Peter Maydell <peter.maydell@xxxxxxxxxx> writes:
> The MMIO virtio transport spec allows the guest to tell the host how
> large the queue size is. Add virtio_queue_set_num() function which
> implements this in the QEMU common virtio support code.
>
> Signed-off-by: Peter Maydell <peter.maydell@xxxxxxxxxx>
> ---
> hw/virtio/virtio.c | 6 ++++++
> include/hw/virtio/virtio.h | 1 +
> 2 files changed, 7 insertions(+)
>
> diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
> index 8176c14..8805b8a 100644
> --- a/hw/virtio/virtio.c
> +++ b/hw/virtio/virtio.c
> @@ -667,6 +667,12 @@ hwaddr virtio_queue_get_addr(VirtIODevice *vdev, int n)
> return vdev->vq[n].pa;
> }
>
> +void virtio_queue_set_num(VirtIODevice *vdev, int n, int num)
> +{
> + vdev->vq[n].vring.num = num;
> + virtqueue_init(&vdev->vq[n]);
I think some level of checking is probably needed on num since we do a
tremendous amount of math on it. I doubt it's exploitable since it's
always treated as a PA, but better to be safe than sorry.
Regards,
Anthony Liguori
> +}
> +
> int virtio_queue_get_num(VirtIODevice *vdev, int n)
> {
> return vdev->vq[n].vring.num;
> diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
> index a6c5c53..95c4772 100644
> --- a/include/hw/virtio/virtio.h
> +++ b/include/hw/virtio/virtio.h
> @@ -198,6 +198,7 @@ void virtio_config_writew(VirtIODevice *vdev, uint32_t addr, uint32_t data);
> void virtio_config_writel(VirtIODevice *vdev, uint32_t addr, uint32_t data);
> void virtio_queue_set_addr(VirtIODevice *vdev, int n, hwaddr addr);
> hwaddr virtio_queue_get_addr(VirtIODevice *vdev, int n);
> +void virtio_queue_set_num(VirtIODevice *vdev, int n, int num);
> int virtio_queue_get_num(VirtIODevice *vdev, int n);
> void virtio_queue_notify(VirtIODevice *vdev, int n);
> uint16_t virtio_queue_vector(VirtIODevice *vdev, int n);
> --
> 1.7.9.5
_______________________________________________
kvmarm mailing list
kvmarm@xxxxxxxxxxxxxxxxxxxxx
https://lists.cs.columbia.edu/cucslists/listinfo/kvmarm
