[Qemu-devel] [PATCH] vhost: Fix size of dirty log sync on resize

[Alex Williamson <alex.williamson@redhat.com>]

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.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
---

 hw/vhost.c |    7 ++++---
 1 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/hw/vhost.c b/hw/vhost.c
index 34c4745..f6a7cef 100644
--- a/hw/vhost.c
+++ b/hw/vhost.c
@@ -27,11 +27,11 @@ 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;
@@ -258,8 +258,9 @@ static inline void vhost_dev_log_resize(struct vhost_dev* dev, uint64_t size)
     log_base = (uint64_t)(unsigned long)log;
     r = ioctl(dev->control, VHOST_SET_LOG_BASE, &log_base);
     assert(r >= 0);
+    /* Sync only the range covered by the old log */
     vhost_client_sync_dirty_bitmap(&dev->client, 0,
-                                   (target_phys_addr_t)~0x0ull);
+                                   dev->log_size * VHOST_LOG_CHUNK - 1);
     if (dev->log) {
         qemu_free(dev->log);
     }