On Thu, Sep 22, 2016 at 01:13:41PM +0100, Felipe Franciosi wrote:
> Vhost-user requires an early GET_FEATURES call to determine if the
> slave supports protocol feature negotiation. An extra GET_FEATURES
> call is made after vhost_backend_init() to actually set the device
> features.
>
> This patch moves the actual setting of the device features to both
> implementations (kernel/user) of vhost_backend_init(), therefore
> eliminating the need for a second call.
>
> Signed-off-by: Felipe Franciosi <fel...@nutanix.com>
Thanks!
Thinking about this, I think it makes sense to keep
both messages around.
This allow backend to change the feature bitmap
depending on the protocol features negotiated.
> ---
> v2. Rebase on d1b4259f
>
> hw/virtio/vhost-backend.c | 27 ++++++++++++++++++---------
> hw/virtio/vhost-user.c | 1 +
> hw/virtio/vhost.c | 9 ---------
> 3 files changed, 19 insertions(+), 18 deletions(-)
>
> diff --git a/hw/virtio/vhost-backend.c b/hw/virtio/vhost-backend.c
> index 272a5ec..0ffa4d1 100644
> --- a/hw/virtio/vhost-backend.c
> +++ b/hw/virtio/vhost-backend.c
> @@ -25,15 +25,6 @@ static int vhost_kernel_call(struct vhost_dev *dev,
> unsigned long int request,
> return ioctl(fd, request, arg);
> }
>
> -static int vhost_kernel_init(struct vhost_dev *dev, void *opaque)
> -{
> - assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_KERNEL);
> -
> - dev->opaque = opaque;
> -
> - return 0;
> -}
> -
> static int vhost_kernel_cleanup(struct vhost_dev *dev)
> {
> int fd = (uintptr_t) dev->opaque;
> @@ -185,6 +176,24 @@ static int vhost_kernel_vsock_set_running(struct
> vhost_dev *dev, int start)
> }
> #endif /* CONFIG_VHOST_VSOCK */
>
> +static int vhost_kernel_init(struct vhost_dev *dev, void *opaque)
> +{
> + uint64_t features;
> + int r;
> +
> + assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_KERNEL);
> +
> + dev->opaque = opaque;
> +
> + r = vhost_kernel_get_features(dev, &features);
> + if (r < 0) {
> + return r;
> + }
> + dev->features = features;
> +
> + return 0;
> +}
> +
> static const VhostOps kernel_ops = {
> .backend_type = VHOST_BACKEND_TYPE_KERNEL,
> .vhost_backend_init = vhost_kernel_init,
> diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
> index b57454a..684f6d7 100644
> --- a/hw/virtio/vhost-user.c
> +++ b/hw/virtio/vhost-user.c
> @@ -578,6 +578,7 @@ static int vhost_user_init(struct vhost_dev *dev, void
> *opaque)
> if (err < 0) {
> return err;
> }
> + dev->features = features;
>
> if (virtio_has_feature(features, VHOST_USER_F_PROTOCOL_FEATURES)) {
> dev->backend_features |= 1ULL << VHOST_USER_F_PROTOCOL_FEATURES;
> diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
> index bd051ab..36fd35f 100644
> --- a/hw/virtio/vhost.c
> +++ b/hw/virtio/vhost.c
> @@ -1051,7 +1051,6 @@ static void vhost_virtqueue_cleanup(struct
> vhost_virtqueue *vq)
> int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
> VhostBackendType backend_type, uint32_t busyloop_timeout)
> {
> - uint64_t features;
> int i, r, n_initialized_vqs = 0;
>
> hdev->migration_blocker = NULL;
> @@ -1077,12 +1076,6 @@ int vhost_dev_init(struct vhost_dev *hdev, void
> *opaque,
> goto fail;
> }
>
> - r = hdev->vhost_ops->vhost_get_features(hdev, &features);
> - if (r < 0) {
> - VHOST_OPS_DEBUG("vhost_get_features failed");
> - goto fail;
> - }
> -
> for (i = 0; i < hdev->nvqs; ++i, ++n_initialized_vqs) {
> r = vhost_virtqueue_init(hdev, hdev->vqs + i, hdev->vq_index + i);
> if (r < 0) {
> @@ -1100,8 +1093,6 @@ int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
> }
> }
>
> - hdev->features = features;
> -
> hdev->memory_listener = (MemoryListener) {
> .begin = vhost_begin,
> .commit = vhost_commit,
> --
> 1.9.5
