From 14cc79b8bda66ace21616adccf6c2ccd65b7256a Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Eugenio=20P=C3=A9rez?= Date: Wed, 20 Jul 2022 08:59:39 +0200 Subject: [PATCH] vhost: Add svq avail_handler callback MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This allows external handlers to be aware of new buffers that the guest places in the virtqueue. When this callback is defined the ownership of the guest's virtqueue element is transferred to the callback. This means that if the user wants to forward the descriptor it needs to manually inject it. The callback is also free to process the command by itself and use the element with svq_push. Signed-off-by: Eugenio Pérez Reviewed-by: Michael S. Tsirkin Signed-off-by: Jason Wang Signed-off-by: fangyi --- hw/virtio/vhost-shadow-virtqueue.c | 14 ++++++++++++-- hw/virtio/vhost-shadow-virtqueue.h | 31 +++++++++++++++++++++++++++++- hw/virtio/vhost-vdpa.c | 3 ++- 3 files changed, 44 insertions(+), 4 deletions(-) diff --git a/hw/virtio/vhost-shadow-virtqueue.c b/hw/virtio/vhost-shadow-virtqueue.c index d2676b94e0..ae443f54fe 100644 --- a/hw/virtio/vhost-shadow-virtqueue.c +++ b/hw/virtio/vhost-shadow-virtqueue.c @@ -305,7 +305,11 @@ static void vhost_handle_guest_kick(VhostShadowVirtqueue *svq) break; } - r = vhost_svq_add_element(svq, elem); + if (svq->ops) { + r = svq->ops->avail_handler(svq, elem, svq->ops_opaque); + } else { + r = vhost_svq_add_element(svq, elem); + } if (unlikely(r != 0)) { if (r == -ENOSPC) { /* @@ -684,12 +688,16 @@ void vhost_svq_stop(VhostShadowVirtqueue *svq) * shadow methods and file descriptors. * * @iova_tree: Tree to perform descriptors translations + * @ops: SVQ owner callbacks + * @ops_opaque: ops opaque pointer * * Returns the new virtqueue or NULL. * * In case of error, reason is reported through error_report. */ -VhostShadowVirtqueue *vhost_svq_new(VhostIOVATree *iova_tree) +VhostShadowVirtqueue *vhost_svq_new(VhostIOVATree *iova_tree, + const VhostShadowVirtqueueOps *ops, + void *ops_opaque) { g_autofree VhostShadowVirtqueue *svq = g_new0(VhostShadowVirtqueue, 1); int r; @@ -711,6 +719,8 @@ VhostShadowVirtqueue *vhost_svq_new(VhostIOVATree *iova_tree) event_notifier_init_fd(&svq->svq_kick, VHOST_FILE_UNBIND); event_notifier_set_handler(&svq->hdev_call, vhost_svq_handle_call); svq->iova_tree = iova_tree; + svq->ops = ops; + svq->ops_opaque = ops_opaque; return g_steal_pointer(&svq); err_init_hdev_call: diff --git a/hw/virtio/vhost-shadow-virtqueue.h b/hw/virtio/vhost-shadow-virtqueue.h index cf442f7dea..d04c34a589 100644 --- a/hw/virtio/vhost-shadow-virtqueue.h +++ b/hw/virtio/vhost-shadow-virtqueue.h @@ -25,6 +25,27 @@ typedef struct SVQDescState { unsigned int ndescs; } SVQDescState; +typedef struct VhostShadowVirtqueue VhostShadowVirtqueue; + +/** + * Callback to handle an avail buffer. + * + * @svq: Shadow virtqueue + * @elem: Element placed in the queue by the guest + * @vq_callback_opaque: Opaque + * + * Returns 0 if the vq is running as expected. + * + * Note that ownership of elem is transferred to the callback. + */ +typedef int (*VirtQueueAvailCallback)(VhostShadowVirtqueue *svq, + VirtQueueElement *elem, + void *vq_callback_opaque); + +typedef struct VhostShadowVirtqueueOps { + VirtQueueAvailCallback avail_handler; +} VhostShadowVirtqueueOps; + /* Shadow virtqueue to relay notifications */ typedef struct VhostShadowVirtqueue { /* Shadow vring */ @@ -69,6 +90,12 @@ typedef struct VhostShadowVirtqueue { */ uint16_t *desc_next; + /* Caller callbacks */ + const VhostShadowVirtqueueOps *ops; + + /* Caller callbacks opaque */ + void *ops_opaque; + /* Next head to expose to the device */ uint16_t shadow_avail_idx; @@ -102,7 +129,9 @@ void vhost_svq_start(VhostShadowVirtqueue *svq, VirtIODevice *vdev, VirtQueue *vq); void vhost_svq_stop(VhostShadowVirtqueue *svq); -VhostShadowVirtqueue *vhost_svq_new(VhostIOVATree *iova_tree); +VhostShadowVirtqueue *vhost_svq_new(VhostIOVATree *iova_tree, + const VhostShadowVirtqueueOps *ops, + void *ops_opaque); void vhost_svq_free(gpointer vq); G_DEFINE_AUTOPTR_CLEANUP_FUNC(VhostShadowVirtqueue, vhost_svq_free); diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c index 73ff599f2b..a8d42655f0 100644 --- a/hw/virtio/vhost-vdpa.c +++ b/hw/virtio/vhost-vdpa.c @@ -420,8 +420,9 @@ static int vhost_vdpa_init_svq(struct vhost_dev *hdev, struct vhost_vdpa *v, shadow_vqs = g_ptr_array_new_full(hdev->nvqs, vhost_svq_free); for (unsigned n = 0; n < hdev->nvqs; ++n) { - g_autoptr(VhostShadowVirtqueue) svq = vhost_svq_new(v->iova_tree); + g_autoptr(VhostShadowVirtqueue) svq; + svq = vhost_svq_new(v->iova_tree, NULL, NULL); if (unlikely(!svq)) { error_setg(errp, "Cannot create svq %u", n); return -1; -- 2.27.0