[Qemu-devel] [PATCH v3] Enable vhost with vhostforce, vhost options for guests without MSI-X support

[Pankaj Gupta]

We use vhostforce to enable vhost even if Guests don't have MSI-X support
and we fall back to QEMU virtio-net. This patch will enable vhost 
unconditionally 
whenever we have vhostforce='ON' or vhost='ON'. 

Initially, I wanted to remove vhostforce completely as an additional argument. 
But after discussing this in mailing list found that some programs are using 
vhostforce
and some vhost. So, we want to keep semantics of both the options.

Changes from v2->v3
Jason Wang : Remove functions which are not being used.

Changes from v1->v2
MST : Keep comamnd line semantic for options vhost= 'ON' ||
      vhostforce = 'ON', vhost should be ON. 

Signed-off-by: Pankaj Gupta <address@hidden>
---
 hw/net/vhost_net.c        | 12 +-----------
 hw/net/virtio-net.c       |  4 ----
 hw/scsi/vhost-scsi.c      |  2 +-
 hw/virtio/vhost.c         | 14 +-------------
 include/hw/virtio/vhost.h |  3 +--
 include/net/vhost_net.h   |  2 --
 net/tap.c                 |  1 -
 net/vhost-user.c          |  1 -
 8 files changed, 4 insertions(+), 35 deletions(-)

diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
index 1c55517..0a4577d 100644
--- a/hw/net/vhost_net.c
+++ b/hw/net/vhost_net.c
@@ -162,7 +162,7 @@ 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;
     }
@@ -187,11 +187,6 @@ 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;
@@ -412,11 +407,6 @@ 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 9281aa1..d728233 100644
--- 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 1941aa1..1c389c4 100644
--- 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 2d6c27a..4f5bb15 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -853,7 +853,7 @@ 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;
@@ -916,7 +916,6 @@ 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) {
@@ -944,17 +943,6 @@ 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 84f170e..dd51050 100644
--- 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 9eb493e..840d4b1 100644
--- 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 aa8b3f5..bb67c6e 100644
--- a/net/tap.c
+++ b/net/tap.c
@@ -646,7 +646,6 @@ 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 3930741..b51bc04 100644
--- 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);
 
-- 
1.9.3