 hot_add_req: start_pfn = 0x158e00 count = 193536 hot_add_req: start_pfn = 0x188400 count = 239616 As the host doesn't specify hot add regions we're trying to create 128Mb-aligned region covering the first request, we create the 0x108000 - 0x160000 region and we add 0x108000 - 0x158e00 memory. The second request passes the pfn_covered() check, we enlarge the region to 0x108000 - 0x190000 and add 0x158e00 - 0x188200 memory. The problem emerges with the third request as it starts at 0x188400 so there is a 0x200 gap which is not covered. As the end of our region is 0x190000 now it again passes the pfn_covered() check were we just adjust the covered_end_pfn and make it 0x188400 instead of 0x188200 which means that we'll try to online 0x188200-0x188400 pages but these pages were never assigned to us and we crash. We can't react to such requests by creating new hot add regions as it may happen that the whole suggested range falls into the previously identified 128Mb-aligned area so we'll end up adding nothing or create intersecting regions and our current logic doesn't allow that. Instead, create a list of such 'gaps' and check for them in the page online callback. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-25 07:23:10 +08:00
INIT_LIST_HEAD(&ha_region->gap_list);
ha_region->start_pfn = rg_start;
ha_region->ha_end_pfn = rg_start;
ha_region->covered_start_pfn = pg_start;
ha_region->covered_end_pfn = pg_start;
ha_region->end_pfn = rg_start + rg_size;
spin_lock_irqsave(&dm_device.ha_lock, flags);
list_add_tail(&ha_region->list, &dm_device.ha_region_list);
spin_unlock_irqrestore(&dm_device.ha_lock, flags);
}
do_pg_range:
/*
* Process the page range specified; bringing them
* online if possible.
*/
return handle_pg_range(pg_start, pfn_cnt);
}
#endif
static void hot_add_req(struct work_struct *dummy)
{
struct dm_hot_add_response resp;
#ifdef CONFIG_MEMORY_HOTPLUG
unsigned long pg_start, pfn_cnt;
unsigned long rg_start, rg_sz;
#endif
struct hv_dynmem_device *dm = &dm_device;
memset(&resp, 0, sizeof(struct dm_hot_add_response));
resp.hdr.type = DM_MEM_HOT_ADD_RESPONSE;
resp.hdr.size = sizeof(struct dm_hot_add_response);
#ifdef CONFIG_MEMORY_HOTPLUG
pg_start = dm->ha_wrk.ha_page_range.finfo.start_page;
pfn_cnt = dm->ha_wrk.ha_page_range.finfo.page_cnt;
rg_start = dm->ha_wrk.ha_region_range.finfo.start_page;
rg_sz = dm->ha_wrk.ha_region_range.finfo.page_cnt;
if ((rg_start == 0) && (!dm->host_specified_ha_region)) {
unsigned long region_size;
unsigned long region_start;
/*
* The host has not specified the hot-add region.
* Based on the hot-add page range being specified,
* compute a hot-add region that can cover the pages
* that need to be hot-added while ensuring the alignment
* and size requirements of Linux as it relates to hot-add.
*/
region_size = (pfn_cnt / HA_CHUNK) * HA_CHUNK;
if (pfn_cnt % HA_CHUNK)
region_size += HA_CHUNK;
region_start = (pg_start / HA_CHUNK) * HA_CHUNK;
rg_start = region_start;
rg_sz = region_size;
}
if (do_hot_add)
resp.page_count = process_hot_add(pg_start, pfn_cnt,
rg_start, rg_sz);
dm->num_pages_added += resp.page_count;
#endif
/*
* The result field of the response structure has the
* following semantics:
*
* 1. If all or some pages hot-added: Guest should return success.
*
* 2. If no pages could be hot-added:
*
* If the guest returns success, then the host
* will not attempt any further hot-add operations. This
* signifies a permanent failure.
*
* If the guest returns failure, then this failure will be
* treated as a transient failure and the host may retry the
* hot-add operation after some delay.
*/
if (resp.page_count > 0)
resp.result = 1;
else if (!do_hot_add)
resp.result = 1;
else
resp.result = 0;
if (!do_hot_add || resp.page_count == 0) {
if (!allow_hibernation)
pr_err("Memory hot add failed\n");
else
pr_info("Ignore hot-add request!\n");
}
dm->state = DM_INITIALIZED;
resp.hdr.trans_id = atomic_inc_return(&trans_id);
vmbus_sendpacket(dm->dev->channel, &resp,
sizeof(struct dm_hot_add_response),
(unsigned long)NULL,
VM_PKT_DATA_INBAND, 0);
}
static void process_info(struct hv_dynmem_device *dm, struct dm_info_msg *msg)
{
struct dm_info_header *info_hdr;
info_hdr = (struct dm_info_header *)msg->info;
switch (info_hdr->type) {
case INFO_TYPE_MAX_PAGE_CNT:
if (info_hdr->data_size == sizeof(__u64)) {
__u64 *max_page_count = (__u64 *)&info_hdr[1];
pr_info("Max. dynamic memory size: %llu MB\n",
(*max_page_count) >> (20 - HV_HYP_PAGE_SHIFT));
}
break;
default:
pr_warn("Received Unknown type: %d\n", info_hdr->type);
}
}
static unsigned long compute_balloon_floor(void)
{
unsigned long min_pages;
unsigned long nr_pages = totalram_pages();
#define MB2PAGES(mb) ((mb) << (20 - PAGE_SHIFT))
/* Simple continuous piecewiese linear function:
* max MiB -> min MiB gradient
* 0 0
* 16 16
* 32 24
* 128 72 (1/2)
* 512 168 (1/4)
* 2048 360 (1/8)
* 8192 744 (1/16)
* 32768 1512 (1/32)
*/
mm: reference totalram_pages and managed_pages once per function Patch series "mm: convert totalram_pages, totalhigh_pages and managed pages to atomic", v5. This series converts totalram_pages, totalhigh_pages and zone->managed_pages to atomic variables. totalram_pages, zone->managed_pages and totalhigh_pages updates are protected by managed_page_count_lock, but readers never care about it. Convert these variables to atomic to avoid readers potentially seeing a store tear. Main motivation was that managed_page_count_lock handling was complicating things. It was discussed in length here, https://lore.kernel.org/patchwork/patch/995739/#1181785 It seemes better to remove the lock and convert variables to atomic. With the change, preventing poteintial store-to-read tearing comes as a bonus. This patch (of 4): This is in preparation to a later patch which converts totalram_pages and zone->managed_pages to atomic variables. Please note that re-reading the value might lead to a different value and as such it could lead to unexpected behavior. There are no known bugs as a result of the current code but it is better to prevent from them in principle. Link: http://lkml.kernel.org/r/1542090790-21750-2-git-send-email-arunks@codeaurora.org Signed-off-by: Arun KS <arunks@codeaurora.org> Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Reviewed-by: David Hildenbrand <david@redhat.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-28 16:34:20 +08:00
if (nr_pages < MB2PAGES(128))
min_pages = MB2PAGES(8) + (nr_pages >> 1);
else if (nr_pages < MB2PAGES(512))
min_pages = MB2PAGES(40) + (nr_pages >> 2);
else if (nr_pages < MB2PAGES(2048))
min_pages = MB2PAGES(104) + (nr_pages >> 3);
else if (nr_pages < MB2PAGES(8192))
min_pages = MB2PAGES(232) + (nr_pages >> 4);
else
