[PATCH V5 00/10] vhost-vDPA multiqueue

[PATCH V5 00/10] vhost-vDPA multiqueue

[Jason Wang]

Hi All:

This patch implements the multiqueue support for vhost-vDPA. The most
important requirement si the control virtqueue support. The virtio-net
and vhost-net core are tweak to support control virtqueue as if what
data queue pairs are done: a dedicated vhost_net device which is
coupled with the NetClientState is intrdouced so most of the existing
vhost codes could be reused with minor changes. This means the control
virtqueue will bypass the Qemu. With the control virtqueue, vhost-vDPA
are extend to support creating and destroying multiqueue queue pairs
plus the control virtqueue.

For the future, if we want to support live migration, we can either do
shadow cvq on top or introduce new interfaces for reporting device
states.

Tests are done via the vp_vdpa driver in L1 guest.

Changes since V4:
- rebase on top of Michael's pci branch

Changes since V3:
- fix build with vhost disabled

Changes since V2:
- rebase to qemu master
- use "queue_pairs" instead of "qps"
- typo fixes

Changes since V1:
- start and stop vhost devices when all queues were setup
- fix the case when driver doesn't support MQ but device support
- correctly set the batching capability to avoid a map/unmap storm
- various other tweaks

Jason Wang (10):
  vhost-vdpa: open device fd in net_init_vhost_vdpa()
  vhost-vdpa: classify one time request
  vhost-vdpa: prepare for the multiqueue support
  vhost-vdpa: let net_vhost_vdpa_init() returns NetClientState *
  net: introduce control client
  vhost-net: control virtqueue support
  virtio-net: use "queue_pairs" instead of "queues" when possible
  vhost: record the last virtqueue index for the virtio device
  virtio-net: vhost control virtqueue support
  vhost-vdpa: multiqueue support

 hw/net/vhost_net-stub.c        |   4 +-
 hw/net/vhost_net.c             |  55 ++++++++---
 hw/net/virtio-net.c            | 165 ++++++++++++++++++---------------
 hw/virtio/vhost-vdpa.c         |  57 ++++++++++--
 include/hw/virtio/vhost-vdpa.h |   1 +
 include/hw/virtio/vhost.h      |   2 +
 include/hw/virtio/virtio-net.h |   5 +-
 include/net/net.h              |   5 +
 include/net/vhost_net.h        |   6 +-
 net/net.c                      |  24 ++++-
 net/vhost-vdpa.c               | 127 ++++++++++++++++++++++---
 11 files changed, 331 insertions(+), 120 deletions(-)

-- 
2.25.1

[PATCH V5 01/10] vhost-vdpa: open device fd in net_init_vhost_vdpa()

[Jason Wang]

This patch switches to open device fd in net_init_vhost_vpda(). This is
used to prepare for the multiqueue support.

Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 net/vhost-vdpa.c | 23 +++++++++++++++--------
 1 file changed, 15 insertions(+), 8 deletions(-)

diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
index 6dc68d8677..fd4ff5a0fb 100644
--- a/net/vhost-vdpa.c
+++ b/net/vhost-vdpa.c
@@ -170,24 +170,19 @@ static NetClientInfo net_vhost_vdpa_info = {
 };
 
 static int net_vhost_vdpa_init(NetClientState *peer, const char *device,
-                               const char *name, const char *vhostdev)
+                               const char *name, int vdpa_device_fd)
 {
     NetClientState *nc = NULL;
     VhostVDPAState *s;
-    int vdpa_device_fd = -1;
     int ret = 0;
     assert(name);
     nc = qemu_new_net_client(&net_vhost_vdpa_info, peer, device, name);
     snprintf(nc->info_str, sizeof(nc->info_str), TYPE_VHOST_VDPA);
     s = DO_UPCAST(VhostVDPAState, nc, nc);
-    vdpa_device_fd = qemu_open_old(vhostdev, O_RDWR);
-    if (vdpa_device_fd == -1) {
-        return -errno;
-    }
+
     s->vhost_vdpa.device_fd = vdpa_device_fd;
     ret = vhost_vdpa_add(nc, (void *)&s->vhost_vdpa);
     if (ret) {
-        qemu_close(vdpa_device_fd);
         qemu_del_net_client(nc);
     }
     return ret;
@@ -197,8 +192,20 @@ int net_init_vhost_vdpa(const Netdev *netdev, const char *name,
                         NetClientState *peer, Error **errp)
 {
     const NetdevVhostVDPAOptions *opts;
+    int vdpa_device_fd, ret;
 
     assert(netdev->type == NET_CLIENT_DRIVER_VHOST_VDPA);
     opts = &netdev->u.vhost_vdpa;
-    return net_vhost_vdpa_init(peer, TYPE_VHOST_VDPA, name, opts->vhostdev);
+
+    vdpa_device_fd = qemu_open_old(opts->vhostdev, O_RDWR);
+    if (vdpa_device_fd == -1) {
+        return -errno;
+    }
+
+    ret = net_vhost_vdpa_init(peer, TYPE_VHOST_VDPA, name, vdpa_device_fd);
+    if (ret) {
+        qemu_close(vdpa_device_fd);
+    }
+
+    return ret;
 }
-- 
2.25.1

[PATCH V5 02/10] vhost-vdpa: classify one time request

[Jason Wang]

Vhost-vdpa uses one device multiqueue queue (pairs) model. So we need
to classify the one time request (e.g SET_OWNER) and make sure those
request were only called once per device.

This is used for multiqueue support.

Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 hw/virtio/vhost-vdpa.c         | 53 ++++++++++++++++++++++++++++++----
 include/hw/virtio/vhost-vdpa.h |  1 +
 2 files changed, 48 insertions(+), 6 deletions(-)

diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
index 7691e904ac..67a3dcf6a5 100644
--- a/hw/virtio/vhost-vdpa.c
+++ b/hw/virtio/vhost-vdpa.c
@@ -317,6 +317,13 @@ static void vhost_vdpa_get_iova_range(struct vhost_vdpa *v)
                                     v->iova_range.last);
 }
 
+static bool vhost_vdpa_one_time_request(struct vhost_dev *dev)
+{
+    struct vhost_vdpa *v = dev->opaque;
+
+    return v->index != 0;
+}
+
 static int vhost_vdpa_init(struct vhost_dev *dev, void *opaque, Error **errp)
 {
     struct vhost_vdpa *v;
@@ -330,6 +337,11 @@ static int vhost_vdpa_init(struct vhost_dev *dev, void *opaque, Error **errp)
     v->msg_type = VHOST_IOTLB_MSG_V2;
 
     vhost_vdpa_get_iova_range(v);
+
+    if (vhost_vdpa_one_time_request(dev)) {
+        return 0;
+    }
+
     vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE |
                                VIRTIO_CONFIG_S_DRIVER);
 
@@ -440,6 +452,10 @@ static int vhost_vdpa_memslots_limit(struct vhost_dev *dev)
 static int vhost_vdpa_set_mem_table(struct vhost_dev *dev,
                                     struct vhost_memory *mem)
 {
+    if (vhost_vdpa_one_time_request(dev)) {
+        return 0;
+    }
+
     trace_vhost_vdpa_set_mem_table(dev, mem->nregions, mem->padding);
     if (trace_event_get_state_backends(TRACE_VHOST_VDPA_SET_MEM_TABLE) &&
         trace_event_get_state_backends(TRACE_VHOST_VDPA_DUMP_REGIONS)) {
@@ -463,6 +479,11 @@ static int vhost_vdpa_set_features(struct vhost_dev *dev,
                                    uint64_t features)
 {
     int ret;
+
+    if (vhost_vdpa_one_time_request(dev)) {
+        return 0;
+    }
+
     trace_vhost_vdpa_set_features(dev, features);
     ret = vhost_vdpa_call(dev, VHOST_SET_FEATURES, &features);
     uint8_t status = 0;
@@ -487,9 +508,12 @@ static int vhost_vdpa_set_backend_cap(struct vhost_dev *dev)
     }
 
     features &= f;
-    r = vhost_vdpa_call(dev, VHOST_SET_BACKEND_FEATURES, &features);
-    if (r) {
-        return -EFAULT;
+
+    if (vhost_vdpa_one_time_request(dev)) {
+        r = vhost_vdpa_call(dev, VHOST_SET_BACKEND_FEATURES, &features);
+        if (r) {
+            return -EFAULT;
+        }
     }
 
     dev->backend_cap = features;
@@ -598,11 +622,21 @@ static int vhost_vdpa_dev_start(struct vhost_dev *dev, bool started)
 {
     struct vhost_vdpa *v = dev->opaque;
     trace_vhost_vdpa_dev_start(dev, started);
+
     if (started) {
-        uint8_t status = 0;
-        memory_listener_register(&v->listener, &address_space_memory);
         vhost_vdpa_host_notifiers_init(dev);
         vhost_vdpa_set_vring_ready(dev);
+    } else {
+        vhost_vdpa_host_notifiers_uninit(dev, dev->nvqs);
+    }
+
+    if (vhost_vdpa_one_time_request(dev)) {
+        return 0;
+    }
+
+    if (started) {
+        uint8_t status = 0;
+        memory_listener_register(&v->listener, &address_space_memory);
         vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
         vhost_vdpa_call(dev, VHOST_VDPA_GET_STATUS, &status);
 
