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xen: features and fixes for 3.20-rc0

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- Reworked handling for foreign (grant mapped) pages to simplify the
   code, enable a number of additional use cases and fix a number of
   long-standing bugs.
 - Prefer the TSC over the Xen PV clock when dom0 (and the TSC is
   stable).
 - Assorted other cleanup and minor bug fixes.
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Merge tag 'stable/for-linus-3.20-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull xen features and fixes from David Vrabel:

 - Reworked handling for foreign (grant mapped) pages to simplify the
   code, enable a number of additional use cases and fix a number of
   long-standing bugs.

 - Prefer the TSC over the Xen PV clock when dom0 (and the TSC is
   stable).

 - Assorted other cleanup and minor bug fixes.

* tag 'stable/for-linus-3.20-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: (25 commits)
  xen/manage: Fix USB interaction issues when resuming
  xenbus: Add proper handling of XS_ERROR from Xenbus for transactions.
  xen/gntdev: provide find_special_page VMA operation
  xen/gntdev: mark userspace PTEs as special on x86 PV guests
  xen-blkback: safely unmap grants in case they are still in use
  xen/gntdev: safely unmap grants in case they are still in use
  xen/gntdev: convert priv->lock to a mutex
  xen/grant-table: add a mechanism to safely unmap pages that are in use
  xen-netback: use foreign page information from the pages themselves
  xen: mark grant mapped pages as foreign
  xen/grant-table: add helpers for allocating pages
  x86/xen: require ballooned pages for grant maps
  xen: remove scratch frames for ballooned pages and m2p override
  xen/grant-table: pre-populate kernel unmap ops for xen_gnttab_unmap_refs()
  mm: add 'foreign' alias for the 'pinned' page flag
  mm: provide a find_special_page vma operation
  x86/xen: cleanup arch/x86/xen/mmu.c
  x86/xen: add some __init annotations in arch/x86/xen/mmu.c
  x86/xen: add some __init and static annotations in arch/x86/xen/setup.c
  x86/xen: use correct types for addresses in arch/x86/xen/setup.c
  ...
This commit is contained in:
Linus Torvalds 2015-02-10 13:56:56 -08:00
commit bdccc4edeb
28 changed files with 509 additions and 594 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
arch/arm/include/asm/xen/page.h
View File

@ -92,7 +92,7 @@ extern int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops,
struct page **pages, unsigned int count);
extern int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops,
struct gnttab_map_grant_ref *kmap_ops,
struct gnttab_unmap_grant_ref *kunmap_ops,
struct page **pages, unsigned int count);
bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn);

4
arch/arm/xen/enlighten.c
View File

@ -29,10 +29,10 @@
struct start_info _xen_start_info;
struct start_info *xen_start_info = &_xen_start_info;
EXPORT_SYMBOL_GPL(xen_start_info);
EXPORT_SYMBOL(xen_start_info);
enum xen_domain_type xen_domain_type = XEN_NATIVE;
EXPORT_SYMBOL_GPL(xen_domain_type);
EXPORT_SYMBOL(xen_domain_type);
struct shared_info xen_dummy_shared_info;
struct shared_info *HYPERVISOR_shared_info = (void *)&xen_dummy_shared_info;

2
arch/arm/xen/mm.c
View File

@ -149,7 +149,7 @@ void xen_destroy_contiguous_region(phys_addr_t pstart, unsigned int order)
EXPORT_SYMBOL_GPL(xen_destroy_contiguous_region);
struct dma_map_ops *xen_dma_ops;
EXPORT_SYMBOL_GPL(xen_dma_ops);
EXPORT_SYMBOL(xen_dma_ops);
static struct dma_map_ops xen_swiotlb_dma_ops = {
.mapping_error = xen_swiotlb_dma_mapping_error,

2
arch/arm/xen/p2m.c
View File

@ -102,7 +102,7 @@ int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops,
EXPORT_SYMBOL_GPL(set_foreign_p2m_mapping);
int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops,
struct gnttab_map_grant_ref *kmap_ops,
struct gnttab_unmap_grant_ref *kunmap_ops,
struct page **pages, unsigned int count)
{
int i;

20
arch/x86/include/asm/xen/page.h
View File

@ -55,9 +55,8 @@ extern int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops,
struct gnttab_map_grant_ref *kmap_ops,
struct page **pages, unsigned int count);
extern int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops,
struct gnttab_map_grant_ref *kmap_ops,
struct gnttab_unmap_grant_ref *kunmap_ops,
struct page **pages, unsigned int count);
extern unsigned long m2p_find_override_pfn(unsigned long mfn, unsigned long pfn);
/*
* Helper functions to write or read unsigned long values to/from
@ -154,21 +153,12 @@ static inline unsigned long mfn_to_pfn(unsigned long mfn)
return mfn;
pfn = mfn_to_pfn_no_overrides(mfn);
if (__pfn_to_mfn(pfn) != mfn) {
/*
* If this appears to be a foreign mfn (because the pfn
* doesn't map back to the mfn), then check the local override
* table to see if there's a better pfn to use.
*
* m2p_find_override_pfn returns ~0 if it doesn't find anything.
*/
pfn = m2p_find_override_pfn(mfn, ~0);
}
if (__pfn_to_mfn(pfn) != mfn)
pfn = ~0;
/*
* pfn is ~0 if there are no entries in the m2p for mfn or if the
* entry doesn't map back to the mfn and m2p_override doesn't have a
* valid entry for it.
* pfn is ~0 if there are no entries in the m2p for mfn or the
* entry doesn't map back to the mfn.
*/
if (pfn == ~0 && __pfn_to_mfn(mfn) == IDENTITY_FRAME(mfn))
pfn = mfn;

17
arch/x86/xen/mmu.c
View File

@ -1489,7 +1489,7 @@ static void __init xen_set_pte_init(pte_t *ptep, pte_t pte)
native_set_pte(ptep, pte);
}
static void pin_pagetable_pfn(unsigned cmd, unsigned long pfn)
static void __init pin_pagetable_pfn(unsigned cmd, unsigned long pfn)
{
struct mmuext_op op;
op.cmd = cmd;
@ -1657,7 +1657,7 @@ void __init xen_reserve_top(void)
* Like __va(), but returns address in the kernel mapping (which is
* all we have until the physical memory mapping has been set up.
*/
static void *__ka(phys_addr_t paddr)
static void * __init __ka(phys_addr_t paddr)
{
#ifdef CONFIG_X86_64
return (void *)(paddr + __START_KERNEL_map);
@ -1667,7 +1667,7 @@ static void *__ka(phys_addr_t paddr)
}
/* Convert a machine address to physical address */
static unsigned long m2p(phys_addr_t maddr)
static unsigned long __init m2p(phys_addr_t maddr)
{
phys_addr_t paddr;
@ -1678,13 +1678,14 @@ static unsigned long m2p(phys_addr_t maddr)
}
/* Convert a machine address to kernel virtual */
static void *m2v(phys_addr_t maddr)
static void * __init m2v(phys_addr_t maddr)
{
return __ka(m2p(maddr));
}
/* Set the page permissions on an identity-mapped pages */
static void set_page_prot_flags(void *addr, pgprot_t prot, unsigned long flags)
static void __init set_page_prot_flags(void *addr, pgprot_t prot,
unsigned long flags)
{
unsigned long pfn = __pa(addr) >> PAGE_SHIFT;
pte_t pte = pfn_pte(pfn, prot);
@ -1696,7 +1697,7 @@ static void set_page_prot_flags(void *addr, pgprot_t prot, unsigned long flags)
if (HYPERVISOR_update_va_mapping((unsigned long)addr, pte, flags))
BUG();
}
static void set_page_prot(void *addr, pgprot_t prot)
static void __init set_page_prot(void *addr, pgprot_t prot)
{
return set_page_prot_flags(addr, prot, UVMF_NONE);
}
@ -1733,10 +1734,8 @@ static void __init xen_map_identity_early(pmd_t *pmd, unsigned long max_pfn)
for (pteidx = 0; pteidx < PTRS_PER_PTE; pteidx++, pfn++) {
pte_t pte;
#ifdef CONFIG_X86_32
if (pfn > max_pfn_mapped)
max_pfn_mapped = pfn;
#endif
if (!pte_none(pte_page[pteidx]))
continue;
@ -1769,7 +1768,7 @@ void __init xen_setup_machphys_mapping(void)
}
#ifdef CONFIG_X86_64
static void convert_pfn_mfn(void *v)
static void __init convert_pfn_mfn(void *v)
{
pte_t *pte = v;
int i;

