vhost: enable vhost without without MSI-X

We use vhostforce to enable vhost even if Guests don't have MSI-X
support and we fall back to QEMU virtio-net.

This gives a very small performance gain, but the disadvantage
is that guest now controls which virtio code is running
(qemu or vhost) so our attack surface is doubled.

This patch will enable vhost unconditionally whenever it's requested.
For compatibility, enable vhost when vhostforce is set, as well.

Signed-off-by: Pankaj Gupta <pagupta@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Jason Wang <jasowang@redhat.com>

diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
index f505c91d420ac6d31de380dd2e80bcec6d5191ff..9bd360bd179bab123b3c76c74796cc48590a9a4a 100644 (file)
--- a/hw/net/vhost_net.c
+++ b/hw/net/vhost_net.c
@@ -163,7 +163,7 @@ struct vhost_net *vhost_net_init(VhostNetOptions *options)
     net->dev.vq_index = net->nc->queue_index;
 
     r = vhost_dev_init(&net->dev, options->opaque,
-                       options->backend_type, options->force);
+                       options->backend_type);
     if (r < 0) {
         goto fail;
     }
@@ -188,11 +188,6 @@ fail:
     return NULL;
 }
 
-bool vhost_net_query(VHostNetState *net, VirtIODevice *dev)
-{
-    return vhost_dev_query(&net->dev, dev);
-}
-
 static void vhost_net_set_vq_index(struct vhost_net *net, int vq_index)
 {
     net->dev.vq_index = vq_index;
@@ -424,11 +419,6 @@ struct vhost_net *vhost_net_init(VhostNetOptions *options)
     return NULL;
 }
 
-bool vhost_net_query(VHostNetState *net, VirtIODevice *dev)
-{
-    return false;
-}
-
 int vhost_net_start(VirtIODevice *dev,
                     NetClientState *ncs,
                     int total_queues)

diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index 9281aa107c477c5db18f43935545d305789b3ee2..d7282335de8b7714ed5100ad7794ad4ed6a44465 100644 (file)
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -128,10 +128,6 @@ static void virtio_net_vhost_status(VirtIONet *n, uint8_t status)
     if (!n->vhost_started) {
         int r, i;
 
-        if (!vhost_net_query(get_vhost_net(nc->peer), vdev)) {
-            return;
-        }
-
         /* Any packets outstanding? Purge them to avoid touching rings
          * when vhost is running.
          */

diff --git a/hw/scsi/vhost-scsi.c b/hw/scsi/vhost-scsi.c
index 1941aa15c0b9878ef411f072d8cc7dd0c85da6bf..1c389c4d7efca5662a280d7a34410d2ae6a85973 100644 (file)
--- a/hw/scsi/vhost-scsi.c
+++ b/hw/scsi/vhost-scsi.c
@@ -246,7 +246,7 @@ static void vhost_scsi_realize(DeviceState *dev, Error **errp)
     s->dev.backend_features = 0;
 
     ret = vhost_dev_init(&s->dev, (void *)(uintptr_t)vhostfd,
-                         VHOST_BACKEND_TYPE_KERNEL, true);
+                         VHOST_BACKEND_TYPE_KERNEL);
     if (ret < 0) {
         error_setg(errp, "vhost-scsi: vhost initialization failed: %s",
                    strerror(-ret));

diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index 7ea45b391ca9d9ff1173329c29c33803bce652d0..b84d21cf7ee5f62ff52186d3a6d5be722972103e 100644 (file)
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -898,7 +898,7 @@ static void vhost_virtqueue_cleanup(struct vhost_virtqueue *vq)
 }
 
 int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
-                   VhostBackendType backend_type, bool force)
+                   VhostBackendType backend_type)
 {
     uint64_t features;
     int i, r;
@@ -961,7 +961,6 @@ int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
     hdev->started = false;
     hdev->memory_changed = false;
     memory_listener_register(&hdev->memory_listener, &address_space_memory);
-    hdev->force = force;
     return 0;
 fail_vq:
     while (--i >= 0) {
@@ -989,17 +988,6 @@ void vhost_dev_cleanup(struct vhost_dev *hdev)
     hdev->vhost_ops->vhost_backend_cleanup(hdev);
 }
 
