[PATCH v6 11/14] vhost-net: implement extended features support

[Paolo Abeni <pabeni@redhat.com>]

Provide extended version of the features manipulation helpers,
and let the device initialization deal with the full features space,
adjusting the relevant format strings accordingly.

Reviewed-by: Akihiko Odaki <odaki@rsg.ci.i.u-tokyo.ac.jp>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
---
v3 -> v4:
  - add missing features initialization
  - use new virtio_features macro names

v2 -> v3:
  - use virtio_features_andnot return value instead of virtio_features_empty
  - rebased on top of "net: Consolidate vhost feature bits into vhost_net
    structure"
  - _array -> _ex

v1 -> v2:
  - uint128_t -> uint64_t[]
  - provide extended variant of the features manipulation helpers
---
 hw/net/vhost_net-stub.c |  8 +++-----
 hw/net/vhost_net.c      | 45 +++++++++++++++++++++++------------------
 include/net/vhost_net.h | 33 +++++++++++++++++++++++++++---
 3 files changed, 58 insertions(+), 28 deletions(-)

diff --git a/hw/net/vhost_net-stub.c b/hw/net/vhost_net-stub.c
index 7d49f82906..0740d5a2eb 100644
--- a/hw/net/vhost_net-stub.c
+++ b/hw/net/vhost_net-stub.c
@@ -46,9 +46,8 @@ void vhost_net_cleanup(struct vhost_net *net)
 {
 }
 
-uint64_t vhost_net_get_features(struct vhost_net *net, uint64_t features)
+void vhost_net_get_features_ex(struct vhost_net *net, uint64_t *features)
 {
-    return features;
 }
 
 int vhost_net_get_config(struct vhost_net *net,  uint8_t *config,
@@ -62,13 +61,12 @@ int vhost_net_set_config(struct vhost_net *net, const uint8_t *data,
     return 0;
 }
 
-void vhost_net_ack_features(struct vhost_net *net, uint64_t features)
+void vhost_net_ack_features_ex(struct vhost_net *net, const uint64_t *features)
 {
 }
 
-uint64_t vhost_net_get_acked_features(VHostNetState *net)
+void vhost_net_get_acked_features_ex(VHostNetState *net, uint64_t *features)
 {
-    return 0;
 }
 
 bool vhost_net_virtqueue_pending(VHostNetState *net, int idx)
diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
index 540492b37d..a8ee18a912 100644
--- a/hw/net/vhost_net.c
+++ b/hw/net/vhost_net.c
@@ -35,10 +35,9 @@
 #include "hw/virtio/virtio-bus.h"
 #include "linux-headers/linux/vhost.h"
 
-uint64_t vhost_net_get_features(struct vhost_net *net, uint64_t features)
+void vhost_net_get_features_ex(struct vhost_net *net, uint64_t *features)
 {
-    return vhost_get_features(&net->dev, net->feature_bits,
-            features);
+    vhost_get_features_ex(&net->dev, net->feature_bits, features);
 }
 int vhost_net_get_config(struct vhost_net *net,  uint8_t *config,
                          uint32_t config_len)
@@ -51,10 +50,11 @@ int vhost_net_set_config(struct vhost_net *net, const uint8_t *data,
     return vhost_dev_set_config(&net->dev, data, offset, size, flags);
 }
 
-void vhost_net_ack_features(struct vhost_net *net, uint64_t features)
+void vhost_net_ack_features_ex(struct vhost_net *net, const uint64_t *features)
 {
-    net->dev.acked_features = net->dev.backend_features;
-    vhost_ack_features(&net->dev, net->feature_bits, features);
+    virtio_features_copy(net->dev.acked_features_ex,
+                         net->dev.backend_features_ex);
+    vhost_ack_features_ex(&net->dev, net->feature_bits, features);
 }
 
 uint64_t vhost_net_get_max_queues(VHostNetState *net)
@@ -62,9 +62,9 @@ uint64_t vhost_net_get_max_queues(VHostNetState *net)
     return net->dev.max_queues;
 }
 
-uint64_t vhost_net_get_acked_features(VHostNetState *net)
+void vhost_net_get_acked_features_ex(VHostNetState *net, uint64_t *features)
 {
-    return net->dev.acked_features;
+    virtio_features_copy(features, net->dev.acked_features_ex);
 }
 
 void vhost_net_save_acked_features(NetClientState *nc)
@@ -234,7 +234,8 @@ struct vhost_net *vhost_net_init(VhostNetOptions *options)
     int r;
     bool backend_kernel = options->backend_type == VHOST_BACKEND_TYPE_KERNEL;
     struct vhost_net *net = g_new0(struct vhost_net, 1);
-    uint64_t features = 0;
+    uint64_t missing_features[VIRTIO_FEATURES_NU64S];
+    uint64_t features[VIRTIO_FEATURES_NU64S];
     Error *local_err = NULL;
 
