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Tsirkin" , Jason Wang , Juan Quintela , Markus Armbruster , virtualization@lists.linux-foundation.org, Harpreet Singh Anand , Xiao W Wang , Stefan Hajnoczi , Eli Cohen , Michael Lilja , Stefano Garzarella Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Signed-off-by: Eugenio Pérez --- hw/virtio/vhost-shadow-virtqueue.h | 3 + include/hw/virtio/vhost.h | 1 + hw/virtio/vhost-shadow-virtqueue.c | 95 ++++++++++++++++++++++++++++++ hw/virtio/vhost.c | 15 +++++ 4 files changed, 114 insertions(+) diff --git a/hw/virtio/vhost-shadow-virtqueue.h b/hw/virtio/vhost-shadow-virtqueue.h index c891c6510d..2ca4b92b12 100644 --- a/hw/virtio/vhost-shadow-virtqueue.h +++ b/hw/virtio/vhost-shadow-virtqueue.h @@ -17,6 +17,9 @@ typedef struct VhostShadowVirtqueue VhostShadowVirtqueue; +void vhost_shadow_vq_mask(VhostShadowVirtqueue *svq, EventNotifier *masked); +void vhost_shadow_vq_unmask(VhostShadowVirtqueue *svq); + bool vhost_shadow_vq_start(struct vhost_dev *dev, unsigned idx, VhostShadowVirtqueue *svq); diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h index 7ffdf9aea0..67cedf83da 100644 --- a/include/hw/virtio/vhost.h +++ b/include/hw/virtio/vhost.h @@ -28,6 +28,7 @@ struct vhost_virtqueue { unsigned avail_size; unsigned long long used_phys; unsigned used_size; + /* Access/writing to notifier_is_masked is protected by BQL */ bool notifier_is_masked; EventNotifier masked_notifier; struct vhost_dev *dev; diff --git a/hw/virtio/vhost-shadow-virtqueue.c b/hw/virtio/vhost-shadow-virtqueue.c index 3e43399e9c..7d76e271a5 100644 --- a/hw/virtio/vhost-shadow-virtqueue.c +++ b/hw/virtio/vhost-shadow-virtqueue.c @@ -32,8 +32,16 @@ typedef struct VhostShadowVirtqueue { */ EventNotifier host_notifier; + /* (Possible) masked notifier */ + struct { + EventNotifier *n; + } masked_notifier; + /* Virtio queue shadowing */ VirtQueue *vq; + + /* Virtio device */ + VirtIODevice *vdev; } VhostShadowVirtqueue; /* Forward guest notifications */ @@ -49,6 +57,58 @@ static void vhost_handle_guest_kick(EventNotifier *n) event_notifier_set(&svq->kick_notifier); } +/* Forward vhost notifications */ +static void vhost_shadow_vq_handle_call_no_test(EventNotifier *n) +{ + VhostShadowVirtqueue *svq = container_of(n, VhostShadowVirtqueue, + call_notifier); + EventNotifier *masked_notifier; + + masked_notifier = svq->masked_notifier.n; + + if (!masked_notifier) { + unsigned n = virtio_get_queue_index(svq->vq); + virtio_queue_invalidate_signalled_used(svq->vdev, n); + virtio_notify_irqfd(svq->vdev, svq->vq); + } else { + event_notifier_set(svq->masked_notifier.n); + } +} + +static void vhost_shadow_vq_handle_call(EventNotifier *n) +{ + if (likely(event_notifier_test_and_clear(n))) { + vhost_shadow_vq_handle_call_no_test(n); + } +} + +/* + * Mask the shadow virtqueue. + * + * It can be called from a guest masking vmexit or shadow virtqueue start + * through QMP. + * + * @vq Shadow virtqueue + * @masked Masked notifier to signal instead of guest + */ +void vhost_shadow_vq_mask(VhostShadowVirtqueue *svq, EventNotifier *masked) +{ + svq->masked_notifier.n = masked; +} + +/* + * Unmask the shadow virtqueue. + * + * It can be called from a guest unmasking vmexit or shadow virtqueue start + * through QMP. + * + * @vq Shadow virtqueue + */ +void vhost_shadow_vq_unmask(VhostShadowVirtqueue *svq) +{ + svq->masked_notifier.n = NULL; +} + /* * Restore the vhost guest to host notifier, i.e., disables svq effect. */ @@ -103,8 +163,33 @@ bool vhost_shadow_vq_start(struct vhost_dev *dev, goto err_set_vring_kick; } + /* Set vhost call */ + file.fd = event_notifier_get_fd(&svq->call_notifier), + r = dev->vhost_ops->vhost_set_vring_call(dev, &file); + if (unlikely(r != 0)) { + error_report("Couldn't set call fd: %s", strerror(errno)); + goto err_set_vring_call; + } + + /* Set shadow vq -> guest notifier */ + assert(dev->shadow_vqs_enabled); + vhost_virtqueue_mask(dev, dev->vdev, dev->vq_index + idx, + dev->vqs[idx].notifier_is_masked); + + if (dev->vqs[idx].notifier_is_masked && + event_notifier_test_and_clear(&dev->vqs[idx].masked_notifier)) { + /* Check for pending notifications from the device */ + vhost_shadow_vq_handle_call_no_test(&svq->call_notifier); + } + return true; +err_set_vring_call: + r = vhost_shadow_vq_restore_vdev_host_notifier(dev, idx, svq); + if (unlikely(r < 0)) { + error_report("Couldn't restore vq kick fd: %s", strerror(-r)); + } + err_set_vring_kick: event_notifier_set_handler(&svq->host_notifier, NULL); @@ -126,7 +211,13 @@ void vhost_shadow_vq_stop(struct vhost_dev *dev, error_report("Couldn't restore vq kick fd: %s", strerror(-r)); } + assert(!dev->shadow_vqs_enabled); + event_notifier_set_handler(&svq->host_notifier, NULL); + + /* Restore vhost call */ + vhost_virtqueue_mask(dev, dev->vdev, dev->vq_index + idx, + dev->vqs[idx].notifier_is_masked); } /* @@ -154,6 +245,9 @@ VhostShadowVirtqueue *vhost_shadow_vq_new(struct vhost_dev *dev, int idx) } svq->vq = virtio_get_queue(dev->vdev, vq_idx); + svq->vdev = dev->vdev; + event_notifier_set_handler(&svq->call_notifier, + vhost_shadow_vq_handle_call); return g_steal_pointer(&svq); err_init_call_notifier: @@ -169,6 +263,7 @@ err_init_kick_notifier: void vhost_shadow_vq_free(VhostShadowVirtqueue *vq) { event_notifier_cleanup(&vq->kick_notifier); + event_notifier_set_handler(&vq->call_notifier, NULL); event_notifier_cleanup(&vq->call_notifier); g_free(vq); } diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c index 84091b5251..9c9c63345b 100644 --- a/hw/virtio/vhost.c +++ b/hw/virtio/vhost.c @@ -1591,6 +1591,21 @@ void vhost_virtqueue_mask(struct vhost_dev *hdev, VirtIODevice *vdev, int n, /* should only be called after backend is connected */ assert(hdev->vhost_ops); + if (hdev->shadow_vqs_enabled) { + if (mask) { + vhost_shadow_vq_mask(hdev->shadow_vqs[index], + &hdev->vqs[index].masked_notifier); + } else { + vhost_shadow_vq_unmask(hdev->shadow_vqs[index]); + } + + /* + * Vhost call fd must remain the same since shadow vq is not polling + * for changes + */ + return; + } + if (mask) { assert(vdev->use_guest_notifier_mask); file.fd = event_notifier_get_fd(&hdev->vqs[index].masked_notifier);