267
arch/x86/xen/p2m.c
View File

@ -84,8 +84,6 @@
#define PMDS_PER_MID_PAGE (P2M_MID_PER_PAGE / PTRS_PER_PTE)
static void __init m2p_override_init(void);
unsigned long *xen_p2m_addr __read_mostly;
EXPORT_SYMBOL_GPL(xen_p2m_addr);
unsigned long xen_p2m_size __read_mostly;
@ -402,8 +400,6 @@ void __init xen_vmalloc_p2m_tree(void)
xen_p2m_size = xen_max_p2m_pfn;
xen_inv_extra_mem();
m2p_override_init();
}
unsigned long get_phys_to_machine(unsigned long pfn)
@ -652,100 +648,21 @@ bool set_phys_to_machine(unsigned long pfn, unsigned long mfn)
return true;
}
#define M2P_OVERRIDE_HASH_SHIFT 10
#define M2P_OVERRIDE_HASH (1 << M2P_OVERRIDE_HASH_SHIFT)
static struct list_head *m2p_overrides;
static DEFINE_SPINLOCK(m2p_override_lock);
static void __init m2p_override_init(void)
{
unsigned i;
m2p_overrides = alloc_bootmem_align(
sizeof(*m2p_overrides) * M2P_OVERRIDE_HASH,
sizeof(unsigned long));
for (i = 0; i < M2P_OVERRIDE_HASH; i++)
INIT_LIST_HEAD(&m2p_overrides[i]);
}
static unsigned long mfn_hash(unsigned long mfn)
{
return hash_long(mfn, M2P_OVERRIDE_HASH_SHIFT);
}
/* Add an MFN override for a particular page */
static int m2p_add_override(unsigned long mfn, struct page *page,
struct gnttab_map_grant_ref *kmap_op)
{
unsigned long flags;
unsigned long pfn;
unsigned long uninitialized_var(address);
unsigned level;
pte_t *ptep = NULL;
pfn = page_to_pfn(page);
if (!PageHighMem(page)) {
address = (unsigned long)__va(pfn << PAGE_SHIFT);
ptep = lookup_address(address, &level);
if (WARN(ptep == NULL || level != PG_LEVEL_4K,
"m2p_add_override: pfn %lx not mapped", pfn))
return -EINVAL;
}
if (kmap_op != NULL) {
if (!PageHighMem(page)) {
struct multicall_space mcs =
xen_mc_entry(sizeof(*kmap_op));
MULTI_grant_table_op(mcs.mc,
GNTTABOP_map_grant_ref, kmap_op, 1);
xen_mc_issue(PARAVIRT_LAZY_MMU);
}
}
spin_lock_irqsave(&m2p_override_lock, flags);
list_add(&page->lru, &m2p_overrides[mfn_hash(mfn)]);
spin_unlock_irqrestore(&m2p_override_lock, flags);
/* p2m(m2p(mfn)) == mfn: the mfn is already present somewhere in
* this domain. Set the FOREIGN_FRAME_BIT in the p2m for the other
* pfn so that the following mfn_to_pfn(mfn) calls will return the
* pfn from the m2p_override (the backend pfn) instead.
* We need to do this because the pages shared by the frontend
* (xen-blkfront) can be already locked (lock_page, called by
* do_read_cache_page); when the userspace backend tries to use them
* with direct_IO, mfn_to_pfn returns the pfn of the frontend, so
* do_blockdev_direct_IO is going to try to lock the same pages
* again resulting in a deadlock.
* As a side effect get_user_pages_fast might not be safe on the
* frontend pages while they are being shared with the backend,
* because mfn_to_pfn (that ends up being called by GUPF) will
* return the backend pfn rather than the frontend pfn. */
pfn = mfn_to_pfn_no_overrides(mfn);
if (__pfn_to_mfn(pfn) == mfn)
set_phys_to_machine(pfn, FOREIGN_FRAME(mfn));
return 0;
}
int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops,
struct gnttab_map_grant_ref *kmap_ops,
struct page **pages, unsigned int count)
{
int i, ret = 0;
bool lazy = false;
pte_t *pte;
if (xen_feature(XENFEAT_auto_translated_physmap))
return 0;
if (kmap_ops &&
!in_interrupt() &&
paravirt_get_lazy_mode() == PARAVIRT_LAZY_NONE) {
arch_enter_lazy_mmu_mode();
lazy = true;
if (kmap_ops) {
ret = HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref,
kmap_ops, count);
if (ret)
goto out;
}
for (i = 0; i < count; i++) {
@ -764,170 +681,28 @@ int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops,
}
pfn = page_to_pfn(pages[i]);
WARN_ON(PagePrivate(pages[i]));
SetPagePrivate(pages[i]);
set_page_private(pages[i], mfn);
pages[i]->index = pfn_to_mfn(pfn);
WARN(pfn_to_mfn(pfn) != INVALID_P2M_ENTRY, "page must be ballooned");
if (unlikely(!set_phys_to_machine(pfn, FOREIGN_FRAME(mfn)))) {
ret = -ENOMEM;
goto out;
}
if (kmap_ops) {
ret = m2p_add_override(mfn, pages[i], &kmap_ops[i]);
if (ret)
goto out;
}
}
out:
if (lazy)
arch_leave_lazy_mmu_mode();
return ret;
}
EXPORT_SYMBOL_GPL(set_foreign_p2m_mapping);
static struct page *m2p_find_override(unsigned long mfn)
{
unsigned long flags;
struct list_head *bucket;
struct page *p, *ret;
if (unlikely(!m2p_overrides))
return NULL;
ret = NULL;
bucket = &m2p_overrides[mfn_hash(mfn)];
spin_lock_irqsave(&m2p_override_lock, flags);
list_for_each_entry(p, bucket, lru) {
if (page_private(p) == mfn) {
ret = p;
break;
}
}
spin_unlock_irqrestore(&m2p_override_lock, flags);
return ret;
}
static int m2p_remove_override(struct page *page,
struct gnttab_map_grant_ref *kmap_op,
unsigned long mfn)
{
unsigned long flags;
unsigned long pfn;
unsigned long uninitialized_var(address);
unsigned level;
pte_t *ptep = NULL;
pfn = page_to_pfn(page);
if (!PageHighMem(page)) {
address = (unsigned long)__va(pfn << PAGE_SHIFT);
ptep = lookup_address(address, &level);
if (WARN(ptep == NULL || level != PG_LEVEL_4K,
"m2p_remove_override: pfn %lx not mapped", pfn))
return -EINVAL;
}
spin_lock_irqsave(&m2p_override_lock, flags);
list_del(&page->lru);
spin_unlock_irqrestore(&m2p_override_lock, flags);
if (kmap_op != NULL) {
if (!PageHighMem(page)) {
struct multicall_space mcs;
struct gnttab_unmap_and_replace *unmap_op;
struct page *scratch_page = get_balloon_scratch_page();
unsigned long scratch_page_address = (unsigned long)
__va(page_to_pfn(scratch_page) << PAGE_SHIFT);
/*
* It might be that we queued all the m2p grant table
* hypercalls in a multicall, then m2p_remove_override
* get called before the multicall has actually been
* issued. In this case handle is going to -1 because
* it hasn't been modified yet.
*/
if (kmap_op->handle == -1)
xen_mc_flush();
/*
* Now if kmap_op->handle is negative it means that the
* hypercall actually returned an error.
*/
if (kmap_op->handle == GNTST_general_error) {
pr_warn("m2p_remove_override: pfn %lx mfn %lx, failed to modify kernel mappings",
pfn, mfn);
put_balloon_scratch_page();
return -1;
}
xen_mc_batch();
mcs = __xen_mc_entry(
sizeof(struct gnttab_unmap_and_replace));
unmap_op = mcs.args;
unmap_op->host_addr = kmap_op->host_addr;
unmap_op->new_addr = scratch_page_address;
unmap_op->handle = kmap_op->handle;
MULTI_grant_table_op(mcs.mc,
GNTTABOP_unmap_and_replace, unmap_op, 1);
mcs = __xen_mc_entry(0);
MULTI_update_va_mapping(mcs.mc, scratch_page_address,
pfn_pte(page_to_pfn(scratch_page),
PAGE_KERNEL_RO), 0);
xen_mc_issue(PARAVIRT_LAZY_MMU);
kmap_op->host_addr = 0;
put_balloon_scratch_page();
}
}
/* p2m(m2p(mfn)) == FOREIGN_FRAME(mfn): the mfn is already present
* somewhere in this domain, even before being added to the
* m2p_override (see comment above in m2p_add_override).
* If there are no other entries in the m2p_override corresponding
* to this mfn, then remove the FOREIGN_FRAME_BIT from the p2m for
* the original pfn (the one shared by the frontend): the backend
* cannot do any IO on this page anymore because it has been
* unshared. Removing the FOREIGN_FRAME_BIT from the p2m entry of
* the original pfn causes mfn_to_pfn(mfn) to return the frontend
* pfn again. */
mfn &= ~FOREIGN_FRAME_BIT;
pfn = mfn_to_pfn_no_overrides(mfn);
if (__pfn_to_mfn(pfn) == FOREIGN_FRAME(mfn) &&
m2p_find_override(mfn) == NULL)
set_phys_to_machine(pfn, mfn);
return 0;
}
int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops,
struct gnttab_map_grant_ref *kmap_ops,
struct gnttab_unmap_grant_ref *kunmap_ops,
struct page **pages, unsigned int count)
{
int i, ret = 0;
bool lazy = false;
if (xen_feature(XENFEAT_auto_translated_physmap))
return 0;
if (kmap_ops &&
!in_interrupt() &&
paravirt_get_lazy_mode() == PARAVIRT_LAZY_NONE) {
arch_enter_lazy_mmu_mode();
lazy = true;
}
for (i = 0; i < count; i++) {
unsigned long mfn = __pfn_to_mfn(page_to_pfn(pages[i]));
unsigned long pfn = page_to_pfn(pages[i]);
@ -937,36 +712,16 @@ int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops,
goto out;
}
set_page_private(pages[i], INVALID_P2M_ENTRY);
WARN_ON(!PagePrivate(pages[i]));
ClearPagePrivate(pages[i]);
set_phys_to_machine(pfn, pages[i]->index);
if (kmap_ops)
ret = m2p_remove_override(pages[i], &kmap_ops[i], mfn);
if (ret)
goto out;
set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
}
if (kunmap_ops)
ret = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref,
kunmap_ops, count);
out:
if (lazy)
arch_leave_lazy_mmu_mode();
return ret;
}
EXPORT_SYMBOL_GPL(clear_foreign_p2m_mapping);
unsigned long m2p_find_override_pfn(unsigned long mfn, unsigned long pfn)
{
struct page *p = m2p_find_override(mfn);
unsigned long ret = pfn;
if (p)
ret = page_to_pfn(p);
return ret;
}
EXPORT_SYMBOL_GPL(m2p_find_override_pfn);
#ifdef CONFIG_XEN_DEBUG_FS
#include <linux/debugfs.h>
#include "debugfs.h"

