On Mon, Apr 22, 2024 at 9:41 AM Wafer <wa...@jaguarmicro.com> wrote: > > The virtio-1.3 specification > <https://docs.oasis-open.org/virtio/virtio/v1.3/virtio-v1.3.html> writes: > 2.8.6 Next Flag: Descriptor Chaining > Buffer ID is included in the last descriptor in the list. > > If the feature (_F_INDIRECT_DESC) has been negotiated, install only > one descriptor in the virtqueue. > Therefor the buffer id should be obtained from the first descriptor. > > In descriptor chaining scenarios, the buffer id should be obtained > from the last descriptor. > > Fixes: 86044b24e8 ("virtio: basic packed virtqueue support") > > Signed-off-by: Wafer <wa...@jaguarmicro.com> > --- > hw/virtio/virtio.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c > index 871674f9be..f65d4b4161 100644 > --- a/hw/virtio/virtio.c > +++ b/hw/virtio/virtio.c > @@ -1739,6 +1739,11 @@ static void *virtqueue_packed_pop(VirtQueue *vq, > size_t sz) > goto err_undo_map; > } > > + if (desc_cache != &indirect_desc_cache) { > + /* Buffer ID is included in the last descriptor in the list. */ > + id = desc.id; > + }
It looks to me we can move this out of the loop. Others look good. Thanks > + > rc = virtqueue_packed_read_next_desc(vq, &desc, desc_cache, max, &i, > desc_cache == > &indirect_desc_cache); > -- > 2.27.0 >