@@ -611,7 +645,6 @@ static int vhost_vdpa_dev_start(struct vhost_dev *dev, bool started)
         vhost_vdpa_reset_device(dev);
         vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE |
                                    VIRTIO_CONFIG_S_DRIVER);
-        vhost_vdpa_host_notifiers_uninit(dev, dev->nvqs);
         memory_listener_unregister(&v->listener);
 
         return 0;
@@ -621,6 +654,10 @@ static int vhost_vdpa_dev_start(struct vhost_dev *dev, bool started)
 static int vhost_vdpa_set_log_base(struct vhost_dev *dev, uint64_t base,
                                      struct vhost_log *log)
 {
+    if (vhost_vdpa_one_time_request(dev)) {
+        return 0;
+    }
+
     trace_vhost_vdpa_set_log_base(dev, base, log->size, log->refcnt, log->fd,
                                   log->log);
     return vhost_vdpa_call(dev, VHOST_SET_LOG_BASE, &base);
@@ -686,6 +723,10 @@ static int vhost_vdpa_get_features(struct vhost_dev *dev,
 
 static int vhost_vdpa_set_owner(struct vhost_dev *dev)
 {
+    if (vhost_vdpa_one_time_request(dev)) {
+        return 0;
+    }
+
     trace_vhost_vdpa_set_owner(dev);
     return vhost_vdpa_call(dev, VHOST_SET_OWNER, NULL);
 }
diff --git a/include/hw/virtio/vhost-vdpa.h b/include/hw/virtio/vhost-vdpa.h
index c288cf7ecb..3ce79a646d 100644
--- a/include/hw/virtio/vhost-vdpa.h
+++ b/include/hw/virtio/vhost-vdpa.h
@@ -22,6 +22,7 @@ typedef struct VhostVDPAHostNotifier {
 
 typedef struct vhost_vdpa {
     int device_fd;
+    int index;
     uint32_t msg_type;
     bool iotlb_batch_begin_sent;
     MemoryListener listener;
-- 
2.25.1

[PATCH V5 03/10] vhost-vdpa: prepare for the multiqueue support

[Jason Wang]

Unlike vhost-kernel, vhost-vdpa adapts a single device multiqueue
model. So we need to simply use virtqueue index as the vhost virtqueue
index. This is a must for multiqueue to work for vhost-vdpa.

Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 hw/virtio/vhost-vdpa.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
index 67a3dcf6a5..40987188cf 100644
--- a/hw/virtio/vhost-vdpa.c
+++ b/hw/virtio/vhost-vdpa.c
@@ -544,8 +544,8 @@ static int vhost_vdpa_get_vq_index(struct vhost_dev *dev, int idx)
 {
     assert(idx >= dev->vq_index && idx < dev->vq_index + dev->nvqs);
 
-    trace_vhost_vdpa_get_vq_index(dev, idx, idx - dev->vq_index);
-    return idx - dev->vq_index;
+    trace_vhost_vdpa_get_vq_index(dev, idx, idx);
+    return idx;
 }
 
 static int vhost_vdpa_set_vring_ready(struct vhost_dev *dev)
-- 
2.25.1

[PATCH V5 04/10] vhost-vdpa: let net_vhost_vdpa_init() returns NetClientState *

[Jason Wang]

This patch switches to let net_vhost_vdpa_init() to return
NetClientState *. This is used for the callers to allocate multiqueue
NetClientState for multiqueue support.

Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 net/vhost-vdpa.c | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
index fd4ff5a0fb..151f60184d 100644
--- a/net/vhost-vdpa.c
+++ b/net/vhost-vdpa.c
@@ -169,8 +169,10 @@ static NetClientInfo net_vhost_vdpa_info = {
         .check_peer_type = vhost_vdpa_check_peer_type,
 };
 
-static int net_vhost_vdpa_init(NetClientState *peer, const char *device,
-                               const char *name, int vdpa_device_fd)
+static NetClientState *net_vhost_vdpa_init(NetClientState *peer,
+                                           const char *device,
+                                           const char *name,
+                                           int vdpa_device_fd)
 {
     NetClientState *nc = NULL;
     VhostVDPAState *s;
@@ -184,15 +186,17 @@ static int net_vhost_vdpa_init(NetClientState *peer, const char *device,
     ret = vhost_vdpa_add(nc, (void *)&s->vhost_vdpa);
     if (ret) {
         qemu_del_net_client(nc);
+        return NULL;
     }
-    return ret;
+    return nc;
 }
 
 int net_init_vhost_vdpa(const Netdev *netdev, const char *name,
                         NetClientState *peer, Error **errp)
 {
     const NetdevVhostVDPAOptions *opts;
-    int vdpa_device_fd, ret;
+    int vdpa_device_fd;
+    NetClientState *nc;
 
     assert(netdev->type == NET_CLIENT_DRIVER_VHOST_VDPA);
     opts = &netdev->u.vhost_vdpa;
@@ -202,10 +206,11 @@ int net_init_vhost_vdpa(const Netdev *netdev, const char *name,
         return -errno;
     }
 
-    ret = net_vhost_vdpa_init(peer, TYPE_VHOST_VDPA, name, vdpa_device_fd);
-    if (ret) {
+    nc = net_vhost_vdpa_init(peer, TYPE_VHOST_VDPA, name, vdpa_device_fd);
+    if (!nc) {
         qemu_close(vdpa_device_fd);
+        return -1;
     }
 
-    return ret;
+    return 0;
 }
-- 
2.25.1

[PATCH V5 05/10] net: introduce control client

[Jason Wang]

This patch introduces a boolean for the device has control queue which
can accepts control command via network queue.

The first user would be the control virtqueue support for vhost.

Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 include/net/net.h |  5 +++++
 net/net.c         | 24 +++++++++++++++++++++---
 2 files changed, 26 insertions(+), 3 deletions(-)

diff --git a/include/net/net.h b/include/net/net.h
index 986288eb07..523136c7ac 100644
--- a/include/net/net.h
+++ b/include/net/net.h
@@ -105,6 +105,7 @@ struct NetClientState {
     int vnet_hdr_len;
     bool is_netdev;
     bool do_not_pad; /* do not pad to the minimum ethernet frame length */
+    bool is_datapath;
     QTAILQ_HEAD(, NetFilterState) filters;
 };
 
@@ -136,6 +137,10 @@ NetClientState *qemu_new_net_client(NetClientInfo *info,
                                     NetClientState *peer,
                                     const char *model,
                                     const char *name);
+NetClientState *qemu_new_net_control_client(NetClientInfo *info,
+                                        NetClientState *peer,
+                                        const char *model,
+                                        const char *name);
 NICState *qemu_new_nic(NetClientInfo *info,
                        NICConf *conf,
                        const char *model,
diff --git a/net/net.c b/net/net.c
index 52c99196c6..f0d14dbfc1 100644
--- a/net/net.c
+++ b/net/net.c
@@ -239,7 +239,8 @@ static void qemu_net_client_setup(NetClientState *nc,
                                   NetClientState *peer,
                                   const char *model,
                                   const char *name,
-                                  NetClientDestructor *destructor)
+                                  NetClientDestructor *destructor,
+                                  bool is_datapath)
 {
     nc->info = info;
     nc->model = g_strdup(model);
@@ -258,6 +259,7 @@ static void qemu_net_client_setup(NetClientState *nc,
 
     nc->incoming_queue = qemu_new_net_queue(qemu_deliver_packet_iov, nc);
     nc->destructor = destructor;
+    nc->is_datapath = is_datapath;
     QTAILQ_INIT(&nc->filters);
 }
 
