hw/vhost_net.c - qemu - Git at Google

 /*
  * 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/net.h"
 #include "net/tap.h"

 #include "virtio-net.h"
 #include "vhost_net.h"
 #include "qemu/error-report.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;

     net->dev.nvqs = 2;
     net->dev.vqs = net->vqs;

     r = vhost_dev_init(&net->dev, devfd, "/dev/vhost-net", 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);
 }

 static int vhost_net_start_one(struct vhost_net *net,
                                VirtIODevice *dev,
                                int vq_index)
 {
     struct vhost_vring_file file = { };
     int r;

     if (net->dev.started) {
         return 0;
     }

     net->dev.nvqs = 2;
     net->dev.vqs = net->vqs;
     net->dev.vq_index = vq_index;

     r = vhost_dev_enable_notifiers(&net->dev, dev);
     if (r < 0) {
         goto fail_notifiers;
     }

     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);
 fail_start:
     vhost_dev_disable_notifiers(&net->dev, dev);
 fail_notifiers:
     return r;
 }

 static void vhost_net_stop_one(struct vhost_net *net,
                                VirtIODevice *dev)
 {
     struct vhost_vring_file file = { .fd = -1 };

     if (!net->dev.started) {
         return;
     }

     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);
     vhost_dev_disable_notifiers(&net->dev, dev);
 }

 int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
                     int total_queues)
 {
     int r, i = 0;

     if (!dev->binding->set_guest_notifiers) {
         error_report("binding does not support guest notifiers");
         r = -ENOSYS;
         goto err;
     }

     for (i = 0; i < total_queues; i++) {
         r = vhost_net_start_one(tap_get_vhost_net(ncs[i].peer), dev, i * 2);

         if (r < 0) {
             goto err;
         }
     }

     r = dev->binding->set_guest_notifiers(dev->binding_opaque,
                                           total_queues * 2,
                                           true);
     if (r < 0) {
         error_report("Error binding guest notifier: %d", -r);
         goto err;
     }

     return 0;

 err:
     while (--i >= 0) {
         vhost_net_stop_one(tap_get_vhost_net(ncs[i].peer), dev);
     }
     return r;
 }

 void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
                     int total_queues)
 {
     int i, r;

     r = dev->binding->set_guest_notifiers(dev->binding_opaque,
                                           total_queues * 2,
                                           false);
     if (r < 0) {
         fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", r);
         fflush(stderr);
     }
     assert(r >= 0);

     for (i = 0; i < total_queues; i++) {
         vhost_net_stop_one(tap_get_vhost_net(ncs[i].peer), dev);
     }
 }

 void vhost_net_cleanup(struct vhost_net *net)
 {
     vhost_dev_cleanup(&net->dev);
     g_free(net);
 }

 bool vhost_net_virtqueue_pending(VHostNetState *net, int idx)
 {
     return vhost_virtqueue_pending(&net->dev, idx);
 }

 void vhost_net_virtqueue_mask(VHostNetState *net, VirtIODevice *dev,
                               int idx, bool mask)
 {
     vhost_virtqueue_mask(&net->dev, dev, idx, mask);
 }
 #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(VirtIODevice *dev,
                     NetClientState *ncs,
                     int total_queues)
 {
     return -ENOSYS;
 }
 void vhost_net_stop(VirtIODevice *dev,
                     NetClientState *ncs,
                     int total_queues)
 {
 }

 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)
 {
 }

 bool vhost_net_virtqueue_pending(VHostNetState *net, int idx)
 {
     return -ENOSYS;
 }

 void vhost_net_virtqueue_mask(VHostNetState *net, VirtIODevice *dev,
                               int idx, bool mask)
 {
 }
 #endif
	/*
	* 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/net.h"
	#include "net/tap.h"

	#include "virtio-net.h"
	#include "vhost_net.h"
	#include "qemu/error-report.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;

	net->dev.nvqs = 2;
	net->dev.vqs = net->vqs;

	r = vhost_dev_init(&net->dev, devfd, "/dev/vhost-net", 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);
	}

	static int vhost_net_start_one(struct vhost_net *net,
	VirtIODevice *dev,
	int vq_index)
	{
	struct vhost_vring_file file = { };
	int r;

	if (net->dev.started) {
	return 0;
	}

	net->dev.nvqs = 2;
	net->dev.vqs = net->vqs;
	net->dev.vq_index = vq_index;

	r = vhost_dev_enable_notifiers(&net->dev, dev);
	if (r < 0) {
	goto fail_notifiers;
	}

	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);
	fail_start:
	vhost_dev_disable_notifiers(&net->dev, dev);
	fail_notifiers:
	return r;
	}

	static void vhost_net_stop_one(struct vhost_net *net,
	VirtIODevice *dev)
	{
	struct vhost_vring_file file = { .fd = -1 };

	if (!net->dev.started) {
	return;
	}

	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);
	vhost_dev_disable_notifiers(&net->dev, dev);
	}

	int vhost_net_start(VirtIODevice dev, NetClientState ncs,
	int total_queues)
	{
	int r, i = 0;

	if (!dev->binding->set_guest_notifiers) {
	error_report("binding does not support guest notifiers");
	r = -ENOSYS;
	goto err;
	}

	for (i = 0; i < total_queues; i++) {
	r = vhost_net_start_one(tap_get_vhost_net(ncs[i].peer), dev, i * 2);

	if (r < 0) {
	goto err;
	}
	}

	r = dev->binding->set_guest_notifiers(dev->binding_opaque,
	total_queues * 2,
	true);
	if (r < 0) {
	error_report("Error binding guest notifier: %d", -r);
	goto err;
	}

	return 0;

	err:
	while (--i >= 0) {
	vhost_net_stop_one(tap_get_vhost_net(ncs[i].peer), dev);
	}
	return r;
	}

	void vhost_net_stop(VirtIODevice dev, NetClientState ncs,
	int total_queues)
	{
	int i, r;

	r = dev->binding->set_guest_notifiers(dev->binding_opaque,
	total_queues * 2,
	false);
	if (r < 0) {
	fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", r);
	fflush(stderr);
	}
	assert(r >= 0);

	for (i = 0; i < total_queues; i++) {
	vhost_net_stop_one(tap_get_vhost_net(ncs[i].peer), dev);
	}
	}

	void vhost_net_cleanup(struct vhost_net *net)
	{
	vhost_dev_cleanup(&net->dev);
	g_free(net);
	}

	bool vhost_net_virtqueue_pending(VHostNetState *net, int idx)
	{
	return vhost_virtqueue_pending(&net->dev, idx);
	}

	void vhost_net_virtqueue_mask(VHostNetState net, VirtIODevice dev,
	int idx, bool mask)
	{
	vhost_virtqueue_mask(&net->dev, dev, idx, mask);
	}
	#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(VirtIODevice *dev,
	NetClientState *ncs,
	int total_queues)
	{
	return -ENOSYS;
	}
	void vhost_net_stop(VirtIODevice *dev,
	NetClientState *ncs,
	int total_queues)
	{
	}

	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)
	{
	}

	bool vhost_net_virtqueue_pending(VHostNetState *net, int idx)
	{
	return -ENOSYS;
	}

	void vhost_net_virtqueue_mask(VHostNetState net, VirtIODevice dev,
	int idx, bool mask)
	{
	}
	#endif