/* * vhost-net support * * Copyright Red Hat, Inc. 2010 * * Authors: * Michael S. Tsirkin <mst@redhat.com> * * This work is licensed under the terms of the GNU GPL, version 2. See * the COPYING file in the top-level directory. * * Contributions after 2012-01-13 are licensed under the terms of the * GNU GPL, version 2 or (at your option) any later version. */ #include "net.h" #include "net/tap.h" #include "virtio-net.h" #include "vhost_net.h" #include "qemu-error.h" #include "config.h" #ifdef CONFIG_VHOST_NET #include <linux/vhost.h> #include <sys/socket.h> #include <linux/kvm.h> #include <fcntl.h> #include <sys/ioctl.h> #include <linux/virtio_ring.h> #include <netpacket/packet.h> #include <net/ethernet.h> #include <net/if.h> #include <netinet/in.h> #include <stdio.h> #include "vhost.h" struct vhost_net { struct vhost_dev dev; struct vhost_virtqueue vqs[2]; int backend; NetClientState *nc; }; unsigned vhost_net_get_features(struct vhost_net *net, unsigned features) { /* Clear features not supported by host kernel. */ if (!(net->dev.features & (1 << VIRTIO_F_NOTIFY_ON_EMPTY))) { features &= ~(1 << VIRTIO_F_NOTIFY_ON_EMPTY); } if (!(net->dev.features & (1 << VIRTIO_RING_F_INDIRECT_DESC))) { features &= ~(1 << VIRTIO_RING_F_INDIRECT_DESC); } if (!(net->dev.features & (1 << VIRTIO_RING_F_EVENT_IDX))) { features &= ~(1 << VIRTIO_RING_F_EVENT_IDX); } if (!(net->dev.features & (1 << VIRTIO_NET_F_MRG_RXBUF))) { features &= ~(1 << VIRTIO_NET_F_MRG_RXBUF); } return features; } void vhost_net_ack_features(struct vhost_net *net, unsigned features) { net->dev.acked_features = net->dev.backend_features; if (features & (1 << VIRTIO_F_NOTIFY_ON_EMPTY)) { net->dev.acked_features |= (1 << VIRTIO_F_NOTIFY_ON_EMPTY); } if (features & (1 << VIRTIO_RING_F_INDIRECT_DESC)) { net->dev.acked_features |= (1 << VIRTIO_RING_F_INDIRECT_DESC); } if (features & (1 << VIRTIO_RING_F_EVENT_IDX)) { net->dev.acked_features |= (1 << VIRTIO_RING_F_EVENT_IDX); } if (features & (1 << VIRTIO_NET_F_MRG_RXBUF)) { net->dev.acked_features |= (1 << VIRTIO_NET_F_MRG_RXBUF); } } static int vhost_net_get_fd(NetClientState *backend) { switch (backend->info->type) { case NET_CLIENT_OPTIONS_KIND_TAP: return tap_get_fd(backend); default: fprintf(stderr, "vhost-net requires tap backend\n"); return -EBADFD; } } struct vhost_net *vhost_net_init(NetClientState *backend, int devfd, bool force) { int r; struct vhost_net *net = g_malloc(sizeof *net); if (!backend) { fprintf(stderr, "vhost-net requires backend to be setup\n"); goto fail; } r = vhost_net_get_fd(backend); if (r < 0) { goto fail; } net->nc = backend; net->dev.backend_features = tap_has_vnet_hdr(backend) ? 0 : (1 << VHOST_NET_F_VIRTIO_NET_HDR); net->backend = r; r = vhost_dev_init(&net->dev, devfd, force); if (r < 0) { goto fail; } if (!tap_has_vnet_hdr_len(backend, sizeof(struct virtio_net_hdr_mrg_rxbuf))) { net->dev.features &= ~(1 << VIRTIO_NET_F_MRG_RXBUF); } if (~net->dev.features & net->dev.backend_features) { fprintf(stderr, "vhost lacks feature mask %" PRIu64 " for backend\n", (uint64_t)(~net->dev.features & net->dev.backend_features)); vhost_dev_cleanup(&net->dev); goto fail; } /* Set sane init value. Override when guest acks. */ vhost_net_ack_features(net, 0); return net; fail: g_free(net); return NULL; } bool vhost_net_query(VHostNetState *net, VirtIODevice *dev) { return vhost_dev_query(&net->dev, dev); } int vhost_net_start(struct vhost_net *net, VirtIODevice *dev) { struct vhost_vring_file file = { }; int r; net->dev.nvqs = 2; net->dev.vqs = net->vqs; r = vhost_dev_enable_notifiers(&net->dev, dev); if (r < 0) { goto fail_notifiers; } if (net->dev.acked_features & (1 << VIRTIO_NET_F_MRG_RXBUF)) { tap_set_vnet_hdr_len(net->nc, sizeof(struct virtio_net_hdr_mrg_rxbuf)); } r = vhost_dev_start(&net->dev, dev); if (r < 0) { goto fail_start; } net->nc->info->poll(net->nc, false); qemu_set_fd_handler(net->backend, NULL, NULL, NULL); file.fd = net->backend; for (file.index = 0; file.index < net->dev.nvqs; ++file.index) { r = ioctl(net->dev.control, VHOST_NET_SET_BACKEND, &file); if (r < 0) { r = -errno; goto fail; } } return 0; fail: file.fd = -1; while (file.index-- > 0) { int r = ioctl(net->dev.control, VHOST_NET_SET_BACKEND, &file); assert(r >= 0); } net->nc->info->poll(net->nc, true); vhost_dev_stop(&net->dev, dev); if (net->dev.acked_features & (1 << VIRTIO_NET_F_MRG_RXBUF)) { tap_set_vnet_hdr_len(net->nc, sizeof(struct virtio_net_hdr)); } fail_start: vhost_dev_disable_notifiers(&net->dev, dev); fail_notifiers: return r; } void vhost_net_stop(struct vhost_net *net, VirtIODevice *dev) { struct vhost_vring_file file = { .fd = -1 }; for (file.index = 0; file.index < net->dev.nvqs; ++file.index) { int r = ioctl(net->dev.control, VHOST_NET_SET_BACKEND, &file); assert(r >= 0); } net->nc->info->poll(net->nc, true); vhost_dev_stop(&net->dev, dev); if (net->dev.acked_features & (1 << VIRTIO_NET_F_MRG_RXBUF)) { tap_set_vnet_hdr_len(net->nc, sizeof(struct virtio_net_hdr)); } vhost_dev_disable_notifiers(&net->dev, dev); } void vhost_net_cleanup(struct vhost_net *net) { vhost_dev_cleanup(&net->dev); if (net->dev.acked_features & (1 << VIRTIO_NET_F_MRG_RXBUF)) { tap_set_vnet_hdr_len(net->nc, sizeof(struct virtio_net_hdr)); } g_free(net); } #else struct vhost_net *vhost_net_init(NetClientState *backend, int devfd, bool force) { error_report("vhost-net support is not compiled in"); return NULL; } bool vhost_net_query(VHostNetState *net, VirtIODevice *dev) { return false; } int vhost_net_start(struct vhost_net *net, VirtIODevice *dev) { return -ENOSYS; } void vhost_net_stop(struct vhost_net *net, VirtIODevice *dev) { } void vhost_net_cleanup(struct vhost_net *net) { } unsigned vhost_net_get_features(struct vhost_net *net, unsigned features) { return features; } void vhost_net_ack_features(struct vhost_net *net, unsigned features) { } #endif