@@ -272,7 +274,23 @@ NetClientState *qemu_new_net_client(NetClientInfo *info,
 
     nc = g_malloc0(info->size);
     qemu_net_client_setup(nc, info, peer, model, name,
-                          qemu_net_client_destructor);
+                          qemu_net_client_destructor, true);
+
+    return nc;
+}
+
+NetClientState *qemu_new_net_control_client(NetClientInfo *info,
+                                            NetClientState *peer,
+                                            const char *model,
+                                            const char *name)
+{
+    NetClientState *nc;
+
+    assert(info->size >= sizeof(NetClientState));
+
+    nc = g_malloc0(info->size);
+    qemu_net_client_setup(nc, info, peer, model, name,
+                          qemu_net_client_destructor, false);
 
     return nc;
 }
@@ -297,7 +315,7 @@ NICState *qemu_new_nic(NetClientInfo *info,
 
     for (i = 0; i < queues; i++) {
         qemu_net_client_setup(&nic->ncs[i], info, peers[i], model, name,
-                              NULL);
+                              NULL, true);
         nic->ncs[i].queue_index = i;
     }
 
-- 
2.25.1

[PATCH V5 06/10] vhost-net: control virtqueue support

[Jason Wang]

We assume there's no cvq in the past, this is not true when we need
control virtqueue support for vhost-user backends. So this patch
implements the control virtqueue support for vhost-net. As datapath,
the control virtqueue is also required to be coupled with the
NetClientState. The vhost_net_start/stop() are tweaked to accept the
number of datapath queue pairs plus the the number of control
virtqueue for us to start and stop the vhost device.

Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 hw/net/vhost_net-stub.c |  4 ++--
 hw/net/vhost_net.c      | 43 ++++++++++++++++++++++++++++++-----------
 hw/net/virtio-net.c     |  4 ++--
 include/net/vhost_net.h |  6 ++++--
 4 files changed, 40 insertions(+), 17 deletions(-)

diff --git a/hw/net/vhost_net-stub.c b/hw/net/vhost_net-stub.c
index a7f4252630..89d71cfb8e 100644
--- a/hw/net/vhost_net-stub.c
+++ b/hw/net/vhost_net-stub.c
@@ -33,13 +33,13 @@ struct vhost_net *vhost_net_init(VhostNetOptions *options)
 
 int vhost_net_start(VirtIODevice *dev,
                     NetClientState *ncs,
-                    int total_queues)
+                    int data_queue_pairs, int cvq)
 {
     return -ENOSYS;
 }
 void vhost_net_stop(VirtIODevice *dev,
                     NetClientState *ncs,
-                    int total_queues)
+                    int data_queue_pairs, int cvq)
 {
 }
 
diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
index 386ec2eaa2..e1e9d1ec89 100644
--- a/hw/net/vhost_net.c
+++ b/hw/net/vhost_net.c
@@ -315,11 +315,14 @@ static void vhost_net_stop_one(struct vhost_net *net,
 }
 
 int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
-                    int total_queues)
+                    int data_queue_pairs, int cvq)
 {
     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(dev)));
     VirtioBusState *vbus = VIRTIO_BUS(qbus);
     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
+    int total_notifiers = data_queue_pairs * 2 + cvq;
+    VirtIONet *n = VIRTIO_NET(dev);
+    int nvhosts = data_queue_pairs + cvq;
     struct vhost_net *net;
     int r, e, i;
     NetClientState *peer;
@@ -329,9 +332,14 @@ int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
         return -ENOSYS;
     }
 
-    for (i = 0; i < total_queues; i++) {
+    for (i = 0; i < nvhosts; i++) {
+
+        if (i < data_queue_pairs) {
+            peer = qemu_get_peer(ncs, i);
+        } else { /* Control Virtqueue */
+            peer = qemu_get_peer(ncs, n->max_queues);
+        }
 
-        peer = qemu_get_peer(ncs, i);
         net = get_vhost_net(peer);
         vhost_net_set_vq_index(net, i * 2);
 
@@ -344,14 +352,18 @@ int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
         }
      }
 
-    r = k->set_guest_notifiers(qbus->parent, total_queues * 2, true);
+    r = k->set_guest_notifiers(qbus->parent, total_notifiers, true);
     if (r < 0) {
         error_report("Error binding guest notifier: %d", -r);
         goto err;
     }
 
-    for (i = 0; i < total_queues; i++) {
-        peer = qemu_get_peer(ncs, i);
+    for (i = 0; i < nvhosts; i++) {
+        if (i < data_queue_pairs) {
+            peer = qemu_get_peer(ncs, i);
+        } else {
+            peer = qemu_get_peer(ncs, n->max_queues);
+        }
         r = vhost_net_start_one(get_vhost_net(peer), dev);
 
         if (r < 0) {
@@ -375,7 +387,7 @@ err_start:
         peer = qemu_get_peer(ncs , i);
         vhost_net_stop_one(get_vhost_net(peer), dev);
     }
-    e = k->set_guest_notifiers(qbus->parent, total_queues * 2, false);
+    e = k->set_guest_notifiers(qbus->parent, total_notifiers, false);
     if (e < 0) {
         fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", e);
         fflush(stderr);
@@ -385,18 +397,27 @@ err:
 }
 
 void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
-                    int total_queues)
+                    int data_queue_pairs, int cvq)
 {
     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(dev)));
     VirtioBusState *vbus = VIRTIO_BUS(qbus);
     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
+    VirtIONet *n = VIRTIO_NET(dev);
+    NetClientState *peer;
+    int total_notifiers = data_queue_pairs * 2 + cvq;
+    int nvhosts = data_queue_pairs + cvq;
     int i, r;
 
-    for (i = 0; i < total_queues; i++) {
-        vhost_net_stop_one(get_vhost_net(ncs[i].peer), dev);
+    for (i = 0; i < nvhosts; i++) {
+        if (i < data_queue_pairs) {
+            peer = qemu_get_peer(ncs, i);
+        } else {
+            peer = qemu_get_peer(ncs, n->max_queues);
+        }
+        vhost_net_stop_one(get_vhost_net(peer), dev);
     }
 
-    r = k->set_guest_notifiers(qbus->parent, total_queues * 2, false);
+    r = k->set_guest_notifiers(qbus->parent, total_notifiers, false);
     if (r < 0) {
         fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", r);
         fflush(stderr);
diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index 3dd2896ff9..5ee6729662 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -285,14 +285,14 @@ static void virtio_net_vhost_status(VirtIONet *n, uint8_t status)
         }
 
         n->vhost_started = 1;
-        r = vhost_net_start(vdev, n->nic->ncs, queues);
+        r = vhost_net_start(vdev, n->nic->ncs, queues, 0);
         if (r < 0) {
             error_report("unable to start vhost net: %d: "
                          "falling back on userspace virtio", -r);
             n->vhost_started = 0;
         }
     } else {
-        vhost_net_stop(vdev, n->nic->ncs, queues);
+        vhost_net_stop(vdev, n->nic->ncs, queues, 0);
         n->vhost_started = 0;
     }
 }
diff --git a/include/net/vhost_net.h b/include/net/vhost_net.h
index fba40cf695..387e913e4e 100644
--- a/include/net/vhost_net.h
+++ b/include/net/vhost_net.h
@@ -21,8 +21,10 @@ typedef struct VhostNetOptions {
 uint64_t vhost_net_get_max_queues(VHostNetState *net);
 struct vhost_net *vhost_net_init(VhostNetOptions *options);
 
-int vhost_net_start(VirtIODevice *dev, NetClientState *ncs, int total_queues);
-void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs, int total_queues);
+int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
+                    int data_queue_pairs, int cvq);
+void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
+                    int data_queue_pairs, int cvq);
 
 void vhost_net_cleanup(VHostNetState *net);
 
-- 
2.25.1

[PATCH V5 07/10] virtio-net: use "queue_pairs" instead of "queues" when possible

[Jason Wang]

Most of the time, "queues" really means queue pairs. So this patch
switch to use "queue_pairs" to avoid confusion.

Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 hw/net/vhost_net.c             |   6 +-
 hw/net/virtio-net.c            | 150 ++++++++++++++++-----------------
 include/hw/virtio/virtio-net.h |   4 +-
 3 files changed, 80 insertions(+), 80 deletions(-)

diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
index e1e9d1ec89..2b594b4642 100644
--- a/hw/net/vhost_net.c
+++ b/hw/net/vhost_net.c
@@ -337,7 +337,7 @@ int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
         if (i < data_queue_pairs) {
             peer = qemu_get_peer(ncs, i);
         } else { /* Control Virtqueue */
-            peer = qemu_get_peer(ncs, n->max_queues);
+            peer = qemu_get_peer(ncs, n->max_queue_pairs);
         }
 
         net = get_vhost_net(peer);
@@ -362,7 +362,7 @@ int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
         if (i < data_queue_pairs) {
             peer = qemu_get_peer(ncs, i);
         } else {
-            peer = qemu_get_peer(ncs, n->max_queues);
+            peer = qemu_get_peer(ncs, n->max_queue_pairs);
         }
         r = vhost_net_start_one(get_vhost_net(peer), dev);
 
@@ -412,7 +412,7 @@ void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
         if (i < data_queue_pairs) {
             peer = qemu_get_peer(ncs, i);
         } else {
-            peer = qemu_get_peer(ncs, n->max_queues);
+            peer = qemu_get_peer(ncs, n->max_queue_pairs);
         }
         vhost_net_stop_one(get_vhost_net(peer), dev);
     }
diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index 5ee6729662..7594f7ea92 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -54,7 +54,7 @@
 #define VIRTIO_NET_RX_QUEUE_DEFAULT_SIZE 256
 #define VIRTIO_NET_TX_QUEUE_DEFAULT_SIZE 256
 
-/* for now, only allow larger queues; with virtio-1, guest can downsize */
+/* for now, only allow larger queue_pairs; with virtio-1, guest can downsize */
 #define VIRTIO_NET_RX_QUEUE_MIN_SIZE VIRTIO_NET_RX_QUEUE_DEFAULT_SIZE
 #define VIRTIO_NET_TX_QUEUE_MIN_SIZE VIRTIO_NET_TX_QUEUE_DEFAULT_SIZE
 
@@ -131,7 +131,7 @@ static void virtio_net_get_config(VirtIODevice *vdev, uint8_t *config)
     int ret = 0;
     memset(&netcfg, 0 , sizeof(struct virtio_net_config));
     virtio_stw_p(vdev, &netcfg.status, n->status);
-    virtio_stw_p(vdev, &netcfg.max_virtqueue_pairs, n->max_queues);
+    virtio_stw_p(vdev, &netcfg.max_virtqueue_pairs, n->max_queue_pairs);
     virtio_stw_p(vdev, &netcfg.mtu, n->net_conf.mtu);
     memcpy(netcfg.mac, n->mac, ETH_ALEN);
     virtio_stl_p(vdev, &netcfg.speed, n->net_conf.speed);
@@ -243,7 +243,7 @@ static void virtio_net_vhost_status(VirtIONet *n, uint8_t status)
 {
     VirtIODevice *vdev = VIRTIO_DEVICE(n);
     NetClientState *nc = qemu_get_queue(n->nic);
-    int queues = n->multiqueue ? n->max_queues : 1;
+    int queue_pairs = n->multiqueue ? n->max_queue_pairs : 1;
 
     if (!get_vhost_net(nc->peer)) {
         return;
@@ -266,7 +266,7 @@ static void virtio_net_vhost_status(VirtIONet *n, uint8_t status)
         /* Any packets outstanding? Purge them to avoid touching rings
          * when vhost is running.
          */
-        for (i = 0;  i < queues; i++) {
+        for (i = 0;  i < queue_pairs; i++) {
             NetClientState *qnc = qemu_get_subqueue(n->nic, i);
 
             /* Purge both directions: TX and RX. */
@@ -285,14 +285,14 @@ static void virtio_net_vhost_status(VirtIONet *n, uint8_t status)
         }
 
         n->vhost_started = 1;
-        r = vhost_net_start(vdev, n->nic->ncs, queues, 0);
+        r = vhost_net_start(vdev, n->nic->ncs, queue_pairs, 0);
         if (r < 0) {
             error_report("unable to start vhost net: %d: "
                          "falling back on userspace virtio", -r);
             n->vhost_started = 0;
         }
     } else {
-        vhost_net_stop(vdev, n->nic->ncs, queues, 0);
+        vhost_net_stop(vdev, n->nic->ncs, queue_pairs, 0);
         n->vhost_started = 0;
     }
 }
@@ -309,11 +309,11 @@ static int virtio_net_set_vnet_endian_one(VirtIODevice *vdev,
 }
 
 static bool virtio_net_set_vnet_endian(VirtIODevice *vdev, NetClientState *ncs,
-                                       int queues, bool enable)
+                                       int queue_pairs, bool enable)
 {
     int i;
 
-    for (i = 0; i < queues; i++) {
+    for (i = 0; i < queue_pairs; i++) {
         if (virtio_net_set_vnet_endian_one(vdev, ncs[i].peer, enable) < 0 &&
             enable) {
             while (--i >= 0) {
@@ -330,7 +330,7 @@ static bool virtio_net_set_vnet_endian(VirtIODevice *vdev, NetClientState *ncs,
 static void virtio_net_vnet_endian_status(VirtIONet *n, uint8_t status)
 {
     VirtIODevice *vdev = VIRTIO_DEVICE(n);
-    int queues = n->multiqueue ? n->max_queues : 1;
+    int queue_pairs = n->multiqueue ? n->max_queue_pairs : 1;
 
     if (virtio_net_started(n, status)) {
         /* Before using the device, we tell the network backend about the
@@ -339,14 +339,14 @@ static void virtio_net_vnet_endian_status(VirtIONet *n, uint8_t status)
          * virtio-net code.
          */
         n->needs_vnet_hdr_swap = virtio_net_set_vnet_endian(vdev, n->nic->ncs,
-                                                            queues, true);
+                                                            queue_pairs, true);
     } else if (virtio_net_started(n, vdev->status)) {
         /* After using the device, we need to reset the network backend to
          * the default (guest native endianness), otherwise the guest may
          * lose network connectivity if it is rebooted into a different
          * endianness.
          */
-        virtio_net_set_vnet_endian(vdev, n->nic->ncs, queues, false);
+        virtio_net_set_vnet_endian(vdev, n->nic->ncs, queue_pairs, false);
     }
 }
 
@@ -368,12 +368,12 @@ static void virtio_net_set_status(struct VirtIODevice *vdev, uint8_t status)
     virtio_net_vnet_endian_status(n, status);
     virtio_net_vhost_status(n, status);
 
-    for (i = 0; i < n->max_queues; i++) {
+    for (i = 0; i < n->max_queue_pairs; i++) {
         NetClientState *ncs = qemu_get_subqueue(n->nic, i);
         bool queue_started;
         q = &n->vqs[i];
 
-        if ((!n->multiqueue && i != 0) || i >= n->curr_queues) {
+        if ((!n->multiqueue && i != 0) || i >= n->curr_queue_pairs) {
             queue_status = 0;
         } else {
             queue_status = status;
@@ -540,7 +540,7 @@ static void virtio_net_reset(VirtIODevice *vdev)
     n->nouni = 0;
     n->nobcast = 0;
     /* multiqueue is disabled by default */
-    n->curr_queues = 1;
+    n->curr_queue_pairs = 1;
     timer_del(n->announce_timer.tm);
     n->announce_timer.round = 0;
     n->status &= ~VIRTIO_NET_S_ANNOUNCE;
@@ -556,7 +556,7 @@ static void virtio_net_reset(VirtIODevice *vdev)
     memset(n->vlans, 0, MAX_VLAN >> 3);
 
