[PATCH RFC v3 11/13] virtio-net: implement extended features support

[Paolo Abeni <pabeni@redhat.com>]

Use the extended types and helpers to manipulate the virtio_net
features.

Note that offloads are still 64bits wide, as per specification,
and extended offloads will be mapped into such range.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
---
v2 -> v3:
  - rebased on top of 2deec9ab7d ("virtio-net: Move
    virtio_net_get_features() down")
  - _array -> _ex

v1 -> v2:
  - uint128_t -> uint64_t[]
  - more verbose macro definitions
---
 hw/net/virtio-net.c            | 136 +++++++++++++++++++--------------
 include/hw/virtio/virtio-net.h |   2 +-
 2 files changed, 80 insertions(+), 58 deletions(-)

diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index 8953c329e7..53413ec4d5 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -90,6 +90,19 @@
                                          VIRTIO_NET_RSS_HASH_TYPE_TCP_EX | \
                                          VIRTIO_NET_RSS_HASH_TYPE_UDP_EX)
 
+/*
+ * Features starting from VIRTIO_NET_FEATURES_MAP_MIN bit correspond
+ * to guest offloads in the VIRTIO_NET_OFFLOAD_MAP range
+ */
+#define VIRTIO_NET_OFFLOAD_MAP_MIN    46
+#define VIRTIO_NET_OFFLOAD_MAP_LENGTH 4
+#define VIRTIO_NET_OFFLOAD_MAP        MAKE_64BIT_MASK(                    \
+                                              VIRTIO_NET_OFFLOAD_MAP_MIN, \
+                                              VIRTIO_NET_OFFLOAD_MAP_LENGTH)
+#define VIRTIO_NET_FEATURES_MAP_MIN   65
+#define VIRTIO_NET_F2O_SHIFT          (VIRTIO_NET_OFFLOAD_MAP_MIN - \
+                                       VIRTIO_NET_FEATURES_MAP_MIN + 64)
+
 static const VirtIOFeature feature_sizes[] = {
     {.flags = 1ULL << VIRTIO_NET_F_MAC,
      .end = endof(struct virtio_net_config, mac)},
@@ -786,7 +799,14 @@ static void virtio_net_apply_guest_offloads(VirtIONet *n)
     qemu_set_offload(qemu_get_queue(n->nic)->peer, &ol);
 }
 
-static uint64_t virtio_net_guest_offloads_by_features(uint64_t features)
+static uint64_t virtio_net_features_to_offload(const uint64_t *features)
+{
+    return (features[0] & ~VIRTIO_NET_OFFLOAD_MAP) |
+           ((features[1] << VIRTIO_NET_F2O_SHIFT) & VIRTIO_NET_OFFLOAD_MAP);
+}
+
+static uint64_t
+virtio_net_guest_offloads_by_features(const uint64_t *features)
 {
     static const uint64_t guest_offloads_mask =
         (1ULL << VIRTIO_NET_F_GUEST_CSUM) |
@@ -797,13 +817,13 @@ static uint64_t virtio_net_guest_offloads_by_features(uint64_t features)
         (1ULL << VIRTIO_NET_F_GUEST_USO4) |
         (1ULL << VIRTIO_NET_F_GUEST_USO6);
 
-    return guest_offloads_mask & features;
+    return guest_offloads_mask & virtio_net_features_to_offload(features);
 }
 
 uint64_t virtio_net_supported_guest_offloads(const VirtIONet *n)
 {
     VirtIODevice *vdev = VIRTIO_DEVICE(n);
-    return virtio_net_guest_offloads_by_features(vdev->guest_features);
+    return virtio_net_guest_offloads_by_features(vdev->guest_features_ex);
 }
 
 typedef struct {
@@ -882,34 +902,39 @@ static void failover_add_primary(VirtIONet *n, Error **errp)
     error_propagate(errp, err);
 }
 
-static void virtio_net_set_features(VirtIODevice *vdev, uint64_t features)
+static void virtio_net_set_features(VirtIODevice *vdev,
+                                    const uint64_t *in_features)
 {
+    uint64_t features[VIRTIO_FEATURES_DWORDS];
     VirtIONet *n = VIRTIO_NET(vdev);
     Error *err = NULL;
     int i;
 