-bool vhost_dev_query(struct vhost_dev *hdev, VirtIODevice *vdev)
-{
-    BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
-    VirtioBusState *vbus = VIRTIO_BUS(qbus);
-    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
-
-    return !k->query_guest_notifiers ||
-           k->query_guest_notifiers(qbus->parent) ||
-           hdev->force;
-}
-
 /* Stop processing guest IO notifications in qemu.
  * Start processing them in vhost in kernel.
  */

diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
index 84f170e789bda3d724503a3c717831bf4aa53a4f..dd510509eb8a27413280074a59084398900a1ca8 100644 (file)
--- a/include/hw/virtio/vhost.h
+++ b/include/hw/virtio/vhost.h
@@ -51,7 +51,6 @@ struct vhost_dev {
     bool log_enabled;
     unsigned long long log_size;
     Error *migration_blocker;
-    bool force;
     bool memory_changed;
     hwaddr mem_changed_start_addr;
     hwaddr mem_changed_end_addr;
@@ -61,7 +60,7 @@ struct vhost_dev {
 };
 
 int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
-                   VhostBackendType backend_type, bool force);
+                   VhostBackendType backend_type);
 void vhost_dev_cleanup(struct vhost_dev *hdev);
 bool vhost_dev_query(struct vhost_dev *hdev, VirtIODevice *vdev);
 int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev);

diff --git a/include/net/vhost_net.h b/include/net/vhost_net.h
index 9eb493efc3c78756c46fa5daec922677bed2e7e1..840d4b16e255ea3b1400c9031e02132d414d60b4 100644 (file)
--- a/include/net/vhost_net.h
+++ b/include/net/vhost_net.h
@@ -11,12 +11,10 @@ typedef struct VhostNetOptions {
     VhostBackendType backend_type;
     NetClientState *net_backend;
     void *opaque;
-    bool force;
 } VhostNetOptions;
 
 struct vhost_net *vhost_net_init(VhostNetOptions *options);
 
-bool vhost_net_query(VHostNetState *net, VirtIODevice *dev);
 int vhost_net_start(VirtIODevice *dev, NetClientState *ncs, int total_queues);
 void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs, int total_queues);
 

diff --git a/net/tap.c b/net/tap.c
index ec12dfd1d8cc2ac8dee31dabe416da07a8ec89e6..3a3f522eac85f2395ab18197c7711b6cc2b3e682 100644 (file)
--- a/net/tap.c
+++ b/net/tap.c
@@ -671,7 +671,6 @@ static void net_init_tap_one(const NetdevTapOptions *tap, NetClientState *peer,
 
         options.backend_type = VHOST_BACKEND_TYPE_KERNEL;
         options.net_backend = &s->nc;
-        options.force = tap->has_vhostforce && tap->vhostforce;
 
         if (tap->has_vhostfd || tap->has_vhostfds) {
             vhostfd = monitor_fd_param(cur_mon, vhostfdname, &err);

diff --git a/net/vhost-user.c b/net/vhost-user.c
index 8d2672846f0f610ce1257b5483be3992c5fd6406..f1df26df9500dfc941b9d5346f62df632bfef3e6 100644 (file)
--- a/net/vhost-user.c
+++ b/net/vhost-user.c
@@ -50,7 +50,6 @@ static int vhost_user_start(VhostUserState *s)
     options.backend_type = VHOST_BACKEND_TYPE_USER;
     options.net_backend = &s->nc;
     options.opaque = s->chr;
-    options.force = true;
 
     s->vhost_net = vhost_net_init(&options);