After features negotiation, kvmtool should tell vhost-net that he's using mergeable rx buffers.
Signed-off-by: Ying-Shiuan Pan <[email protected]> --- 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 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
