vhost-vdpa: introduce vhost-vdpa backend

Currently we have 2 types of vhost backends in QEMU: vhost kernel and
vhost-user. The above patch provides a generic device for vDPA purpose,
this vDPA device exposes to user space a non-vendor-specific configuration
interface for setting up a vhost HW accelerator, this patch set introduces
a third vhost backend called vhost-vdpa based on the vDPA interface.

Vhost-vdpa usage:

qemu-system-x86_64 -cpu host -enable-kvm \
    ......
    -netdev type=vhost-vdpa,vhostdev=/dev/vhost-vdpa-id,id=vhost-vdpa0 \
    -device virtio-net-pci,netdev=vhost-vdpa0,page-per-vq=on \

Signed-off-by: Lingshan zhu <lingshan.zhu@intel.com>
Signed-off-by: Tiwei Bie <tiwei.bie@intel.com>
Signed-off-by: Cindy Lu <lulu@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20200701145538.22333-14-lulu@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>

2 files changed, 31 insertions, 6 deletions

diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
index 4561665..24d555e 100644
--- a/hw/net/vhost_net.c
+++ b/hw/net/vhost_net.c
@@ -17,6 +17,7 @@
 #include "net/net.h"
 #include "net/tap.h"
 #include "net/vhost-user.h"
+#include "net/vhost-vdpa.h"
 
 #include "standard-headers/linux/vhost_types.h"
 #include "hw/virtio/virtio-net.h"
@@ -33,12 +34,6 @@
 #include "hw/virtio/vhost.h"
 #include "hw/virtio/virtio-bus.h"
 
-struct vhost_net {
-    struct vhost_dev dev;
-    struct vhost_virtqueue vqs[2];
-    int backend;
-    NetClientState *nc;
-};
 
 /* Features supported by host kernel. */
 static const int kernel_feature_bits[] = {
@@ -96,6 +91,11 @@ static const int *vhost_net_get_feature_bits(struct vhost_net *net)
     case NET_CLIENT_DRIVER_VHOST_USER:
         feature_bits = user_feature_bits;
         break;
+#ifdef CONFIG_VHOST_NET_VDPA
+    case NET_CLIENT_DRIVER_VHOST_VDPA:
+        feature_bits = vdpa_feature_bits;
+        break;
+#endif
     default:
         error_report("Feature bits not defined for this type: %d",
                 net->nc->info->type);
@@ -444,6 +444,12 @@ VHostNetState *get_vhost_net(NetClientState *nc)
         assert(vhost_net);
         break;
 #endif
+#ifdef CONFIG_VHOST_NET_VDPA
+    case NET_CLIENT_DRIVER_VHOST_VDPA:
+        vhost_net = vhost_vdpa_get_vhost_net(nc);
+        assert(vhost_net);
+        break;
+#endif
     default:
         break;
     }
diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index aff67a9..0a54b19 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -43,6 +43,7 @@
 #include "monitor/qdev.h"
 #include "hw/pci/pci.h"
 #include "net_rx_pkt.h"
+#include "hw/virtio/vhost.h"
 
 #define VIRTIO_NET_VM_VERSION    11
 
@@ -125,6 +126,8 @@ static void virtio_net_get_config(VirtIODevice *vdev, uint8_t *config)
     VirtIONet *n = VIRTIO_NET(vdev);
     struct virtio_net_config netcfg;
 
+    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.mtu, n->net_conf.mtu);
@@ -138,6 +141,15 @@ static void virtio_net_get_config(VirtIODevice *vdev, uint8_t *config)
     virtio_stl_p(vdev, &netcfg.supported_hash_types,
                  VIRTIO_NET_RSS_SUPPORTED_HASHES);
     memcpy(config, &netcfg, n->config_size);
+
+    NetClientState *nc = qemu_get_queue(n->nic);
+    if (nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_VDPA) {
+        ret = vhost_net_get_config(get_vhost_net(nc->peer), (uint8_t *)&netcfg,
+                             n->config_size);
+    if (ret != -1) {
+        memcpy(config, &netcfg, n->config_size);
+    }
+    }
 }
 
 static void virtio_net_set_config(VirtIODevice *vdev, const uint8_t *config)
@@ -153,6 +165,13 @@ static void virtio_net_set_config(VirtIODevice *vdev, const uint8_t *config)
         memcpy(n->mac, netcfg.mac, ETH_ALEN);
         qemu_format_nic_info_str(qemu_get_queue(n->nic), n->mac);
     }
+
+    NetClientState *nc = qemu_get_queue(n->nic);
+    if (nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_VDPA) {
+        vhost_net_set_config(get_vhost_net(nc->peer), (uint8_t *)&netcfg,
+                               0, n->config_size,
+                        VHOST_SET_CONFIG_TYPE_MASTER);
+      }
 }
 
 static bool virtio_net_started(VirtIONet *n, uint8_t status)