37
arch/x86/xen/setup.c
View File

@ -32,16 +32,6 @@
#include "p2m.h"
#include "mmu.h"
/* These are code, but not functions. Defined in entry.S */
extern const char xen_hypervisor_callback[];
extern const char xen_failsafe_callback[];
#ifdef CONFIG_X86_64
extern asmlinkage void nmi(void);
#endif
extern void xen_sysenter_target(void);
extern void xen_syscall_target(void);
extern void xen_syscall32_target(void);
/* Amount of extra memory space we add to the e820 ranges */
struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS] __initdata;
@ -74,7 +64,7 @@ static unsigned long xen_remap_mfn __initdata = INVALID_P2M_ENTRY;
*/
#define EXTRA_MEM_RATIO (10)
static void __init xen_add_extra_mem(u64 start, u64 size)
static void __init xen_add_extra_mem(phys_addr_t start, phys_addr_t size)
{
int i;
@ -97,10 +87,10 @@ static void __init xen_add_extra_mem(u64 start, u64 size)
memblock_reserve(start, size);
}
static void __init xen_del_extra_mem(u64 start, u64 size)
static void __init xen_del_extra_mem(phys_addr_t start, phys_addr_t size)
{
int i;
u64 start_r, size_r;
phys_addr_t start_r, size_r;
for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
start_r = xen_extra_mem[i].start;
@ -267,7 +257,7 @@ static void __init xen_set_identity_and_release_chunk(unsigned long start_pfn,
static void __init xen_update_mem_tables(unsigned long pfn, unsigned long mfn)
{
struct mmu_update update = {
.ptr = ((unsigned long long)mfn << PAGE_SHIFT) | MMU_MACHPHYS_UPDATE,
.ptr = ((uint64_t)mfn << PAGE_SHIFT) | MMU_MACHPHYS_UPDATE,
.val = pfn
};
@ -545,20 +535,21 @@ static unsigned long __init xen_get_max_pages(void)
return min(max_pages, MAX_DOMAIN_PAGES);
}
static void xen_align_and_add_e820_region(u64 start, u64 size, int type)
static void __init xen_align_and_add_e820_region(phys_addr_t start,
phys_addr_t size, int type)
{
u64 end = start + size;
phys_addr_t end = start + size;
/* Align RAM regions to page boundaries. */
if (type == E820_RAM) {
start = PAGE_ALIGN(start);
end &= ~((u64)PAGE_SIZE - 1);
end &= ~((phys_addr_t)PAGE_SIZE - 1);
}
e820_add_region(start, end - start, type);
}
void xen_ignore_unusable(struct e820entry *list, size_t map_size)
static void __init xen_ignore_unusable(struct e820entry *list, size_t map_size)
{
struct e820entry *entry;
unsigned int i;
@ -577,7 +568,7 @@ char * __init xen_memory_setup(void)
static struct e820entry map[E820MAX] __initdata;
unsigned long max_pfn = xen_start_info->nr_pages;
unsigned long long mem_end;
phys_addr_t mem_end;
int rc;
struct xen_memory_map memmap;
unsigned long max_pages;
@ -652,16 +643,16 @@ char * __init xen_memory_setup(void)
extra_pages);
i = 0;
while (i < memmap.nr_entries) {
u64 addr = map[i].addr;
u64 size = map[i].size;
phys_addr_t addr = map[i].addr;
phys_addr_t size = map[i].size;
u32 type = map[i].type;
if (type == E820_RAM) {
if (addr < mem_end) {
size = min(size, mem_end - addr);
} else if (extra_pages) {
size = min(size, (u64)extra_pages * PAGE_SIZE);
extra_pages -= size / PAGE_SIZE;
size = min(size, PFN_PHYS(extra_pages));
extra_pages -= PFN_DOWN(size);
xen_add_extra_mem(addr, size);
xen_max_p2m_pfn = PFN_DOWN(addr + size);
} else

2
arch/x86/xen/smp.c
View File

@ -507,7 +507,7 @@ static int xen_cpu_disable(void)
static void xen_cpu_die(unsigned int cpu)
{
while (xen_pv_domain() && HYPERVISOR_vcpu_op(VCPUOP_is_up, cpu, NULL)) {
current->state = TASK_UNINTERRUPTIBLE;
__set_current_state(TASK_UNINTERRUPTIBLE);
schedule_timeout(HZ/10);
}

4
arch/x86/xen/time.c
View File

@ -479,6 +479,10 @@ static void __init xen_time_init(void)
int cpu = smp_processor_id();
struct timespec tp;
/* As Dom0 is never moved, no penalty on using TSC there */
if (xen_initial_domain())
xen_clocksource.rating = 275;
clocksource_register_hz(&xen_clocksource, NSEC_PER_SEC);
if (HYPERVISOR_vcpu_op(VCPUOP_stop_periodic_timer, cpu, NULL) == 0) {

6
arch/x86/xen/xen-ops.h
View File

@ -10,6 +10,12 @@
extern const char xen_hypervisor_callback[];
extern const char xen_failsafe_callback[];
void xen_sysenter_target(void);
#ifdef CONFIG_X86_64
void xen_syscall_target(void);
void xen_syscall32_target(void);
#endif
extern void *xen_initial_gdt;
struct trap_info;

