Re: [libvirt PATCH 06/80] qemu: Keep domain running on dst on failed post-copy migration
On Tue, May 10, 2022 at 17:20:27 +0200, Jiri Denemark wrote:
There's no need to artificially pause a domain when post-copy
fails. The
virtual CPUs may continue running, only the guest tasks that decide to
read a page which has not been migrated yet will get blocked.
IMO not pausing the VM is a policy decision (same way as pausing it was
though) and should be user-configurable at migration start.
I can see that users might want to prevent a half-broken VM from
executing until it gets attention needed to fix it, even when it's safe
from a "theoretical" standpoint.
Signed-off-by: Jiri Denemark <jdenemar(a)redhat.com>
---
src/qemu/qemu_migration.c | 37 +++++++++++++++++++++++++++++++++----
src/qemu/qemu_migration.h | 6 ++++--
src/qemu/qemu_process.c | 8 ++++----
3 files changed, 41 insertions(+), 10 deletions(-)
The code looks okay, but I think this needs more justification if it's
to be accepted in this state.