On Thu, Mar 14, 2024 at 5:06 PM Jonah Palmer <jonah.pal...@oracle.com> wrote: > > > > On 3/14/24 10:55 AM, Eugenio Perez Martin wrote: > > On Thu, Mar 14, 2024 at 1:16 PM Jonah Palmer <jonah.pal...@oracle.com> > > wrote: > >> > >> > >> > >> On 3/13/24 11:01 PM, Jason Wang wrote: > >>> On Wed, Mar 13, 2024 at 7:55 PM Jonah Palmer <jonah.pal...@oracle.com> > >>> wrote: > >>>> > >>>> Add support to virtio-pci devices for handling the extra data sent > >>>> from the driver to the device when the VIRTIO_F_NOTIFICATION_DATA > >>>> transport feature has been negotiated. > >>>> > >>>> The extra data that's passed to the virtio-pci device when this > >>>> feature is enabled varies depending on the device's virtqueue > >>>> layout. > >>>> > >>>> In a split virtqueue layout, this data includes: > >>>> - upper 16 bits: shadow_avail_idx > >>>> - lower 16 bits: virtqueue index > >>>> > >>>> In a packed virtqueue layout, this data includes: > >>>> - upper 16 bits: 1-bit wrap counter & 15-bit shadow_avail_idx > >>>> - lower 16 bits: virtqueue index > >>>> > >>>> Tested-by: Lei Yang <leiy...@redhat.com> > >>>> Reviewed-by: Eugenio Pérez <epere...@redhat.com> > >>>> Signed-off-by: Jonah Palmer <jonah.pal...@oracle.com> > >>>> --- > >>>> hw/virtio/virtio-pci.c | 10 +++++++--- > >>>> hw/virtio/virtio.c | 18 ++++++++++++++++++ > >>>> include/hw/virtio/virtio.h | 1 + > >>>> 3 files changed, 26 insertions(+), 3 deletions(-) > >>>> > >>>> diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c > >>>> index cb6940fc0e..0f5c3c3b2f 100644 > >>>> --- a/hw/virtio/virtio-pci.c > >>>> +++ b/hw/virtio/virtio-pci.c > >>>> @@ -384,7 +384,7 @@ static void virtio_ioport_write(void *opaque, > >>>> uint32_t addr, uint32_t val) > >>>> { > >>>> VirtIOPCIProxy *proxy = opaque; > >>>> VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus); > >>>> - uint16_t vector; > >>>> + uint16_t vector, vq_idx; > >>>> hwaddr pa; > >>>> > >>>> switch (addr) { > >>>> @@ -408,8 +408,12 @@ static void virtio_ioport_write(void *opaque, > >>>> uint32_t addr, uint32_t val) > >>>> vdev->queue_sel = val; > >>>> break; > >>>> case VIRTIO_PCI_QUEUE_NOTIFY: > >>>> - if (val < VIRTIO_QUEUE_MAX) { > >>>> - virtio_queue_notify(vdev, val); > >>>> + vq_idx = val; > >>>> + if (vq_idx < VIRTIO_QUEUE_MAX) { > >>>> + if (virtio_vdev_has_feature(vdev, > >>>> VIRTIO_F_NOTIFICATION_DATA)) { > >>>> + virtio_queue_set_shadow_avail_data(vdev, val); > >>>> + } > >>>> + virtio_queue_notify(vdev, vq_idx); > >>>> } > >>>> break; > >>>> case VIRTIO_PCI_STATUS: > >>>> diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c > >>>> index d229755eae..bcb9e09df0 100644 > >>>> --- a/hw/virtio/virtio.c > >>>> +++ b/hw/virtio/virtio.c > >>>> @@ -2255,6 +2255,24 @@ void virtio_queue_set_align(VirtIODevice *vdev, > >>>> int n, int align) > >>>> } > >>>> } > >>>> > >>>> +void virtio_queue_set_shadow_avail_data(VirtIODevice *vdev, uint32_t > >>>> data) > > > > Maybe I didn't explain well, but I think it is better to pass directly > > idx to a VirtQueue *. That way only the caller needs to check for a > > valid vq idx, and (my understanding is) the virtio.c interface is > > migrating to VirtQueue * use anyway. > > > > Oh, are you saying to just pass in a VirtQueue *vq instead of > VirtIODevice *vdev and get rid of the vq->vring.desc check in the function? >
No, that needs to be kept. I meant the access to vdev->vq[i] without checking for a valid i. You can get the VirtQueue in the caller with virtio_get_queue. Which also does not check for a valid index, but that way is clearer the caller needs to check it. As a side note, the check for desc != 0 is widespread in QEMU but the driver may use 0 address for desc, so it's not 100% valid. But to change that now requires a deeper change out of the scope of this series, so let's keep it for now :). Thanks! > >>>> +{ > >>>> + /* Lower 16 bits is the virtqueue index */ > >>>> + uint16_t i = data; > >>>> + VirtQueue *vq = &vdev->vq[i]; > >>>> + > >>>> + if (!vq->vring.desc) { > >>>> + return; > >>>> + } > >>>> + > >>>> + if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) { > >>>> + vq->shadow_avail_wrap_counter = (data >> 31) & 0x1; > >>>> + vq->shadow_avail_idx = (data >> 16) & 0x7FFF; > >>>> + } else { > >>>> + vq->shadow_avail_idx = (data >> 16); > >>> > >>> Do we need to do a sanity check for this value? > >>> > >>> Thanks > >>> > >> > >> It can't hurt, right? What kind of check did you have in mind? > >> > >> if (vq->shadow_avail_idx >= vq->vring.num) > >> > > > > I'm a little bit lost too. shadow_avail_idx can take all uint16_t > > values. Maybe you meant checking for a valid vq index, Jason? > > > > Thanks! > > > >> Or something else? > >> > >>>> + } > >>>> +} > >>>> + > >>>> static void virtio_queue_notify_vq(VirtQueue *vq) > >>>> { > >>>> if (vq->vring.desc && vq->handle_output) { > >>>> diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h > >>>> index c8f72850bc..53915947a7 100644 > >>>> --- a/include/hw/virtio/virtio.h > >>>> +++ b/include/hw/virtio/virtio.h > >>>> @@ -335,6 +335,7 @@ void virtio_queue_update_rings(VirtIODevice *vdev, > >>>> int n); > >>>> void virtio_init_region_cache(VirtIODevice *vdev, int n); > >>>> void virtio_queue_set_align(VirtIODevice *vdev, int n, int align); > >>>> void virtio_queue_notify(VirtIODevice *vdev, int n); > >>>> +void virtio_queue_set_shadow_avail_data(VirtIODevice *vdev, uint32_t > >>>> data); > >>>> uint16_t virtio_queue_vector(VirtIODevice *vdev, int n); > >>>> void virtio_queue_set_vector(VirtIODevice *vdev, int n, uint16_t > >>>> vector); > >>>> int virtio_queue_set_host_notifier_mr(VirtIODevice *vdev, int n, > >>>> -- > >>>> 2.39.3 > >>>> > >>> > >> > > >