net/vhost-user.c - qemu - Git at Google

 /*
  * vhost-user.c
  *
  * Copyright (c) 2013 Virtual Open Systems Sarl.
  *
  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  * See the COPYING file in the top-level directory.
  *
  */

 #include "qemu/osdep.h"
 #include "clients.h"
 #include "net/vhost_net.h"
 #include "net/vhost-user.h"
 #include "sysemu/char.h"
 #include "qemu/config-file.h"
 #include "qemu/error-report.h"
 #include "qmp-commands.h"
 #include "trace.h"

 typedef struct VhostUserState {
     NetClientState nc;
     CharDriverState *chr;
     VHostNetState *vhost_net;
     guint watch;
     uint64_t acked_features;
 } VhostUserState;

 typedef struct VhostUserChardevProps {
     bool is_socket;
     bool is_unix;
 } VhostUserChardevProps;

 VHostNetState *vhost_user_get_vhost_net(NetClientState *nc)
 {
     VhostUserState *s = DO_UPCAST(VhostUserState, nc, nc);
     assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER);
     return s->vhost_net;
 }

 uint64_t vhost_user_get_acked_features(NetClientState *nc)
 {
     VhostUserState *s = DO_UPCAST(VhostUserState, nc, nc);
     assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER);
     return s->acked_features;
 }

 static int vhost_user_running(VhostUserState *s)
 {
     return (s->vhost_net) ? 1 : 0;
 }

 static void vhost_user_stop(int queues, NetClientState *ncs[])
 {
     VhostUserState *s;
     int i;

     for (i = 0; i < queues; i++) {
         assert (ncs[i]->info->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER);

         s = DO_UPCAST(VhostUserState, nc, ncs[i]);
         if (!vhost_user_running(s)) {
             continue;
         }

         if (s->vhost_net) {
             /* save acked features */
             s->acked_features = vhost_net_get_acked_features(s->vhost_net);
             vhost_net_cleanup(s->vhost_net);
             s->vhost_net = NULL;
         }
     }
 }

 static int vhost_user_start(int queues, NetClientState *ncs[])
 {
     VhostNetOptions options;
     VhostUserState *s;
     int max_queues;
     int i;

     options.backend_type = VHOST_BACKEND_TYPE_USER;

     for (i = 0; i < queues; i++) {
         assert (ncs[i]->info->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER);

         s = DO_UPCAST(VhostUserState, nc, ncs[i]);
         if (vhost_user_running(s)) {
             continue;
         }

         options.net_backend = ncs[i];
         options.opaque      = s->chr;
         s->vhost_net = vhost_net_init(&options);
         if (!s->vhost_net) {
             error_report("failed to init vhost_net for queue %d", i);
             goto err;
         }

         if (i == 0) {
             max_queues = vhost_net_get_max_queues(s->vhost_net);
             if (queues > max_queues) {
                 error_report("you are asking more queues than supported: %d",
                              max_queues);
                 goto err;
             }
         }
     }

     return 0;

 err:
     vhost_user_stop(i + 1, ncs);
     return -1;
 }

 static ssize_t vhost_user_receive(NetClientState *nc, const uint8_t *buf,
                                   size_t size)
 {
     /* In case of RARP (message size is 60) notify backup to send a fake RARP.
        This fake RARP will be sent by backend only for guest
        without GUEST_ANNOUNCE capability.
      */
     if (size == 60) {
         VhostUserState *s = DO_UPCAST(VhostUserState, nc, nc);
         int r;
         static int display_rarp_failure = 1;
         char mac_addr[6];

         /* extract guest mac address from the RARP message */
         memcpy(mac_addr, &buf[6], 6);

         r = vhost_net_notify_migration_done(s->vhost_net, mac_addr);

         if ((r != 0) && (display_rarp_failure)) {
             fprintf(stderr,
                     "Vhost user backend fails to broadcast fake RARP\n");
             fflush(stderr);
             display_rarp_failure = 0;
         }
     }

     return size;
 }

 static void vhost_user_cleanup(NetClientState *nc)
 {
     VhostUserState *s = DO_UPCAST(VhostUserState, nc, nc);

     if (s->vhost_net) {
         vhost_net_cleanup(s->vhost_net);
         s->vhost_net = NULL;
     }
     if (s->chr) {
         qemu_chr_add_handlers(s->chr, NULL, NULL, NULL, NULL);
         qemu_chr_fe_release(s->chr);
         s->chr = NULL;
     }

     qemu_purge_queued_packets(nc);
 }

 static bool vhost_user_has_vnet_hdr(NetClientState *nc)
 {
     assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER);