mm: reference totalram_pages and managed_pages once per function Patch series "mm: convert totalram_pages, totalhigh_pages and managed pages to atomic", v5. This series converts totalram_pages, totalhigh_pages and zone->managed_pages to atomic variables. totalram_pages, zone->managed_pages and totalhigh_pages updates are protected by managed_page_count_lock, but readers never care about it. Convert these variables to atomic to avoid readers potentially seeing a store tear. Main motivation was that managed_page_count_lock handling was complicating things. It was discussed in length here, https://lore.kernel.org/patchwork/patch/995739/#1181785 It seemes better to remove the lock and convert variables to atomic. With the change, preventing poteintial store-to-read tearing comes as a bonus. This patch (of 4): This is in preparation to a later patch which converts totalram_pages and zone->managed_pages to atomic variables. Please note that re-reading the value might lead to a different value and as such it could lead to unexpected behavior. There are no known bugs as a result of the current code but it is better to prevent from them in principle. Link: http://lkml.kernel.org/r/1542090790-21750-2-git-send-email-arunks@codeaurora.org Signed-off-by: Arun KS <arunks@codeaurora.org> Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Reviewed-by: David Hildenbrand <david@redhat.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-28 16:34:20 +08:00
min_pages = MB2PAGES(488) + (nr_pages >> 5);
#undef MB2PAGES
return min_pages;
}
/*
* Post our status as it relates memory pressure to the
* host. Host expects the guests to post this status
* periodically at 1 second intervals.
*
* The metrics specified in this protocol are very Windows
* specific and so we cook up numbers here to convey our memory
* pressure.
*/
static void post_status(struct hv_dynmem_device *dm)
{
struct dm_status status;
unsigned long now = jiffies;
unsigned long last_post = last_post_time;
unsigned long num_pages_avail, num_pages_committed;
if (pressure_report_delay > 0) {
--pressure_report_delay;
return;
}
if (!time_after(now, (last_post_time + HZ)))
return;
memset(&status, 0, sizeof(struct dm_status));
status.hdr.type = DM_STATUS_REPORT;
status.hdr.size = sizeof(struct dm_status);
status.hdr.trans_id = atomic_inc_return(&trans_id);
/*
* The host expects the guest to report free and committed memory.
* Furthermore, the host expects the pressure information to include
* the ballooned out pages. For a given amount of memory that we are
* managing we need to compute a floor below which we should not
* balloon. Compute this and add it to the pressure report.
* We also need to report all offline pages (num_pages_added -
* num_pages_onlined) as committed to the host, otherwise it can try
* asking us to balloon them out.
*/
num_pages_avail = si_mem_available();
num_pages_committed = vm_memory_committed() +
dm->num_pages_ballooned +
(dm->num_pages_added > dm->num_pages_onlined ?
dm->num_pages_added - dm->num_pages_onlined : 0) +
compute_balloon_floor();
trace_balloon_status(num_pages_avail, num_pages_committed,
vm_memory_committed(), dm->num_pages_ballooned,
dm->num_pages_added, dm->num_pages_onlined);
/* Convert numbers of pages into numbers of HV_HYP_PAGEs. */
status.num_avail = num_pages_avail * NR_HV_HYP_PAGES_IN_PAGE;
status.num_committed = num_pages_committed * NR_HV_HYP_PAGES_IN_PAGE;
/*
* If our transaction ID is no longer current, just don't
* send the status. This can happen if we were interrupted
* after we picked our transaction ID.
*/
if (status.hdr.trans_id != atomic_read(&trans_id))
return;
/*
* If the last post time that we sampled has changed,
* we have raced, don't post the status.
*/
if (last_post != last_post_time)
return;
last_post_time = jiffies;
vmbus_sendpacket(dm->dev->channel, &status,
sizeof(struct dm_status),
(unsigned long)NULL,
VM_PKT_DATA_INBAND, 0);
}
static void free_balloon_pages(struct hv_dynmem_device *dm,
union dm_mem_page_range *range_array)
{
int num_pages = range_array->finfo.page_cnt;
__u64 start_frame = range_array->finfo.start_page;
struct page *pg;
int i;
for (i = 0; i < num_pages; i++) {
pg = pfn_to_page(i + start_frame);
hv_balloon: mark inflated pages PG_offline Mark inflated and never onlined pages PG_offline, to tell the world that the content is stale and should not be dumped. Link: http://lkml.kernel.org/r/20181119101616.8901-6-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Pankaj gupta <pagupta@redhat.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Kairui Song <kasong@redhat.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Christian Hansen <chansen3@cisco.com> Cc: Dave Young <dyoung@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Juergen Gross <jgross@suse.com> Cc: Julien Freche <jfreche@vmware.com> Cc: Kazuhito Hagio <k-hagio@ab.jp.nec.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Len Brown <len.brown@intel.com> Cc: Lianbo Jiang <lijiang@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Miles Chen <miles.chen@mediatek.com> Cc: Nadav Amit <namit@vmware.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Omar Sandoval <osandov@fb.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Pavel Tatashin <pasha.tatashin@oracle.com> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xavier Deguillard <xdeguillard@vmware.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-06 07:42:36 +08:00
__ClearPageOffline(pg);
__free_page(pg);
dm->num_pages_ballooned--;
adjust_managed_page_count(pg, 1);
}
}
static unsigned int alloc_balloon_pages(struct hv_dynmem_device *dm,
unsigned int num_pages,
struct dm_balloon_response *bl_resp,
int alloc_unit)
{
hv_balloon: mark inflated pages PG_offline Mark inflated and never onlined pages PG_offline, to tell the world that the content is stale and should not be dumped. Link: http://lkml.kernel.org/r/20181119101616.8901-6-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Pankaj gupta <pagupta@redhat.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Kairui Song <kasong@redhat.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Christian Hansen <chansen3@cisco.com> Cc: Dave Young <dyoung@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Juergen Gross <jgross@suse.com> Cc: Julien Freche <jfreche@vmware.com> Cc: Kazuhito Hagio <k-hagio@ab.jp.nec.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Len Brown <len.brown@intel.com> Cc: Lianbo Jiang <lijiang@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Miles Chen <miles.chen@mediatek.com> Cc: Nadav Amit <namit@vmware.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Omar Sandoval <osandov@fb.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Pavel Tatashin <pasha.tatashin@oracle.com> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xavier Deguillard <xdeguillard@vmware.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-06 07:42:36 +08:00
unsigned int i, j;
struct page *pg;
for (i = 0; i < num_pages / alloc_unit; i++) {
if (bl_resp->hdr.size + sizeof(union dm_mem_page_range) >
HV_HYP_PAGE_SIZE)
return i * alloc_unit;
/*
* We execute this code in a thread context. Furthermore,
* we don't want the kernel to try too hard.
