On Thu, May 11, 2017 at 02:32:43PM +0200, Maxime Coquelin wrote:
> Vhost-kernel backend need to receive IOTLB entries for rings
> information early, but vhost-user need the same information
> earlier, before VHOST_USER_SET_VRING_ADDR is sent.
Weird. What does VHOST_USER_SET_VRING_ADDR have to do with it?
According to
Starting and stopping rings
in vhost user spec, vhost user does not access
anything until ring is started and enabled.
> This patch also trigger IOTLB miss for all rings informations
> for robustness, even if in practice these adresses are on the
> same page.
>
> Signed-off-by: Maxime Coquelin <maxime.coque...@redhat.com>
> ---
> hw/virtio/vhost.c | 19 +++++++++++--------
> 1 file changed, 11 insertions(+), 8 deletions(-)
>
> diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
> index 748e331..817f6d0 100644
> --- a/hw/virtio/vhost.c
> +++ b/hw/virtio/vhost.c
> @@ -799,7 +799,17 @@ static int vhost_virtqueue_set_addr(struct vhost_dev
> *dev,
> .log_guest_addr = vq->used_phys,
> .flags = enable_log ? (1 << VHOST_VRING_F_LOG) : 0,
> };
> - int r = dev->vhost_ops->vhost_set_vring_addr(dev, &addr);
> + int r;
> +
> + /* Update rings information for IOTLB to work correctly,
> + * vhost-kernel & vhost-user backends require for this.*/
Any requirements must be in the spec. Pls add them there.
Pls fix comment style as you move code.
> + if (vhost_dev_has_iommu(dev)) {
> + vhost_device_iotlb_miss(dev, addr.desc_user_addr, true);
> + vhost_device_iotlb_miss(dev, addr.used_user_addr, true);
> + vhost_device_iotlb_miss(dev, addr.avail_user_addr, true);
> + }
> +
> + r = dev->vhost_ops->vhost_set_vring_addr(dev, &addr);
> if (r < 0) {
> VHOST_OPS_DEBUG("vhost_set_vring_addr failed");
> return -errno;
> @@ -1551,13 +1561,6 @@ int vhost_dev_start(struct vhost_dev *hdev,
> VirtIODevice *vdev)
>
> if (vhost_dev_has_iommu(hdev)) {
> hdev->vhost_ops->vhost_set_iotlb_callback(hdev, true);
> -
> - /* Update used ring information for IOTLB to work correctly,
> - * vhost-kernel code requires for this.*/
> - for (i = 0; i < hdev->nvqs; ++i) {
> - struct vhost_virtqueue *vq = hdev->vqs + i;
> - vhost_device_iotlb_miss(hdev, vq->used_phys, true);
> - }
> }
> return 0;
> fail_log:
> --
> 2.9.3