+    virtio_features_copy(features, in_features);
     if (n->mtu_bypass_backend &&
             !virtio_has_feature(vdev->backend_features, VIRTIO_NET_F_MTU)) {
-        features &= ~(1ULL << VIRTIO_NET_F_MTU);
+        virtio_clear_feature_ex(features, VIRTIO_NET_F_MTU);
     }
 
     virtio_net_set_multiqueue(n,
-                              virtio_has_feature(features, VIRTIO_NET_F_RSS) ||
-                              virtio_has_feature(features, VIRTIO_NET_F_MQ));
+                              virtio_has_feature_ex(features,
+                                                    VIRTIO_NET_F_RSS) ||
+                              virtio_has_feature_ex(features,
+                                                    VIRTIO_NET_F_MQ));
 
     virtio_net_set_mrg_rx_bufs(n,
-                               virtio_has_feature(features,
+                               virtio_has_feature_ex(features,
                                                   VIRTIO_NET_F_MRG_RXBUF),
-                               virtio_has_feature(features,
+                               virtio_has_feature_ex(features,
                                                   VIRTIO_F_VERSION_1),
-                               virtio_has_feature(features,
+                               virtio_has_feature_ex(features,
                                                   VIRTIO_NET_F_HASH_REPORT));
 
-    n->rsc4_enabled = virtio_has_feature(features, VIRTIO_NET_F_RSC_EXT) &&
-        virtio_has_feature(features, VIRTIO_NET_F_GUEST_TSO4);
-    n->rsc6_enabled = virtio_has_feature(features, VIRTIO_NET_F_RSC_EXT) &&
-        virtio_has_feature(features, VIRTIO_NET_F_GUEST_TSO6);
-    n->rss_data.redirect = virtio_has_feature(features, VIRTIO_NET_F_RSS);
+    n->rsc4_enabled = virtio_has_feature_ex(features, VIRTIO_NET_F_RSC_EXT) &&
+        virtio_has_feature_ex(features, VIRTIO_NET_F_GUEST_TSO4);
+    n->rsc6_enabled = virtio_has_feature_ex(features, VIRTIO_NET_F_RSC_EXT) &&
+        virtio_has_feature_ex(features, VIRTIO_NET_F_GUEST_TSO6);
+    n->rss_data.redirect = virtio_has_feature_ex(features, VIRTIO_NET_F_RSS);
 
     if (n->has_vnet_hdr) {
         n->curr_guest_offloads =
@@ -923,7 +948,7 @@ static void virtio_net_set_features(VirtIODevice *vdev, uint64_t features)
         if (!get_vhost_net(nc->peer)) {
             continue;
         }
-        vhost_net_ack_features(get_vhost_net(nc->peer), features);
+        vhost_net_ack_features_ex(get_vhost_net(nc->peer), features);
 
         /*
          * keep acked_features in NetVhostUserState up-to-date so it
@@ -932,11 +957,11 @@ static void virtio_net_set_features(VirtIODevice *vdev, uint64_t features)
         vhost_net_save_acked_features(nc->peer);
     }
 
-    if (!virtio_has_feature(features, VIRTIO_NET_F_CTRL_VLAN)) {
+    if (!virtio_has_feature_ex(features, VIRTIO_NET_F_CTRL_VLAN)) {
         memset(n->vlans, 0xff, MAX_VLAN >> 3);
     }
 