*/
pg = alloc_pages(GFP_HIGHUSER | __GFP_NORETRY |
__GFP_NOMEMALLOC | __GFP_NOWARN,
get_order(alloc_unit << PAGE_SHIFT));
Drivers: hv: hv_balloon: survive ballooning request with num_pages=0 ... and simplify alloc_balloon_pages() interface by removing redundant alloc_error from it. If we happen to enter balloon_up() with balloon_wrk.num_pages = 0 we will enter infinite 'while (!done)' loop as alloc_balloon_pages() will be always returning 0 and not setting alloc_error. We will also be sending a meaningless message to the host on every iteration. The 'alloc_unit == 1 && alloc_error -> num_ballooned == 0' change and alloc_error elimination requires a special comment. We do alloc_balloon_pages() with 2 different alloc_unit values and there are 4 different alloc_balloon_pages() results, let's check them all. alloc_unit = 512: 1) num_ballooned = 0, alloc_error = 0: we do 'alloc_unit=1' and retry pre- and post-patch. 2) num_ballooned > 0, alloc_error = 0: we check 'num_ballooned == num_pages' and act accordingly, pre- and post-patch. 3) num_ballooned > 0, alloc_error > 0: we report this chunk and remain within the loop, no changes here. 4) num_ballooned = 0, alloc_error > 0: we do 'alloc_unit=1' and retry pre- and post-patch. alloc_unit = 1: 1) num_ballooned = 0, alloc_error = 0: this can happen in two cases: when we passed 'num_pages=0' to alloc_balloon_pages() or when there was no space in bl_resp to place a single response. The second option is not possible as bl_resp is of PAGE_SIZE size and single response 'union dm_mem_page_range' is 8 bytes, but the first one is (in theory, I think that Hyper-V host never places such requests). Pre-patch code loops forever, post-patch code sends a reply with more_pages = 0 and finishes. 2) num_ballooned > 0, alloc_error = 0: we ran out of space in bl_resp, we report partial success and remain within the loop, no changes pre- and post-patch. 3) num_ballooned > 0, alloc_error > 0: pre-patch code finishes, post-patch code does one more try and if there is no progress (we finish with 'num_ballooned = 0') we finish. So we try a bit harder with this patch. 4) num_ballooned = 0, alloc_error > 0: both pre- and post-patch code enter 'more_pages = 0' branch and finish. So this patch has two real effects: 1) We reply with an empty response to 'num_pages=0' request. 2) We try a bit harder on alloc_unit=1 allocations (and reply with an empty tail reply in case we fail). An empty reply should be supported by host as we were able to send it even with pre-patch code when we were not able to allocate a single page. Suggested-by: Laszlo Ersek <lersek@redhat.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-28 00:10:13 +08:00
if (!pg)
return i * alloc_unit;
dm->num_pages_ballooned += alloc_unit;
/*
* If we allocatted 2M pages; split them so we
* can free them in any order we get.
*/
if (alloc_unit != 1)
split_page(pg, get_order(alloc_unit << PAGE_SHIFT));
hv_balloon: mark inflated pages PG_offline Mark inflated and never onlined pages PG_offline, to tell the world that the content is stale and should not be dumped. Link: http://lkml.kernel.org/r/20181119101616.8901-6-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Pankaj gupta <pagupta@redhat.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Kairui Song <kasong@redhat.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Christian Hansen <chansen3@cisco.com> Cc: Dave Young <dyoung@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Juergen Gross <jgross@suse.com> Cc: Julien Freche <jfreche@vmware.com> Cc: Kazuhito Hagio <k-hagio@ab.jp.nec.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Len Brown <len.brown@intel.com> Cc: Lianbo Jiang <lijiang@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Miles Chen <miles.chen@mediatek.com> Cc: Nadav Amit <namit@vmware.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Omar Sandoval <osandov@fb.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Pavel Tatashin <pasha.tatashin@oracle.com> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xavier Deguillard <xdeguillard@vmware.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-06 07:42:36 +08:00
/* mark all pages offline */
for (j = 0; j < alloc_unit; j++) {
hv_balloon: mark inflated pages PG_offline Mark inflated and never onlined pages PG_offline, to tell the world that the content is stale and should not be dumped. Link: http://lkml.kernel.org/r/20181119101616.8901-6-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Pankaj gupta <pagupta@redhat.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Kairui Song <kasong@redhat.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Christian Hansen <chansen3@cisco.com> Cc: Dave Young <dyoung@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Juergen Gross <jgross@suse.com> Cc: Julien Freche <jfreche@vmware.com> Cc: Kazuhito Hagio <k-hagio@ab.jp.nec.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Len Brown <len.brown@intel.com> Cc: Lianbo Jiang <lijiang@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Miles Chen <miles.chen@mediatek.com> Cc: Nadav Amit <namit@vmware.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Omar Sandoval <osandov@fb.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Pavel Tatashin <pasha.tatashin@oracle.com> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xavier Deguillard <xdeguillard@vmware.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-06 07:42:36 +08:00
__SetPageOffline(pg + j);
adjust_managed_page_count(pg + j, -1);
}
hv_balloon: mark inflated pages PG_offline Mark inflated and never onlined pages PG_offline, to tell the world that the content is stale and should not be dumped. Link: http://lkml.kernel.org/r/20181119101616.8901-6-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Pankaj gupta <pagupta@redhat.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Kairui Song <kasong@redhat.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Christian Hansen <chansen3@cisco.com> Cc: Dave Young <dyoung@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Juergen Gross <jgross@suse.com> Cc: Julien Freche <jfreche@vmware.com> Cc: Kazuhito Hagio <k-hagio@ab.jp.nec.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Len Brown <len.brown@intel.com> Cc: Lianbo Jiang <lijiang@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Miles Chen <miles.chen@mediatek.com> Cc: Nadav Amit <namit@vmware.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Omar Sandoval <osandov@fb.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Pavel Tatashin <pasha.tatashin@oracle.com> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xavier Deguillard <xdeguillard@vmware.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-06 07:42:36 +08:00
bl_resp->range_count++;
bl_resp->range_array[i].finfo.start_page =
page_to_pfn(pg);
bl_resp->range_array[i].finfo.page_cnt = alloc_unit;
bl_resp->hdr.size += sizeof(union dm_mem_page_range);
}
return i * alloc_unit;
}
static void balloon_up(struct work_struct *dummy)
{
unsigned int num_pages = dm_device.balloon_wrk.num_pages;
unsigned int num_ballooned = 0;
struct dm_balloon_response *bl_resp;
int alloc_unit;
int ret;
bool done = false;
int i;
long avail_pages;
unsigned long floor;
/*
* We will attempt 2M allocations. However, if we fail to
* allocate 2M chunks, we will go back to PAGE_SIZE allocations.
