kvm: Rework dirty bitmap synchronization

Extend kvm_physical_sync_dirty_bitmap() so that is can sync across
multiple slots. Useful for updating the whole dirty log during
migration. Moreover, properly pass down errors the whole call chain.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This commit is contained in:
Jan Kiszka 2009-05-01 20:52:47 +02:00 committed by Anthony Liguori
parent 62518b8b1d
commit 151f7749f2
4 changed files with 56 additions and 40 deletions

View file

@ -901,7 +901,8 @@ int cpu_physical_memory_set_dirty_tracking(int enable);
int cpu_physical_memory_get_dirty_tracking(void);
void cpu_physical_sync_dirty_bitmap(target_phys_addr_t start_addr, target_phys_addr_t end_addr);
int cpu_physical_sync_dirty_bitmap(target_phys_addr_t start_addr,
target_phys_addr_t end_addr);
void dump_exec_info(FILE *f,
int (*cpu_fprintf)(FILE *f, const char *fmt, ...));

8
exec.c
View file

@ -1931,10 +1931,14 @@ int cpu_physical_memory_get_dirty_tracking(void)
return in_migration;
}
void cpu_physical_sync_dirty_bitmap(target_phys_addr_t start_addr, target_phys_addr_t end_addr)
int cpu_physical_sync_dirty_bitmap(target_phys_addr_t start_addr,
target_phys_addr_t end_addr)
{
int ret = 0;
if (kvm_enabled())
kvm_physical_sync_dirty_bitmap(start_addr, end_addr);
ret = kvm_physical_sync_dirty_bitmap(start_addr, end_addr);
return ret;
}
static inline void tlb_update_dirty(CPUTLBEntry *tlb_entry)

View file

@ -272,47 +272,58 @@ int kvm_set_migration_log(int enable)
* @start_add: start of logged region.
* @end_addr: end of logged region.
*/
void kvm_physical_sync_dirty_bitmap(target_phys_addr_t start_addr,
target_phys_addr_t end_addr)
int kvm_physical_sync_dirty_bitmap(target_phys_addr_t start_addr,
target_phys_addr_t end_addr)
{
KVMState *s = kvm_state;
KVMDirtyLog d;
KVMSlot *mem = kvm_lookup_matching_slot(s, start_addr, end_addr);
unsigned long alloc_size;
unsigned long size, allocated_size = 0;
target_phys_addr_t phys_addr;
ram_addr_t addr;
target_phys_addr_t phys_addr = start_addr;
KVMDirtyLog d;
KVMSlot *mem;
int ret = 0;
dprintf("sync addr: " TARGET_FMT_lx " into %lx\n", start_addr,
mem->phys_offset);
if (mem == NULL) {
fprintf(stderr, "BUG: %s: invalid parameters " TARGET_FMT_plx "-"
TARGET_FMT_plx "\n", __func__, phys_addr, end_addr - 1);
return;
d.dirty_bitmap = NULL;
while (start_addr < end_addr) {
mem = kvm_lookup_overlapping_slot(s, start_addr, end_addr);
if (mem == NULL) {
break;
}
size = ((mem->memory_size >> TARGET_PAGE_BITS) + 7) / 8;
if (!d.dirty_bitmap) {
d.dirty_bitmap = qemu_malloc(size);
} else if (size > allocated_size) {
d.dirty_bitmap = qemu_realloc(d.dirty_bitmap, size);
}
allocated_size = size;
memset(d.dirty_bitmap, 0, allocated_size);
d.slot = mem->slot;
if (kvm_vm_ioctl(s, KVM_GET_DIRTY_LOG, &d) == -1) {
dprintf("ioctl failed %d\n", errno);
ret = -1;
break;
}
for (phys_addr = mem->start_addr, addr = mem->phys_offset;
phys_addr < mem->start_addr + mem->memory_size;
phys_addr += TARGET_PAGE_SIZE, addr += TARGET_PAGE_SIZE) {
unsigned long *bitmap = (unsigned long *)d.dirty_bitmap;
unsigned nr = (phys_addr - mem->start_addr) >> TARGET_PAGE_BITS;
unsigned word = nr / (sizeof(*bitmap) * 8);
unsigned bit = nr % (sizeof(*bitmap) * 8);
if ((bitmap[word] >> bit) & 1) {
cpu_physical_memory_set_dirty(addr);
}
}
start_addr = phys_addr;
}
alloc_size = ((mem->memory_size >> TARGET_PAGE_BITS) + 7) / 8;
d.dirty_bitmap = qemu_mallocz(alloc_size);
d.slot = mem->slot;
dprintf("slot %d, phys_addr %llx, uaddr: %llx\n",
d.slot, mem->start_addr, mem->phys_offset);
if (kvm_vm_ioctl(s, KVM_GET_DIRTY_LOG, &d) == -1) {
dprintf("ioctl failed %d\n", errno);
goto out;
}
phys_addr = start_addr;
for (addr = mem->phys_offset; phys_addr < end_addr; phys_addr+= TARGET_PAGE_SIZE, addr += TARGET_PAGE_SIZE) {
unsigned long *bitmap = (unsigned long *)d.dirty_bitmap;
unsigned nr = (phys_addr - start_addr) >> TARGET_PAGE_BITS;
unsigned word = nr / (sizeof(*bitmap) * 8);
unsigned bit = nr % (sizeof(*bitmap) * 8);
if ((bitmap[word] >> bit) & 1)
cpu_physical_memory_set_dirty(addr);
}
out:
qemu_free(d.dirty_bitmap);
return ret;
}
int kvm_coalesce_mmio_region(target_phys_addr_t start, ram_addr_t size)

4
kvm.h
View file

@ -40,8 +40,8 @@ void kvm_set_phys_mem(target_phys_addr_t start_addr,
ram_addr_t size,
ram_addr_t phys_offset);
void kvm_physical_sync_dirty_bitmap(target_phys_addr_t start_addr,
target_phys_addr_t end_addr);
int kvm_physical_sync_dirty_bitmap(target_phys_addr_t start_addr,
target_phys_addr_t end_addr);
int kvm_log_start(target_phys_addr_t phys_addr, ram_addr_t size);
int kvm_log_stop(target_phys_addr_t phys_addr, ram_addr_t size);