-    if (virtio_has_feature(features, VIRTIO_NET_F_STANDBY)) {
+    if (virtio_has_feature_ex(features, VIRTIO_NET_F_STANDBY)) {
         qapi_event_send_failover_negotiated(n->netclient_name);
         qatomic_set(&n->failover_primary_hidden, false);
         failover_add_primary(n, &err);
@@ -1901,10 +1926,10 @@ static ssize_t virtio_net_receive_rcu(NetClientState *nc, const uint8_t *buf,
                 virtio_error(vdev, "virtio-net unexpected empty queue: "
                              "i %zd mergeable %d offset %zd, size %zd, "
                              "guest hdr len %zd, host hdr len %zd "
-                             "guest features 0x%" PRIx64,
+                             "guest features 0x" VIRTIO_FEATURES_FMT,
                              i, n->mergeable_rx_bufs, offset, size,
                              n->guest_hdr_len, n->host_hdr_len,
-                             vdev->guest_features);
+                             VIRTIO_FEATURES_PR(vdev->guest_features_ex));
             }
             err = -1;
             goto err;
@@ -3011,8 +3036,8 @@ static int virtio_net_pre_load_queues(VirtIODevice *vdev, uint32_t n)
     return 0;
 }
 
-static uint64_t virtio_net_get_features(VirtIODevice *vdev, uint64_t features,
-                                        Error **errp)
+static void virtio_net_get_features(VirtIODevice *vdev, uint64_t *features,
+                                    Error **errp)
 {
     VirtIONet *n = VIRTIO_NET(vdev);
     NetClientState *nc = qemu_get_queue(n->nic);
@@ -3026,68 +3051,67 @@ static uint64_t virtio_net_get_features(VirtIODevice *vdev, uint64_t features,
         (supported_hash_types & peer_hash_types) == supported_hash_types;
 
     /* Firstly sync all virtio-net possible supported features */
-    features |= n->host_features;
+    virtio_features_or(features, features, n->host_features_ex);
 
-    virtio_add_feature(&features, VIRTIO_NET_F_MAC);
+    virtio_add_feature_ex(features, VIRTIO_NET_F_MAC);
 
     if (!peer_has_vnet_hdr(n)) {
-        virtio_clear_feature(&features, VIRTIO_NET_F_CSUM);
-        virtio_clear_feature(&features, VIRTIO_NET_F_HOST_TSO4);
-        virtio_clear_feature(&features, VIRTIO_NET_F_HOST_TSO6);
-        virtio_clear_feature(&features, VIRTIO_NET_F_HOST_ECN);
+        virtio_clear_feature_ex(features, VIRTIO_NET_F_CSUM);
+        virtio_clear_feature_ex(features, VIRTIO_NET_F_HOST_TSO4);
+        virtio_clear_feature_ex(features, VIRTIO_NET_F_HOST_TSO6);
+        virtio_clear_feature_ex(features, VIRTIO_NET_F_HOST_ECN);
 
-        virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_CSUM);
-        virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_TSO4);
-        virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_TSO6);
-        virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_ECN);
+        virtio_clear_feature_ex(features, VIRTIO_NET_F_GUEST_CSUM);
+        virtio_clear_feature_ex(features, VIRTIO_NET_F_GUEST_TSO4);
+        virtio_clear_feature_ex(features, VIRTIO_NET_F_GUEST_TSO6);
+        virtio_clear_feature_ex(features, VIRTIO_NET_F_GUEST_ECN);
 
-        virtio_clear_feature(&features, VIRTIO_NET_F_HOST_USO);
-        virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_USO4);
-        virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_USO6);
+        virtio_clear_feature_ex(features, VIRTIO_NET_F_HOST_USO);
+        virtio_clear_feature_ex(features, VIRTIO_NET_F_GUEST_USO4);
+        virtio_clear_feature_ex(features, VIRTIO_NET_F_GUEST_USO6);
 
-        virtio_clear_feature(&features, VIRTIO_NET_F_HASH_REPORT);
+        virtio_clear_feature_ex(features, VIRTIO_NET_F_HASH_REPORT);
     }
 
     if (!peer_has_vnet_hdr(n) || !peer_has_ufo(n)) {
-        virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_UFO);
-        virtio_clear_feature(&features, VIRTIO_NET_F_HOST_UFO);
+        virtio_clear_feature_ex(features, VIRTIO_NET_F_GUEST_UFO);
+        virtio_clear_feature_ex(features, VIRTIO_NET_F_HOST_UFO);
     }
-
     if (!peer_has_uso(n)) {
-        virtio_clear_feature(&features, VIRTIO_NET_F_HOST_USO);
-        virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_USO4);
-        virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_USO6);
+        virtio_clear_feature_ex(features, VIRTIO_NET_F_HOST_USO);
+        virtio_clear_feature_ex(features, VIRTIO_NET_F_GUEST_USO4);
+        virtio_clear_feature_ex(features, VIRTIO_NET_F_GUEST_USO6);
     }
 