*/
alloc_unit = PAGES_IN_2M;
avail_pages = si_mem_available();
floor = compute_balloon_floor();
/* Refuse to balloon below the floor. */
if (avail_pages < num_pages || avail_pages - num_pages < floor) {
pr_info("Balloon request will be partially fulfilled. %s\n",
avail_pages < num_pages ? "Not enough memory." :
"Balloon floor reached.");
num_pages = avail_pages > floor ? (avail_pages - floor) : 0;
}
while (!done) {
memset(balloon_up_send_buffer, 0, HV_HYP_PAGE_SIZE);
bl_resp = (struct dm_balloon_response *)balloon_up_send_buffer;
bl_resp->hdr.type = DM_BALLOON_RESPONSE;
bl_resp->hdr.size = sizeof(struct dm_balloon_response);
bl_resp->more_pages = 1;
num_pages -= num_ballooned;
num_ballooned = alloc_balloon_pages(&dm_device, num_pages,
Drivers: hv: hv_balloon: survive ballooning request with num_pages=0 ... and simplify alloc_balloon_pages() interface by removing redundant alloc_error from it. If we happen to enter balloon_up() with balloon_wrk.num_pages = 0 we will enter infinite 'while (!done)' loop as alloc_balloon_pages() will be always returning 0 and not setting alloc_error. We will also be sending a meaningless message to the host on every iteration. The 'alloc_unit == 1 && alloc_error -> num_ballooned == 0' change and alloc_error elimination requires a special comment. We do alloc_balloon_pages() with 2 different alloc_unit values and there are 4 different alloc_balloon_pages() results, let's check them all. alloc_unit = 512: 1) num_ballooned = 0, alloc_error = 0: we do 'alloc_unit=1' and retry pre- and post-patch. 2) num_ballooned > 0, alloc_error = 0: we check 'num_ballooned == num_pages' and act accordingly, pre- and post-patch. 3) num_ballooned > 0, alloc_error > 0: we report this chunk and remain within the loop, no changes here. 4) num_ballooned = 0, alloc_error > 0: we do 'alloc_unit=1' and retry pre- and post-patch. alloc_unit = 1: 1) num_ballooned = 0, alloc_error = 0: this can happen in two cases: when we passed 'num_pages=0' to alloc_balloon_pages() or when there was no space in bl_resp to place a single response. The second option is not possible as bl_resp is of PAGE_SIZE size and single response 'union dm_mem_page_range' is 8 bytes, but the first one is (in theory, I think that Hyper-V host never places such requests). Pre-patch code loops forever, post-patch code sends a reply with more_pages = 0 and finishes. 2) num_ballooned > 0, alloc_error = 0: we ran out of space in bl_resp, we report partial success and remain within the loop, no changes pre- and post-patch. 3) num_ballooned > 0, alloc_error > 0: pre-patch code finishes, post-patch code does one more try and if there is no progress (we finish with 'num_ballooned = 0') we finish. So we try a bit harder with this patch. 4) num_ballooned = 0, alloc_error > 0: both pre- and post-patch code enter 'more_pages = 0' branch and finish. So this patch has two real effects: 1) We reply with an empty response to 'num_pages=0' request. 2) We try a bit harder on alloc_unit=1 allocations (and reply with an empty tail reply in case we fail). An empty reply should be supported by host as we were able to send it even with pre-patch code when we were not able to allocate a single page. Suggested-by: Laszlo Ersek <lersek@redhat.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-28 00:10:13 +08:00
bl_resp, alloc_unit);
if (alloc_unit != 1 && num_ballooned == 0) {
alloc_unit = 1;
continue;
}
Drivers: hv: hv_balloon: survive ballooning request with num_pages=0 ... and simplify alloc_balloon_pages() interface by removing redundant alloc_error from it. If we happen to enter balloon_up() with balloon_wrk.num_pages = 0 we will enter infinite 'while (!done)' loop as alloc_balloon_pages() will be always returning 0 and not setting alloc_error. We will also be sending a meaningless message to the host on every iteration. The 'alloc_unit == 1 && alloc_error -> num_ballooned == 0' change and alloc_error elimination requires a special comment. We do alloc_balloon_pages() with 2 different alloc_unit values and there are 4 different alloc_balloon_pages() results, let's check them all. alloc_unit = 512: 1) num_ballooned = 0, alloc_error = 0: we do 'alloc_unit=1' and retry pre- and post-patch. 2) num_ballooned > 0, alloc_error = 0: we check 'num_ballooned == num_pages' and act accordingly, pre- and post-patch. 3) num_ballooned > 0, alloc_error > 0: we report this chunk and remain within the loop, no changes here. 4) num_ballooned = 0, alloc_error > 0: we do 'alloc_unit=1' and retry pre- and post-patch. alloc_unit = 1: 1) num_ballooned = 0, alloc_error = 0: this can happen in two cases: when we passed 'num_pages=0' to alloc_balloon_pages() or when there was no space in bl_resp to place a single response. The second option is not possible as bl_resp is of PAGE_SIZE size and single response 'union dm_mem_page_range' is 8 bytes, but the first one is (in theory, I think that Hyper-V host never places such requests). Pre-patch code loops forever, post-patch code sends a reply with more_pages = 0 and finishes. 2) num_ballooned > 0, alloc_error = 0: we ran out of space in bl_resp, we report partial success and remain within the loop, no changes pre- and post-patch. 3) num_ballooned > 0, alloc_error > 0: pre-patch code finishes, post-patch code does one more try and if there is no progress (we finish with 'num_ballooned = 0') we finish. So we try a bit harder with this patch. 4) num_ballooned = 0, alloc_error > 0: both pre- and post-patch code enter 'more_pages = 0' branch and finish. So this patch has two real effects: 1) We reply with an empty response to 'num_pages=0' request. 2) We try a bit harder on alloc_unit=1 allocations (and reply with an empty tail reply in case we fail). An empty reply should be supported by host as we were able to send it even with pre-patch code when we were not able to allocate a single page. Suggested-by: Laszlo Ersek <lersek@redhat.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-28 00:10:13 +08:00
if (num_ballooned == 0 || num_ballooned == num_pages) {
pr_debug("Ballooned %u out of %u requested pages.\n",
num_pages, dm_device.balloon_wrk.num_pages);
bl_resp->more_pages = 0;
done = true;
dm_device.state = DM_INITIALIZED;
}
/*
* We are pushing a lot of data through the channel;
* deal with transient failures caused because of the
* lack of space in the ring buffer.
