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0dc3f44aca
qemu/arch_init.c
Mike Day 0dc3f44aca Convert ram_list to RCU 
Allow "unlocked" reads of the ram_list by using an RCU-enabled QLIST.

The ramlist mutex is kept.  call_rcu callbacks are run with the iothread
lock taken, but that may change in the future.  Writers still take the
ramlist mutex, but they no longer need to assume that the iothread lock
is taken.

Readers of the list, instead, no longer require either the iothread
or ramlist mutex, but they need to use rcu_read_lock() and
rcu_read_unlock().

One place in arch_init.c was downgrading from write side to read side
like this:

    qemu_mutex_lock_iothread()
    qemu_mutex_lock_ramlist()
    ...
    qemu_mutex_unlock_iothread()
    ...
    qemu_mutex_unlock_ramlist()

and the equivalent idiom is:

    qemu_mutex_lock_ramlist()
    rcu_read_lock()
    ...
    qemu_mutex_unlock_ramlist()
    ...
    rcu_read_unlock()

Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Mike Day <ncmike@ncultra.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-02-16 17:31:55 +01:00

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/*
* QEMU System Emulator
*
* Copyright (c) 2003-2008 Fabrice Bellard
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include <stdint.h>
#include <stdarg.h>
#include <stdlib.h>
#ifndef _WIN32
#include <sys/types.h>
#include <sys/mman.h>
#endif
#include "config.h"
#include "monitor/monitor.h"
#include "sysemu/sysemu.h"
#include "qemu/bitops.h"
#include "qemu/bitmap.h"
#include "sysemu/arch_init.h"
#include "audio/audio.h"
#include "hw/i386/pc.h"
#include "hw/pci/pci.h"
#include "hw/audio/audio.h"
#include "sysemu/kvm.h"
#include "migration/migration.h"
#include "hw/i386/smbios.h"
#include "exec/address-spaces.h"
#include "hw/audio/pcspk.h"
#include "migration/page_cache.h"
#include "qemu/config-file.h"
#include "qemu/error-report.h"
#include "qmp-commands.h"
#include "trace.h"
#include "exec/cpu-all.h"
#include "exec/ram_addr.h"
#include "hw/acpi/acpi.h"
#include "qemu/host-utils.h"
#include "qemu/rcu_queue.h"
#ifdef DEBUG_ARCH_INIT
#define DPRINTF(fmt, ...) \
do { fprintf(stdout, "arch_init: " fmt, ## __VA_ARGS__); } while (0)
#else
#define DPRINTF(fmt, ...) \
do { } while (0)
#endif
#ifdef TARGET_SPARC
int graphic_width = 1024;
int graphic_height = 768;
int graphic_depth = 8;
#else
int graphic_width = 800;
int graphic_height = 600;
int graphic_depth = 32;
#endif
#if defined(TARGET_ALPHA)
#define QEMU_ARCH QEMU_ARCH_ALPHA
#elif defined(TARGET_ARM)
#define QEMU_ARCH QEMU_ARCH_ARM
#elif defined(TARGET_CRIS)
#define QEMU_ARCH QEMU_ARCH_CRIS
#elif defined(TARGET_I386)
#define QEMU_ARCH QEMU_ARCH_I386
#elif defined(TARGET_M68K)
#define QEMU_ARCH QEMU_ARCH_M68K
#elif defined(TARGET_LM32)
#define QEMU_ARCH QEMU_ARCH_LM32
#elif defined(TARGET_MICROBLAZE)
#define QEMU_ARCH QEMU_ARCH_MICROBLAZE
#elif defined(TARGET_MIPS)
#define QEMU_ARCH QEMU_ARCH_MIPS
#elif defined(TARGET_MOXIE)
#define QEMU_ARCH QEMU_ARCH_MOXIE
#elif defined(TARGET_OPENRISC)
#define QEMU_ARCH QEMU_ARCH_OPENRISC
#elif defined(TARGET_PPC)
#define QEMU_ARCH QEMU_ARCH_PPC
#elif defined(TARGET_S390X)
#define QEMU_ARCH QEMU_ARCH_S390X
#elif defined(TARGET_SH4)
#define QEMU_ARCH QEMU_ARCH_SH4
#elif defined(TARGET_SPARC)
#define QEMU_ARCH QEMU_ARCH_SPARC
#elif defined(TARGET_XTENSA)
#define QEMU_ARCH QEMU_ARCH_XTENSA
#elif defined(TARGET_UNICORE32)
#define QEMU_ARCH QEMU_ARCH_UNICORE32
#elif defined(TARGET_TRICORE)
#define QEMU_ARCH QEMU_ARCH_TRICORE
#endif
const uint32_t arch_type = QEMU_ARCH;
static bool mig_throttle_on;
static int dirty_rate_high_cnt;
static void check_guest_throttling(void);
static uint64_t bitmap_sync_count;
/***********************************************************/
/* ram save/restore */
#define RAM_SAVE_FLAG_FULL 0x01 /* Obsolete, not used anymore */
#define RAM_SAVE_FLAG_COMPRESS 0x02
#define RAM_SAVE_FLAG_MEM_SIZE 0x04
#define RAM_SAVE_FLAG_PAGE 0x08
#define RAM_SAVE_FLAG_EOS 0x10
#define RAM_SAVE_FLAG_CONTINUE 0x20
#define RAM_SAVE_FLAG_XBZRLE 0x40
/* 0x80 is reserved in migration.h start with 0x100 next */
static struct defconfig_file {
const char *filename;