177
drivers/block/xen-blkback/blkback.c
View File

@ -47,6 +47,7 @@
#include <asm/xen/hypervisor.h>
#include <asm/xen/hypercall.h>
#include <xen/balloon.h>
#include <xen/grant_table.h>
#include "common.h"
/*
@ -100,7 +101,7 @@ module_param(log_stats, int, 0644);
#define BLKBACK_INVALID_HANDLE (~0)
/* Number of free pages to remove on each call to free_xenballooned_pages */
/* Number of free pages to remove on each call to gnttab_free_pages */
#define NUM_BATCH_FREE_PAGES 10
static inline int get_free_page(struct xen_blkif *blkif, struct page **page)
@ -111,7 +112,7 @@ static inline int get_free_page(struct xen_blkif *blkif, struct page **page)
if (list_empty(&blkif->free_pages)) {
BUG_ON(blkif->free_pages_num != 0);
spin_unlock_irqrestore(&blkif->free_pages_lock, flags);
return alloc_xenballooned_pages(1, page, false);
return gnttab_alloc_pages(1, page);
}
BUG_ON(blkif->free_pages_num == 0);
page[0] = list_first_entry(&blkif->free_pages, struct page, lru);
@ -151,14 +152,14 @@ static inline void shrink_free_pagepool(struct xen_blkif *blkif, int num)
blkif->free_pages_num--;
if (++num_pages == NUM_BATCH_FREE_PAGES) {
spin_unlock_irqrestore(&blkif->free_pages_lock, flags);
free_xenballooned_pages(num_pages, page);
gnttab_free_pages(num_pages, page);
spin_lock_irqsave(&blkif->free_pages_lock, flags);
num_pages = 0;
}
}
spin_unlock_irqrestore(&blkif->free_pages_lock, flags);
if (num_pages != 0)
free_xenballooned_pages(num_pages, page);
gnttab_free_pages(num_pages, page);
}
#define vaddr(page) ((unsigned long)pfn_to_kaddr(page_to_pfn(page)))
@ -262,6 +263,17 @@ static void put_persistent_gnt(struct xen_blkif *blkif,
atomic_dec(&blkif->persistent_gnt_in_use);
}
static void free_persistent_gnts_unmap_callback(int result,
struct gntab_unmap_queue_data *data)
{
struct completion *c = data->data;
/* BUG_ON used to reproduce existing behaviour,
but is this the best way to deal with this? */
BUG_ON(result);
complete(c);
}
static void free_persistent_gnts(struct xen_blkif *blkif, struct rb_root *root,
unsigned int num)
{
@ -269,8 +281,17 @@ static void free_persistent_gnts(struct xen_blkif *blkif, struct rb_root *root,
struct page *pages[BLKIF_MAX_SEGMENTS_PER_REQUEST];
struct persistent_gnt *persistent_gnt;
struct rb_node *n;
int ret = 0;
int segs_to_unmap = 0;
struct gntab_unmap_queue_data unmap_data;
struct completion unmap_completion;
init_completion(&unmap_completion);
unmap_data.data = &unmap_completion;
unmap_data.done = &free_persistent_gnts_unmap_callback;
unmap_data.pages = pages;
unmap_data.unmap_ops = unmap;
unmap_data.kunmap_ops = NULL;
foreach_grant_safe(persistent_gnt, n, root, node) {
BUG_ON(persistent_gnt->handle ==
@ -285,9 +306,11 @@ static void free_persistent_gnts(struct xen_blkif *blkif, struct rb_root *root,
if (++segs_to_unmap == BLKIF_MAX_SEGMENTS_PER_REQUEST ||
!rb_next(&persistent_gnt->node)) {
ret = gnttab_unmap_refs(unmap, NULL, pages,
segs_to_unmap);
BUG_ON(ret);
unmap_data.count = segs_to_unmap;
gnttab_unmap_refs_async(&unmap_data);
wait_for_completion(&unmap_completion);
put_free_pages(blkif, pages, segs_to_unmap);
segs_to_unmap = 0;
}
@ -653,18 +676,14 @@ void xen_blkbk_free_caches(struct xen_blkif *blkif)
shrink_free_pagepool(blkif, 0 /* All */);
}
/*
* Unmap the grant references, and also remove the M2P over-rides
* used in the 'pending_req'.
*/
static void xen_blkbk_unmap(struct xen_blkif *blkif,
struct grant_page *pages[],
int num)
static unsigned int xen_blkbk_unmap_prepare(
struct xen_blkif *blkif,
struct grant_page **pages,
unsigned int num,
struct gnttab_unmap_grant_ref *unmap_ops,
struct page **unmap_pages)
{
struct gnttab_unmap_grant_ref unmap[BLKIF_MAX_SEGMENTS_PER_REQUEST];
struct page *unmap_pages[BLKIF_MAX_SEGMENTS_PER_REQUEST];
unsigned int i, invcount = 0;
int ret;
for (i = 0; i < num; i++) {
if (pages[i]->persistent_gnt != NULL) {
@ -674,21 +693,95 @@ static void xen_blkbk_unmap(struct xen_blkif *blkif,
if (pages[i]->handle == BLKBACK_INVALID_HANDLE)
continue;
unmap_pages[invcount] = pages[i]->page;
gnttab_set_unmap_op(&unmap[invcount], vaddr(pages[i]->page),
gnttab_set_unmap_op(&unmap_ops[invcount], vaddr(pages[i]->page),
GNTMAP_host_map, pages[i]->handle);
pages[i]->handle = BLKBACK_INVALID_HANDLE;
if (++invcount == BLKIF_MAX_SEGMENTS_PER_REQUEST) {
ret = gnttab_unmap_refs(unmap, NULL, unmap_pages,
invcount);
invcount++;
}
return invcount;
}
static void xen_blkbk_unmap_and_respond_callback(int result, struct gntab_unmap_queue_data *data)
{
struct pending_req* pending_req = (struct pending_req*) (data->data);
struct xen_blkif *blkif = pending_req->blkif;
/* BUG_ON used to reproduce existing behaviour,
but is this the best way to deal with this? */
BUG_ON(result);
put_free_pages(blkif, data->pages, data->count);
make_response(blkif, pending_req->id,
pending_req->operation, pending_req->status);
free_req(blkif, pending_req);
/*
* Make sure the request is freed before releasing blkif,
* or there could be a race between free_req and the
* cleanup done in xen_blkif_free during shutdown.
*
* NB: The fact that we might try to wake up pending_free_wq
* before drain_complete (in case there's a drain going on)
* it's not a problem with our current implementation
* because we can assure there's no thread waiting on
* pending_free_wq if there's a drain going on, but it has
* to be taken into account if the current model is changed.
*/
if (atomic_dec_and_test(&blkif->inflight) && atomic_read(&blkif->drain)) {
complete(&blkif->drain_complete);
}
xen_blkif_put(blkif);
}
static void xen_blkbk_unmap_and_respond(struct pending_req *req)
{
struct gntab_unmap_queue_data* work = &req->gnttab_unmap_data;
struct xen_blkif *blkif = req->blkif;
struct grant_page **pages = req->segments;
unsigned int invcount;
invcount = xen_blkbk_unmap_prepare(blkif, pages, req->nr_pages,
req->unmap, req->unmap_pages);
work->data = req;
work->done = xen_blkbk_unmap_and_respond_callback;
work->unmap_ops = req->unmap;
work->kunmap_ops = NULL;
work->pages = req->unmap_pages;
work->count = invcount;
gnttab_unmap_refs_async(&req->gnttab_unmap_data);
}
/*
* Unmap the grant references.
*
* This could accumulate ops up to the batch size to reduce the number
* of hypercalls, but since this is only used in error paths there's
* no real need.
*/
static void xen_blkbk_unmap(struct xen_blkif *blkif,
struct grant_page *pages[],
int num)
{
struct gnttab_unmap_grant_ref unmap[BLKIF_MAX_SEGMENTS_PER_REQUEST];
struct page *unmap_pages[BLKIF_MAX_SEGMENTS_PER_REQUEST];
unsigned int invcount = 0;
int ret;
while (num) {
unsigned int batch = min(num, BLKIF_MAX_SEGMENTS_PER_REQUEST);
invcount = xen_blkbk_unmap_prepare(blkif, pages, batch,
unmap, unmap_pages);
if (invcount) {
ret = gnttab_unmap_refs(unmap, NULL, unmap_pages, invcount);
BUG_ON(ret);
put_free_pages(blkif, unmap_pages, invcount);
invcount = 0;
}
}
if (invcount) {
ret = gnttab_unmap_refs(unmap, NULL, unmap_pages, invcount);
BUG_ON(ret);
put_free_pages(blkif, unmap_pages, invcount);
pages += batch;
num -= batch;
}
}
@ -982,32 +1075,8 @@ static void __end_block_io_op(struct pending_req *pending_req, int error)
* the grant references associated with 'request' and provide
* the proper response on the ring.
*/
if (atomic_dec_and_test(&pending_req->pendcnt)) {
struct xen_blkif *blkif = pending_req->blkif;
xen_blkbk_unmap(blkif,
pending_req->segments,
pending_req->nr_pages);
make_response(blkif, pending_req->id,
pending_req->operation, pending_req->status);
free_req(blkif, pending_req);
/*
* Make sure the request is freed before releasing blkif,
* or there could be a race between free_req and the
* cleanup done in xen_blkif_free during shutdown.
*
* NB: The fact that we might try to wake up pending_free_wq
* before drain_complete (in case there's a drain going on)
* it's not a problem with our current implementation
* because we can assure there's no thread waiting on
* pending_free_wq if there's a drain going on, but it has
* to be taken into account if the current model is changed.
*/
if (atomic_dec_and_test(&blkif->inflight) && atomic_read(&blkif->drain)) {
complete(&blkif->drain_complete);
}
xen_blkif_put(blkif);
}
if (atomic_dec_and_test(&pending_req->pendcnt))
xen_blkbk_unmap_and_respond(pending_req);
}
/*

3
drivers/block/xen-blkback/common.h
View File

@ -350,6 +350,9 @@ struct pending_req {
struct grant_page *indirect_pages[MAX_INDIRECT_PAGES];
struct seg_buf seg[MAX_INDIRECT_SEGMENTS];
struct bio *biolist[MAX_INDIRECT_SEGMENTS];
struct gnttab_unmap_grant_ref unmap[MAX_INDIRECT_SEGMENTS];
struct page *unmap_pages[MAX_INDIRECT_SEGMENTS];
struct gntab_unmap_queue_data gnttab_unmap_data;
};

7
drivers/net/xen-netback/interface.c
View File

@ -483,9 +483,8 @@ int xenvif_init_queue(struct xenvif_queue *queue)
* better enable it. The long term solution would be to use just a
* bunch of valid page descriptors, without dependency on ballooning
*/
err = alloc_xenballooned_pages(MAX_PENDING_REQS,
queue->mmap_pages,
false);
err = gnttab_alloc_pages(MAX_PENDING_REQS,
queue->mmap_pages);
if (err) {
netdev_err(queue->vif->dev, "Could not reserve mmap_pages\n");
return -ENOMEM;
@ -664,7 +663,7 @@ void xenvif_disconnect(struct xenvif *vif)
*/
void xenvif_deinit_queue(struct xenvif_queue *queue)
{
free_xenballooned_pages(MAX_PENDING_REQS, queue->mmap_pages);
gnttab_free_pages(MAX_PENDING_REQS, queue->mmap_pages);
}
void xenvif_free(struct xenvif *vif)