     if (!options->net_backend) {
@@ -247,6 +248,7 @@ struct vhost_net *vhost_net_init(VhostNetOptions *options)
     net->save_acked_features = options->save_acked_features;
     net->max_tx_queue_size = options->max_tx_queue_size;
     net->is_vhost_user = options->is_vhost_user;
+    virtio_features_clear(features);
 
     net->dev.max_queues = 1;
     net->dev.vqs = net->vqs;
@@ -261,7 +263,7 @@ struct vhost_net *vhost_net_init(VhostNetOptions *options)
         net->backend = r;
         net->dev.protocol_features = 0;
     } else {
-        net->dev.backend_features = 0;
+        virtio_features_clear(net->dev.backend_features_ex);
         net->dev.protocol_features = 0;
         net->backend = -1;
 
@@ -281,26 +283,29 @@ struct vhost_net *vhost_net_init(VhostNetOptions *options)
                                sizeof(struct virtio_net_hdr_mrg_rxbuf))) {
             net->dev.features &= ~(1ULL << VIRTIO_NET_F_MRG_RXBUF);
         }
-        if (~net->dev.features & net->dev.backend_features) {
-            fprintf(stderr, "vhost lacks feature mask 0x%" PRIx64
-                   " for backend\n",
-                   (uint64_t)(~net->dev.features & net->dev.backend_features));
+
+        if (virtio_features_andnot(missing_features,
+                                   net->dev.backend_features_ex,
+                                   net->dev.features_ex)) {
+            fprintf(stderr, "vhost lacks feature mask 0x" VIRTIO_FEATURES_FMT
+                   " for backend\n", VIRTIO_FEATURES_PR(missing_features));
             goto fail;
         }
     }
 
     /* Set sane init value. Override when guest acks. */
     if (options->get_acked_features) {
-        features = options->get_acked_features(net->nc);
-        if (~net->dev.features & features) {
-            fprintf(stderr, "vhost lacks feature mask 0x%" PRIx64
-                    " for backend\n",
-                    (uint64_t)(~net->dev.features & features));
+        virtio_features_from_u64(features,
+                                 options->get_acked_features(net->nc));
+        if (virtio_features_andnot(missing_features, features,
+                                   net->dev.features_ex)) {
+            fprintf(stderr, "vhost lacks feature mask 0x" VIRTIO_FEATURES_FMT
+                    " for backend\n", VIRTIO_FEATURES_PR(missing_features));
             goto fail;
         }
     }
 
-    vhost_net_ack_features(net, features);
+    vhost_net_ack_features_ex(net, features);
 
     return net;
 
diff --git a/include/net/vhost_net.h b/include/net/vhost_net.h
index 879781dad7..0225207491 100644
--- a/include/net/vhost_net.h
+++ b/include/net/vhost_net.h
@@ -2,6 +2,7 @@
 #define VHOST_NET_H
 
 #include "net/net.h"
+#include "hw/virtio/virtio-features.h"
 #include "hw/virtio/vhost-backend.h"
 
 struct vhost_net;
@@ -33,8 +34,26 @@ void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
 
 void vhost_net_cleanup(VHostNetState *net);
 
-uint64_t vhost_net_get_features(VHostNetState *net, uint64_t features);
-void vhost_net_ack_features(VHostNetState *net, uint64_t features);
+void vhost_net_get_features_ex(VHostNetState *net, uint64_t *features);
+static inline uint64_t vhost_net_get_features(VHostNetState *net,
+                                              uint64_t features)
+{
+    uint64_t features_array[VIRTIO_FEATURES_NU64S];
+
+    virtio_features_from_u64(features_array, features);
+    vhost_net_get_features_ex(net, features_array);
+    return features_array[0];
+}
+
+void vhost_net_ack_features_ex(VHostNetState *net, const uint64_t *features);
+static inline void vhost_net_ack_features(VHostNetState *net,
+                                          uint64_t features)
+{
+    uint64_t features_array[VIRTIO_FEATURES_NU64S];
+
+    virtio_features_from_u64(features_array, features);
+    vhost_net_ack_features_ex(net, features_array);
+}
 
 int vhost_net_get_config(struct vhost_net *net,  uint8_t *config,
                          uint32_t config_len);
@@ -51,7 +70,15 @@ VHostNetState *get_vhost_net(NetClientState *nc);
 
 int vhost_net_set_vring_enable(NetClientState *nc, int enable);
 
-uint64_t vhost_net_get_acked_features(VHostNetState *net);
+void vhost_net_get_acked_features_ex(VHostNetState *net, uint64_t *features);
+static inline uint64_t vhost_net_get_acked_features(VHostNetState *net)
+{
+    uint64_t features[VIRTIO_FEATURES_NU64S];
+
+    vhost_net_get_acked_features_ex(net, features);
+    assert(!virtio_features_use_ex(features));
+    return features[0];
+}
 
 int vhost_net_set_mtu(struct vhost_net *net, uint16_t mtu);
 
-- 
2.51.0