/* Indicates it is an user config file (disabled by -no-user-config) */
bool userconfig;
} default_config_files[] = {
{ CONFIG_QEMU_CONFDIR "/qemu.conf", true },
{ CONFIG_QEMU_CONFDIR "/target-" TARGET_NAME ".conf", true },
{ NULL }, /* end of list */
};
static const uint8_t ZERO_TARGET_PAGE[TARGET_PAGE_SIZE];
int qemu_read_default_config_files(bool userconfig)
{
int ret;
struct defconfig_file *f;
for (f = default_config_files; f->filename; f++) {
if (!userconfig && f->userconfig) {
continue;
}
ret = qemu_read_config_file(f->filename);
if (ret < 0 && ret != -ENOENT) {
return ret;
}
}
return 0;
}
static inline bool is_zero_range(uint8_t *p, uint64_t size)
{
return buffer_find_nonzero_offset(p, size) == size;
}
/* struct contains XBZRLE cache and a static page
used by the compression */
static struct {
/* buffer used for XBZRLE encoding */
uint8_t *encoded_buf;
/* buffer for storing page content */
uint8_t *current_buf;
/* Cache for XBZRLE, Protected by lock. */
PageCache *cache;
QemuMutex lock;
} XBZRLE;
/* buffer used for XBZRLE decoding */
static uint8_t *xbzrle_decoded_buf;
static void XBZRLE_cache_lock(void)
{
if (migrate_use_xbzrle())
qemu_mutex_lock(&XBZRLE.lock);
}
static void XBZRLE_cache_unlock(void)
{
if (migrate_use_xbzrle())
qemu_mutex_unlock(&XBZRLE.lock);
}
/*
* called from qmp_migrate_set_cache_size in main thread, possibly while
* a migration is in progress.
* A running migration maybe using the cache and might finish during this
* call, hence changes to the cache are protected by XBZRLE.lock().
*/
int64_t xbzrle_cache_resize(int64_t new_size)
{
PageCache *new_cache;
int64_t ret;
if (new_size < TARGET_PAGE_SIZE) {
return -1;
}
XBZRLE_cache_lock();
if (XBZRLE.cache != NULL) {
if (pow2floor(new_size) == migrate_xbzrle_cache_size()) {
goto out_new_size;
}
new_cache = cache_init(new_size / TARGET_PAGE_SIZE,
TARGET_PAGE_SIZE);
if (!new_cache) {
error_report("Error creating cache");
ret = -1;
goto out;
}
cache_fini(XBZRLE.cache);
XBZRLE.cache = new_cache;
}
out_new_size:
ret = pow2floor(new_size);
out:
XBZRLE_cache_unlock();
return ret;
}
/* accounting for migration statistics */
typedef struct AccountingInfo {
uint64_t dup_pages;
uint64_t skipped_pages;
uint64_t norm_pages;
uint64_t iterations;
uint64_t xbzrle_bytes;
uint64_t xbzrle_pages;
uint64_t xbzrle_cache_miss;
double xbzrle_cache_miss_rate;
uint64_t xbzrle_overflows;
} AccountingInfo;
static AccountingInfo acct_info;
static void acct_clear(void)
{
memset(&acct_info, 0, sizeof(acct_info));
}
uint64_t dup_mig_bytes_transferred(void)
{
return acct_info.dup_pages * TARGET_PAGE_SIZE;
}
uint64_t dup_mig_pages_transferred(void)
{
return acct_info.dup_pages;
}
uint64_t skipped_mig_bytes_transferred(void)
{
return acct_info.skipped_pages * TARGET_PAGE_SIZE;
}
uint64_t skipped_mig_pages_transferred(void)
{
return acct_info.skipped_pages;
}
uint64_t norm_mig_bytes_transferred(void)
{
return acct_info.norm_pages * TARGET_PAGE_SIZE;
}
uint64_t norm_mig_pages_transferred(void)
{
return acct_info.norm_pages;
}
uint64_t xbzrle_mig_bytes_transferred(void)
{
return acct_info.xbzrle_bytes;
}
uint64_t xbzrle_mig_pages_transferred(void)
{
return acct_info.xbzrle_pages;
}
uint64_t xbzrle_mig_pages_cache_miss(void)
{
return acct_info.xbzrle_cache_miss;
}
double xbzrle_mig_cache_miss_rate(void)
{
return acct_info.xbzrle_cache_miss_rate;
}
uint64_t xbzrle_mig_pages_overflow(void)
{
return acct_info.xbzrle_overflows;
}
static size_t save_block_hdr(QEMUFile *f, RAMBlock *block, ram_addr_t offset,
int cont, int flag)
{
size_t size;
qemu_put_be64(f, offset | cont | flag);
size = 8;
if (!cont) {
qemu_put_byte(f, strlen(block->idstr));
qemu_put_buffer(f, (uint8_t *)block->idstr,
strlen(block->idstr));
size += 1 + strlen(block->idstr);
}
return size;
}
/* This is the last block that we have visited serching for dirty pages
*/
static RAMBlock *last_seen_block;
/* This is the last block from where we have sent data */
static RAMBlock *last_sent_block;
static ram_addr_t last_offset;
static unsigned long *migration_bitmap;
static uint64_t migration_dirty_pages;
static uint32_t last_version;
static bool ram_bulk_stage;
/* Update the xbzrle cache to reflect a page that's been sent as all 0.
