vhost: correctly set bits of dirty pages

Fix two bugs in dirty page logging:
When counting pages we should increase address by 1 instead of
VHOST_PAGE_SIZE. Make log_write() correctly process requests
that cross pages with write_address not starting at page boundary.

Reported-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Michael S. Tsirkin 2010-11-29 10:19:07 +02:00
parent a290aec88a
commit 3bf9be40ff

View file

@ -885,6 +885,7 @@ static int log_write(void __user *log_base,
int r;
if (!write_length)
return 0;
write_length += write_address % VHOST_PAGE_SIZE;
write_address /= VHOST_PAGE_SIZE;
for (;;) {
u64 base = (u64)(unsigned long)log_base;
@ -898,7 +899,7 @@ static int log_write(void __user *log_base,
if (write_length <= VHOST_PAGE_SIZE)
break;
write_length -= VHOST_PAGE_SIZE;
write_address += VHOST_PAGE_SIZE;
write_address += 1;
}
return r;
}