After features negotiation, kvmtool should tell vhost-net that he's
using mergeable rx buffers.
Signed-off-by: Ying-Shiuan Pan <yspan@xxxxxxxxxxx>
---
tools/kvm/virtio/net.c | 23 +++++++++++++++++++----
1 file changed, 19 insertions(+), 4 deletions(-)
diff --git a/tools/kvm/virtio/net.c b/tools/kvm/virtio/net.c
index dfc4aad..2f61718 100644
--- a/tools/kvm/virtio/net.c
+++ b/tools/kvm/virtio/net.c
@@ -384,6 +384,22 @@ static u32 get_host_features(struct kvm *kvm, void *dev)
| 1UL << (ndev->queue_pairs > 1 ? VIRTIO_NET_F_MQ : 0);
}
+static int virtio_net__vhost_set_features(struct net_dev *ndev)
+{
+ u64 features = 1UL << VIRTIO_RING_F_EVENT_IDX;
+ u64 vhost_features;
+
+ if (ioctl(ndev->vhost_fd, VHOST_GET_FEATURES, &vhost_features) != 0)
+ die_perror("VHOST_GET_FEATURES failed");
+
+ /* make sure both side support mergable rx buffers */
+ if (vhost_features & 1UL << VIRTIO_NET_F_MRG_RXBUF &&
+ has_virtio_feature(ndev, VIRTIO_NET_F_MRG_RXBUF))
+ features |= 1UL << VIRTIO_NET_F_MRG_RXBUF;
+
+ return ioctl(ndev->vhost_fd, VHOST_SET_FEATURES, &features);
+}
+
static void set_guest_features(struct kvm *kvm, void *dev, u32 features)
{
struct net_dev *ndev = dev;
@@ -393,6 +409,9 @@ static void set_guest_features(struct kvm *kvm, void *dev, u32 features)
if (ndev->mode == NET_MODE_TAP) {
if (!virtio_net__tap_init(ndev))
die_perror("You have requested a TAP device, but creation of one has failed because");
+ if (ndev->vhost_fd &&
+ virtio_net__vhost_set_features(ndev) != 0)
+ die_perror("VHOST_SET_FEATURES failed");
} else {
ndev->info.vnet_hdr_len = has_virtio_feature(ndev, VIRTIO_NET_F_MRG_RXBUF) ?
sizeof(struct virtio_net_hdr_mrg_rxbuf) :
@@ -555,7 +574,6 @@ static struct virtio_ops net_dev_virtio_ops = (struct virtio_ops) {
static void virtio_net__vhost_init(struct kvm *kvm, struct net_dev *ndev)
{
- u64 features = 1UL << VIRTIO_RING_F_EVENT_IDX;
struct vhost_memory *mem;
int r;
@@ -578,9 +596,6 @@ static void virtio_net__vhost_init(struct kvm *kvm, struct net_dev *ndev)
if (r != 0)
die_perror("VHOST_SET_OWNER failed");
- r = ioctl(ndev->vhost_fd, VHOST_SET_FEATURES, &features);
- if (r != 0)
- die_perror("VHOST_SET_FEATURES failed");
r = ioctl(ndev->vhost_fd, VHOST_SET_MEM_TABLE, mem);
if (r != 0)
die_perror("VHOST_SET_MEM_TABLE failed");
--
1.8.1.2
--
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