David Hildenbrand <da...@redhat.com> 于2020年8月14日周五 上午1:15写道：
>
> On 13.08.20 18:46, Li Qiang wrote:
>
> For now we use "virtio-mem:" for the subject, without the "hw: "part.
>
> > If error occurs while processing the virtio request we should call
> > 'virtqueue_detach_element' to detach the element from the virtqueue
> > before free the elem.
>
> What's the effect of this? In all cases we trigger a virtio_error(), so
> do we really have to bother?
>
Though the 'in_use' will be reset to 0 while reseting the virtio device.
The mapped sglist will not be unammped.
There maybe some undesired behavior. CC Paolo to make a confirmation.
Thanks,
Li Qiang
> >
> > Signed-off-by: Li Qiang <liq...@163.com>
> > ---
> > hw/virtio/virtio-mem.c | 13 +++++++------
> > 1 file changed, 7 insertions(+), 6 deletions(-)
> >
> > diff --git a/hw/virtio/virtio-mem.c b/hw/virtio/virtio-mem.c
> > index 7740fc613f..5ac6c3ec67 100644
> > --- a/hw/virtio/virtio-mem.c
> > +++ b/hw/virtio/virtio-mem.c
> > @@ -318,8 +318,7 @@ static void virtio_mem_handle_request(VirtIODevice
> > *vdev, VirtQueue *vq)
> > if (iov_to_buf(elem->out_sg, elem->out_num, 0, &req, len) < len) {
> > virtio_error(vdev, "virtio-mem protocol violation: invalid
> > request"
> > " size: %d", len);
> > - g_free(elem);
> > - return;
> > + goto out_free;
> > }
> >
> > if (iov_size(elem->in_sg, elem->in_num) <
> > @@ -327,8 +326,7 @@ static void virtio_mem_handle_request(VirtIODevice
> > *vdev, VirtQueue *vq)
> > virtio_error(vdev, "virtio-mem protocol violation: not enough
> > space"
> > " for response: %zu",
> > iov_size(elem->in_sg, elem->in_num));
> > - g_free(elem);
> > - return;
> > + goto out_free;
> > }
> >
> > type = le16_to_cpu(req.type);
> > @@ -348,12 +346,15 @@ static void virtio_mem_handle_request(VirtIODevice
> > *vdev, VirtQueue *vq)
> > default:
> > virtio_error(vdev, "virtio-mem protocol violation: unknown
> > request"
> > " type: %d", type);
> > - g_free(elem);
> > - return;
> > + goto out_free;
> > }
> >
> > g_free(elem);
> > }
> > +
> > +out_free:
> > + virtqueue_detach_element(vq, elem, 0);
> > + g_free(elem);
> > }
> >
> > static void virtio_mem_get_config(VirtIODevice *vdev, uint8_t *config_data)
> >
>
>
> --
> Thanks,
>
> David / dhildenb
>