*/
do {
bl_resp->hdr.trans_id = atomic_inc_return(&trans_id);
ret = vmbus_sendpacket(dm_device.dev->channel,
bl_resp,
bl_resp->hdr.size,
(unsigned long)NULL,
VM_PKT_DATA_INBAND, 0);
if (ret == -EAGAIN)
msleep(20);
post_status(&dm_device);
} while (ret == -EAGAIN);
if (ret) {
/*
* Free up the memory we allocatted.
*/
pr_err("Balloon response failed\n");
for (i = 0; i < bl_resp->range_count; i++)
free_balloon_pages(&dm_device,
&bl_resp->range_array[i]);
done = true;
}
}
}
static void balloon_down(struct hv_dynmem_device *dm,
struct dm_unballoon_request *req)
{
union dm_mem_page_range *range_array = req->range_array;
int range_count = req->range_count;
struct dm_unballoon_response resp;
int i;
unsigned int prev_pages_ballooned = dm->num_pages_ballooned;
for (i = 0; i < range_count; i++) {
free_balloon_pages(dm, &range_array[i]);
complete(&dm_device.config_event);
}
pr_debug("Freed %u ballooned pages.\n",
prev_pages_ballooned - dm->num_pages_ballooned);
if (req->more_pages == 1)
return;
memset(&resp, 0, sizeof(struct dm_unballoon_response));
resp.hdr.type = DM_UNBALLOON_RESPONSE;
resp.hdr.trans_id = atomic_inc_return(&trans_id);
resp.hdr.size = sizeof(struct dm_unballoon_response);
vmbus_sendpacket(dm_device.dev->channel, &resp,
sizeof(struct dm_unballoon_response),
(unsigned long)NULL,
VM_PKT_DATA_INBAND, 0);
dm->state = DM_INITIALIZED;
}
static void balloon_onchannelcallback(void *context);
static int dm_thread_func(void *dm_dev)
{
struct hv_dynmem_device *dm = dm_dev;
while (!kthread_should_stop()) {
wait_for_completion_interruptible_timeout(
&dm_device.config_event, 1*HZ);
/*
* The host expects us to post information on the memory
* pressure every second.
*/
reinit_completion(&dm_device.config_event);
post_status(dm);
}
return 0;
}
static void version_resp(struct hv_dynmem_device *dm,
struct dm_version_response *vresp)
{
struct dm_version_request version_req;
int ret;
if (vresp->is_accepted) {
/*
* We are done; wakeup the
* context waiting for version
* negotiation.
*/
complete(&dm->host_event);
return;
}
/*
* If there are more versions to try, continue
* with negotiations; if not
* shutdown the service since we are not able
* to negotiate a suitable version number
* with the host.
*/
if (dm->next_version == 0)
goto version_error;
memset(&version_req, 0, sizeof(struct dm_version_request));
version_req.hdr.type = DM_VERSION_REQUEST;
version_req.hdr.size = sizeof(struct dm_version_request);
version_req.hdr.trans_id = atomic_inc_return(&trans_id);
version_req.version.version = dm->next_version;
dm->version = version_req.version.version;
/*
* Set the next version to try in case current version fails.
* Win7 protocol ought to be the last one to try.
*/
switch (version_req.version.version) {
case DYNMEM_PROTOCOL_VERSION_WIN8:
dm->next_version = DYNMEM_PROTOCOL_VERSION_WIN7;
version_req.is_last_attempt = 0;
break;
default:
dm->next_version = 0;
version_req.is_last_attempt = 1;
}
ret = vmbus_sendpacket(dm->dev->channel, &version_req,
sizeof(struct dm_version_request),
(unsigned long)NULL,
VM_PKT_DATA_INBAND, 0);
if (ret)
goto version_error;
return;
version_error:
dm->state = DM_INIT_ERROR;
complete(&dm->host_event);
}
static void cap_resp(struct hv_dynmem_device *dm,
struct dm_capabilities_resp_msg *cap_resp)
{
if (!cap_resp->is_accepted) {
pr_err("Capabilities not accepted by host\n");
dm->state = DM_INIT_ERROR;
}
complete(&dm->host_event);
}
static void balloon_onchannelcallback(void *context)
{
struct hv_device *dev = context;
u32 recvlen;
u64 requestid;
struct dm_message *dm_msg;
struct dm_header *dm_hdr;
struct hv_dynmem_device *dm = hv_get_drvdata(dev);
struct dm_balloon *bal_msg;
struct dm_hot_add *ha_msg;
union dm_mem_page_range *ha_pg_range;
union dm_mem_page_range *ha_region;
memset(recv_buffer, 0, sizeof(recv_buffer));
vmbus_recvpacket(dev->channel, recv_buffer,
HV_HYP_PAGE_SIZE, &recvlen, &requestid);
if (recvlen > 0) {
dm_msg = (struct dm_message *)recv_buffer;
dm_hdr = &dm_msg->hdr;
switch (dm_hdr->type) {
case DM_VERSION_RESPONSE:
version_resp(dm,
(struct dm_version_response *)dm_msg);
break;
case DM_CAPABILITIES_RESPONSE:
cap_resp(dm,
(struct dm_capabilities_resp_msg *)dm_msg);
break;
case DM_BALLOON_REQUEST:
if (allow_hibernation) {
pr_info("Ignore balloon-up request!\n");
break;
}
if (dm->state == DM_BALLOON_UP)
pr_warn("Currently ballooning\n");
bal_msg = (struct dm_balloon *)recv_buffer;
dm->state = DM_BALLOON_UP;
dm_device.balloon_wrk.num_pages = bal_msg->num_pages;
schedule_work(&dm_device.balloon_wrk.wrk);
break;
case DM_UNBALLOON_REQUEST:
if (allow_hibernation) {
pr_info("Ignore balloon-down request!\n");
break;
}
dm->state = DM_BALLOON_DOWN;
balloon_down(dm,
(struct dm_unballoon_request *)recv_buffer);
break;
case DM_MEM_HOT_ADD_REQUEST:
if (dm->state == DM_HOT_ADD)
pr_warn("Currently hot-adding\n");
dm->state = DM_HOT_ADD;
ha_msg = (struct dm_hot_add *)recv_buffer;
if (ha_msg->hdr.size == sizeof(struct dm_hot_add)) {
/*
* This is a normal hot-add request specifying
* hot-add memory.
