On Mon, Jan 16, 2023 at 7:48 AM Jason Wang <jasow...@redhat.com> wrote:
>
>
> 在 2023/1/13 16:45, Eugenio Perez Martin 写道:
> > On Fri, Jan 13, 2023 at 5:39 AM Jason Wang <jasow...@redhat.com> wrote:
> >> On Fri, Jan 13, 2023 at 1:25 AM Eugenio Pérez <epere...@redhat.com> wrote:
> >>> This is needed for qemu to know it can suspend the device to retrieve
> >>> its status and enable SVQ with it, so all the process is transparent to
> >>> the guest.
> >>>
> >>> Signed-off-by: Eugenio Pérez <epere...@redhat.com>
> >> Acked-by: Jason Wang <jasow...@redhat.com>
> >>
> >> We probably need to add the resume in the future to have a quick
> >> recovery from migration failures.
> >>
> > The capability of a resume can be useful here but only in a small
> > window. During the most time of the migration SVQ is enabled, so in
> > the event of a migration failure we may need to reset the whole device
> > to enable passthrough again.
>
>
> Yes.
>
>
> >
> > But maybe is it worth giving a quick review and adding some TODOs
> > where it can be useful in this series?
>
>
> We can start by having a TODO in this series, and leave resume in for
> the future.
>
Got it, I'll add in the next series.
Thanks!
> Thanks
>
>
> >
> > Thanks!
> >
> >> Thanks
> >>
> >>> ---
> >>> hw/virtio/vhost-vdpa.c | 3 ++-
> >>> 1 file changed, 2 insertions(+), 1 deletion(-)
> >>>
> >>> diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
> >>> index 4296427a69..a61a6b2a74 100644
> >>> --- a/hw/virtio/vhost-vdpa.c
> >>> +++ b/hw/virtio/vhost-vdpa.c
> >>> @@ -659,7 +659,8 @@ static int vhost_vdpa_set_backend_cap(struct
> >>> vhost_dev *dev)
> >>> uint64_t features;
> >>> uint64_t f = 0x1ULL << VHOST_BACKEND_F_IOTLB_MSG_V2 |
> >>> 0x1ULL << VHOST_BACKEND_F_IOTLB_BATCH |
> >>> - 0x1ULL << VHOST_BACKEND_F_IOTLB_ASID;
> >>> + 0x1ULL << VHOST_BACKEND_F_IOTLB_ASID |
> >>> + 0x1ULL << VHOST_BACKEND_F_SUSPEND;
> >>> int r;
> >>>
> >>> if (vhost_vdpa_call(dev, VHOST_GET_BACKEND_FEATURES, &features)) {
> >>> --
> >>> 2.31.1
> >>>
>