* The important thing is that a stale (not-yet-0'd) page be replaced
* by the new data.
* As a bonus, if the page wasn't in the cache it gets added so that
* when a small write is made into the 0'd page it gets XBZRLE sent
*/
static void xbzrle_cache_zero_page(ram_addr_t current_addr)
{
if (ram_bulk_stage || !migrate_use_xbzrle()) {
return;
}
/* We don't care if this fails to allocate a new cache page
* as long as it updated an old one */
cache_insert(XBZRLE.cache, current_addr, ZERO_TARGET_PAGE,
bitmap_sync_count);
}
#define ENCODING_FLAG_XBZRLE 0x1
static int save_xbzrle_page(QEMUFile *f, uint8_t **current_data,
ram_addr_t current_addr, RAMBlock *block,
ram_addr_t offset, int cont, bool last_stage)
{
int encoded_len = 0, bytes_sent = -1;
uint8_t *prev_cached_page;
if (!cache_is_cached(XBZRLE.cache, current_addr, bitmap_sync_count)) {
acct_info.xbzrle_cache_miss++;
if (!last_stage) {
if (cache_insert(XBZRLE.cache, current_addr, *current_data,
bitmap_sync_count) == -1) {
return -1;
} else {
/* update *current_data when the page has been
inserted into cache */
*current_data = get_cached_data(XBZRLE.cache, current_addr);
}
}
return -1;
}
prev_cached_page = get_cached_data(XBZRLE.cache, current_addr);
/* save current buffer into memory */
memcpy(XBZRLE.current_buf, *current_data, TARGET_PAGE_SIZE);
/* XBZRLE encoding (if there is no overflow) */
encoded_len = xbzrle_encode_buffer(prev_cached_page, XBZRLE.current_buf,
TARGET_PAGE_SIZE, XBZRLE.encoded_buf,
TARGET_PAGE_SIZE);
if (encoded_len == 0) {
DPRINTF("Skipping unmodified page\n");
return 0;
} else if (encoded_len == -1) {
DPRINTF("Overflow\n");
acct_info.xbzrle_overflows++;
/* update data in the cache */
if (!last_stage) {
memcpy(prev_cached_page, *current_data, TARGET_PAGE_SIZE);
*current_data = prev_cached_page;
}
return -1;
}
/* we need to update the data in the cache, in order to get the same data */
if (!last_stage) {
memcpy(prev_cached_page, XBZRLE.current_buf, TARGET_PAGE_SIZE);
}
/* Send XBZRLE based compressed page */
bytes_sent = save_block_hdr(f, block, offset, cont, RAM_SAVE_FLAG_XBZRLE);
qemu_put_byte(f, ENCODING_FLAG_XBZRLE);
qemu_put_be16(f, encoded_len);
qemu_put_buffer(f, XBZRLE.encoded_buf, encoded_len);
bytes_sent += encoded_len + 1 + 2;
acct_info.xbzrle_pages++;
acct_info.xbzrle_bytes += bytes_sent;
return bytes_sent;
}
static inline
ram_addr_t migration_bitmap_find_and_reset_dirty(MemoryRegion *mr,
ram_addr_t start)
{
unsigned long base = mr->ram_addr >> TARGET_PAGE_BITS;
unsigned long nr = base + (start >> TARGET_PAGE_BITS);
uint64_t mr_size = TARGET_PAGE_ALIGN(memory_region_size(mr));
unsigned long size = base + (mr_size >> TARGET_PAGE_BITS);
unsigned long next;
if (ram_bulk_stage && nr > base) {
next = nr + 1;
} else {
next = find_next_bit(migration_bitmap, size, nr);
}
if (next < size) {
clear_bit(next, migration_bitmap);
migration_dirty_pages--;
}
return (next - base) << TARGET_PAGE_BITS;
}
static inline bool migration_bitmap_set_dirty(ram_addr_t addr)
{
bool ret;
int nr = addr >> TARGET_PAGE_BITS;
ret = test_and_set_bit(nr, migration_bitmap);
if (!ret) {
migration_dirty_pages++;
}
return ret;
}
static void migration_bitmap_sync_range(ram_addr_t start, ram_addr_t length)
{
ram_addr_t addr;
unsigned long page = BIT_WORD(start >> TARGET_PAGE_BITS);
/* start address is aligned at the start of a word? */
if (((page * BITS_PER_LONG) << TARGET_PAGE_BITS) == start) {
int k;
int nr = BITS_TO_LONGS(length >> TARGET_PAGE_BITS);
unsigned long *src = ram_list.dirty_memory[DIRTY_MEMORY_MIGRATION];
for (k = page; k < page + nr; k++) {
if (src[k]) {
unsigned long new_dirty;
new_dirty = ~migration_bitmap[k];
migration_bitmap[k] |= src[k];
new_dirty &= src[k];
migration_dirty_pages += ctpopl(new_dirty);
src[k] = 0;
}
}
} else {
for (addr = 0; addr < length; addr += TARGET_PAGE_SIZE) {
if (cpu_physical_memory_get_dirty(start + addr,
TARGET_PAGE_SIZE,
DIRTY_MEMORY_MIGRATION)) {
cpu_physical_memory_reset_dirty(start + addr,
TARGET_PAGE_SIZE,
DIRTY_MEMORY_MIGRATION);
migration_bitmap_set_dirty(start + addr);
}
}
}
}
/* Fix me: there are too many global variables used in migration process. */
static int64_t start_time;
static int64_t bytes_xfer_prev;
static int64_t num_dirty_pages_period;
