Re: [PATCH 00/10] migration/colo: small cleanup series

[Peter Xu <peterx@redhat.com>]

On Sun, Jan 25, 2026 at 08:29:15PM +0100, Lukas Straub wrote:
> On Wed, 21 Jan 2026 17:33:25 -0500
> Peter Xu <peterx@redhat.com> wrote:
> 
> > CI: https://gitlab.com/peterx/qemu/-/pipelines/2277445319
> > 
> > While reading COLO in the past two days, I got a few small patches to clean
> > up here and there.  I also ran this with the COLO qtests [*] and it ran all fine.
> > 
> > Comments welcomed, thanks.
> > 
> > [*] https://lore.kernel.org/r/20260117-colo_unit_test_multifd-v2-0-ab521777fa51@web.de
> 
> Hmm,
> It fails for me on top of current master, but works fine wthout this patchset:
> # Running /x86_64/migration/colo/plain/primary_failover
> # Using machine type: pc-i440fx-11.0
> # starting QEMU: exec ./qemu-system-x86_64 -qtest unix:/tmp/qtest-3157.sock -qtest-log /dev/null -chardev socket,path=/tmp/qtest-3157.qmp,id=char0 -mon chardev=char0,mode=control -display none -audio none -run-with exit-with-parent=on -accel kvm -accel tcg -machine pc-i440fx-11.0, -name source,debug-threads=on -machine memory-backend=mig.mem -object memory-backend-ram,id=mig.mem,size=150M,share=off -serial file:/tmp/migration-test-OZFSJ3/src_serial -drive if=none,id=d0,file=/tmp/migration-test-OZFSJ3/bootsect,format=raw -device ide-hd,drive=d0,secs=1,cyls=1,heads=1 -snapshot  -accel qtest
> # starting QEMU: exec ./qemu-system-x86_64 -qtest unix:/tmp/qtest-3157.sock -qtest-log /dev/null -chardev socket,path=/tmp/qtest-3157.qmp,id=char0 -mon chardev=char0,mode=control -display none -audio none -run-with exit-with-parent=on -accel kvm -accel tcg -machine pc-i440fx-11.0, -name target,debug-threads=on -machine memory-backend=mig.mem -object memory-backend-ram,id=mig.mem,size=150M,share=off -serial file:/tmp/migration-test-OZFSJ3/dest_serial -incoming tcp:127.0.0.1:0  -drive if=none,id=d0,file=/tmp/migration-test-OZFSJ3/bootsect,format=raw -device ide-hd,drive=d0,secs=1,cyls=1,heads=1 -snapshot  -accel qtest
> qemu-system-x86_64: error while loading state for instance 0x0 of device '0000:00:03.0/e1000': Loading VM subsection 'e1000/full_mac_state' in 'e1000' failed: -5: Failed to load e1000/full_mac_state state: stream error: -5

Somehow I didn't hit it previously, but at least when using your latest
patches it hangs for me (rather than failing..).

Patch 9 is broken, because I overlooked COLO_MESSAGE_VMSTATE_SIZE also
needs to reference bioc->usage.

I'll fix patch 9 when repost.  Thanks for the report.

--
Peter Xu