virtio-blk: Avoid zeroing every request structure
[qemu/aliguori-queue.git] / hw / vhost_net.c
blob2e292eea260dd56955200d80f5cb9154f54f0e18
1 /*
2 * vhost-net support
4 * Copyright Red Hat, Inc. 2010
6 * Authors:
7 * Michael S. Tsirkin <mst@redhat.com>
9 * This work is licensed under the terms of the GNU GPL, version 2. See
10 * the COPYING file in the top-level directory.
13 #include "net.h"
14 #include "net/tap.h"
16 #include "virtio-net.h"
17 #include "vhost_net.h"
19 #include "config.h"
21 #ifdef CONFIG_VHOST_NET
22 #include <linux/vhost.h>
23 #include <sys/eventfd.h>
24 #include <sys/socket.h>
25 #include <linux/kvm.h>
26 #include <fcntl.h>
27 #include <sys/ioctl.h>
28 #include <linux/virtio_ring.h>
29 #include <netpacket/packet.h>
30 #include <net/ethernet.h>
31 #include <net/if.h>
32 #include <netinet/in.h>
34 #include <stdio.h>
36 #include "vhost.h"
38 struct vhost_net {
39 struct vhost_dev dev;
40 struct vhost_virtqueue vqs[2];
41 int backend;
42 VLANClientState *vc;
45 unsigned vhost_net_get_features(struct vhost_net *net, unsigned features)
47 /* Clear features not supported by host kernel. */
48 if (!(net->dev.features & (1 << VIRTIO_F_NOTIFY_ON_EMPTY))) {
49 features &= ~(1 << VIRTIO_F_NOTIFY_ON_EMPTY);
51 if (!(net->dev.features & (1 << VIRTIO_RING_F_INDIRECT_DESC))) {
52 features &= ~(1 << VIRTIO_RING_F_INDIRECT_DESC);
54 features &= ~(1 << VIRTIO_NET_F_MRG_RXBUF);
55 return features;
58 void vhost_net_ack_features(struct vhost_net *net, unsigned features)
60 net->dev.acked_features = net->dev.backend_features;
61 if (features & (1 << VIRTIO_F_NOTIFY_ON_EMPTY)) {
62 net->dev.acked_features |= (1 << VIRTIO_F_NOTIFY_ON_EMPTY);
64 if (features & (1 << VIRTIO_RING_F_INDIRECT_DESC)) {
65 net->dev.acked_features |= (1 << VIRTIO_RING_F_INDIRECT_DESC);
69 static int vhost_net_get_fd(VLANClientState *backend)
71 switch (backend->info->type) {
72 case NET_CLIENT_TYPE_TAP:
73 return tap_get_fd(backend);
74 default:
75 fprintf(stderr, "vhost-net requires tap backend\n");
76 return -EBADFD;
80 struct vhost_net *vhost_net_init(VLANClientState *backend, int devfd)
82 int r;
83 struct vhost_net *net = qemu_malloc(sizeof *net);
84 if (!backend) {
85 fprintf(stderr, "vhost-net requires backend to be setup\n");
86 goto fail;
88 r = vhost_net_get_fd(backend);
89 if (r < 0) {
90 goto fail;
92 net->vc = backend;
93 net->dev.backend_features = tap_has_vnet_hdr(backend) ? 0 :
94 (1 << VHOST_NET_F_VIRTIO_NET_HDR);
95 net->backend = r;
97 r = vhost_dev_init(&net->dev, devfd);
98 if (r < 0) {
99 goto fail;
101 if (~net->dev.features & net->dev.backend_features) {
102 fprintf(stderr, "vhost lacks feature mask %llu for backend\n",
103 ~net->dev.features & net->dev.backend_features);
104 vhost_dev_cleanup(&net->dev);
105 goto fail;
108 /* Set sane init value. Override when guest acks. */
109 vhost_net_ack_features(net, 0);
110 return net;
111 fail:
112 qemu_free(net);
113 return NULL;
116 int vhost_net_start(struct vhost_net *net,
117 VirtIODevice *dev)
119 struct vhost_vring_file file = { };
120 int r;
122 net->dev.nvqs = 2;
123 net->dev.vqs = net->vqs;
124 r = vhost_dev_start(&net->dev, dev);
125 if (r < 0) {
126 return r;
129 net->vc->info->poll(net->vc, false);
130 qemu_set_fd_handler(net->backend, NULL, NULL, NULL);
131 file.fd = net->backend;
132 for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
133 r = ioctl(net->dev.control, VHOST_NET_SET_BACKEND, &file);
134 if (r < 0) {
135 r = -errno;
136 goto fail;
139 return 0;
140 fail:
141 file.fd = -1;
142 while (--file.index >= 0) {
143 int r = ioctl(net->dev.control, VHOST_NET_SET_BACKEND, &file);
144 assert(r >= 0);
146 net->vc->info->poll(net->vc, true);
147 vhost_dev_stop(&net->dev, dev);
148 return r;
151 void vhost_net_stop(struct vhost_net *net,
152 VirtIODevice *dev)
154 struct vhost_vring_file file = { .fd = -1 };
156 for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
157 int r = ioctl(net->dev.control, VHOST_NET_SET_BACKEND, &file);
158 assert(r >= 0);
160 net->vc->info->poll(net->vc, true);
161 vhost_dev_stop(&net->dev, dev);
164 void vhost_net_cleanup(struct vhost_net *net)
166 vhost_dev_cleanup(&net->dev);
167 qemu_free(net);
169 #else
170 struct vhost_net *vhost_net_init(VLANClientState *backend, int devfd)
172 return NULL;
175 int vhost_net_start(struct vhost_net *net,
176 VirtIODevice *dev)
178 return -ENOSYS;
180 void vhost_net_stop(struct vhost_net *net,
181 VirtIODevice *dev)
185 void vhost_net_cleanup(struct vhost_net *net)
189 unsigned vhost_net_get_features(struct vhost_net *net, unsigned features)
191 return features;
193 void vhost_net_ack_features(struct vhost_net *net, unsigned features)
196 #endif