From e314672a8a95f5dc98534f0682fce50fb83dbc5c Mon Sep 17 00:00:00 2001 From: Alex Williamson Date: Fri, 13 Aug 2010 09:54:52 -0400 Subject: [PATCH] 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 Signed-off-by: Bruce Rogers Signed-off-by: Alex Williamson Signed-off-by: Michael S. Tsirkin --- hw/vhost.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/hw/vhost.c b/hw/vhost.c index 8d3ba5b..7e282dd 100644 --- a/hw/vhost.c +++ b/hw/vhost.c @@ -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); -- 2.7.4