     /* Flush any async TX */
-    for (i = 0;  i < n->max_queues; i++) {
+    for (i = 0;  i < n->max_queue_pairs; i++) {
         NetClientState *nc = qemu_get_subqueue(n->nic, i);
 
         if (nc->peer) {
@@ -610,7 +610,7 @@ static void virtio_net_set_mrg_rx_bufs(VirtIONet *n, int mergeable_rx_bufs,
             sizeof(struct virtio_net_hdr);
     }
 
-    for (i = 0; i < n->max_queues; i++) {
+    for (i = 0; i < n->max_queue_pairs; i++) {
         nc = qemu_get_subqueue(n->nic, i);
 
         if (peer_has_vnet_hdr(n) &&
@@ -655,7 +655,7 @@ static int peer_attach(VirtIONet *n, int index)
         return 0;
     }
 
-    if (n->max_queues == 1) {
+    if (n->max_queue_pairs == 1) {
         return 0;
     }
 
@@ -681,7 +681,7 @@ static int peer_detach(VirtIONet *n, int index)
     return tap_disable(nc->peer);
 }
 
-static void virtio_net_set_queues(VirtIONet *n)
+static void virtio_net_set_queue_pairs(VirtIONet *n)
 {
     int i;
     int r;
@@ -690,8 +690,8 @@ static void virtio_net_set_queues(VirtIONet *n)
         return;
     }
 
-    for (i = 0; i < n->max_queues; i++) {
-        if (i < n->curr_queues) {
+    for (i = 0; i < n->max_queue_pairs; i++) {
+        if (i < n->curr_queue_pairs) {
             r = peer_attach(n, i);
             assert(!r);
         } else {
@@ -905,7 +905,7 @@ static void virtio_net_set_features(VirtIODevice *vdev, uint64_t features)
         virtio_net_apply_guest_offloads(n);
     }
 
-    for (i = 0;  i < n->max_queues; i++) {
+    for (i = 0;  i < n->max_queue_pairs; i++) {
         NetClientState *nc = qemu_get_subqueue(n->nic, i);
 
         if (!get_vhost_net(nc->peer)) {
@@ -1232,7 +1232,7 @@ static uint16_t virtio_net_handle_rss(VirtIONet *n,
     VirtIODevice *vdev = VIRTIO_DEVICE(n);
     struct virtio_net_rss_config cfg;
     size_t s, offset = 0, size_get;
-    uint16_t queues, i;
+    uint16_t queue_pairs, i;
     struct {
         uint16_t us;
         uint8_t b;
@@ -1274,7 +1274,7 @@ static uint16_t virtio_net_handle_rss(VirtIONet *n,
     }
     n->rss_data.default_queue = do_rss ?
         virtio_lduw_p(vdev, &cfg.unclassified_queue) : 0;
-    if (n->rss_data.default_queue >= n->max_queues) {
+    if (n->rss_data.default_queue >= n->max_queue_pairs) {
         err_msg = "Invalid default queue";
         err_value = n->rss_data.default_queue;
         goto error;
@@ -1303,14 +1303,14 @@ static uint16_t virtio_net_handle_rss(VirtIONet *n,
     size_get = sizeof(temp);
     s = iov_to_buf(iov, iov_cnt, offset, &temp, size_get);
     if (s != size_get) {
-        err_msg = "Can't get queues";
+        err_msg = "Can't get queue_pairs";
         err_value = (uint32_t)s;
         goto error;
     }
-    queues = do_rss ? virtio_lduw_p(vdev, &temp.us) : n->curr_queues;
-    if (queues == 0 || queues > n->max_queues) {
-        err_msg = "Invalid number of queues";
-        err_value = queues;
+    queue_pairs = do_rss ? virtio_lduw_p(vdev, &temp.us) : n->curr_queue_pairs;
+    if (queue_pairs == 0 || queue_pairs > n->max_queue_pairs) {
+        err_msg = "Invalid number of queue_pairs";
+        err_value = queue_pairs;
         goto error;
     }
     if (temp.b > VIRTIO_NET_RSS_MAX_KEY_SIZE) {
@@ -1325,7 +1325,7 @@ static uint16_t virtio_net_handle_rss(VirtIONet *n,
     }
     if (!temp.b && !n->rss_data.hash_types) {
         virtio_net_disable_rss(n);
-        return queues;
+        return queue_pairs;
     }
     offset += size_get;
     size_get = temp.b;
@@ -1358,7 +1358,7 @@ static uint16_t virtio_net_handle_rss(VirtIONet *n,
     trace_virtio_net_rss_enable(n->rss_data.hash_types,
                                 n->rss_data.indirections_len,
                                 temp.b);
-    return queues;
+    return queue_pairs;
 error:
     trace_virtio_net_rss_error(err_msg, err_value);
     virtio_net_disable_rss(n);
@@ -1369,15 +1369,15 @@ static int virtio_net_handle_mq(VirtIONet *n, uint8_t cmd,
                                 struct iovec *iov, unsigned int iov_cnt)
 {
     VirtIODevice *vdev = VIRTIO_DEVICE(n);
-    uint16_t queues;
+    uint16_t queue_pairs;
 
     virtio_net_disable_rss(n);
     if (cmd == VIRTIO_NET_CTRL_MQ_HASH_CONFIG) {
-        queues = virtio_net_handle_rss(n, iov, iov_cnt, false);
-        return queues ? VIRTIO_NET_OK : VIRTIO_NET_ERR;
+        queue_pairs = virtio_net_handle_rss(n, iov, iov_cnt, false);
+        return queue_pairs ? VIRTIO_NET_OK : VIRTIO_NET_ERR;
     }
     if (cmd == VIRTIO_NET_CTRL_MQ_RSS_CONFIG) {
-        queues = virtio_net_handle_rss(n, iov, iov_cnt, true);
+        queue_pairs = virtio_net_handle_rss(n, iov, iov_cnt, true);
     } else if (cmd == VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET) {
         struct virtio_net_ctrl_mq mq;
         size_t s;
@@ -1388,24 +1388,24 @@ static int virtio_net_handle_mq(VirtIONet *n, uint8_t cmd,
         if (s != sizeof(mq)) {
             return VIRTIO_NET_ERR;
         }
-        queues = virtio_lduw_p(vdev, &mq.virtqueue_pairs);
+        queue_pairs = virtio_lduw_p(vdev, &mq.virtqueue_pairs);
 
     } else {
         return VIRTIO_NET_ERR;
     }
 
-    if (queues < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
-        queues > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX ||
-        queues > n->max_queues ||
+    if (queue_pairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
+        queue_pairs > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX ||
+        queue_pairs > n->max_queue_pairs ||
         !n->multiqueue) {
         return VIRTIO_NET_ERR;
     }
 
-    n->curr_queues = queues;
-    /* stop the backend before changing the number of queues to avoid handling a
+    n->curr_queue_pairs = queue_pairs;
+    /* stop the backend before changing the number of queue_pairs to avoid handling a
      * disabled queue */
     virtio_net_set_status(vdev, vdev->status);
-    virtio_net_set_queues(n);
+    virtio_net_set_queue_pairs(n);
 
     return VIRTIO_NET_OK;
 }
@@ -1483,7 +1483,7 @@ static bool virtio_net_can_receive(NetClientState *nc)
         return false;
     }
 
-    if (nc->queue_index >= n->curr_queues) {
+    if (nc->queue_index >= n->curr_queue_pairs) {
         return false;
     }
 
@@ -2763,11 +2763,11 @@ static void virtio_net_del_queue(VirtIONet *n, int index)
     virtio_del_queue(vdev, index * 2 + 1);
 }
 
-static void virtio_net_change_num_queues(VirtIONet *n, int new_max_queues)
+static void virtio_net_change_num_queue_pairs(VirtIONet *n, int new_max_queue_pairs)
 {
     VirtIODevice *vdev = VIRTIO_DEVICE(n);
     int old_num_queues = virtio_get_num_queues(vdev);
-    int new_num_queues = new_max_queues * 2 + 1;
+    int new_num_queues = new_max_queue_pairs * 2 + 1;
     int i;
 
     assert(old_num_queues >= 3);
@@ -2800,12 +2800,12 @@ static void virtio_net_change_num_queues(VirtIONet *n, int new_max_queues)
 
 static void virtio_net_set_multiqueue(VirtIONet *n, int multiqueue)
 {
-    int max = multiqueue ? n->max_queues : 1;
+    int max = multiqueue ? n->max_queue_pairs : 1;
 
     n->multiqueue = multiqueue;
-    virtio_net_change_num_queues(n, max);
+    virtio_net_change_num_queue_pairs(n, max);
 