     if (!get_vhost_net(nc->peer)) {
         if (!use_own_hash) {
-            virtio_clear_feature(&features, VIRTIO_NET_F_HASH_REPORT);
-            virtio_clear_feature(&features, VIRTIO_NET_F_RSS);
-        } else if (virtio_has_feature(features, VIRTIO_NET_F_RSS)) {
+            virtio_clear_feature_ex(features, VIRTIO_NET_F_HASH_REPORT);
+            virtio_clear_feature_ex(features, VIRTIO_NET_F_RSS);
+        } else if (virtio_has_feature_ex(features, VIRTIO_NET_F_RSS)) {
             virtio_net_load_ebpf(n, errp);
         }
 
-        return features;
+        return;
     }
 
     if (!use_peer_hash) {
-        virtio_clear_feature(&features, VIRTIO_NET_F_HASH_REPORT);
+        virtio_clear_feature_ex(features, VIRTIO_NET_F_HASH_REPORT);
 
         if (!use_own_hash || !virtio_net_attach_ebpf_to_backend(n->nic, -1)) {
             if (!virtio_net_load_ebpf(n, errp)) {
-                return features;
+                return;
             }
 
-            virtio_clear_feature(&features, VIRTIO_NET_F_RSS);
+            virtio_clear_feature_ex(features, VIRTIO_NET_F_RSS);
         }
     }
 
-    features = vhost_net_get_features(get_vhost_net(nc->peer), features);
-    vdev->backend_features = features;
+    vhost_net_get_features_ex(get_vhost_net(nc->peer), features);
+    virtio_features_copy(vdev->backend_features_ex, features);
 
     if (n->mtu_bypass_backend &&
             (n->host_features & 1ULL << VIRTIO_NET_F_MTU)) {
-        features |= (1ULL << VIRTIO_NET_F_MTU);
+        virtio_add_feature_ex(features, VIRTIO_NET_F_MTU);
     }
 
     /*
@@ -3102,10 +3126,8 @@ static uint64_t virtio_net_get_features(VirtIODevice *vdev, uint64_t features,
      * support it.
      */
     if (!virtio_has_feature(vdev->backend_features, VIRTIO_NET_F_CTRL_VQ)) {
-        virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_ANNOUNCE);
+        virtio_clear_feature_ex(features, VIRTIO_NET_F_GUEST_ANNOUNCE);
     }
-
-    return features;
 }
 
 static int virtio_net_post_load_device(void *opaque, int version_id)
@@ -4237,8 +4259,8 @@ static void virtio_net_class_init(ObjectClass *klass, const void *data)
     vdc->unrealize = virtio_net_device_unrealize;
     vdc->get_config = virtio_net_get_config;
     vdc->set_config = virtio_net_set_config;
-    vdc->get_features = virtio_net_get_features;
-    vdc->set_features = virtio_net_set_features;
+    vdc->get_features_ex = virtio_net_get_features;
+    vdc->set_features_ex = virtio_net_set_features;
     vdc->bad_features = virtio_net_bad_features;
     vdc->reset = virtio_net_reset;
     vdc->queue_reset = virtio_net_queue_reset;
diff --git a/include/hw/virtio/virtio-net.h b/include/hw/virtio/virtio-net.h
index 73fdefc0dc..5b8ab7bda7 100644
--- a/include/hw/virtio/virtio-net.h
+++ b/include/hw/virtio/virtio-net.h
@@ -182,7 +182,7 @@ struct VirtIONet {
     uint32_t has_vnet_hdr;
     size_t host_hdr_len;
     size_t guest_hdr_len;
-    uint64_t host_features;
+    VIRTIO_DECLARE_FEATURES(host_features);
     uint32_t rsc_timeout;
     uint8_t rsc4_enabled;
     uint8_t rsc6_enabled;
-- 
2.50.0