106
drivers/net/xen-netback/netback.c
View File

@ -314,9 +314,7 @@ static struct xenvif_rx_meta *get_next_rx_buffer(struct xenvif_queue *queue,
static void xenvif_gop_frag_copy(struct xenvif_queue *queue, struct sk_buff *skb,
struct netrx_pending_operations *npo,
struct page *page, unsigned long size,
unsigned long offset, int *head,
struct xenvif_queue *foreign_queue,
grant_ref_t foreign_gref)
unsigned long offset, int *head)
{
struct gnttab_copy *copy_gop;
struct xenvif_rx_meta *meta;
@ -333,6 +331,8 @@ static void xenvif_gop_frag_copy(struct xenvif_queue *queue, struct sk_buff *skb
offset &= ~PAGE_MASK;
while (size > 0) {
struct xen_page_foreign *foreign;
BUG_ON(offset >= PAGE_SIZE);
BUG_ON(npo->copy_off > MAX_BUFFER_OFFSET);
@ -361,9 +361,10 @@ static void xenvif_gop_frag_copy(struct xenvif_queue *queue, struct sk_buff *skb
copy_gop->flags = GNTCOPY_dest_gref;
copy_gop->len = bytes;
if (foreign_queue) {
copy_gop->source.domid = foreign_queue->vif->domid;
copy_gop->source.u.ref = foreign_gref;
foreign = xen_page_foreign(page);
if (foreign) {
copy_gop->source.domid = foreign->domid;
copy_gop->source.u.ref = foreign->gref;
copy_gop->flags |= GNTCOPY_source_gref;
} else {
copy_gop->source.domid = DOMID_SELF;
@ -405,35 +406,6 @@ static void xenvif_gop_frag_copy(struct xenvif_queue *queue, struct sk_buff *skb
}
}
/*
* Find the grant ref for a given frag in a chain of struct ubuf_info's
* skb: the skb itself
* i: the frag's number
* ubuf: a pointer to an element in the chain. It should not be NULL
*
* Returns a pointer to the element in the chain where the page were found. If
* not found, returns NULL.
* See the definition of callback_struct in common.h for more details about
* the chain.
*/
static const struct ubuf_info *xenvif_find_gref(const struct sk_buff *const skb,
const int i,
const struct ubuf_info *ubuf)
{
struct xenvif_queue *foreign_queue = ubuf_to_queue(ubuf);
do {
u16 pending_idx = ubuf->desc;
if (skb_shinfo(skb)->frags[i].page.p ==
foreign_queue->mmap_pages[pending_idx])
break;
ubuf = (struct ubuf_info *) ubuf->ctx;
} while (ubuf);
return ubuf;
}
/*
* Prepare an SKB to be transmitted to the frontend.
*
@ -459,8 +431,6 @@ static int xenvif_gop_skb(struct sk_buff *skb,
int head = 1;
int old_meta_prod;
int gso_type;
const struct ubuf_info *ubuf = skb_shinfo(skb)->destructor_arg;
const struct ubuf_info *const head_ubuf = ubuf;
old_meta_prod = npo->meta_prod;
@ -507,68 +477,16 @@ static int xenvif_gop_skb(struct sk_buff *skb,
len = skb_tail_pointer(skb) - data;
xenvif_gop_frag_copy(queue, skb, npo,
virt_to_page(data), len, offset, &head,
NULL,
0);
virt_to_page(data), len, offset, &head);
data += len;
}
for (i = 0; i < nr_frags; i++) {
/* This variable also signals whether foreign_gref has a real
* value or not.
*/
struct xenvif_queue *foreign_queue = NULL;
grant_ref_t foreign_gref;
if ((skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY) &&
(ubuf->callback == &xenvif_zerocopy_callback)) {
const struct ubuf_info *const startpoint = ubuf;
/* Ideally ubuf points to the chain element which
* belongs to this frag. Or if frags were removed from
* the beginning, then shortly before it.
*/
ubuf = xenvif_find_gref(skb, i, ubuf);
/* Try again from the beginning of the list, if we
* haven't tried from there. This only makes sense in
* the unlikely event of reordering the original frags.
* For injected local pages it's an unnecessary second
* run.
*/
if (unlikely(!ubuf) && startpoint != head_ubuf)
ubuf = xenvif_find_gref(skb, i, head_ubuf);
if (likely(ubuf)) {
u16 pending_idx = ubuf->desc;
foreign_queue = ubuf_to_queue(ubuf);
foreign_gref =
foreign_queue->pending_tx_info[pending_idx].req.gref;
/* Just a safety measure. If this was the last
* element on the list, the for loop will
* iterate again if a local page were added to
* the end. Using head_ubuf here prevents the
* second search on the chain. Or the original
* frags changed order, but that's less likely.
* In any way, ubuf shouldn't be NULL.
*/
ubuf = ubuf->ctx ?
(struct ubuf_info *) ubuf->ctx :
head_ubuf;
} else
/* This frag was a local page, added to the
* array after the skb left netback.
*/
ubuf = head_ubuf;
}
xenvif_gop_frag_copy(queue, skb, npo,
skb_frag_page(&skb_shinfo(skb)->frags[i]),
skb_frag_size(&skb_shinfo(skb)->frags[i]),
skb_shinfo(skb)->frags[i].page_offset,
&head,
foreign_queue,
foreign_queue ? foreign_gref : UINT_MAX);
&head);
}
return npo->meta_prod - old_meta_prod;
@ -1241,12 +1159,6 @@ static void xenvif_fill_frags(struct xenvif_queue *queue, struct sk_buff *skb)
/* Take an extra reference to offset network stack's put_page */
get_page(queue->mmap_pages[pending_idx]);
}
/* FIXME: __skb_fill_page_desc set this to true because page->pfmemalloc
* overlaps with "index", and "mapping" is not set. I think mapping
* should be set. If delivered to local stack, it would drop this
* skb in sk_filter unless the socket has the right to use it.
*/
skb->pfmemalloc = false;
}
static int xenvif_get_extras(struct xenvif_queue *queue,

86
drivers/xen/balloon.c
View File

@ -92,7 +92,6 @@ EXPORT_SYMBOL_GPL(balloon_stats);
/* We increase/decrease in batches which fit in a page */
static xen_pfn_t frame_list[PAGE_SIZE / sizeof(unsigned long)];
static DEFINE_PER_CPU(struct page *, balloon_scratch_page);
/* List of ballooned pages, threaded through the mem_map array. */
@ -423,22 +422,12 @@ static enum bp_state decrease_reservation(unsigned long nr_pages, gfp_t gfp)
page = pfn_to_page(pfn);
#ifdef CONFIG_XEN_HAVE_PVMMU
/*
* Ballooned out frames are effectively replaced with
* a scratch frame. Ensure direct mappings and the
* p2m are consistent.
*/
if (!xen_feature(XENFEAT_auto_translated_physmap)) {
if (!PageHighMem(page)) {
struct page *scratch_page = get_balloon_scratch_page();
ret = HYPERVISOR_update_va_mapping(
(unsigned long)__va(pfn << PAGE_SHIFT),
pfn_pte(page_to_pfn(scratch_page),
PAGE_KERNEL_RO), 0);
__pte_ma(0), 0);
BUG_ON(ret);
put_balloon_scratch_page();
}
__set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
}
@ -500,18 +489,6 @@ static void balloon_process(struct work_struct *work)
mutex_unlock(&balloon_mutex);
}
struct page *get_balloon_scratch_page(void)
{
struct page *ret = get_cpu_var(balloon_scratch_page);
BUG_ON(ret == NULL);
return ret;
}
void put_balloon_scratch_page(void)
{
put_cpu_var(balloon_scratch_page);
}
/* Resets the Xen limit, sets new target, and kicks off processing. */
void balloon_set_new_target(unsigned long target)
{
@ -605,61 +582,13 @@ static void __init balloon_add_region(unsigned long start_pfn,
}
}
static int alloc_balloon_scratch_page(int cpu)
{
if (per_cpu(balloon_scratch_page, cpu) != NULL)
return 0;
per_cpu(balloon_scratch_page, cpu) = alloc_page(GFP_KERNEL);
if (per_cpu(balloon_scratch_page, cpu) == NULL) {
pr_warn("Failed to allocate balloon_scratch_page for cpu %d\n", cpu);
return -ENOMEM;
}
return 0;
}
static int balloon_cpu_notify(struct notifier_block *self,
unsigned long action, void *hcpu)
{
int cpu = (long)hcpu;
switch (action) {
case CPU_UP_PREPARE:
if (alloc_balloon_scratch_page(cpu))
return NOTIFY_BAD;
break;
default:
break;
}
return NOTIFY_OK;
}
static struct notifier_block balloon_cpu_notifier = {
.notifier_call = balloon_cpu_notify,
};
static int __init balloon_init(void)
{
int i, cpu;
int i;
if (!xen_domain())
return -ENODEV;
if (!xen_feature(XENFEAT_auto_translated_physmap)) {
register_cpu_notifier(&balloon_cpu_notifier);
get_online_cpus();
for_each_online_cpu(cpu) {
if (alloc_balloon_scratch_page(cpu)) {
put_online_cpus();
unregister_cpu_notifier(&balloon_cpu_notifier);
return -ENOMEM;
}
}
put_online_cpus();
}
pr_info("Initialising balloon driver\n");
balloon_stats.current_pages = xen_pv_domain()
@ -696,15 +625,4 @@ static int __init balloon_init(void)
subsys_initcall(balloon_init);
static int __init balloon_clear(void)
{
int cpu;
for_each_possible_cpu(cpu)
per_cpu(balloon_scratch_page, cpu) = NULL;
return 0;
}
early_initcall(balloon_clear);
MODULE_LICENSE("GPL");