-    virtio_net_set_queues(n);
+    virtio_net_set_queue_pairs(n);
 }
 
 static int virtio_net_post_load_device(void *opaque, int version_id)
@@ -2838,7 +2838,7 @@ static int virtio_net_post_load_device(void *opaque, int version_id)
      */
     n->saved_guest_offloads = n->curr_guest_offloads;
 
-    virtio_net_set_queues(n);
+    virtio_net_set_queue_pairs(n);
 
     /* Find the first multicast entry in the saved MAC filter */
     for (i = 0; i < n->mac_table.in_use; i++) {
@@ -2851,7 +2851,7 @@ static int virtio_net_post_load_device(void *opaque, int version_id)
     /* nc.link_down can't be migrated, so infer link_down according
      * to link status bit in n->status */
     link_down = (n->status & VIRTIO_NET_S_LINK_UP) == 0;
-    for (i = 0; i < n->max_queues; i++) {
+    for (i = 0; i < n->max_queue_pairs; i++) {
         qemu_get_subqueue(n->nic, i)->link_down = link_down;
     }
 
@@ -2916,9 +2916,9 @@ static const VMStateDescription vmstate_virtio_net_queue_tx_waiting = {
    },
 };
 
-static bool max_queues_gt_1(void *opaque, int version_id)
+static bool max_queue_pairs_gt_1(void *opaque, int version_id)
 {
-    return VIRTIO_NET(opaque)->max_queues > 1;
+    return VIRTIO_NET(opaque)->max_queue_pairs > 1;
 }
 
 static bool has_ctrl_guest_offloads(void *opaque, int version_id)
@@ -2943,13 +2943,13 @@ static bool mac_table_doesnt_fit(void *opaque, int version_id)
 struct VirtIONetMigTmp {
     VirtIONet      *parent;
     VirtIONetQueue *vqs_1;
-    uint16_t        curr_queues_1;
+    uint16_t        curr_queue_pairs_1;
     uint8_t         has_ufo;
     uint32_t        has_vnet_hdr;
 };
 
 /* The 2nd and subsequent tx_waiting flags are loaded later than
- * the 1st entry in the queues and only if there's more than one
+ * the 1st entry in the queue_pairs and only if there's more than one
  * entry.  We use the tmp mechanism to calculate a temporary
  * pointer and count and also validate the count.
  */
@@ -2959,9 +2959,9 @@ static int virtio_net_tx_waiting_pre_save(void *opaque)
     struct VirtIONetMigTmp *tmp = opaque;
 
     tmp->vqs_1 = tmp->parent->vqs + 1;
-    tmp->curr_queues_1 = tmp->parent->curr_queues - 1;
-    if (tmp->parent->curr_queues == 0) {
-        tmp->curr_queues_1 = 0;
+    tmp->curr_queue_pairs_1 = tmp->parent->curr_queue_pairs - 1;
+    if (tmp->parent->curr_queue_pairs == 0) {
+        tmp->curr_queue_pairs_1 = 0;
     }
 
     return 0;
@@ -2974,9 +2974,9 @@ static int virtio_net_tx_waiting_pre_load(void *opaque)
     /* Reuse the pointer setup from save */
     virtio_net_tx_waiting_pre_save(opaque);
 
-    if (tmp->parent->curr_queues > tmp->parent->max_queues) {
-        error_report("virtio-net: curr_queues %x > max_queues %x",
-            tmp->parent->curr_queues, tmp->parent->max_queues);
+    if (tmp->parent->curr_queue_pairs > tmp->parent->max_queue_pairs) {
+        error_report("virtio-net: curr_queue_pairs %x > max_queue_pairs %x",
+            tmp->parent->curr_queue_pairs, tmp->parent->max_queue_pairs);
 
         return -EINVAL;
     }
@@ -2990,7 +2990,7 @@ static const VMStateDescription vmstate_virtio_net_tx_waiting = {
     .pre_save  = virtio_net_tx_waiting_pre_save,
     .fields    = (VMStateField[]) {
         VMSTATE_STRUCT_VARRAY_POINTER_UINT16(vqs_1, struct VirtIONetMigTmp,
-                                     curr_queues_1,
+                                     curr_queue_pairs_1,
                                      vmstate_virtio_net_queue_tx_waiting,
                                      struct VirtIONetQueue),
         VMSTATE_END_OF_LIST()
@@ -3132,9 +3132,9 @@ static const VMStateDescription vmstate_virtio_net_device = {
         VMSTATE_UINT8(nobcast, VirtIONet),
         VMSTATE_WITH_TMP(VirtIONet, struct VirtIONetMigTmp,
                          vmstate_virtio_net_has_ufo),
-        VMSTATE_SINGLE_TEST(max_queues, VirtIONet, max_queues_gt_1, 0,
+        VMSTATE_SINGLE_TEST(max_queue_pairs, VirtIONet, max_queue_pairs_gt_1, 0,
                             vmstate_info_uint16_equal, uint16_t),
-        VMSTATE_UINT16_TEST(curr_queues, VirtIONet, max_queues_gt_1),
+        VMSTATE_UINT16_TEST(curr_queue_pairs, VirtIONet, max_queue_pairs_gt_1),
         VMSTATE_WITH_TMP(VirtIONet, struct VirtIONetMigTmp,
                          vmstate_virtio_net_tx_waiting),
         VMSTATE_UINT64_TEST(curr_guest_offloads, VirtIONet,
@@ -3411,16 +3411,16 @@ static void virtio_net_device_realize(DeviceState *dev, Error **errp)
         return;
     }
 
-    n->max_queues = MAX(n->nic_conf.peers.queues, 1);
-    if (n->max_queues * 2 + 1 > VIRTIO_QUEUE_MAX) {
-        error_setg(errp, "Invalid number of queues (= %" PRIu32 "), "
+    n->max_queue_pairs = MAX(n->nic_conf.peers.queues, 1);
+    if (n->max_queue_pairs * 2 + 1 > VIRTIO_QUEUE_MAX) {
+        error_setg(errp, "Invalid number of queue_pairs (= %" PRIu32 "), "
                    "must be a positive integer less than %d.",
-                   n->max_queues, (VIRTIO_QUEUE_MAX - 1) / 2);
+                   n->max_queue_pairs, (VIRTIO_QUEUE_MAX - 1) / 2);
         virtio_cleanup(vdev);
         return;
     }
-    n->vqs = g_malloc0(sizeof(VirtIONetQueue) * n->max_queues);
-    n->curr_queues = 1;
+    n->vqs = g_malloc0(sizeof(VirtIONetQueue) * n->max_queue_pairs);
+    n->curr_queue_pairs = 1;
     n->tx_timeout = n->net_conf.txtimer;
 
     if (n->net_conf.tx && strcmp(n->net_conf.tx, "timer")
@@ -3434,7 +3434,7 @@ static void virtio_net_device_realize(DeviceState *dev, Error **errp)
     n->net_conf.tx_queue_size = MIN(virtio_net_max_tx_queue_size(n),
                                     n->net_conf.tx_queue_size);
 
-    for (i = 0; i < n->max_queues; i++) {
+    for (i = 0; i < n->max_queue_pairs; i++) {
         virtio_net_add_queue(n, i);
     }
 
@@ -3458,13 +3458,13 @@ static void virtio_net_device_realize(DeviceState *dev, Error **errp)
                               object_get_typename(OBJECT(dev)), dev->id, n);
     }
 