*/
dm->host_specified_ha_region = false;
ha_pg_range = &ha_msg->range;
dm->ha_wrk.ha_page_range = *ha_pg_range;
dm->ha_wrk.ha_region_range.page_range = 0;
} else {
/*
* Host is specifying that we first hot-add
* a region and then partially populate this
* region.
*/
dm->host_specified_ha_region = true;
ha_pg_range = &ha_msg->range;
ha_region = &ha_pg_range[1];
dm->ha_wrk.ha_page_range = *ha_pg_range;
dm->ha_wrk.ha_region_range = *ha_region;
}
schedule_work(&dm_device.ha_wrk.wrk);
break;
case DM_INFO_MESSAGE:
process_info(dm, (struct dm_info_msg *)dm_msg);
break;
default:
pr_warn_ratelimited("Unhandled message: type: %d\n", dm_hdr->type);
}
}
}
/* Hyper-V only supports reporting 2MB pages or higher */
#define HV_MIN_PAGE_REPORTING_ORDER 9
#define HV_MIN_PAGE_REPORTING_LEN (HV_HYP_PAGE_SIZE << HV_MIN_PAGE_REPORTING_ORDER)
static int hv_free_page_report(struct page_reporting_dev_info *pr_dev_info,
struct scatterlist *sgl, unsigned int nents)
{
unsigned long flags;
struct hv_memory_hint *hint;
int i;
u64 status;
struct scatterlist *sg;
WARN_ON_ONCE(nents > HV_MEMORY_HINT_MAX_GPA_PAGE_RANGES);
WARN_ON_ONCE(sgl->length < HV_MIN_PAGE_REPORTING_LEN);
local_irq_save(flags);
hint = *(struct hv_memory_hint **)this_cpu_ptr(hyperv_pcpu_input_arg);
if (!hint) {
local_irq_restore(flags);
return -ENOSPC;
}
hint->type = HV_EXT_MEMORY_HEAT_HINT_TYPE_COLD_DISCARD;
hint->reserved = 0;
for_each_sg(sgl, sg, nents, i) {
union hv_gpa_page_range *range;
range = &hint->ranges[i];
range->address_space = 0;
/* page reporting only reports 2MB pages or higher */
range->page.largepage = 1;
range->page.additional_pages =
(sg->length / HV_MIN_PAGE_REPORTING_LEN) - 1;
range->page_size = HV_GPA_PAGE_RANGE_PAGE_SIZE_2MB;
range->base_large_pfn =
page_to_hvpfn(sg_page(sg)) >> HV_MIN_PAGE_REPORTING_ORDER;
}
status = hv_do_rep_hypercall(HV_EXT_CALL_MEMORY_HEAT_HINT, nents, 0,
hint, NULL);
local_irq_restore(flags);
if ((status & HV_HYPERCALL_RESULT_MASK) != HV_STATUS_SUCCESS) {
pr_err("Cold memory discard hypercall failed with status %llx\n",
status);
return -EINVAL;
}
return 0;
}
static void enable_page_reporting(void)
{
int ret;
/* Essentially, validating 'PAGE_REPORTING_MIN_ORDER' is big enough. */
if (pageblock_order < HV_MIN_PAGE_REPORTING_ORDER) {
pr_debug("Cold memory discard is only supported on 2MB pages and above\n");
return;
}
if (!hv_query_ext_cap(HV_EXT_CAPABILITY_MEMORY_COLD_DISCARD_HINT)) {
pr_debug("Cold memory discard hint not supported by Hyper-V\n");
return;
}
BUILD_BUG_ON(PAGE_REPORTING_CAPACITY > HV_MEMORY_HINT_MAX_GPA_PAGE_RANGES);
dm_device.pr_dev_info.report = hv_free_page_report;
ret = page_reporting_register(&dm_device.pr_dev_info);
if (ret < 0) {
dm_device.pr_dev_info.report = NULL;
pr_err("Failed to enable cold memory discard: %d\n", ret);
} else {
pr_info("Cold memory discard hint enabled\n");
}
}
static void disable_page_reporting(void)
{
if (dm_device.pr_dev_info.report) {
page_reporting_unregister(&dm_device.pr_dev_info);
dm_device.pr_dev_info.report = NULL;
}
}
static int ballooning_enabled(void)
{
/*
* Disable ballooning if the page size is not 4k (HV_HYP_PAGE_SIZE),
* since currently it's unclear to us whether an unballoon request can
* make sure all page ranges are guest page size aligned.
*/
if (PAGE_SIZE != HV_HYP_PAGE_SIZE) {
pr_info("Ballooning disabled because page size is not 4096 bytes\n");
return 0;
}
return 1;
}
static int hot_add_enabled(void)
{
/*
* Disable hot add on ARM64, because we currently rely on
* memory_add_physaddr_to_nid() to get a node id of a hot add range,
* however ARM64's memory_add_physaddr_to_nid() always return 0 and
* DM_MEM_HOT_ADD_REQUEST doesn't have the NUMA node information for
* add_memory().
