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[PULL 02/15] vhost: Add VhostShadowVirtqueue
From: |
Jason Wang |
Subject: |
[PULL 02/15] vhost: Add VhostShadowVirtqueue |
Date: |
Tue, 8 Mar 2022 21:34:38 +0800 |
From: Eugenio Pérez <eperezma@redhat.com>
Vhost shadow virtqueue (SVQ) is an intermediate jump for virtqueue
notifications and buffers, allowing qemu to track them. While qemu is
forwarding the buffers and virtqueue changes, it is able to commit the
memory it's being dirtied, the same way regular qemu's VirtIO devices
do.
This commit only exposes basic SVQ allocation and free. Next patches of
the series add functionality like notifications and buffers forwarding.
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
hw/virtio/meson.build | 2 +-
hw/virtio/vhost-shadow-virtqueue.c | 62 ++++++++++++++++++++++++++++++++++++++
hw/virtio/vhost-shadow-virtqueue.h | 28 +++++++++++++++++
3 files changed, 91 insertions(+), 1 deletion(-)
create mode 100644 hw/virtio/vhost-shadow-virtqueue.c
create mode 100644 hw/virtio/vhost-shadow-virtqueue.h
diff --git a/hw/virtio/meson.build b/hw/virtio/meson.build
index 521f7d6..2dc8761 100644
--- a/hw/virtio/meson.build
+++ b/hw/virtio/meson.build
@@ -11,7 +11,7 @@ softmmu_ss.add(when: 'CONFIG_ALL', if_true:
files('vhost-stub.c'))
virtio_ss = ss.source_set()
virtio_ss.add(files('virtio.c'))
-virtio_ss.add(when: 'CONFIG_VHOST', if_true: files('vhost.c',
'vhost-backend.c'))
+virtio_ss.add(when: 'CONFIG_VHOST', if_true: files('vhost.c',
'vhost-backend.c', 'vhost-shadow-virtqueue.c'))
virtio_ss.add(when: 'CONFIG_VHOST_USER', if_true: files('vhost-user.c'))
virtio_ss.add(when: 'CONFIG_VHOST_VDPA', if_true: files('vhost-vdpa.c'))
virtio_ss.add(when: 'CONFIG_VIRTIO_BALLOON', if_true:
files('virtio-balloon.c'))
diff --git a/hw/virtio/vhost-shadow-virtqueue.c
b/hw/virtio/vhost-shadow-virtqueue.c
new file mode 100644
index 0000000..c1db02c
--- /dev/null
+++ b/hw/virtio/vhost-shadow-virtqueue.c
@@ -0,0 +1,62 @@
+/*
+ * vhost shadow virtqueue
+ *
+ * SPDX-FileCopyrightText: Red Hat, Inc. 2021
+ * SPDX-FileContributor: Author: Eugenio Pérez <eperezma@redhat.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "qemu/osdep.h"
+#include "hw/virtio/vhost-shadow-virtqueue.h"
+
+#include "qemu/error-report.h"
+
+/**
+ * Creates vhost shadow virtqueue, and instructs the vhost device to use the
+ * shadow methods and file descriptors.
+ *
+ * Returns the new virtqueue or NULL.
+ *
+ * In case of error, reason is reported through error_report.
+ */
+VhostShadowVirtqueue *vhost_svq_new(void)
+{
+ g_autofree VhostShadowVirtqueue *svq = g_new0(VhostShadowVirtqueue, 1);
+ int r;
+
+ r = event_notifier_init(&svq->hdev_kick, 0);
+ if (r != 0) {
+ error_report("Couldn't create kick event notifier: %s (%d)",
+ g_strerror(errno), errno);
+ goto err_init_hdev_kick;
+ }
+
+ r = event_notifier_init(&svq->hdev_call, 0);
+ if (r != 0) {
+ error_report("Couldn't create call event notifier: %s (%d)",
+ g_strerror(errno), errno);
+ goto err_init_hdev_call;
+ }
+
+ return g_steal_pointer(&svq);
+
+err_init_hdev_call:
+ event_notifier_cleanup(&svq->hdev_kick);
+
+err_init_hdev_kick:
+ return NULL;
+}
+
+/**
+ * Free the resources of the shadow virtqueue.
+ *
+ * @pvq: gpointer to SVQ so it can be used by autofree functions.
+ */
+void vhost_svq_free(gpointer pvq)
+{
+ VhostShadowVirtqueue *vq = pvq;
+ event_notifier_cleanup(&vq->hdev_kick);
+ event_notifier_cleanup(&vq->hdev_call);
+ g_free(vq);
+}
diff --git a/hw/virtio/vhost-shadow-virtqueue.h
b/hw/virtio/vhost-shadow-virtqueue.h
new file mode 100644
index 0000000..f1519e3
--- /dev/null
+++ b/hw/virtio/vhost-shadow-virtqueue.h
@@ -0,0 +1,28 @@
+/*
+ * vhost shadow virtqueue
+ *
+ * SPDX-FileCopyrightText: Red Hat, Inc. 2021
+ * SPDX-FileContributor: Author: Eugenio Pérez <eperezma@redhat.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#ifndef VHOST_SHADOW_VIRTQUEUE_H
+#define VHOST_SHADOW_VIRTQUEUE_H
+
+#include "qemu/event_notifier.h"
+
+/* Shadow virtqueue to relay notifications */
+typedef struct VhostShadowVirtqueue {
+ /* Shadow kick notifier, sent to vhost */
+ EventNotifier hdev_kick;
+ /* Shadow call notifier, sent to vhost */
+ EventNotifier hdev_call;
+} VhostShadowVirtqueue;
+
+VhostShadowVirtqueue *vhost_svq_new(void);
+
+void vhost_svq_free(gpointer vq);
+G_DEFINE_AUTOPTR_CLEANUP_FUNC(VhostShadowVirtqueue, vhost_svq_free);
+
+#endif
--
2.7.4
- [PULL 00/15] Net patches, Jason Wang, 2022/03/08
- [PULL 01/15] virtio-net: fix map leaking on error during receive, Jason Wang, 2022/03/08
- [PULL 02/15] vhost: Add VhostShadowVirtqueue,
Jason Wang <=
- [PULL 03/15] vhost: Add Shadow VirtQueue kick forwarding capabilities, Jason Wang, 2022/03/08
- [PULL 04/15] vhost: Add Shadow VirtQueue call forwarding capabilities, Jason Wang, 2022/03/08
- [PULL 06/15] virtio: Add vhost_svq_get_vring_addr, Jason Wang, 2022/03/08
- [PULL 05/15] vhost: Add vhost_svq_valid_features to shadow vq, Jason Wang, 2022/03/08
- [PULL 07/15] vdpa: adapt vhost_ops callbacks to svq, Jason Wang, 2022/03/08
- [PULL 08/15] vhost: Shadow virtqueue buffers forwarding, Jason Wang, 2022/03/08
- [PULL 09/15] util: Add iova_tree_alloc_map, Jason Wang, 2022/03/08
- [PULL 10/15] util: add iova_tree_find_iova, Jason Wang, 2022/03/08
- [PULL 12/15] vdpa: Add custom IOTLB translations to SVQ, Jason Wang, 2022/03/08
- [PULL 11/15] vhost: Add VhostIOVATree, Jason Wang, 2022/03/08