static void migration_bitmap_sync_init(void)
{
start_time = 0;
bytes_xfer_prev = 0;
num_dirty_pages_period = 0;
}
/* Called with iothread lock held, to protect ram_list.dirty_memory[] */
static void migration_bitmap_sync(void)
{
RAMBlock *block;
uint64_t num_dirty_pages_init = migration_dirty_pages;
MigrationState *s = migrate_get_current();
int64_t end_time;
int64_t bytes_xfer_now;
static uint64_t xbzrle_cache_miss_prev;
static uint64_t iterations_prev;
bitmap_sync_count++;
if (!bytes_xfer_prev) {
bytes_xfer_prev = ram_bytes_transferred();
}
if (!start_time) {
start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
}
trace_migration_bitmap_sync_start();
address_space_sync_dirty_bitmap(&address_space_memory);
rcu_read_lock();
QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
migration_bitmap_sync_range(block->mr->ram_addr, block->used_length);
}
rcu_read_unlock();
trace_migration_bitmap_sync_end(migration_dirty_pages
- num_dirty_pages_init);
num_dirty_pages_period += migration_dirty_pages - num_dirty_pages_init;
end_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
/* more than 1 second = 1000 millisecons */
if (end_time > start_time + 1000) {
if (migrate_auto_converge()) {
/* The following detection logic can be refined later. For now:
Check to see if the dirtied bytes is 50% more than the approx.
amount of bytes that just got transferred since the last time we
were in this routine. If that happens >N times (for now N==4)
we turn on the throttle down logic */
bytes_xfer_now = ram_bytes_transferred();
if (s->dirty_pages_rate &&
(num_dirty_pages_period * TARGET_PAGE_SIZE >
(bytes_xfer_now - bytes_xfer_prev)/2) &&
(dirty_rate_high_cnt++ > 4)) {
trace_migration_throttle();
mig_throttle_on = true;
dirty_rate_high_cnt = 0;
}
bytes_xfer_prev = bytes_xfer_now;
} else {
mig_throttle_on = false;
}
if (migrate_use_xbzrle()) {
if (iterations_prev != 0) {
acct_info.xbzrle_cache_miss_rate =
(double)(acct_info.xbzrle_cache_miss -
xbzrle_cache_miss_prev) /
(acct_info.iterations - iterations_prev);
}
iterations_prev = acct_info.iterations;
xbzrle_cache_miss_prev = acct_info.xbzrle_cache_miss;
}
s->dirty_pages_rate = num_dirty_pages_period * 1000
/ (end_time - start_time);
s->dirty_bytes_rate = s->dirty_pages_rate * TARGET_PAGE_SIZE;
start_time = end_time;
num_dirty_pages_period = 0;
s->dirty_sync_count = bitmap_sync_count;
}
}
/*
* ram_save_page: Send the given page to the stream
*
* Returns: Number of bytes written.
*/
static int ram_save_page(QEMUFile *f, RAMBlock* block, ram_addr_t offset,
bool last_stage)
{
int bytes_sent;
int cont;
ram_addr_t current_addr;
MemoryRegion *mr = block->mr;
uint8_t *p;
int ret;
bool send_async = true;
cont = (block == last_sent_block) ? RAM_SAVE_FLAG_CONTINUE : 0;
p = memory_region_get_ram_ptr(mr) + offset;
/* In doubt sent page as normal */
bytes_sent = -1;
ret = ram_control_save_page(f, block->offset,
offset, TARGET_PAGE_SIZE, &bytes_sent);
XBZRLE_cache_lock();
current_addr = block->offset + offset;
if (ret != RAM_SAVE_CONTROL_NOT_SUPP) {
if (ret != RAM_SAVE_CONTROL_DELAYED) {
if (bytes_sent > 0) {
acct_info.norm_pages++;
} else if (bytes_sent == 0) {
acct_info.dup_pages++;
}
}
} else if (is_zero_range(p, TARGET_PAGE_SIZE)) {
acct_info.dup_pages++;
bytes_sent = save_block_hdr(f, block, offset, cont,
RAM_SAVE_FLAG_COMPRESS);
qemu_put_byte(f, 0);
bytes_sent++;
/* Must let xbzrle know, otherwise a previous (now 0'd) cached
* page would be stale
*/
xbzrle_cache_zero_page(current_addr);
} else if (!ram_bulk_stage && migrate_use_xbzrle()) {
bytes_sent = save_xbzrle_page(f, &p, current_addr, block,
offset, cont, last_stage);
if (!last_stage) {
/* Can't send this cached data async, since the cache page
* might get updated before it gets to the wire
*/
send_async = false;
}
}
/* XBZRLE overflow or normal page */
if (bytes_sent == -1) {
bytes_sent = save_block_hdr(f, block, offset, cont, RAM_SAVE_FLAG_PAGE);
if (send_async) {
qemu_put_buffer_async(f, p, TARGET_PAGE_SIZE);
} else {
qemu_put_buffer(f, p, TARGET_PAGE_SIZE);
}
bytes_sent += TARGET_PAGE_SIZE;
acct_info.norm_pages++;
}
XBZRLE_cache_unlock();
return bytes_sent;
}
/*
* ram_find_and_save_block: Finds a page to send and sends it to f
*
* Called within an RCU critical section.
