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/*
* 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/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);
}
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_NET_F_MRG_RXBUF)) {
net->dev.acked_features |= (1 << VIRTIO_NET_F_MRG_RXBUF);
}
}
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 (!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:
qemu_free(net);
return NULL;
}
int vhost_net_start(struct vhost_net *net,
VirtIODevice *dev)
{
struct vhost_vring_file file = { };
int r;
if (net->dev.acked_features & (1 << VIRTIO_NET_F_MRG_RXBUF)) {
tap_set_vnet_hdr_len(net->vc,
sizeof(struct virtio_net_hdr_mrg_rxbuf));
}
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);
if (net->dev.acked_features & (1 << VIRTIO_NET_F_MRG_RXBUF)) {
tap_set_vnet_hdr_len(net->vc, sizeof(struct virtio_net_hdr));
}
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);
if (net->dev.acked_features & (1 << VIRTIO_NET_F_MRG_RXBUF)) {
tap_set_vnet_hdr_len(net->vc, sizeof(struct virtio_net_hdr));
}
}
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->vc, sizeof(struct virtio_net_hdr));
}
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
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