[RFC,v8,20/21] vdpa: Add x-svq to NetdevVhostVDPAOptions

Commit Message

Eugenio Perez Martin May 19, 2022, 7:13 p.m. UTC

Finally offering the possibility to enable SVQ from the command line.

Signed-off-by: Eugenio Pérez <[e-mail]>
---
 qapi/net.json    |  9 ++++++++-
 net/vhost-vdpa.c | 38 +++++++++++++++++++++++++++++++++++---
 2 files changed, 43 insertions(+), 4 deletions(-)

Patch

diff --git a/qapi/net.json b/qapi/net.json
index d6f7cfd4d6..cd7a1b32fe 100644
--- a/qapi/net.json
+++ b/qapi/net.json
@@ -445,12 +445,19 @@ 
 # @queues: number of queues to be created for multiqueue vhost-vdpa
 #          (default: 1)
 #
+# @x-svq: Start device with (experimental) shadow virtqueue. (Since 7.1)
+#         (default: false)
+#
+# Features:
+# @unstable: Member @x-svq is experimental.
+#
 # Since: 5.1
 ##
 { 'struct': 'NetdevVhostVDPAOptions',
   'data': {
     '*vhostdev':     'str',
-    '*queues':       'int' } }
+    '*queues':       'int',
+    '*x-svq':        {'type': 'bool', 'features' : [ 'unstable'] } } }
 
 ##
 # @NetdevVmnetHostOptions:
diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
index 8960b8db74..ef8c82f92e 100644
--- a/net/vhost-vdpa.c
+++ b/net/vhost-vdpa.c
@@ -129,6 +129,7 @@  static void vhost_vdpa_cleanup(NetClientState *nc)
 {
     VhostVDPAState *s = DO_UPCAST(VhostVDPAState, nc, nc);
 
+    g_clear_pointer(&s->vhost_vdpa.iova_tree, vhost_iova_tree_release);
     if (s->vhost_net) {
         vhost_net_cleanup(s->vhost_net);
         g_free(s->vhost_net);
@@ -188,6 +189,14 @@  static NetClientInfo net_vhost_vdpa_info = {
         .check_peer_type = vhost_vdpa_check_peer_type,
 };
 
+static int vhost_vdpa_get_iova_range(int fd,
+                                     struct vhost_vdpa_iova_range *iova_range)
+{
+    int ret = ioctl(fd, VHOST_VDPA_GET_IOVA_RANGE, iova_range);
+
+    return ret < 0 ? -errno : 0;
+}
+
 static int vhost_vdpa_start_control_svq(VhostShadowVirtqueue *svq,
                                         struct vhost_dev *dev)
 {
@@ -295,7 +304,9 @@  static NetClientState *net_vhost_vdpa_init(NetClientState *peer,
                                            int vdpa_device_fd,
                                            int queue_pair_index,
                                            int nvqs,
-                                           bool is_datapath)
+                                           bool is_datapath,
+                                           bool svq,
+                                           VhostIOVATree *iova_tree)
 {
     NetClientState *nc = NULL;
     VhostVDPAState *s;
@@ -313,12 +324,18 @@  static NetClientState *net_vhost_vdpa_init(NetClientState *peer,
 
     s->vhost_vdpa.device_fd = vdpa_device_fd;
     s->vhost_vdpa.index = queue_pair_index;
+    s->vhost_vdpa.shadow_vqs_enabled = svq;
+    s->vhost_vdpa.iova_tree = iova_tree ? vhost_iova_tree_acquire(iova_tree) :
+                              NULL;
     if (!is_datapath) {
         s->vhost_vdpa.shadow_vq_ops = &vhost_vdpa_net_svq_ops;
         s->vhost_vdpa.svq_copy_descs = true;
     }
     ret = vhost_vdpa_add(nc, (void *)&s->vhost_vdpa, queue_pair_index, nvqs);
     if (ret) {
+        if (iova_tree) {
+            vhost_iova_tree_release(iova_tree);
+        }
         qemu_del_net_client(nc);
         return NULL;
     }
@@ -377,6 +394,7 @@  int net_init_vhost_vdpa(const Netdev *netdev, const char *name,
     g_autofree NetClientState **ncs = NULL;
     NetClientState *nc;
     int queue_pairs, r, i, has_cvq = 0;
+    g_autoptr(VhostIOVATree) iova_tree = NULL;
 
     assert(netdev->type == NET_CLIENT_DRIVER_VHOST_VDPA);
     opts = &netdev->u.vhost_vdpa;
@@ -401,19 +419,31 @@  int net_init_vhost_vdpa(const Netdev *netdev, const char *name,
         qemu_close(vdpa_device_fd);
         return queue_pairs;
     }
+    if (opts->x_svq) {
+        struct vhost_vdpa_iova_range iova_range;
+
+        if (has_cvq) {
+            error_setg(errp, "vdpa svq does not work with cvq");
+            goto err_svq;
+        }
+        vhost_vdpa_get_iova_range(vdpa_device_fd, &iova_range);
+        iova_tree = vhost_iova_tree_new(iova_range.first, iova_range.last);
+    }
 
     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);
+                                     vdpa_device_fd, i, 2, true, opts->x_svq,
+                                     iova_tree);
         if (!ncs[i])
             goto err;
     }
 
     if (has_cvq) {
         nc = net_vhost_vdpa_init(peer, TYPE_VHOST_VDPA, name,
-                                 vdpa_device_fd, i, 1, false);
+                                 vdpa_device_fd, i, 1, false, opts->x_svq,
+                                 iova_tree);
         if (!nc)
             goto err;
     }
@@ -426,6 +456,8 @@  err:
             qemu_del_net_client(ncs[i]);
         }
     }
+
+err_svq:
     qemu_close(vdpa_device_fd);
 
     return -1;