     return true;
 }

 static bool vhost_user_has_ufo(NetClientState *nc)
 {
     assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER);

     return true;
 }

 static NetClientInfo net_vhost_user_info = {
         .type = NET_CLIENT_OPTIONS_KIND_VHOST_USER,
         .size = sizeof(VhostUserState),
         .receive = vhost_user_receive,
         .cleanup = vhost_user_cleanup,
         .has_vnet_hdr = vhost_user_has_vnet_hdr,
         .has_ufo = vhost_user_has_ufo,
 };

 static gboolean net_vhost_user_watch(GIOChannel *chan, GIOCondition cond,
                                            void *opaque)
 {
     VhostUserState *s = opaque;
     uint8_t buf[1];

     /* We don't actually want to read anything, but CHR_EVENT_CLOSED will be
      * raised as a side-effect of the read.
      */
     qemu_chr_fe_read_all(s->chr, buf, sizeof(buf));

     return FALSE;
 }

 static void net_vhost_user_event(void *opaque, int event)
 {
     const char *name = opaque;
     NetClientState *ncs[MAX_QUEUE_NUM];
     VhostUserState *s;
     Error *err = NULL;
     int queues;

     queues = qemu_find_net_clients_except(name, ncs,
                                           NET_CLIENT_OPTIONS_KIND_NIC,
                                           MAX_QUEUE_NUM);
     assert(queues < MAX_QUEUE_NUM);

     s = DO_UPCAST(VhostUserState, nc, ncs[0]);
     trace_vhost_user_event(s->chr->label, event);
     switch (event) {
     case CHR_EVENT_OPENED:
         s->watch = qemu_chr_fe_add_watch(s->chr, G_IO_HUP,
                                          net_vhost_user_watch, s);
         if (vhost_user_start(queues, ncs) < 0) {
             qemu_chr_disconnect(s->chr);
             return;
         }
         qmp_set_link(name, true, &err);
         break;
     case CHR_EVENT_CLOSED:
         qmp_set_link(name, false, &err);
         vhost_user_stop(queues, ncs);
         g_source_remove(s->watch);
         s->watch = 0;
         break;
     }

     if (err) {
         error_report_err(err);
     }
 }

 static int net_vhost_user_init(NetClientState *peer, const char *device,
                                const char *name, CharDriverState *chr,
                                int queues)
 {
     NetClientState *nc;
     VhostUserState *s;
     int i;

     assert(name);
     assert(queues > 0);

     for (i = 0; i < queues; i++) {
         nc = qemu_new_net_client(&net_vhost_user_info, peer, device, name);

         snprintf(nc->info_str, sizeof(nc->info_str), "vhost-user%d to %s",
                  i, chr->label);

         nc->queue_index = i;

         s = DO_UPCAST(VhostUserState, nc, nc);
         s->chr = chr;
     }

     qemu_chr_add_handlers(chr, NULL, NULL, net_vhost_user_event, nc[0].name);

     return 0;
 }

 static int net_vhost_chardev_opts(void *opaque,
                                   const char *name, const char *value,
                                   Error **errp)
 {
     VhostUserChardevProps *props = opaque;

     if (strcmp(name, "backend") == 0 && strcmp(value, "socket") == 0) {
         props->is_socket = true;
     } else if (strcmp(name, "path") == 0) {
         props->is_unix = true;
     } else if (strcmp(name, "server") == 0) {
     } else {
         error_setg(errp,
                    "vhost-user does not support a chardev with option %s=%s",
                    name, value);
         return -1;
     }
     return 0;
 }

 static CharDriverState *net_vhost_parse_chardev(
     const NetdevVhostUserOptions *opts, Error **errp)
 {
     CharDriverState *chr = qemu_chr_find(opts->chardev);
     VhostUserChardevProps props;

     if (chr == NULL) {
         error_setg(errp, "chardev \"%s\" not found", opts->chardev);
         return NULL;
     }