*
* Returns: The number of bytes written.
* 0 means no dirty pages
*/
static int ram_find_and_save_block(QEMUFile *f, bool last_stage)
{
RAMBlock *block = last_seen_block;
ram_addr_t offset = last_offset;
bool complete_round = false;
int bytes_sent = 0;
MemoryRegion *mr;
if (!block)
block = QLIST_FIRST_RCU(&ram_list.blocks);
while (true) {
mr = block->mr;
offset = migration_bitmap_find_and_reset_dirty(mr, offset);
if (complete_round && block == last_seen_block &&
offset >= last_offset) {
break;
}
if (offset >= block->used_length) {
offset = 0;
block = QLIST_NEXT_RCU(block, next);
if (!block) {
block = QLIST_FIRST_RCU(&ram_list.blocks);
complete_round = true;
ram_bulk_stage = false;
}
} else {
bytes_sent = ram_save_page(f, block, offset, last_stage);
/* if page is unmodified, continue to the next */
if (bytes_sent > 0) {
last_sent_block = block;
break;
}
}
}
last_seen_block = block;
last_offset = offset;
return bytes_sent;
}
static uint64_t bytes_transferred;
void acct_update_position(QEMUFile *f, size_t size, bool zero)
{
uint64_t pages = size / TARGET_PAGE_SIZE;
if (zero) {
acct_info.dup_pages += pages;
} else {
acct_info.norm_pages += pages;
bytes_transferred += size;
qemu_update_position(f, size);
}
}
static ram_addr_t ram_save_remaining(void)
{
return migration_dirty_pages;
}
uint64_t ram_bytes_remaining(void)
{
return ram_save_remaining() * TARGET_PAGE_SIZE;
}
uint64_t ram_bytes_transferred(void)
{
return bytes_transferred;
}
uint64_t ram_bytes_total(void)
{
RAMBlock *block;
uint64_t total = 0;
rcu_read_lock();
QLIST_FOREACH_RCU(block, &ram_list.blocks, next)
total += block->used_length;
rcu_read_unlock();
return total;
}
void free_xbzrle_decoded_buf(void)
{
g_free(xbzrle_decoded_buf);
xbzrle_decoded_buf = NULL;
}
static void migration_end(void)
{
if (migration_bitmap) {
memory_global_dirty_log_stop();
g_free(migration_bitmap);
migration_bitmap = NULL;
}
XBZRLE_cache_lock();
if (XBZRLE.cache) {
cache_fini(XBZRLE.cache);
g_free(XBZRLE.encoded_buf);
g_free(XBZRLE.current_buf);
XBZRLE.cache = NULL;
XBZRLE.encoded_buf = NULL;
XBZRLE.current_buf = NULL;
}
XBZRLE_cache_unlock();
}
static void ram_migration_cancel(void *opaque)
{
migration_end();
}
static void reset_ram_globals(void)
{
last_seen_block = NULL;
last_sent_block = NULL;
last_offset = 0;
last_version = ram_list.version;
ram_bulk_stage = true;
}
#define MAX_WAIT 50 /* ms, half buffered_file limit */
/* Each of ram_save_setup, ram_save_iterate and ram_save_complete has
* long-running RCU critical section. When rcu-reclaims in the code
* start to become numerous it will be necessary to reduce the
* granularity of these critical sections.
*/
static int ram_save_setup(QEMUFile *f, void *opaque)
{
RAMBlock *block;
int64_t ram_bitmap_pages; /* Size of bitmap in pages, including gaps */
mig_throttle_on = false;
dirty_rate_high_cnt = 0;
bitmap_sync_count = 0;
migration_bitmap_sync_init();
if (migrate_use_xbzrle()) {
XBZRLE_cache_lock();
XBZRLE.cache = cache_init(migrate_xbzrle_cache_size() /
TARGET_PAGE_SIZE,
TARGET_PAGE_SIZE);
if (!XBZRLE.cache) {
XBZRLE_cache_unlock();
error_report("Error creating cache");
return -1;
}
XBZRLE_cache_unlock();
/* We prefer not to abort if there is no memory */
XBZRLE.encoded_buf = g_try_malloc0(TARGET_PAGE_SIZE);
if (!XBZRLE.encoded_buf) {
error_report("Error allocating encoded_buf");
return -1;
}
XBZRLE.current_buf = g_try_malloc(TARGET_PAGE_SIZE);
if (!XBZRLE.current_buf) {
error_report("Error allocating current_buf");
g_free(XBZRLE.encoded_buf);
XBZRLE.encoded_buf = NULL;
return -1;
}
acct_clear();
}
/* iothread lock needed for ram_list.dirty_memory[] */
qemu_mutex_lock_iothread();
qemu_mutex_lock_ramlist();
rcu_read_lock();
bytes_transferred = 0;
reset_ram_globals();
ram_bitmap_pages = last_ram_offset() >> TARGET_PAGE_BITS;
migration_bitmap = bitmap_new(ram_bitmap_pages);
bitmap_set(migration_bitmap, 0, ram_bitmap_pages);
/*
* Count the total number of pages used by ram blocks not including any
* gaps due to alignment or unplugs.
