XBZRLE: Fix one XBZRLE corruption issues

The page may not be inserted into cache after executing save_xbzrle_page.
In case of failure to insert, the original page should be sent rather
than the page in the cache.

Signed-off-by: ChenLiang <chenliang88@huawei.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
This commit is contained in:
ChenLiang 2014-04-04 17:57:53 +08:00 committed by Juan Quintela
parent 21a246a43b
commit 1534ee93cc

View File

@ -341,7 +341,7 @@ static void xbzrle_cache_zero_page(ram_addr_t current_addr)
#define ENCODING_FLAG_XBZRLE 0x1
static int save_xbzrle_page(QEMUFile *f, uint8_t *current_data,
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)
{
@ -349,19 +349,23 @@ static int save_xbzrle_page(QEMUFile *f, uint8_t *current_data,
uint8_t *prev_cached_page;
if (!cache_is_cached(XBZRLE.cache, current_addr)) {
acct_info.xbzrle_cache_miss++;
if (!last_stage) {
if (cache_insert(XBZRLE.cache, current_addr, current_data) == -1) {
if (cache_insert(XBZRLE.cache, current_addr, *current_data) == -1) {
return -1;
} else {
/* update *current_data when the page has been
inserted into cache */
*current_data = get_cached_data(XBZRLE.cache, current_addr);
}
}
acct_info.xbzrle_cache_miss++;
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);
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,
@ -374,7 +378,10 @@ static int save_xbzrle_page(QEMUFile *f, uint8_t *current_data,
DPRINTF("Overflow\n");
acct_info.xbzrle_overflows++;
/* update data in the cache */
memcpy(prev_cached_page, current_data, TARGET_PAGE_SIZE);
if (!last_stage) {
memcpy(prev_cached_page, *current_data, TARGET_PAGE_SIZE);
*current_data = prev_cached_page;
}
return -1;
}
@ -599,15 +606,9 @@ static int ram_save_block(QEMUFile *f, bool last_stage)
*/
xbzrle_cache_zero_page(current_addr);
} else if (!ram_bulk_stage && migrate_use_xbzrle()) {
bytes_sent = save_xbzrle_page(f, p, current_addr, block,
bytes_sent = save_xbzrle_page(f, &p, current_addr, block,
offset, cont, last_stage);
if (!last_stage) {
/* We must send exactly what's in the xbzrle cache
* even if the page wasn't xbzrle compressed, so that
* it's right next time.
*/
p = get_cached_data(XBZRLE.cache, current_addr);
/* Can't send this cached data async, since the cache page
* might get updated before it gets to the wire
*/