Launching the destination VM before the source VM gives us a regression
test for HEAD^:
The guest device causes a read from the disk image through
guess_disk_lchs(). This will not work if the first sector (containing
the partition table) is yet unallocated, we use COR, and the node is
inactive.
By launching the source VM before the destination, however, the COR
filter on the source will allocate that area in the image shared between
both VMs, thus the problem will not become apparent.
Switching the launch order causes the sector to still be unallocated
when guess_disk_lchs() runs on the inactive node in the destination VM,
and thus we get our test case.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20191001174827.11081-3-mreitz@redhat.com
Message-Id: <20191001174827.11081-3-mreitz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This test case is motivated by commit 2b23f28639 ('block/copy-on-read:
Fix permissions for inactive node'). Instead of just testing
copy-on-read on migration, let's stack all sorts of filter nodes on top
of each other and try if the resulting VM can still migrate
successfully. For good measure, put everything into an iothread, because
why not?
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Max Reitz
Kevin Wolf