Re: [PATCH] qemu: snapshot: Collect 'query-named-block-nodes' prior to memory migration

When doing an external snapshot we migrate memory to a file as a form of taking the memory state. This creates a problem as qemu deactivates all active bitmaps after a successful migration. This means that calling 'query-named-block-nodes' will return an empty list of bitmaps for devices. We use the bitmap list to propagate the active bitmaps into the overlay files being created which is required for backups to work after a snapshot. Since we wouldn't propagate anythign a subsequent backup

will fail with: invalid argument: missing or broken bitmap 'testchck' for disk 'vda' To fix this, we can simply collect the bitmap list prior to the migration. https://bugzilla.redhat.com/show_bug.cgi?id=1862472 Signed-off-by: Peter Krempa <pkrempa(a)redhat.com&gt; --- Note that with current qemu the above steps will still fail as qemu fails to 'cont' after a migration if backing images contain bitmaps which is the case here. See: https://lists.nongnu.org/archive/html/qemu-block/2020-07/msg01833.html

src/qemu/qemu_driver.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index 0ad6359102..b655df8c98 100644 --- a/src/qemu/qemu_driver.c