diff options
Diffstat (limited to 'hw/vhost_net.c')
| -rw-r--r-- | hw/vhost_net.c | 195 |
1 files changed, 195 insertions, 0 deletions
diff --git a/hw/vhost_net.c b/hw/vhost_net.c new file mode 100644 index 0000000000..39643f1e99 --- /dev/null +++ b/hw/vhost_net.c @@ -0,0 +1,195 @@ +/* + * 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. + */ + +#include "net.h" +#include "net/tap.h" + +#include "virtio-net.h" +#include "vhost_net.h" + +#include "config.h" + +#ifdef CONFIG_VHOST_NET +#include <linux/vhost.h> +#include <sys/eventfd.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; + VLANClientState *vc; +}; + +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); + } + 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); + } +} + +static int vhost_net_get_fd(VLANClientState *backend) +{ + switch (backend->info->type) { + case NET_CLIENT_TYPE_TAP: + return tap_get_fd(backend); + default: + fprintf(stderr, "vhost-net requires tap backend\n"); + return -EBADFD; + } +} + +struct vhost_net *vhost_net_init(VLANClientState *backend, int devfd) +{ + int r; + struct vhost_net *net = qemu_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->vc = 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); + if (r < 0) { + goto fail; + } + if (~net->dev.features & net->dev.backend_features) { + fprintf(stderr, "vhost lacks feature mask %llu for backend\n", + ~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: + qemu_free(net); + return NULL; +} + +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_start(&net->dev, dev); + if (r < 0) { + return r; + } + + net->vc->info->poll(net->vc, 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->vc->info->poll(net->vc, true); + vhost_dev_stop(&net->dev, dev); + 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->vc->info->poll(net->vc, true); + vhost_dev_stop(&net->dev, dev); +} + +void vhost_net_cleanup(struct vhost_net *net) +{ + vhost_dev_cleanup(&net->dev); + qemu_free(net); +} +#else +struct vhost_net *vhost_net_init(VLANClientState *backend, int devfd) +{ + return NULL; +} + +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 |