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bh=wndRUAl0yqcDZHg+lrz+7s4nniC0MTgzWuOP5HXK5QE=; b=OvUIwfMy5i/9UaCPAX4RK73yO49Y27ButvR3Ib+ALCwwrqc7gW6j/SxSVjqzGtJgqjMoVG utDKMSlHMDBQEM2VBI+f3Atlb1CMDvNVqJpvKC9blFl0YfBVjdpgroQxhtMa+fz6NwJ/vL m3zF6i/Xqgn/bIXWx/GyI26mNvnuxQ0= X-MC-Unique: RCiFpXrDOLO-U8uNDQBAxA-1 From: =?UTF-8?q?Eugenio=20P=C3=A9rez?= To: qemu-devel@nongnu.org Subject: [RFC v3 08/29] vhost: Route host->guest notification through shadow virtqueue Date: Wed, 19 May 2021 18:28:42 +0200 Message-Id: <20210519162903.1172366-9-eperezma@redhat.com> In-Reply-To: <20210519162903.1172366-1-eperezma@redhat.com> References: <20210519162903.1172366-1-eperezma@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=eperezma@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=170.10.133.124; envelope-from=eperezma@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -31 X-Spam_score: -3.2 X-Spam_bar: --- X-Spam_report: (-3.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.39, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Parav Pandit , "Michael S. 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+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) Signed-off-by: Eugenio P=C3=A9rez --- 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-vi= rtqueue.h index c891c6510d..2ca4b92b12 100644 --- a/hw/virtio/vhost-shadow-virtqueue.h +++ b/hw/virtio/vhost-shadow-virtqueue.h @@ -17,6 +17,9 @@ =20 typedef struct VhostShadowVirtqueue VhostShadowVirtqueue; =20 +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-vi= rtqueue.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; =20 + /* (Possible) masked notifier */ + struct { + EventNotifier *n; + } masked_notifier; + /* Virtio queue shadowing */ VirtQueue *vq; + + /* Virtio device */ + VirtIODevice *vdev; } VhostShadowVirtqueue; =20 /* Forward guest notifications */ @@ -49,6 +57,58 @@ static void vhost_handle_guest_kick(EventNotifier *n) event_notifier_set(&svq->kick_notifier); } =20 +/* Forward vhost notifications */ +static void vhost_shadow_vq_handle_call_no_test(EventNotifier *n) +{ + VhostShadowVirtqueue *svq =3D container_of(n, VhostShadowVirtqueue, + call_notifier); + EventNotifier *masked_notifier; + + masked_notifier =3D svq->masked_notifier.n; + + if (!masked_notifier) { + unsigned n =3D 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 =3D 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 =3D 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; } =20 + /* Set vhost call */ + file.fd =3D event_notifier_get_fd(&svq->call_notifier), + r =3D dev->vhost_ops->vhost_set_vring_call(dev, &file); + if (unlikely(r !=3D 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_notifie= r)) { + /* Check for pending notifications from the device */ + vhost_shadow_vq_handle_call_no_test(&svq->call_notifier); + } + return true; =20 +err_set_vring_call: + r =3D 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); =20 @@ -126,7 +211,13 @@ void vhost_shadow_vq_stop(struct vhost_dev *dev, error_report("Couldn't restore vq kick fd: %s", strerror(-r)); } =20 + 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); } =20 /* @@ -154,6 +245,9 @@ VhostShadowVirtqueue *vhost_shadow_vq_new(struct vhost_= dev *dev, int idx) } =20 svq->vq =3D virtio_get_queue(dev->vdev, vq_idx); + svq->vdev =3D dev->vdev; + event_notifier_set_handler(&svq->call_notifier, + vhost_shadow_vq_handle_call); return g_steal_pointer(&svq); =20 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, Vi= rtIODevice *vdev, int n, /* should only be called after backend is connected */ assert(hdev->vhost_ops); =20 + 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 polli= ng + * for changes + */ + return; + } + if (mask) { assert(vdev->use_guest_notifier_mask); file.fd =3D event_notifier_get_fd(&hdev->vqs[index].masked_notifie= r); --=20 2.27.0