vhost: Fix size of dirty log sync on resize

When the vhost log is resized, we want to sync up to
the size of the old log.  With that end address in place,
ignore regions that start after then end rather than
hitting assert.

This also addresses the following crash report:
When migrating a vm using vhost-net we hit the following assertion:

qemu-kvm: /usr/src/packages/BUILD/qemu-kvm-0.15.1/hw/vhost.c:30:
vhost_dev_sync_region: Assertion `start / (0x1000 * (8 *
sizeof(vhost_log_chunk_t))) < dev->log_size' failed.

The cases which the end < start check is intended to catch, such as
for vga video memory, will also likely trigger the assertion.
Reorder the code to handle this correctly.

Reported-by: Josh Durgin <josh.durgin@dreamhost.com>
Signed-off-by: Bruce Rogers <brogers@suse.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Alex Williamson 2010-08-13 09:54:52 -04:00 committed by Michael S. Tsirkin
parent d6c730086c
commit e314672a8a

View File

@ -31,11 +31,11 @@ static void vhost_dev_sync_region(struct vhost_dev *dev,
vhost_log_chunk_t *to = dev->log + end / VHOST_LOG_CHUNK + 1;
uint64_t addr = (start / VHOST_LOG_CHUNK) * VHOST_LOG_CHUNK;
assert(end / VHOST_LOG_CHUNK < dev->log_size);
assert(start / VHOST_LOG_CHUNK < dev->log_size);
if (end < start) {
return;
}
assert(end / VHOST_LOG_CHUNK < dev->log_size);
for (;from < to; ++from) {
vhost_log_chunk_t log;
int bit;
@ -277,8 +277,9 @@ static inline void vhost_dev_log_resize(struct vhost_dev* dev, uint64_t size)
r = ioctl(dev->control, VHOST_SET_LOG_BASE, &log_base);
assert(r >= 0);
for (i = 0; i < dev->n_mem_sections; ++i) {
vhost_sync_dirty_bitmap(dev, &dev->mem_sections[i],
0, (target_phys_addr_t)~0x0ull);
/* Sync only the range covered by the old log */
vhost_sync_dirty_bitmap(dev, &dev->mem_sections[i], 0,
dev->log_size * VHOST_LOG_CHUNK - 1);
}
if (dev->log) {
g_free(dev->log);