Re: [Qemu-discuss] Suspending a Windows VM with PCI devices attached

[Maxim Levitsky]

On Wed, 2018-07-18 at 23:49 -0700, Christopher Snowhill (kode54) wrote:
> Is there any possibility of doing this? I realize that suspending is not
> possible with PCI devices attached, but would it be possible to instead
> automate the process of hot removing all the PCI devices first, then
> suspending, then hot adding them back again when resuming the machine? That'll
> probably be a firm "no".

I tried actually to suspends guests with the pci devices attached, and it sort
of worked (back when I only played with KVM stack (before I joined redhat)).

In theory you can enable suspend to ram/disk in the guest and use it (google on
how to do this).
Then you suspend the guest with 'virsh guest dopmsuspend --target mem/disk' -
not sure about the exect name, and you wake it with 'dopmwakeup' or so.

While the guest is suspended you can in theory suspend the host. The problem was
that on my machine that didn't work reliably, most of the times the guest would
either crash on resume, or crash *after* few munutes, suggesting some kind of
memory corruption. This is for sure not a supported feature.

Hot remove/add of the pci devices should work too, I am not aware of any scripts
that do that automatically. I haven't tried.

Best regards,
       Maxim Levitsky