*/
if (IS_ENABLED(CONFIG_ARM64)) {
pr_info("Memory hot add disabled on ARM64\n");
return 0;
}
return 1;
}
static int balloon_connect_vsp(struct hv_device *dev)
{
struct dm_version_request version_req;
struct dm_capabilities cap_msg;
unsigned long t;
int ret;
/*
* max_pkt_size should be large enough for one vmbus packet header plus
* our receive buffer size. Hyper-V sends messages up to
* HV_HYP_PAGE_SIZE bytes long on balloon channel.
*/
dev->channel->max_pkt_size = HV_HYP_PAGE_SIZE * 2;
ret = vmbus_open(dev->channel, dm_ring_size, dm_ring_size, NULL, 0,
balloon_onchannelcallback, dev);
if (ret)
return ret;
/*
* Initiate the hand shake with the host and negotiate
* a version that the host can support. We start with the
* highest version number and go down if the host cannot
* support it.
*/
memset(&version_req, 0, sizeof(struct dm_version_request));
version_req.hdr.type = DM_VERSION_REQUEST;
version_req.hdr.size = sizeof(struct dm_version_request);
version_req.hdr.trans_id = atomic_inc_return(&trans_id);
version_req.version.version = DYNMEM_PROTOCOL_VERSION_WIN10;
version_req.is_last_attempt = 0;
dm_device.version = version_req.version.version;
ret = vmbus_sendpacket(dev->channel, &version_req,
sizeof(struct dm_version_request),
(unsigned long)NULL, VM_PKT_DATA_INBAND, 0);
if (ret)
goto out;
t = wait_for_completion_timeout(&dm_device.host_event, 5*HZ);
if (t == 0) {
ret = -ETIMEDOUT;
goto out;
}
/*
* If we could not negotiate a compatible version with the host
* fail the probe function.
*/
if (dm_device.state == DM_INIT_ERROR) {
ret = -EPROTO;
goto out;
}
pr_info("Using Dynamic Memory protocol version %u.%u\n",
DYNMEM_MAJOR_VERSION(dm_device.version),
DYNMEM_MINOR_VERSION(dm_device.version));
/*
* Now submit our capabilities to the host.
*/
memset(&cap_msg, 0, sizeof(struct dm_capabilities));
cap_msg.hdr.type = DM_CAPABILITIES_REPORT;
cap_msg.hdr.size = sizeof(struct dm_capabilities);
cap_msg.hdr.trans_id = atomic_inc_return(&trans_id);
/*
* When hibernation (i.e. virtual ACPI S4 state) is enabled, the host
* currently still requires the bits to be set, so we have to add code
* to fail the host's hot-add and balloon up/down requests, if any.
*/
cap_msg.caps.cap_bits.balloon = ballooning_enabled();
cap_msg.caps.cap_bits.hot_add = hot_add_enabled();
/*
* Specify our alignment requirements as it relates
* memory hot-add. Specify 128MB alignment.
*/
cap_msg.caps.cap_bits.hot_add_alignment = 7;
/*
* Currently the host does not use these
* values and we set them to what is done in the
* Windows driver.
*/
cap_msg.min_page_cnt = 0;
cap_msg.max_page_number = -1;
ret = vmbus_sendpacket(dev->channel, &cap_msg,
sizeof(struct dm_capabilities),
(unsigned long)NULL, VM_PKT_DATA_INBAND, 0);
if (ret)
goto out;
t = wait_for_completion_timeout(&dm_device.host_event, 5*HZ);
if (t == 0) {
ret = -ETIMEDOUT;
goto out;
}
/*
* If the host does not like our capabilities,
* fail the probe function.
*/
if (dm_device.state == DM_INIT_ERROR) {
ret = -EPROTO;
goto out;
}
return 0;
out:
vmbus_close(dev->channel);
return ret;
}
static int balloon_probe(struct hv_device *dev,
const struct hv_vmbus_device_id *dev_id)
{
int ret;
allow_hibernation = hv_is_hibernation_supported();
if (allow_hibernation)
hot_add = false;
#ifdef CONFIG_MEMORY_HOTPLUG
do_hot_add = hot_add;
#else
do_hot_add = false;
#endif
dm_device.dev = dev;
dm_device.state = DM_INITIALIZING;
dm_device.next_version = DYNMEM_PROTOCOL_VERSION_WIN8;
init_completion(&dm_device.host_event);
init_completion(&dm_device.config_event);
INIT_LIST_HEAD(&dm_device.ha_region_list);
spin_lock_init(&dm_device.ha_lock);
INIT_WORK(&dm_device.balloon_wrk.wrk, balloon_up);
INIT_WORK(&dm_device.ha_wrk.wrk, hot_add_req);
dm_device.host_specified_ha_region = false;
#ifdef CONFIG_MEMORY_HOTPLUG
set_online_page_callback(&hv_online_page);
hv_balloon: don't check for memhp_auto_online manually We get the MEM_ONLINE notifier call if memory is added right from the kernel via add_memory() or later from user space. Let's get rid of the "ha_waiting" flag - the wait event has an inbuilt mechanism (->done) for that. Initialize the wait event only once and reinitialize before adding memory. Unconditionally call complete() and wait_for_completion_timeout(). If there are no waiters, complete() will only increment ->done - which will be reset by reinit_completion(). If complete() has already been called, wait_for_completion_timeout() will not wait. There is still the chance for a small race between concurrent reinit_completion() and complete(). If complete() wins, we would not wait - which is tolerable (and the race exists in current code as well). Note: We only wait for "some" memory to get onlined, which seems to be good enough for now. [akpm@linux-foundation.org: register_memory_notifier() after init_completion(), per David] Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Baoquan He <bhe@redhat.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Wei Liu <wei.liu@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Eduardo Habkost <ehabkost@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Igor Mammedov <imammedo@redhat.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Yumei Huang <yuhuang@redhat.com> Link: http://lkml.kernel.org/r/20200317104942.11178-6-david@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-07 11:07:32 +08:00
init_completion(&dm_device.ol_waitevent);
register_memory_notifier(&hv_memory_nb);
#endif
hv_set_drvdata(dev, &dm_device);
ret = balloon_connect_vsp(dev);
if (ret != 0)
goto connect_error;
enable_page_reporting();
dm_device.state = DM_INITIALIZED;
dm_device.thread =
kthread_run(dm_thread_func, &dm_device, "hv_balloon");
if (IS_ERR(dm_device.thread)) {
ret = PTR_ERR(dm_device.thread);
goto probe_error;
}
return 0;
probe_error:
dm_device.state = DM_INIT_ERROR;