*/
migration_dirty_pages = 0;
QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
uint64_t block_pages;
block_pages = block->used_length >> TARGET_PAGE_BITS;
migration_dirty_pages += block_pages;
}
memory_global_dirty_log_start();
migration_bitmap_sync();
qemu_mutex_unlock_ramlist();
qemu_mutex_unlock_iothread();
qemu_put_be64(f, ram_bytes_total() | RAM_SAVE_FLAG_MEM_SIZE);
QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
qemu_put_byte(f, strlen(block->idstr));
qemu_put_buffer(f, (uint8_t *)block->idstr, strlen(block->idstr));
qemu_put_be64(f, block->used_length);
}
rcu_read_unlock();
ram_control_before_iterate(f, RAM_CONTROL_SETUP);
ram_control_after_iterate(f, RAM_CONTROL_SETUP);
qemu_put_be64(f, RAM_SAVE_FLAG_EOS);
return 0;
}
static int ram_save_iterate(QEMUFile *f, void *opaque)
{
int ret;
int i;
int64_t t0;
int total_sent = 0;
rcu_read_lock();
if (ram_list.version != last_version) {
reset_ram_globals();
}
/* Read version before ram_list.blocks */
smp_rmb();
ram_control_before_iterate(f, RAM_CONTROL_ROUND);
t0 = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
i = 0;
while ((ret = qemu_file_rate_limit(f)) == 0) {
int bytes_sent;
bytes_sent = ram_find_and_save_block(f, false);
/* no more blocks to sent */
if (bytes_sent == 0) {
break;
}
total_sent += bytes_sent;
acct_info.iterations++;
check_guest_throttling();
/* we want to check in the 1st loop, just in case it was the 1st time
and we had to sync the dirty bitmap.
qemu_get_clock_ns() is a bit expensive, so we only check each some
iterations
*/
if ((i & 63) == 0) {
uint64_t t1 = (qemu_clock_get_ns(QEMU_CLOCK_REALTIME) - t0) / 1000000;
if (t1 > MAX_WAIT) {
DPRINTF("big wait: %" PRIu64 " milliseconds, %d iterations\n",
t1, i);
break;
}
}
i++;
}
rcu_read_unlock();
/*
* Must occur before EOS (or any QEMUFile operation)
* because of RDMA protocol.
*/
ram_control_after_iterate(f, RAM_CONTROL_ROUND);
bytes_transferred += total_sent;
/*
* Do not count these 8 bytes into total_sent, so that we can
* return 0 if no page had been dirtied.
*/
qemu_put_be64(f, RAM_SAVE_FLAG_EOS);
bytes_transferred += 8;
ret = qemu_file_get_error(f);
if (ret < 0) {
return ret;
}
return total_sent;
}
/* Called with iothread lock */
static int ram_save_complete(QEMUFile *f, void *opaque)
{
rcu_read_lock();
migration_bitmap_sync();
ram_control_before_iterate(f, RAM_CONTROL_FINISH);
/* try transferring iterative blocks of memory */
/* flush all remaining blocks regardless of rate limiting */
while (true) {
int bytes_sent;
bytes_sent = ram_find_and_save_block(f, true);
/* no more blocks to sent */
if (bytes_sent == 0) {
break;
}
bytes_transferred += bytes_sent;
}
ram_control_after_iterate(f, RAM_CONTROL_FINISH);
migration_end();
rcu_read_unlock();
qemu_put_be64(f, RAM_SAVE_FLAG_EOS);
return 0;
}
static uint64_t ram_save_pending(QEMUFile *f, void *opaque, uint64_t max_size)
{
uint64_t remaining_size;
remaining_size = ram_save_remaining() * TARGET_PAGE_SIZE;
if (remaining_size < max_size) {
qemu_mutex_lock_iothread();
rcu_read_lock();
migration_bitmap_sync();
rcu_read_unlock();
qemu_mutex_unlock_iothread();
remaining_size = ram_save_remaining() * TARGET_PAGE_SIZE;
}
return remaining_size;
}
static int load_xbzrle(QEMUFile *f, ram_addr_t addr, void *host)
{
unsigned int xh_len;
int xh_flags;
if (!xbzrle_decoded_buf) {
xbzrle_decoded_buf = g_malloc(TARGET_PAGE_SIZE);
}
/* extract RLE header */
xh_flags = qemu_get_byte(f);
xh_len = qemu_get_be16(f);
if (xh_flags != ENCODING_FLAG_XBZRLE) {
error_report("Failed to load XBZRLE page - wrong compression!");
return -1;
}
if (xh_len > TARGET_PAGE_SIZE) {
error_report("Failed to load XBZRLE page - len overflow!");
return -1;
}
/* load data and decode */
qemu_get_buffer(f, xbzrle_decoded_buf, xh_len);
/* decode RLE */
if (xbzrle_decode_buffer(xbzrle_decoded_buf, xh_len, host,
TARGET_PAGE_SIZE) == -1) {
error_report("Failed to load XBZRLE page - decode error!");
return -1;
}
return 0;
}
/* Must be called from within a rcu critical section.
* Returns a pointer from within the RCU-protected ram_list.