143
drivers/xen/gntdev.c
View File

@ -67,7 +67,7 @@ struct gntdev_priv {
* Only populated if populate_freeable_maps == 1 */
struct list_head freeable_maps;
/* lock protects maps and freeable_maps */
spinlock_t lock;
struct mutex lock;
struct mm_struct *mm;
struct mmu_notifier mn;
};
@ -91,7 +91,9 @@ struct grant_map {
struct gnttab_map_grant_ref *map_ops;
struct gnttab_unmap_grant_ref *unmap_ops;
struct gnttab_map_grant_ref *kmap_ops;
struct gnttab_unmap_grant_ref *kunmap_ops;
struct page **pages;
unsigned long pages_vm_start;
};
static int unmap_grant_pages(struct grant_map *map, int offset, int pages);
@ -118,12 +120,13 @@ static void gntdev_free_map(struct grant_map *map)
return;
if (map->pages)
free_xenballooned_pages(map->count, map->pages);
gnttab_free_pages(map->count, map->pages);
kfree(map->pages);
kfree(map->grants);
kfree(map->map_ops);
kfree(map->unmap_ops);
kfree(map->kmap_ops);
kfree(map->kunmap_ops);
kfree(map);
}
@ -140,21 +143,24 @@ static struct grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count)
add->map_ops = kcalloc(count, sizeof(add->map_ops[0]), GFP_KERNEL);
add->unmap_ops = kcalloc(count, sizeof(add->unmap_ops[0]), GFP_KERNEL);
add->kmap_ops = kcalloc(count, sizeof(add->kmap_ops[0]), GFP_KERNEL);
add->kunmap_ops = kcalloc(count, sizeof(add->kunmap_ops[0]), GFP_KERNEL);
add->pages = kcalloc(count, sizeof(add->pages[0]), GFP_KERNEL);
if (NULL == add->grants ||
NULL == add->map_ops ||
NULL == add->unmap_ops ||
NULL == add->kmap_ops ||
NULL == add->kunmap_ops ||
NULL == add->pages)
goto err;
if (alloc_xenballooned_pages(count, add->pages, false /* lowmem */))
if (gnttab_alloc_pages(count, add->pages))
goto err;
for (i = 0; i < count; i++) {
add->map_ops[i].handle = -1;
add->unmap_ops[i].handle = -1;
add->kmap_ops[i].handle = -1;
add->kunmap_ops[i].handle = -1;
}
add->index = 0;
@ -216,9 +222,9 @@ static void gntdev_put_map(struct gntdev_priv *priv, struct grant_map *map)
}
if (populate_freeable_maps && priv) {
spin_lock(&priv->lock);
mutex_lock(&priv->lock);
list_del(&map->next);
spin_unlock(&priv->lock);
mutex_unlock(&priv->lock);
}
if (map->pages && !use_ptemod)
@ -239,6 +245,14 @@ static int find_grant_ptes(pte_t *pte, pgtable_t token,
BUG_ON(pgnr >= map->count);
pte_maddr = arbitrary_virt_to_machine(pte).maddr;
/*
* Set the PTE as special to force get_user_pages_fast() fall
* back to the slow path. If this is not supported as part of
* the grant map, it will be done afterwards.
*/
if (xen_feature(XENFEAT_gnttab_map_avail_bits))
flags |= (1 << _GNTMAP_guest_avail0);
gnttab_set_map_op(&map->map_ops[pgnr], pte_maddr, flags,
map->grants[pgnr].ref,
map->grants[pgnr].domid);
@ -247,6 +261,15 @@ static int find_grant_ptes(pte_t *pte, pgtable_t token,
return 0;
}
#ifdef CONFIG_X86
static int set_grant_ptes_as_special(pte_t *pte, pgtable_t token,
unsigned long addr, void *data)
{
set_pte_at(current->mm, addr, pte, pte_mkspecial(*pte));
return 0;
}
#endif
static int map_grant_pages(struct grant_map *map)
{
int i, err = 0;
@ -280,6 +303,8 @@ static int map_grant_pages(struct grant_map *map)
map->flags | GNTMAP_host_map,
map->grants[i].ref,
map->grants[i].domid);
gnttab_set_unmap_op(&map->kunmap_ops[i], address,
map->flags | GNTMAP_host_map, -1);
}
}
@ -290,20 +315,42 @@ static int map_grant_pages(struct grant_map *map)
return err;
for (i = 0; i < map->count; i++) {
if (map->map_ops[i].status)
if (map->map_ops[i].status) {
err = -EINVAL;
else {
BUG_ON(map->map_ops[i].handle == -1);
map->unmap_ops[i].handle = map->map_ops[i].handle;
pr_debug("map handle=%d\n", map->map_ops[i].handle);
continue;
}
map->unmap_ops[i].handle = map->map_ops[i].handle;
if (use_ptemod)
map->kunmap_ops[i].handle = map->kmap_ops[i].handle;
}
return err;
}
struct unmap_grant_pages_callback_data
{
struct completion completion;
int result;
};
static void unmap_grant_callback(int result,
struct gntab_unmap_queue_data *data)
{
struct unmap_grant_pages_callback_data* d = data->data;
d->result = result;
complete(&d->completion);
}
static int __unmap_grant_pages(struct grant_map *map, int offset, int pages)
{
int i, err = 0;
struct gntab_unmap_queue_data unmap_data;
struct unmap_grant_pages_callback_data data;
init_completion(&data.completion);
unmap_data.data = &data;
unmap_data.done= &unmap_grant_callback;
if (map->notify.flags & UNMAP_NOTIFY_CLEAR_BYTE) {
int pgno = (map->notify.addr >> PAGE_SHIFT);
@ -315,11 +362,16 @@ static int __unmap_grant_pages(struct grant_map *map, int offset, int pages)
}
}
err = gnttab_unmap_refs(map->unmap_ops + offset,
use_ptemod ? map->kmap_ops + offset : NULL, map->pages + offset,
pages);
if (err)
return err;
unmap_data.unmap_ops = map->unmap_ops + offset;
unmap_data.kunmap_ops = use_ptemod ? map->kunmap_ops + offset : NULL;
unmap_data.pages = map->pages + offset;
unmap_data.count = pages;
gnttab_unmap_refs_async(&unmap_data);
wait_for_completion(&data.completion);
if (data.result)
return data.result;
for (i = 0; i < pages; i++) {
if (map->unmap_ops[offset+i].status)
@ -387,17 +439,26 @@ static void gntdev_vma_close(struct vm_area_struct *vma)
* not do any unmapping, since that has been done prior to
* closing the vma, but it may still iterate the unmap_ops list.
*/
spin_lock(&priv->lock);
mutex_lock(&priv->lock);
map->vma = NULL;
spin_unlock(&priv->lock);
mutex_unlock(&priv->lock);
}
vma->vm_private_data = NULL;
gntdev_put_map(priv, map);
}
static struct page *gntdev_vma_find_special_page(struct vm_area_struct *vma,
unsigned long addr)
{
struct grant_map *map = vma->vm_private_data;
return map->pages[(addr - map->pages_vm_start) >> PAGE_SHIFT];
}
static struct vm_operations_struct gntdev_vmops = {
.open = gntdev_vma_open,
.close = gntdev_vma_close,
.find_special_page = gntdev_vma_find_special_page,
};
/* ------------------------------------------------------------------ */
@ -433,14 +494,14 @@ static void mn_invl_range_start(struct mmu_notifier *mn,
struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn);
struct grant_map *map;
spin_lock(&priv->lock);
mutex_lock(&priv->lock);
list_for_each_entry(map, &priv->maps, next) {
unmap_if_in_range(map, start, end);
}
list_for_each_entry(map, &priv->freeable_maps, next) {
unmap_if_in_range(map, start, end);
}
spin_unlock(&priv->lock);
mutex_unlock(&priv->lock);
}
static void mn_invl_page(struct mmu_notifier *mn,
@ -457,7 +518,7 @@ static void mn_release(struct mmu_notifier *mn,
struct grant_map *map;
int err;
spin_lock(&priv->lock);
mutex_lock(&priv->lock);
list_for_each_entry(map, &priv->maps, next) {
if (!map->vma)
continue;
@ -476,7 +537,7 @@ static void mn_release(struct mmu_notifier *mn,
err = unmap_grant_pages(map, /* offset */ 0, map->count);
WARN_ON(err);
}
spin_unlock(&priv->lock);
mutex_unlock(&priv->lock);
}
static struct mmu_notifier_ops gntdev_mmu_ops = {
@ -498,7 +559,7 @@ static int gntdev_open(struct inode *inode, struct file *flip)
INIT_LIST_HEAD(&priv->maps);
INIT_LIST_HEAD(&priv->freeable_maps);
spin_lock_init(&priv->lock);
mutex_init(&priv->lock);
if (use_ptemod) {
priv->mm = get_task_mm(current);
@ -572,10 +633,10 @@ static long gntdev_ioctl_map_grant_ref(struct gntdev_priv *priv,
return -EFAULT;
}
spin_lock(&priv->lock);
mutex_lock(&priv->lock);
gntdev_add_map(priv, map);
op.index = map->index << PAGE_SHIFT;
spin_unlock(&priv->lock);
mutex_unlock(&priv->lock);
if (copy_to_user(u, &op, sizeof(op)) != 0)
return -EFAULT;
@ -594,7 +655,7 @@ static long gntdev_ioctl_unmap_grant_ref(struct gntdev_priv *priv,
return -EFAULT;
pr_debug("priv %p, del %d+%d\n", priv, (int)op.index, (int)op.count);
spin_lock(&priv->lock);
mutex_lock(&priv->lock);
map = gntdev_find_map_index(priv, op.index >> PAGE_SHIFT, op.count);
if (map) {
list_del(&map->next);
@ -602,7 +663,7 @@ static long gntdev_ioctl_unmap_grant_ref(struct gntdev_priv *priv,
list_add_tail(&map->next, &priv->freeable_maps);
err = 0;
}
spin_unlock(&priv->lock);
mutex_unlock(&priv->lock);
if (map)
gntdev_put_map(priv, map);
return err;
@ -670,7 +731,7 @@ static long gntdev_ioctl_notify(struct gntdev_priv *priv, void __user *u)
out_flags = op.action;
out_event = op.event_channel_port;
spin_lock(&priv->lock);
mutex_lock(&priv->lock);
list_for_each_entry(map, &priv->maps, next) {
uint64_t begin = map->index << PAGE_SHIFT;
@ -698,7 +759,7 @@ static long gntdev_ioctl_notify(struct gntdev_priv *priv, void __user *u)
rc = 0;
unlock_out:
spin_unlock(&priv->lock);
mutex_unlock(&priv->lock);
/* Drop the reference to the event channel we did not save in the map */
if (out_flags & UNMAP_NOTIFY_SEND_EVENT)
@ -748,7 +809,7 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma)
pr_debug("map %d+%d at %lx (pgoff %lx)\n",
index, count, vma->vm_start, vma->vm_pgoff);
spin_lock(&priv->lock);
mutex_lock(&priv->lock);
map = gntdev_find_map_index(priv, index, count);
if (!map)
goto unlock_out;
@ -783,7 +844,7 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma)
map->flags |= GNTMAP_readonly;
}
spin_unlock(&priv->lock);
mutex_unlock(&priv->lock);
if (use_ptemod) {
err = apply_to_page_range(vma->vm_mm, vma->vm_start,
@ -806,16 +867,34 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma)
if (err)
goto out_put_map;
}
} else {
#ifdef CONFIG_X86
/*
* If the PTEs were not made special by the grant map
* hypercall, do so here.
*
* This is racy since the mapping is already visible
* to userspace but userspace should be well-behaved
* enough to not touch it until the mmap() call
* returns.
*/
if (!xen_feature(XENFEAT_gnttab_map_avail_bits)) {
apply_to_page_range(vma->vm_mm, vma->vm_start,
vma->vm_end - vma->vm_start,
set_grant_ptes_as_special, NULL);
}
#endif
map->pages_vm_start = vma->vm_start;
}
return 0;
unlock_out:
spin_unlock(&priv->lock);
mutex_unlock(&priv->lock);
return err;
out_unlock_put:
spin_unlock(&priv->lock);
mutex_unlock(&priv->lock);
out_put_map:
if (use_ptemod)
map->vma = NULL;

