[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[RFC v3 08/29] vhost: Route host->guest notification through shadow virt
From: |
Eugenio Pérez |
Subject: |
[RFC v3 08/29] vhost: Route host->guest notification through shadow virtqueue |
Date: |
Wed, 19 May 2021 18:28:42 +0200 |
Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
---
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);
--
2.27.0
- [RFC v3 02/29] vhost: Save masked_notifier state, (continued)
- [RFC v3 02/29] vhost: Save masked_notifier state, Eugenio Pérez, 2021/05/19
- [RFC v3 03/29] vhost: Add VhostShadowVirtqueue, Eugenio Pérez, 2021/05/19
- [RFC v3 05/29] virtio: Add VIRTIO_F_QUEUE_STATE, Eugenio Pérez, 2021/05/19
- [RFC v3 04/29] vhost: Add x-vhost-enable-shadow-vq qmp, Eugenio Pérez, 2021/05/19
- [RFC v3 06/29] virtio-net: Honor VIRTIO_CONFIG_S_DEVICE_STOPPED, Eugenio Pérez, 2021/05/19
- [RFC v3 07/29] vhost: Route guest->host notification through shadow virtqueue, Eugenio Pérez, 2021/05/19
- [RFC v3 08/29] vhost: Route host->guest notification through shadow virtqueue,
Eugenio Pérez <=
- [RFC v3 09/29] vhost: Avoid re-set masked notifier in shadow vq, Eugenio Pérez, 2021/05/19
- [RFC v3 10/29] virtio: Add vhost_shadow_vq_get_vring_addr, Eugenio Pérez, 2021/05/19
- [RFC v3 11/29] vhost: Add vhost_vring_pause operation, Eugenio Pérez, 2021/05/19
- [RFC v3 12/29] vhost: add vhost_kernel_vring_pause, Eugenio Pérez, 2021/05/19
- [RFC v3 13/29] vhost: Add vhost_get_iova_range operation, Eugenio Pérez, 2021/05/19
- [RFC v3 14/29] vhost: add vhost_has_limited_iova_range, Eugenio Pérez, 2021/05/19
- [RFC v3 15/29] vhost: Add enable_custom_iommu to VhostOps, Eugenio Pérez, 2021/05/19