*/
static inline void *host_from_stream_offset(QEMUFile *f,
ram_addr_t offset,
int flags)
{
static RAMBlock *block = NULL;
char id[256];
uint8_t len;
if (flags & RAM_SAVE_FLAG_CONTINUE) {
if (!block || block->max_length <= offset) {
error_report("Ack, bad migration stream!");
return NULL;
}
return memory_region_get_ram_ptr(block->mr) + offset;
}
len = qemu_get_byte(f);
qemu_get_buffer(f, (uint8_t *)id, len);
id[len] = 0;
QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
if (!strncmp(id, block->idstr, sizeof(id)) &&
block->max_length > offset) {
return memory_region_get_ram_ptr(block->mr) + offset;
}
}
error_report("Can't find block %s!", id);
return NULL;
}
/*
* If a page (or a whole RDMA chunk) has been
* determined to be zero, then zap it.
*/
void ram_handle_compressed(void *host, uint8_t ch, uint64_t size)
{
if (ch != 0 || !is_zero_range(host, size)) {
memset(host, ch, size);
}
}
static int ram_load(QEMUFile *f, void *opaque, int version_id)
{
int flags = 0, ret = 0;
static uint64_t seq_iter;
seq_iter++;
if (version_id != 4) {
ret = -EINVAL;
}
/* This RCU critical section can be very long running.
* When RCU reclaims in the code start to become numerous,
* it will be necessary to reduce the granularity of this
* critical section.
*/
rcu_read_lock();
while (!ret && !(flags & RAM_SAVE_FLAG_EOS)) {
ram_addr_t addr, total_ram_bytes;
void *host;
uint8_t ch;
addr = qemu_get_be64(f);
flags = addr & ~TARGET_PAGE_MASK;
addr &= TARGET_PAGE_MASK;
switch (flags & ~RAM_SAVE_FLAG_CONTINUE) {
case RAM_SAVE_FLAG_MEM_SIZE:
/* Synchronize RAM block list */
total_ram_bytes = addr;
while (!ret && total_ram_bytes) {
RAMBlock *block;
uint8_t len;
char id[256];
ram_addr_t length;
len = qemu_get_byte(f);
qemu_get_buffer(f, (uint8_t *)id, len);
id[len] = 0;
length = qemu_get_be64(f);
QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
if (!strncmp(id, block->idstr, sizeof(id))) {
if (length != block->used_length) {
Error *local_err = NULL;
ret = qemu_ram_resize(block->offset, length, &local_err);
if (local_err) {
error_report("%s", error_get_pretty(local_err));
error_free(local_err);
}
}
break;
}
}
if (!block) {
error_report("Unknown ramblock \"%s\", cannot "
"accept migration", id);
ret = -EINVAL;
}
total_ram_bytes -= length;
}
break;
case RAM_SAVE_FLAG_COMPRESS:
host = host_from_stream_offset(f, addr, flags);
if (!host) {
error_report("Illegal RAM offset " RAM_ADDR_FMT, addr);
ret = -EINVAL;
break;
}
ch = qemu_get_byte(f);
ram_handle_compressed(host, ch, TARGET_PAGE_SIZE);
break;
case RAM_SAVE_FLAG_PAGE:
host = host_from_stream_offset(f, addr, flags);
if (!host) {
error_report("Illegal RAM offset " RAM_ADDR_FMT, addr);
ret = -EINVAL;
break;
}
qemu_get_buffer(f, host, TARGET_PAGE_SIZE);
break;
case RAM_SAVE_FLAG_XBZRLE:
host = host_from_stream_offset(f, addr, flags);
if (!host) {
error_report("Illegal RAM offset " RAM_ADDR_FMT, addr);
ret = -EINVAL;
break;
}
if (load_xbzrle(f, addr, host) < 0) {
error_report("Failed to decompress XBZRLE page at "
RAM_ADDR_FMT, addr);
ret = -EINVAL;
break;
}
break;
case RAM_SAVE_FLAG_EOS:
/* normal exit */
break;
default:
if (flags & RAM_SAVE_FLAG_HOOK) {
ram_control_load_hook(f, flags);
} else {
error_report("Unknown combination of migration flags: %#x",
flags);
ret = -EINVAL;
}
}
if (!ret) {
ret = qemu_file_get_error(f);
}
}
rcu_read_unlock();
DPRINTF("Completed load of VM with exit code %d seq iteration "
"%" PRIu64 "\n", ret, seq_iter);
return ret;
}
static SaveVMHandlers savevm_ram_handlers = {
.save_live_setup = ram_save_setup,
.save_live_iterate = ram_save_iterate,
.save_live_complete = ram_save_complete,
.save_live_pending = ram_save_pending,
.load_state = ram_load,
.cancel = ram_migration_cancel,
};
void ram_mig_init(void)
{
qemu_mutex_init(&XBZRLE.lock);
register_savevm_live(NULL, "ram", 0, 4, &savevm_ram_handlers, NULL);
}
struct soundhw {
const char *name;
const char *descr;
int enabled;
int isa;
union {
int (*init_isa) (ISABus *bus);
int (*init_pci) (PCIBus *bus);
} init;
};
static struct soundhw soundhw[9];
static int soundhw_count;
void isa_register_soundhw(const char *name, const char *descr,
int (*init_isa)(ISABus *bus))
{
assert(soundhw_count < ARRAY_SIZE(soundhw) - 1);
soundhw[soundhw_count].name = name;
