From 433106c286a1961737300ebaece6f10b2747e7d8 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Eugenio=20P=C3=A9rez?= Date: Thu, 21 Jul 2022 15:38:55 +0200 Subject: [PATCH 20/32] vhost: Add svq avail_handler callback MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit RH-Author: Eugenio Pérez RH-MergeRequest: 108: Net Control Virtqueue shadow Support RH-Commit: [20/27] d228eb89d204f8be623bc870503bbf0078dfc9ae (eperezmartin/qemu-kvm) RH-Bugzilla: 1939363 RH-Acked-by: Stefano Garzarella RH-Acked-by: Cindy Lu RH-Acked-by: Laurent Vivier Bugzilla: https://bugzilla.redhat.com/1939363 Upstream Status: git://git.qemu.org/qemu.git commit e966c0b781aebabd2c0f5eef91678f08ce1d068c Author: Eugenio Pérez Date: Wed Jul 20 08:59:39 2022 +0200 vhost: Add svq avail_handler callback 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: Eugenio Pérez --- 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 95d0d7a7ee..e53aac45f6 100644 --- a/hw/virtio/vhost-shadow-virtqueue.c +++ b/hw/virtio/vhost-shadow-virtqueue.c @@ -306,7 +306,11 @@ 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) { /* @@ -685,12 +689,16 @@ 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; @@ -712,6 +720,8 @@ 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 33dcaa135e..28df57b12e 100644 --- a/hw/virtio/vhost-vdpa.c +++ b/hw/virtio/vhost-vdpa.c @@ -416,8 +416,9 @@ 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; -- 2.31.1