-    for (i = 0; i < n->max_queues; i++) {
+    for (i = 0; i < n->max_queue_pairs; i++) {
         n->nic->ncs[i].do_not_pad = true;
     }
 
     peer_test_vnet_hdr(n);
     if (peer_has_vnet_hdr(n)) {
-        for (i = 0; i < n->max_queues; i++) {
+        for (i = 0; i < n->max_queue_pairs; i++) {
             qemu_using_vnet_hdr(qemu_get_subqueue(n->nic, i)->peer, true);
         }
         n->host_hdr_len = sizeof(struct virtio_net_hdr);
@@ -3506,7 +3506,7 @@ static void virtio_net_device_unrealize(DeviceState *dev)
 {
     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
     VirtIONet *n = VIRTIO_NET(dev);
-    int i, max_queues;
+    int i, max_queue_pairs;
 
     if (virtio_has_feature(n->host_features, VIRTIO_NET_F_RSS)) {
         virtio_net_unload_ebpf(n);
@@ -3531,12 +3531,12 @@ static void virtio_net_device_unrealize(DeviceState *dev)
         assert(n->primary_opts == NULL);
     }
 
-    max_queues = n->multiqueue ? n->max_queues : 1;
-    for (i = 0; i < max_queues; i++) {
+    max_queue_pairs = n->multiqueue ? n->max_queue_pairs : 1;
+    for (i = 0; i < max_queue_pairs; i++) {
         virtio_net_del_queue(n, i);
     }
     /* delete also control vq */
-    virtio_del_queue(vdev, max_queues * 2);
+    virtio_del_queue(vdev, max_queue_pairs * 2);
     qemu_announce_timer_del(&n->announce_timer, false);
     g_free(n->vqs);
     qemu_del_nic(n->nic);
diff --git a/include/hw/virtio/virtio-net.h b/include/hw/virtio/virtio-net.h
index 74a10ebe85..2903b79a92 100644
--- a/include/hw/virtio/virtio-net.h
+++ b/include/hw/virtio/virtio-net.h
@@ -194,8 +194,8 @@ struct VirtIONet {
     NICConf nic_conf;
     DeviceState *qdev;
     int multiqueue;
-    uint16_t max_queues;
-    uint16_t curr_queues;
+    uint16_t max_queue_pairs;
+    uint16_t curr_queue_pairs;
     size_t config_size;
     char *netclient_name;
     char *netclient_type;
-- 
2.25.1

[PATCH V5 08/10] vhost: record the last virtqueue index for the virtio device

[Jason Wang]

This patch introduces a new field in the vhost_dev structure to record
the last virtqueue index for the virtio device. This will be useful
for the vhost backends with 1:N model to start or stop the device
after all the vhost_dev structures were started or stopped.

Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 hw/net/vhost_net.c        | 12 +++++++++---
 include/hw/virtio/vhost.h |  2 ++
 2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
index 2b594b4642..3aabab06ea 100644
--- a/hw/net/vhost_net.c
+++ b/hw/net/vhost_net.c
@@ -231,9 +231,11 @@ fail:
     return NULL;
 }
 
-static void vhost_net_set_vq_index(struct vhost_net *net, int vq_index)
+static void vhost_net_set_vq_index(struct vhost_net *net, int vq_index,
+                                   int last_index)
 {
     net->dev.vq_index = vq_index;
+    net->dev.last_index = last_index;
 }
 
 static int vhost_net_start_one(struct vhost_net *net,
@@ -324,9 +326,13 @@ int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
     VirtIONet *n = VIRTIO_NET(dev);
     int nvhosts = data_queue_pairs + cvq;
     struct vhost_net *net;
-    int r, e, i;
+    int r, e, i, last_index = data_qps * 2;
     NetClientState *peer;
 
+    if (!cvq) {
+        last_index -= 1;
+    }
+
     if (!k->set_guest_notifiers) {
         error_report("binding does not support guest notifiers");
         return -ENOSYS;
@@ -341,7 +347,7 @@ int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
         }
 
         net = get_vhost_net(peer);
-        vhost_net_set_vq_index(net, i * 2);
+        vhost_net_set_vq_index(net, i * 2, last_index);
 
         /* Suppress the masking guest notifiers on vhost user
          * because vhost user doesn't interrupt masking/unmasking
diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
index 1a9fc65089..3fa0b554ef 100644
--- a/include/hw/virtio/vhost.h
+++ b/include/hw/virtio/vhost.h
@@ -74,6 +74,8 @@ struct vhost_dev {
     unsigned int nvqs;
     /* the first virtqueue which would be used by this vhost dev */
     int vq_index;
+    /* the last vq index for the virtio device (not vhost) */
+    int last_index;
     /* if non-zero, minimum required value for max_queues */
     int num_queues;
     uint64_t features;
-- 
2.25.1

[PATCH V5 09/10] virtio-net: vhost control virtqueue support

[Jason Wang]

This patch implements the control virtqueue support for vhost. This
requires virtio-net to figure out the datapath queue pairs and control
virtqueue via is_datapath and pass the number of those two types
of virtqueues to vhost_net_start()/vhost_net_stop().

Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 hw/net/vhost_net.c             |  2 +-
 hw/net/virtio-net.c            | 23 +++++++++++++++++++----
 include/hw/virtio/virtio-net.h |  1 +
 3 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
index 3aabab06ea..0d888f29a6 100644
--- a/hw/net/vhost_net.c
+++ b/hw/net/vhost_net.c
@@ -326,7 +326,7 @@ int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
     VirtIONet *n = VIRTIO_NET(dev);
     int nvhosts = data_queue_pairs + cvq;
     struct vhost_net *net;
-    int r, e, i, last_index = data_qps * 2;
+    int r, e, i, last_index = data_queue_pairs * 2;
     NetClientState *peer;
 
     if (!cvq) {
diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index 7594f7ea92..f2014d5ea0 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -244,6 +244,7 @@ static void virtio_net_vhost_status(VirtIONet *n, uint8_t status)
     VirtIODevice *vdev = VIRTIO_DEVICE(n);
     NetClientState *nc = qemu_get_queue(n->nic);
     int queue_pairs = n->multiqueue ? n->max_queue_pairs : 1;
+    int cvq = n->max_ncs - n->max_queue_pairs;
 
     if (!get_vhost_net(nc->peer)) {
         return;
@@ -285,14 +286,14 @@ static void virtio_net_vhost_status(VirtIONet *n, uint8_t status)
         }
 
         n->vhost_started = 1;
-        r = vhost_net_start(vdev, n->nic->ncs, queue_pairs, 0);
+        r = vhost_net_start(vdev, n->nic->ncs, queue_pairs, cvq);
         if (r < 0) {
             error_report("unable to start vhost net: %d: "
                          "falling back on userspace virtio", -r);
             n->vhost_started = 0;
         }
     } else {
-        vhost_net_stop(vdev, n->nic->ncs, queue_pairs, 0);
+        vhost_net_stop(vdev, n->nic->ncs, queue_pairs, cvq);
         n->vhost_started = 0;
     }
 }
@@ -3411,9 +3412,23 @@ static void virtio_net_device_realize(DeviceState *dev, Error **errp)
         return;
     }
 
-    n->max_queue_pairs = MAX(n->nic_conf.peers.queues, 1);
+    n->max_ncs = MAX(n->nic_conf.peers.queues, 1);
+
+    /*
+     * Figure out the datapath queue pairs since the backend could
+     * provide control queue via peers as well.
+     */
+    if (n->nic_conf.peers.queues) {
+        for (i = 0; i < n->max_ncs; i++) {
+            if (n->nic_conf.peers.ncs[i]->is_datapath) {
+                ++n->max_queue_pairs;
+            }
+        }
+    }
+    n->max_queue_pairs = MAX(n->max_queue_pairs, 1);
+
     if (n->max_queue_pairs * 2 + 1 > VIRTIO_QUEUE_MAX) {
-        error_setg(errp, "Invalid number of queue_pairs (= %" PRIu32 "), "
+        error_setg(errp, "Invalid number of queue pairs (= %" PRIu32 "), "
                    "must be a positive integer less than %d.",
                    n->max_queue_pairs, (VIRTIO_QUEUE_MAX - 1) / 2);
         virtio_cleanup(vdev);
diff --git a/include/hw/virtio/virtio-net.h b/include/hw/virtio/virtio-net.h
index 2903b79a92..eb87032627 100644
--- a/include/hw/virtio/virtio-net.h
+++ b/include/hw/virtio/virtio-net.h
@@ -196,6 +196,7 @@ struct VirtIONet {
     int multiqueue;
     uint16_t max_queue_pairs;
     uint16_t curr_queue_pairs;
+    uint16_t max_ncs;
     size_t config_size;
     char *netclient_name;
     char *netclient_type;
-- 
2.25.1

[PATCH V5 10/10] vhost-vdpa: multiqueue support

[Jason Wang]

This patch implements the multiqueue support for vhost-vdpa. This is
done simply by reading the number of queue pairs from the config space
and initialize the datapath and control path net client.

Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 hw/virtio/vhost-vdpa.c |   2 +-
 net/vhost-vdpa.c       | 105 +++++++++++++++++++++++++++++++++++++----
 2 files changed, 97 insertions(+), 10 deletions(-)

diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
index 40987188cf..ce0a297481 100644
--- a/hw/virtio/vhost-vdpa.c
+++ b/hw/virtio/vhost-vdpa.c
@@ -630,7 +630,7 @@ static int vhost_vdpa_dev_start(struct vhost_dev *dev, bool started)
         vhost_vdpa_host_notifiers_uninit(dev, dev->nvqs);
     }
 
-    if (vhost_vdpa_one_time_request(dev)) {
+    if (dev->vq_index + dev->nvqs != dev->last_index) {
         return 0;
     }
 
diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
index 151f60184d..49ab322511 100644
--- a/net/vhost-vdpa.c
+++ b/net/vhost-vdpa.c
@@ -18,6 +18,7 @@
 #include "qemu/error-report.h"
 #include "qemu/option.h"
 #include "qapi/error.h"
+#include <linux/vhost.h>
 #include <sys/ioctl.h>
 #include <err.h>
 #include "standard-headers/linux/virtio_net.h"
@@ -51,6 +52,14 @@ const int vdpa_feature_bits[] = {
     VIRTIO_NET_F_HOST_UFO,
     VIRTIO_NET_F_MRG_RXBUF,
     VIRTIO_NET_F_MTU,
+    VIRTIO_NET_F_CTRL_RX,
+    VIRTIO_NET_F_CTRL_RX_EXTRA,
+    VIRTIO_NET_F_CTRL_VLAN,
+    VIRTIO_NET_F_GUEST_ANNOUNCE,
+    VIRTIO_NET_F_CTRL_MAC_ADDR,
+    VIRTIO_NET_F_RSS,
+    VIRTIO_NET_F_MQ,
+    VIRTIO_NET_F_CTRL_VQ,
     VIRTIO_F_IOMMU_PLATFORM,
     VIRTIO_F_RING_PACKED,
     VIRTIO_NET_F_RSS,
@@ -81,7 +90,8 @@ static int vhost_vdpa_net_check_device_id(struct vhost_net *net)
     return ret;
 }
 
-static int vhost_vdpa_add(NetClientState *ncs, void *be)
+static int vhost_vdpa_add(NetClientState *ncs, void *be,
+                          int queue_pair_index, int nvqs)
 {
     VhostNetOptions options;
     struct vhost_net *net = NULL;
@@ -94,7 +104,7 @@ static int vhost_vdpa_add(NetClientState *ncs, void *be)
     options.net_backend = ncs;
     options.opaque      = be;
     options.busyloop_timeout = 0;
-    options.nvqs = 2;
+    options.nvqs = nvqs;
 
     net = vhost_net_init(&options);
     if (!net) {
@@ -172,18 +182,28 @@ static NetClientInfo net_vhost_vdpa_info = {
 static NetClientState *net_vhost_vdpa_init(NetClientState *peer,
                                            const char *device,
                                            const char *name,
-                                           int vdpa_device_fd)
+                                           int vdpa_device_fd,
+                                           int queue_pair_index,
+                                           int nvqs,
+                                           bool is_datapath)
 {
     NetClientState *nc = NULL;
     VhostVDPAState *s;
     int ret = 0;
     assert(name);
-    nc = qemu_new_net_client(&net_vhost_vdpa_info, peer, device, name);
+    if (is_datapath) {
+        nc = qemu_new_net_client(&net_vhost_vdpa_info, peer, device,
+                                 name);
+    } else {
+        nc = qemu_new_net_control_client(&net_vhost_vdpa_info, peer,
+                                         device, name);
+    }
     snprintf(nc->info_str, sizeof(nc->info_str), TYPE_VHOST_VDPA);
     s = DO_UPCAST(VhostVDPAState, nc, nc);
 
     s->vhost_vdpa.device_fd = vdpa_device_fd;
-    ret = vhost_vdpa_add(nc, (void *)&s->vhost_vdpa);
+    s->vhost_vdpa.index = queue_pair_index;
+    ret = vhost_vdpa_add(nc, (void *)&s->vhost_vdpa, queue_pair_index, nvqs);
     if (ret) {
         qemu_del_net_client(nc);
         return NULL;
@@ -191,12 +211,52 @@ static NetClientState *net_vhost_vdpa_init(NetClientState *peer,
     return nc;
 }
 
+static int vhost_vdpa_get_max_queue_pairs(int fd, int *has_cvq, Error **errp)
+{
+    unsigned long config_size = offsetof(struct vhost_vdpa_config, buf);
+    struct vhost_vdpa_config *config;
+    __virtio16 *max_queue_pairs;
+    uint64_t features;
+    int ret;
+
+    ret = ioctl(fd, VHOST_GET_FEATURES, &features);
+    if (ret) {
+        error_setg(errp, "Fail to query features from vhost-vDPA device");
+        return ret;
+    }
+
+    if (features & (1 << VIRTIO_NET_F_CTRL_VQ)) {
+        *has_cvq = 1;
+    } else {
+        *has_cvq = 0;
+    }
+
+    if (features & (1 << VIRTIO_NET_F_MQ)) {
+        config = g_malloc0(config_size + sizeof(*max_queue_pairs));
+        config->off = offsetof(struct virtio_net_config, max_virtqueue_pairs);
+        config->len = sizeof(*max_queue_pairs);
+
+        ret = ioctl(fd, VHOST_VDPA_GET_CONFIG, config);
+        if (ret) {
+            error_setg(errp, "Fail to get config from vhost-vDPA device");
+            return -ret;
+        }
+
+        max_queue_pairs = (__virtio16 *)&config->buf;
+
+        return lduw_le_p(max_queue_pairs);
+    }
+
+    return 1;
+}
+
 int net_init_vhost_vdpa(const Netdev *netdev, const char *name,
                         NetClientState *peer, Error **errp)
 {
     const NetdevVhostVDPAOptions *opts;
     int vdpa_device_fd;
-    NetClientState *nc;
+    NetClientState **ncs, *nc;
+    int queue_pairs, i, has_cvq = 0;
 
     assert(netdev->type == NET_CLIENT_DRIVER_VHOST_VDPA);
     opts = &netdev->u.vhost_vdpa;
@@ -206,11 +266,38 @@ int net_init_vhost_vdpa(const Netdev *netdev, const char *name,
         return -errno;
     }
 
-    nc = net_vhost_vdpa_init(peer, TYPE_VHOST_VDPA, name, vdpa_device_fd);
-    if (!nc) {
+    queue_pairs = vhost_vdpa_get_max_queue_pairs(vdpa_device_fd,
+                                                 &has_cvq, errp);
+    if (queue_pairs < 0) {
         qemu_close(vdpa_device_fd);
-        return -1;
+        return queue_pairs;
+    }
+
+    ncs = g_malloc0(sizeof(*ncs) * queue_pairs);
+
+    for (i = 0; i < queue_pairs; i++) {
+        ncs[i] = net_vhost_vdpa_init(peer, TYPE_VHOST_VDPA, name,
+                                     vdpa_device_fd, i, 2, true);
+        if (!ncs[i])
+            goto err;
     }
 
+    if (has_cvq) {
+        nc = net_vhost_vdpa_init(peer, TYPE_VHOST_VDPA, name,
+                                 vdpa_device_fd, i, 1, false);
+        if (!nc)
+            goto err;
+    }
+
+    g_free(ncs);
     return 0;
+
+err:
+    if (i) {
+        qemu_del_net_client(ncs[0]);
+    }
+    qemu_close(vdpa_device_fd);
+    g_free(ncs);
+
+    return -1;
 }
-- 
2.25.1