Date:   Wed, 12 Jan 2022 01:30:45 -0500
From:   "Michael S. Tsirkin" <mst@redhat.com>
To:     Jason Wang <jasowang@redhat.com>
Cc:     =?utf-8?B?5p2O5Lic5Y2H?= <lidongsheng@dayudpu.com>,
        virtualization <virtualization@lists.linux-foundation.org>,
        linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] virtio_vdpa: Support surprise removal of virtio vdpa
 device
Message-ID: <20220112013018-mutt-send-email-mst@kernel.org>
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On Wed, Jan 12, 2022 at 10:23:07AM +0800, Jason Wang wrote:
> On Tue, Jan 11, 2022 at 7:52 PM Michael S. Tsirkin <mst@redhat.com> wrote:
> >
> > On Tue, Jan 11, 2022 at 11:36:42AM +0800, 李东升 wrote:
> > > When virtio vdpa device removed, the abnormal damage of the device cannot be
> > > perceived normally, which will cause problems similar to:
> > >
> > > 43bb40c5b926
> >
> >
> > Should include the subject of the patch too.
> >
> > > Hence, add the ability to abort the command on surprise removal
> > >
> > > Signed-off-by: dongsheng li <lidongsheng@dayudpu.com>
> >
> > When removing gracefully,
> > I am not sure we should break device unconditionally like this
> > before giving drivers a chance to clean up.
> > Should we just do it for surprise removal?
> 
> That requires a new method to query whether it's a surprise removal.
> 
> Thanks

We can check pci_device_is_present like virtio does.

> >
> > > ---
> > >  drivers/virtio/virtio_vdpa.c | 1 +
> > >  1 file changed, 1 insertion(+)
> > >
> > > diff --git a/drivers/virtio/virtio_vdpa.c b/drivers/virtio/virtio_vdpa.c
> > > index 4a9ddb44b2a7..fd930409d190 100644
> > > --- a/drivers/virtio/virtio_vdpa.c
> > > +++ b/drivers/virtio/virtio_vdpa.c
> > > @@ -374,6 +374,7 @@ static void virtio_vdpa_remove(struct vdpa_device *vdpa)
> > >  {
> > >   struct virtio_vdpa_device *vd_dev = vdpa_get_drvdata(vdpa);
> > >
> > > + virtio_break_device(vd_dev->vdev);
> > >   unregister_virtio_device(&vd_dev->vdev);
> > >  }
> > >
> > > --
> > > 2.17.1
> >