On Mon, 2 Feb 2026 09:12:33 -0500 Peter Xu <[email protected]> wrote:
> On Fri, Jan 30, 2026 at 01:49:42PM +0100, Lukas Straub wrote: > > On Tue, 27 Jan 2026 15:38:55 -0500 > > Peter Xu <[email protected]> wrote: > > > > > On Sun, Jan 25, 2026 at 09:40:10PM +0100, Lukas Straub wrote: > > > > With colo we load device vmstate during each checkpoint, on top of > > > > a vm that was already running. Some devices expect a reset before > > > > loading vmstate on such a previously running vm. > > > > > > > > This fixes a crash when using COLO with Q35 machine. > > > > > > > > Signed-off-by: Lukas Straub <[email protected]> > > > > > > Yes makes sense, maybe you can add some comments into the code too since > > > this was overlooked before, > > > > > > Reviewed-by: Peter Xu <[email protected]> > > > > > > Have you tried to measure how many overheads will this introduce to > > > loading > > > each snapshot? > > > > It's a large overhead actually, between 10-20 milliseconds. > > This can be mentioned in the commit message. > > IIUC reset() may or may not be required while loading a snapshot. > Normally, a device reset() should reset all dev registers and internal > states, OTOH loadvm() will reload most of them once more.. so less > efficient. > > Maybe there's chance to "fix" q35 instead reducing this overhead, but I'll > leave that to be your call; to me this fix is clean from maint POV. > > Thanks, > Yes, I think this fix is fine for now. It more correct like this and we can improve performance later while keeping it correct. Regards, Lukas Straub
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