soundhw[soundhw_count].descr = descr;
soundhw[soundhw_count].isa = 1;
soundhw[soundhw_count].init.init_isa = init_isa;
soundhw_count++;
}
void pci_register_soundhw(const char *name, const char *descr,
int (*init_pci)(PCIBus *bus))
{
assert(soundhw_count < ARRAY_SIZE(soundhw) - 1);
soundhw[soundhw_count].name = name;
soundhw[soundhw_count].descr = descr;
soundhw[soundhw_count].isa = 0;
soundhw[soundhw_count].init.init_pci = init_pci;
soundhw_count++;
}
void select_soundhw(const char *optarg)
{
struct soundhw *c;
if (is_help_option(optarg)) {
show_valid_cards:
if (soundhw_count) {
printf("Valid sound card names (comma separated):\n");
for (c = soundhw; c->name; ++c) {
printf ("%-11s %s\n", c->name, c->descr);
}
printf("\n-soundhw all will enable all of the above\n");
} else {
printf("Machine has no user-selectable audio hardware "
"(it may or may not have always-present audio hardware).\n");
}
exit(!is_help_option(optarg));
}
else {
size_t l;
const char *p;
char *e;
int bad_card = 0;
if (!strcmp(optarg, "all")) {
for (c = soundhw; c->name; ++c) {
c->enabled = 1;
}
return;
}
p = optarg;
while (*p) {
e = strchr(p, ',');
l = !e ? strlen(p) : (size_t) (e - p);
for (c = soundhw; c->name; ++c) {
if (!strncmp(c->name, p, l) && !c->name[l]) {
c->enabled = 1;
break;
}
}
if (!c->name) {
if (l > 80) {
error_report("Unknown sound card name (too big to show)");
}
else {
error_report("Unknown sound card name `%.*s'",
(int) l, p);
}
bad_card = 1;
}
p += l + (e != NULL);
}
if (bad_card) {
goto show_valid_cards;
}
}
}
void audio_init(void)
{
struct soundhw *c;
ISABus *isa_bus = (ISABus *) object_resolve_path_type("", TYPE_ISA_BUS, NULL);
PCIBus *pci_bus = (PCIBus *) object_resolve_path_type("", TYPE_PCI_BUS, NULL);
for (c = soundhw; c->name; ++c) {
if (c->enabled) {
if (c->isa) {
if (!isa_bus) {
error_report("ISA bus not available for %s", c->name);
exit(1);
}
c->init.init_isa(isa_bus);
} else {
if (!pci_bus) {
error_report("PCI bus not available for %s", c->name);
exit(1);
}
c->init.init_pci(pci_bus);
}
}
}
}
int qemu_uuid_parse(const char *str, uint8_t *uuid)
{
int ret;
if (strlen(str) != 36) {
return -1;
}
ret = sscanf(str, UUID_FMT, &uuid[0], &uuid[1], &uuid[2], &uuid[3],
&uuid[4], &uuid[5], &uuid[6], &uuid[7], &uuid[8], &uuid[9],
&uuid[10], &uuid[11], &uuid[12], &uuid[13], &uuid[14],
&uuid[15]);
if (ret != 16) {
return -1;
}
return 0;
}
void do_acpitable_option(const QemuOpts *opts)
{
#ifdef TARGET_I386
Error *err = NULL;
acpi_table_add(opts, &err);
if (err) {
error_report("Wrong acpi table provided: %s",
error_get_pretty(err));
error_free(err);
exit(1);
}
#endif
}
void do_smbios_option(QemuOpts *opts)
{
#ifdef TARGET_I386
smbios_entry_add(opts);
#endif
}
void cpudef_init(void)
{
#if defined(cpudef_setup)
cpudef_setup(); /* parse cpu definitions in target config file */
#endif
}
int kvm_available(void)
{
#ifdef CONFIG_KVM
return 1;
#else
return 0;
#endif
}
int xen_available(void)
{
#ifdef CONFIG_XEN
return 1;
#else
return 0;
#endif
}
TargetInfo *qmp_query_target(Error **errp)
{
TargetInfo *info = g_malloc0(sizeof(*info));
info->arch = g_strdup(TARGET_NAME);
return info;
}
/* Stub function that's gets run on the vcpu when its brought out of the
VM to run inside qemu via async_run_on_cpu()*/
static void mig_sleep_cpu(void *opq)
{
qemu_mutex_unlock_iothread();
g_usleep(30*1000);
qemu_mutex_lock_iothread();
}
/* To reduce the dirty rate explicitly disallow the VCPUs from spending
much time in the VM. The migration thread will try to catchup.
Workload will experience a performance drop.
*/
static void mig_throttle_guest_down(void)
{
CPUState *cpu;
qemu_mutex_lock_iothread();
CPU_FOREACH(cpu) {
async_run_on_cpu(cpu, mig_sleep_cpu, NULL);
}
qemu_mutex_unlock_iothread();
}
static void check_guest_throttling(void)
{
static int64_t t0;
int64_t t1;
if (!mig_throttle_on) {
return;
}
if (!t0) {
t0 = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
return;
}
t1 = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
/* If it has been more than 40 ms since the last time the guest
* was throttled then do it again.
*/
if (40 < (t1-t0)/1000000) {
mig_throttle_guest_down();
t0 = t1;
}
}
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