savevm: Migrate RAM based on name/offset

Synchronize RAM blocks with the target and migrate using name/offset
pairs.  This ensures both source and target have the same view of
RAM and that we get the right bits into the right slot.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This commit is contained in:
Alex Williamson 2010-06-25 11:09:50 -06:00 committed by Anthony Liguori
parent cc9e98cb8f
commit 97ab12d466
2 changed files with 108 additions and 12 deletions

View File

@ -113,20 +113,33 @@ static int ram_save_block(QEMUFile *f)
while (addr < total_ram) {
if (cpu_physical_memory_get_dirty(current_addr, MIGRATION_DIRTY_FLAG)) {
RAMBlock *block;
ram_addr_t offset;
uint8_t *p;
cpu_physical_memory_reset_dirty(current_addr,
current_addr + TARGET_PAGE_SIZE,
MIGRATION_DIRTY_FLAG);
p = qemu_get_ram_ptr(current_addr);
QLIST_FOREACH(block, &ram_list.blocks, next) {
if (current_addr - block->offset < block->length)
break;
}
offset = current_addr - block->offset;
p = block->host + offset;
if (is_dup_page(p, *p)) {
qemu_put_be64(f, current_addr | RAM_SAVE_FLAG_COMPRESS);
qemu_put_be64(f, offset | RAM_SAVE_FLAG_COMPRESS);
qemu_put_byte(f, strlen(block->idstr));
qemu_put_buffer(f, (uint8_t *)block->idstr,
strlen(block->idstr));
qemu_put_byte(f, *p);
bytes_sent = 1;
} else {
qemu_put_be64(f, current_addr | RAM_SAVE_FLAG_PAGE);
qemu_put_be64(f, offset | RAM_SAVE_FLAG_PAGE);
qemu_put_byte(f, strlen(block->idstr));
qemu_put_buffer(f, (uint8_t *)block->idstr,
strlen(block->idstr));
qemu_put_buffer(f, p, TARGET_PAGE_SIZE);
bytes_sent = TARGET_PAGE_SIZE;
}
@ -196,6 +209,7 @@ int ram_save_live(Monitor *mon, QEMUFile *f, int stage, void *opaque)
}
if (stage == 1) {
RAMBlock *block;
uint64_t total_ram = ram_bytes_total();
bytes_transferred = 0;
@ -210,6 +224,12 @@ int ram_save_live(Monitor *mon, QEMUFile *f, int stage, void *opaque)
cpu_physical_memory_set_dirty_tracking(1);
qemu_put_be64(f, total_ram | RAM_SAVE_FLAG_MEM_SIZE);
QLIST_FOREACH(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->length);
}
}
bytes_transferred_last = bytes_transferred;
@ -257,7 +277,7 @@ int ram_load(QEMUFile *f, void *opaque, int version_id)
ram_addr_t addr;
int flags;
if (version_id != 3) {
if (version_id < 3 || version_id > 4) {
return -EINVAL;
}
@ -268,23 +288,99 @@ int ram_load(QEMUFile *f, void *opaque, int version_id)
addr &= TARGET_PAGE_MASK;
if (flags & RAM_SAVE_FLAG_MEM_SIZE) {
if (addr != ram_bytes_total()) {
return -EINVAL;
if (version_id == 3) {
if (addr != ram_bytes_total()) {
return -EINVAL;
}
} else {
/* Synchronize RAM block list */
char id[256];
ram_addr_t length;
ram_addr_t total_ram_bytes = addr;
while (total_ram_bytes) {
RAMBlock *block;
uint8_t len;
len = qemu_get_byte(f);
qemu_get_buffer(f, (uint8_t *)id, len);
id[len] = 0;
length = qemu_get_be64(f);
QLIST_FOREACH(block, &ram_list.blocks, next) {
if (!strncmp(id, block->idstr, sizeof(id))) {
if (block->length != length)
return -EINVAL;
break;
}
}
if (!block) {
if (!qemu_ram_alloc(NULL, id, length))
return -ENOMEM;
}
total_ram_bytes -= length;
}
}
}
if (flags & RAM_SAVE_FLAG_COMPRESS) {
uint8_t ch = qemu_get_byte(f);
memset(qemu_get_ram_ptr(addr), ch, TARGET_PAGE_SIZE);
void *host;
uint8_t ch;
if (version_id == 3) {
host = qemu_get_ram_ptr(addr);
} else {
RAMBlock *block;
char id[256];
uint8_t len;
len = qemu_get_byte(f);
qemu_get_buffer(f, (uint8_t *)id, len);
id[len] = 0;
QLIST_FOREACH(block, &ram_list.blocks, next) {
if (!strncmp(id, block->idstr, sizeof(id)))
break;
}
if (!block)
return -EINVAL;
host = block->host + addr;
}
ch = qemu_get_byte(f);
memset(host, ch, TARGET_PAGE_SIZE);
#ifndef _WIN32
if (ch == 0 &&
(!kvm_enabled() || kvm_has_sync_mmu())) {
madvise(qemu_get_ram_ptr(addr), TARGET_PAGE_SIZE,
MADV_DONTNEED);
madvise(host, TARGET_PAGE_SIZE, MADV_DONTNEED);
}
#endif
} else if (flags & RAM_SAVE_FLAG_PAGE) {
qemu_get_buffer(f, qemu_get_ram_ptr(addr), TARGET_PAGE_SIZE);
void *host;
if (version_id == 3) {
host = qemu_get_ram_ptr(addr);
} else {
RAMBlock *block;
char id[256];
uint8_t len;
len = qemu_get_byte(f);
qemu_get_buffer(f, (uint8_t *)id, len);
id[len] = 0;
QLIST_FOREACH(block, &ram_list.blocks, next) {
if (!strncmp(id, block->idstr, sizeof(id)))
break;
}
if (!block)
return -EINVAL;
host = block->host + addr;
}
qemu_get_buffer(f, host, TARGET_PAGE_SIZE);
}
if (qemu_file_has_error(f)) {
return -EIO;

2
vl.c
View File

@ -2794,7 +2794,7 @@ int main(int argc, char **argv, char **envp)
if (qemu_opts_foreach(&qemu_drive_opts, drive_init_func, &machine->use_scsi, 1) != 0)
exit(1);
register_savevm_live(NULL, "ram", 0, 3, NULL, ram_save_live, NULL,
register_savevm_live(NULL, "ram", 0, 4, NULL, ram_save_live, NULL,
ram_load, NULL);
if (nb_numa_nodes > 0) {