dm_device.thread = NULL;
disable_page_reporting();
vmbus_close(dev->channel);
connect_error:
#ifdef CONFIG_MEMORY_HOTPLUG
unregister_memory_notifier(&hv_memory_nb);
restore_online_page_callback(&hv_online_page);
#endif
return ret;
}
static int balloon_remove(struct hv_device *dev)
{
struct hv_dynmem_device *dm = hv_get_drvdata(dev);
struct hv_hotadd_state *has, *tmp;
Drivers: hv: balloon: account for gaps in hot add regions I'm observing the following hot add requests from the WS2012 host: hot_add_req: start_pfn = 0x108200 count = 330752 hot_add_req: start_pfn = 0x158e00 count = 193536 hot_add_req: start_pfn = 0x188400 count = 239616 As the host doesn't specify hot add regions we're trying to create 128Mb-aligned region covering the first request, we create the 0x108000 - 0x160000 region and we add 0x108000 - 0x158e00 memory. The second request passes the pfn_covered() check, we enlarge the region to 0x108000 - 0x190000 and add 0x158e00 - 0x188200 memory. The problem emerges with the third request as it starts at 0x188400 so there is a 0x200 gap which is not covered. As the end of our region is 0x190000 now it again passes the pfn_covered() check were we just adjust the covered_end_pfn and make it 0x188400 instead of 0x188200 which means that we'll try to online 0x188200-0x188400 pages but these pages were never assigned to us and we crash. We can't react to such requests by creating new hot add regions as it may happen that the whole suggested range falls into the previously identified 128Mb-aligned area so we'll end up adding nothing or create intersecting regions and our current logic doesn't allow that. Instead, create a list of such 'gaps' and check for them in the page online callback. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-25 07:23:10 +08:00
struct hv_hotadd_gap *gap, *tmp_gap;
unsigned long flags;
if (dm->num_pages_ballooned != 0)
pr_warn("Ballooned pages: %d\n", dm->num_pages_ballooned);
cancel_work_sync(&dm->balloon_wrk.wrk);
cancel_work_sync(&dm->ha_wrk.wrk);
kthread_stop(dm->thread);
/*
* This is to handle the case when balloon_resume()
* call has failed and some cleanup has been done as
* a part of the error handling.
*/
if (dm_device.state != DM_INIT_ERROR) {
disable_page_reporting();
vmbus_close(dev->channel);
#ifdef CONFIG_MEMORY_HOTPLUG
unregister_memory_notifier(&hv_memory_nb);
restore_online_page_callback(&hv_online_page);
#endif
}
spin_lock_irqsave(&dm_device.ha_lock, flags);
list_for_each_entry_safe(has, tmp, &dm->ha_region_list, list) {
Drivers: hv: balloon: account for gaps in hot add regions I'm observing the following hot add requests from the WS2012 host: hot_add_req: start_pfn = 0x108200 count = 330752 hot_add_req: start_pfn = 0x158e00 count = 193536 hot_add_req: start_pfn = 0x188400 count = 239616 As the host doesn't specify hot add regions we're trying to create 128Mb-aligned region covering the first request, we create the 0x108000 - 0x160000 region and we add 0x108000 - 0x158e00 memory. The second request passes the pfn_covered() check, we enlarge the region to 0x108000 - 0x190000 and add 0x158e00 - 0x188200 memory. The problem emerges with the third request as it starts at 0x188400 so there is a 0x200 gap which is not covered. As the end of our region is 0x190000 now it again passes the pfn_covered() check were we just adjust the covered_end_pfn and make it 0x188400 instead of 0x188200 which means that we'll try to online 0x188200-0x188400 pages but these pages were never assigned to us and we crash. We can't react to such requests by creating new hot add regions as it may happen that the whole suggested range falls into the previously identified 128Mb-aligned area so we'll end up adding nothing or create intersecting regions and our current logic doesn't allow that. Instead, create a list of such 'gaps' and check for them in the page online callback. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-25 07:23:10 +08:00
list_for_each_entry_safe(gap, tmp_gap, &has->gap_list, list) {
list_del(&gap->list);
kfree(gap);
}
list_del(&has->list);
kfree(has);
}
spin_unlock_irqrestore(&dm_device.ha_lock, flags);
return 0;
}
static int balloon_suspend(struct hv_device *hv_dev)
{
struct hv_dynmem_device *dm = hv_get_drvdata(hv_dev);
tasklet_disable(&hv_dev->channel->callback_event);
cancel_work_sync(&dm->balloon_wrk.wrk);
cancel_work_sync(&dm->ha_wrk.wrk);
if (dm->thread) {
kthread_stop(dm->thread);
dm->thread = NULL;
vmbus_close(hv_dev->channel);
}
tasklet_enable(&hv_dev->channel->callback_event);
return 0;
}
static int balloon_resume(struct hv_device *dev)
{
int ret;
dm_device.state = DM_INITIALIZING;
ret = balloon_connect_vsp(dev);
if (ret != 0)
goto out;
dm_device.thread =
kthread_run(dm_thread_func, &dm_device, "hv_balloon");
if (IS_ERR(dm_device.thread)) {
ret = PTR_ERR(dm_device.thread);
dm_device.thread = NULL;
goto close_channel;
}
dm_device.state = DM_INITIALIZED;
return 0;
close_channel:
vmbus_close(dev->channel);
out:
dm_device.state = DM_INIT_ERROR;
disable_page_reporting();
#ifdef CONFIG_MEMORY_HOTPLUG
unregister_memory_notifier(&hv_memory_nb);
restore_online_page_callback(&hv_online_page);
#endif
return ret;
}
static const struct hv_vmbus_device_id id_table[] = {
/* Dynamic Memory Class ID */
/* 525074DC-8985-46e2-8057-A307DC18A502 */
{ HV_DM_GUID, },
{ },
};
MODULE_DEVICE_TABLE(vmbus, id_table);
static struct hv_driver balloon_drv = {
.name = "hv_balloon",
.id_table = id_table,
.probe = balloon_probe,
.remove = balloon_remove,
.suspend = balloon_suspend,
.resume = balloon_resume,
.driver = {
.probe_type = PROBE_PREFER_ASYNCHRONOUS,
},
};
static int __init init_balloon_drv(void)
{
return vmbus_driver_register(&balloon_drv);
}
module_init(init_balloon_drv);
MODULE_DESCRIPTION("Hyper-V Balloon");
MODULE_LICENSE("GPL");