120
drivers/xen/grant-table.c
View File

@ -42,6 +42,7 @@
#include <linux/io.h>
#include <linux/delay.h>
#include <linux/hardirq.h>
#include <linux/workqueue.h>
#include <xen/xen.h>
#include <xen/interface/xen.h>
@ -50,6 +51,7 @@
#include <xen/interface/memory.h>
#include <xen/hvc-console.h>
#include <xen/swiotlb-xen.h>
#include <xen/balloon.h>
#include <asm/xen/hypercall.h>
#include <asm/xen/interface.h>
@ -671,6 +673,59 @@ void gnttab_free_auto_xlat_frames(void)
}
EXPORT_SYMBOL_GPL(gnttab_free_auto_xlat_frames);
/**
* gnttab_alloc_pages - alloc pages suitable for grant mapping into
* @nr_pages: number of pages to alloc
* @pages: returns the pages
*/
int gnttab_alloc_pages(int nr_pages, struct page **pages)
{
int i;
int ret;
ret = alloc_xenballooned_pages(nr_pages, pages, false);
if (ret < 0)
return ret;
for (i = 0; i < nr_pages; i++) {
#if BITS_PER_LONG < 64
struct xen_page_foreign *foreign;
foreign = kzalloc(sizeof(*foreign), GFP_KERNEL);
if (!foreign) {
gnttab_free_pages(nr_pages, pages);
return -ENOMEM;
}
set_page_private(pages[i], (unsigned long)foreign);
#endif
SetPagePrivate(pages[i]);
}
return 0;
}
EXPORT_SYMBOL(gnttab_alloc_pages);
/**
* gnttab_free_pages - free pages allocated by gnttab_alloc_pages()
* @nr_pages; number of pages to free
* @pages: the pages
*/
void gnttab_free_pages(int nr_pages, struct page **pages)
{
int i;
for (i = 0; i < nr_pages; i++) {
if (PagePrivate(pages[i])) {
#if BITS_PER_LONG < 64
kfree((void *)page_private(pages[i]));
#endif
ClearPagePrivate(pages[i]);
}
}
free_xenballooned_pages(nr_pages, pages);
}
EXPORT_SYMBOL(gnttab_free_pages);
/* Handling of paged out grant targets (GNTST_eagain) */
#define MAX_DELAY 256
static inline void
@ -727,30 +782,87 @@ int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops,
if (ret)
return ret;
/* Retry eagain maps */
for (i = 0; i < count; i++)
for (i = 0; i < count; i++) {
/* Retry eagain maps */
if (map_ops[i].status == GNTST_eagain)
gnttab_retry_eagain_gop(GNTTABOP_map_grant_ref, map_ops + i,
&map_ops[i].status, __func__);
if (map_ops[i].status == GNTST_okay) {
struct xen_page_foreign *foreign;
SetPageForeign(pages[i]);
foreign = xen_page_foreign(pages[i]);
foreign->domid = map_ops[i].dom;
foreign->gref = map_ops[i].ref;
}
}
return set_foreign_p2m_mapping(map_ops, kmap_ops, pages, count);
}
EXPORT_SYMBOL_GPL(gnttab_map_refs);
int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops,
struct gnttab_map_grant_ref *kmap_ops,
struct gnttab_unmap_grant_ref *kunmap_ops,
struct page **pages, unsigned int count)
{
unsigned int i;
int ret;
ret = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, unmap_ops, count);
if (ret)
return ret;
return clear_foreign_p2m_mapping(unmap_ops, kmap_ops, pages, count);
for (i = 0; i < count; i++)
ClearPageForeign(pages[i]);
return clear_foreign_p2m_mapping(unmap_ops, kunmap_ops, pages, count);
}
EXPORT_SYMBOL_GPL(gnttab_unmap_refs);
#define GNTTAB_UNMAP_REFS_DELAY 5
static void __gnttab_unmap_refs_async(struct gntab_unmap_queue_data* item);
static void gnttab_unmap_work(struct work_struct *work)
{
struct gntab_unmap_queue_data
*unmap_data = container_of(work,
struct gntab_unmap_queue_data,
gnttab_work.work);
if (unmap_data->age != UINT_MAX)
unmap_data->age++;
__gnttab_unmap_refs_async(unmap_data);
}
static void __gnttab_unmap_refs_async(struct gntab_unmap_queue_data* item)
{
int ret;
int pc;
for (pc = 0; pc < item->count; pc++) {
if (page_count(item->pages[pc]) > 1) {
unsigned long delay = GNTTAB_UNMAP_REFS_DELAY * (item->age + 1);
schedule_delayed_work(&item->gnttab_work,
msecs_to_jiffies(delay));
return;
}
}
ret = gnttab_unmap_refs(item->unmap_ops, item->kunmap_ops,
item->pages, item->count);
item->done(ret, item);
}
void gnttab_unmap_refs_async(struct gntab_unmap_queue_data* item)
{
INIT_DELAYED_WORK(&item->gnttab_work, gnttab_unmap_work);
item->age = 0;
__gnttab_unmap_refs_async(item);
}
EXPORT_SYMBOL_GPL(gnttab_unmap_refs_async);
static int gnttab_map_frames_v1(xen_pfn_t *frames, unsigned int nr_gframes)
{
int rc;

8
drivers/xen/manage.c
View File

@ -105,10 +105,16 @@ static void do_suspend(void)
err = freeze_processes();
if (err) {
pr_err("%s: freeze failed %d\n", __func__, err);
pr_err("%s: freeze processes failed %d\n", __func__, err);
goto out;
}
err = freeze_kernel_threads();
if (err) {
pr_err("%s: freeze kernel threads failed %d\n", __func__, err);
goto out_thaw;
}
err = dpm_suspend_start(PMSG_FREEZE);
if (err) {
pr_err("%s: dpm_suspend_start %d\n", __func__, err);

2
drivers/xen/tmem.c
View File

@ -374,7 +374,7 @@ static struct frontswap_ops tmem_frontswap_ops = {
};
#endif
static int xen_tmem_init(void)
static int __init xen_tmem_init(void)
{
if (!xen_domain())
return 0;

6
drivers/xen/xen-scsiback.c
View File

@ -227,7 +227,7 @@ static void put_free_pages(struct page **page, int num)
return;
if (i > scsiback_max_buffer_pages) {
n = min(num, i - scsiback_max_buffer_pages);
free_xenballooned_pages(n, page + num - n);
gnttab_free_pages(n, page + num - n);
n = num - n;
}
spin_lock_irqsave(&free_pages_lock, flags);
@ -244,7 +244,7 @@ static int get_free_page(struct page **page)
spin_lock_irqsave(&free_pages_lock, flags);
if (list_empty(&scsiback_free_pages)) {
spin_unlock_irqrestore(&free_pages_lock, flags);
return alloc_xenballooned_pages(1, page, false);
return gnttab_alloc_pages(1, page);
}
page[0] = list_first_entry(&scsiback_free_pages, struct page, lru);
list_del(&page[0]->lru);
@ -2106,7 +2106,7 @@ static void __exit scsiback_exit(void)
while (free_pages_num) {
if (get_free_page(&page))
BUG();
free_xenballooned_pages(1, &page);
gnttab_free_pages(1, &page);
}
scsiback_deregister_configfs();
xenbus_unregister_driver(&scsiback_driver);

11
drivers/xen/xenbus/xenbus_dev_frontend.c
View File

@ -326,10 +326,13 @@ static int xenbus_write_transaction(unsigned msg_type,
}
if (msg_type == XS_TRANSACTION_START) {
trans->handle.id = simple_strtoul(reply, NULL, 0);
list_add(&trans->list, &u->transactions);
} else if (msg_type == XS_TRANSACTION_END) {
if (u->u.msg.type == XS_ERROR)
kfree(trans);
else {
trans->handle.id = simple_strtoul(reply, NULL, 0);
list_add(&trans->list, &u->transactions);
}
} else if (u->u.msg.type == XS_TRANSACTION_END) {
list_for_each_entry(trans, &u->transactions, list)
if (trans->handle.id == u->u.msg.tx_id)
break;

8
include/linux/mm.h
View File

@ -290,6 +290,14 @@ struct vm_operations_struct {
/* called by sys_remap_file_pages() to populate non-linear mapping */
int (*remap_pages)(struct vm_area_struct *vma, unsigned long addr,
unsigned long size, pgoff_t pgoff);
/*
* Called by vm_normal_page() for special PTEs to find the
* page for @addr. This is useful if the default behavior
* (using pte_page()) would not find the correct page.
*/
struct page *(*find_special_page)(struct vm_area_struct *vma,
unsigned long addr);
};
struct mmu_gather;

5
include/linux/page-flags.h
View File

@ -121,8 +121,12 @@ enum pageflags {
PG_fscache = PG_private_2, /* page backed by cache */
/* XEN */
/* Pinned in Xen as a read-only pagetable page. */
PG_pinned = PG_owner_priv_1,
/* Pinned as part of domain save (see xen_mm_pin_all()). */
PG_savepinned = PG_dirty,
/* Has a grant mapping of another (foreign) domain's page. */
PG_foreign = PG_owner_priv_1,
/* SLOB */
PG_slob_free = PG_private,
@ -215,6 +219,7 @@ __PAGEFLAG(Slab, slab)
PAGEFLAG(Checked, checked) /* Used by some filesystems */
PAGEFLAG(Pinned, pinned) TESTSCFLAG(Pinned, pinned) /* Xen */
PAGEFLAG(SavePinned, savepinned); /* Xen */
PAGEFLAG(Foreign, foreign); /* Xen */
PAGEFLAG(Reserved, reserved) __CLEARPAGEFLAG(Reserved, reserved)
PAGEFLAG(SwapBacked, swapbacked) __CLEARPAGEFLAG(SwapBacked, swapbacked)
__SETPAGEFLAG(SwapBacked, swapbacked)

43
include/xen/grant_table.h
View File

@ -45,6 +45,8 @@
#include <asm/xen/hypervisor.h>
#include <xen/features.h>
#include <linux/mm_types.h>
#include <linux/page-flags.h>
#define GNTTAB_RESERVED_XENSTORE 1
@ -58,6 +60,22 @@ struct gnttab_free_callback {
u16 count;
};
struct gntab_unmap_queue_data;
typedef void (*gnttab_unmap_refs_done)(int result, struct gntab_unmap_queue_data *data);
struct gntab_unmap_queue_data
{
struct delayed_work gnttab_work;
void *data;
gnttab_unmap_refs_done done;
struct gnttab_unmap_grant_ref *unmap_ops;
struct gnttab_unmap_grant_ref *kunmap_ops;
struct page **pages;
unsigned int count;
unsigned int age;
};
int gnttab_init(void);
int gnttab_suspend(void);
int gnttab_resume(void);
@ -163,12 +181,17 @@ void gnttab_free_auto_xlat_frames(void);
#define gnttab_map_vaddr(map) ((void *)(map.host_virt_addr))
int gnttab_alloc_pages(int nr_pages, struct page **pages);
void gnttab_free_pages(int nr_pages, struct page **pages);
int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops,
struct gnttab_map_grant_ref *kmap_ops,
struct page **pages, unsigned int count);
int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops,
struct gnttab_map_grant_ref *kunmap_ops,
struct gnttab_unmap_grant_ref *kunmap_ops,
struct page **pages, unsigned int count);
void gnttab_unmap_refs_async(struct gntab_unmap_queue_data* item);
/* Perform a batch of grant map/copy operations. Retry every batch slot
* for which the hypervisor returns GNTST_eagain. This is typically due
@ -182,4 +205,22 @@ int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops,
void gnttab_batch_map(struct gnttab_map_grant_ref *batch, unsigned count);
void gnttab_batch_copy(struct gnttab_copy *batch, unsigned count);
struct xen_page_foreign {
domid_t domid;
grant_ref_t gref;
};
static inline struct xen_page_foreign *xen_page_foreign(struct page *page)
{
if (!PageForeign(page))
return NULL;
#if BITS_PER_LONG < 64
return (struct xen_page_foreign *)page->private;
#else
BUILD_BUG_ON(sizeof(struct xen_page_foreign) > BITS_PER_LONG);
return (struct xen_page_foreign *)&page->private;
#endif
}
#endif /* __ASM_GNTTAB_H__ */

6
include/xen/interface/features.h
View File

@ -41,6 +41,12 @@
/* x86: Does this Xen host support the MMU_PT_UPDATE_PRESERVE_AD hypercall? */
#define XENFEAT_mmu_pt_update_preserve_ad 5
/*
* If set, GNTTABOP_map_grant_ref honors flags to be placed into guest kernel
* available pte bits.
*/
#define XENFEAT_gnttab_map_avail_bits 7
/* x86: Does this Xen host support the HVM callback vector type? */
#define XENFEAT_hvm_callback_vector 8

7
include/xen/interface/grant_table.h
View File

@ -525,6 +525,13 @@ DEFINE_GUEST_HANDLE_STRUCT(gnttab_cache_flush);
#define _GNTMAP_contains_pte (4)
#define GNTMAP_contains_pte (1<<_GNTMAP_contains_pte)
/*
* Bits to be placed in guest kernel available PTE bits (architecture
* dependent; only supported when XENFEAT_gnttab_map_avail_bits is set).
*/
#define _GNTMAP_guest_avail0 (16)
#define GNTMAP_guest_avail_mask ((uint32_t)~0 << _GNTMAP_guest_avail0)
/*
* Values for error status returns. All errors are -ve.
*/

2
mm/memory.c
View File

@ -754,6 +754,8 @@ struct page *vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
if (HAVE_PTE_SPECIAL) {
if (likely(!pte_special(pte)))
goto check_pfn;
if (vma->vm_ops && vma->vm_ops->find_special_page)
return vma->vm_ops->find_special_page(vma, addr);
if (vma->vm_flags & (VM_PFNMAP | VM_MIXEDMAP))
return NULL;
if (!is_zero_pfn(pfn))