     /* inspect chardev opts */
     memset(&props, 0, sizeof(props));
     if (qemu_opt_foreach(chr->opts, net_vhost_chardev_opts, &props, errp)) {
         return NULL;
     }

     if (!props.is_socket || !props.is_unix) {
         error_setg(errp, "chardev \"%s\" is not a unix socket",
                    opts->chardev);
         return NULL;
     }

     qemu_chr_fe_claim_no_fail(chr);

     return chr;
 }

 static int net_vhost_check_net(void *opaque, QemuOpts *opts, Error **errp)
 {
     const char *name = opaque;
     const char *driver, *netdev;
     const char virtio_name[] = "virtio-net-";

     driver = qemu_opt_get(opts, "driver");
     netdev = qemu_opt_get(opts, "netdev");

     if (!driver || !netdev) {
         return 0;
     }

     if (strcmp(netdev, name) == 0 &&
         strncmp(driver, virtio_name, strlen(virtio_name)) != 0) {
         error_setg(errp, "vhost-user requires frontend driver virtio-net-*");
         return -1;
     }

     return 0;
 }

 int net_init_vhost_user(const NetClientOptions *opts, const char *name,
                         NetClientState *peer, Error **errp)
 {
     int queues;
     const NetdevVhostUserOptions *vhost_user_opts;
     CharDriverState *chr;

     assert(opts->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER);
     vhost_user_opts = opts->u.vhost_user.data;

     chr = net_vhost_parse_chardev(vhost_user_opts, errp);
     if (!chr) {
         return -1;
     }

     /* verify net frontend */
     if (qemu_opts_foreach(qemu_find_opts("device"), net_vhost_check_net,
                           (char *)name, errp)) {
         return -1;
     }

     queues = vhost_user_opts->has_queues ? vhost_user_opts->queues : 1;
     if (queues < 1 || queues > MAX_QUEUE_NUM) {
         error_setg(errp,
                    "vhost-user number of queues must be in range [1, %d]",
                    MAX_QUEUE_NUM);
         return -1;
     }

     return net_vhost_user_init(peer, "vhost_user", name, chr, queues);
 }
	/*
	* vhost-user.c
	*
	* Copyright (c) 2013 Virtual Open Systems Sarl.
	*
	* This work is licensed under the terms of the GNU GPL, version 2 or later.
	* See the COPYING file in the top-level directory.
	*
	*/

	#include "qemu/osdep.h"
	#include "clients.h"
	#include "net/vhost_net.h"
	#include "net/vhost-user.h"
	#include "sysemu/char.h"
	#include "qemu/config-file.h"
	#include "qemu/error-report.h"
	#include "qmp-commands.h"
	#include "trace.h"

	typedef struct VhostUserState {
	NetClientState nc;
	CharDriverState *chr;
	VHostNetState *vhost_net;
	guint watch;
	uint64_t acked_features;
	} VhostUserState;

	typedef struct VhostUserChardevProps {
	bool is_socket;
	bool is_unix;
	} VhostUserChardevProps;

	VHostNetState vhost_user_get_vhost_net(NetClientState nc)
	{
	VhostUserState *s = DO_UPCAST(VhostUserState, nc, nc);
	assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER);
	return s->vhost_net;
	}

	uint64_t vhost_user_get_acked_features(NetClientState *nc)
	{
	VhostUserState *s = DO_UPCAST(VhostUserState, nc, nc);
	assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER);
	return s->acked_features;
	}

	static int vhost_user_running(VhostUserState *s)
	{
	return (s->vhost_net) ? 1 : 0;
	}

	static void vhost_user_stop(int queues, NetClientState *ncs[])
	{
	VhostUserState *s;
	int i;

	for (i = 0; i < queues; i++) {
	assert (ncs[i]->info->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER);

	s = DO_UPCAST(VhostUserState, nc, ncs[i]);
	if (!vhost_user_running(s)) {
	continue;
	}

	if (s->vhost_net) {
	/* save acked features */
	s->acked_features = vhost_net_get_acked_features(s->vhost_net);
	vhost_net_cleanup(s->vhost_net);
	s->vhost_net = NULL;
	}
	}
	}

	static int vhost_user_start(int queues, NetClientState *ncs[])
	{
	VhostNetOptions options;
	VhostUserState *s;
	int max_queues;
	int i;

	options.backend_type = VHOST_BACKEND_TYPE_USER;

	for (i = 0; i < queues; i++) {
	assert (ncs[i]->info->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER);

	s = DO_UPCAST(VhostUserState, nc, ncs[i]);
	if (vhost_user_running(s)) {
	continue;
	}

	options.net_backend = ncs[i];
	options.opaque = s->chr;
	s->vhost_net = vhost_net_init(&options);
	if (!s->vhost_net) {
	error_report("failed to init vhost_net for queue %d", i);
	goto err;
	}

	if (i == 0) {
	max_queues = vhost_net_get_max_queues(s->vhost_net);
	if (queues > max_queues) {
	error_report("you are asking more queues than supported: %d",
	max_queues);
	goto err;
	}
	}
	}

	return 0;

	err:
	vhost_user_stop(i + 1, ncs);
	return -1;
	}

	static ssize_t vhost_user_receive(NetClientState nc, const uint8_t buf,
	size_t size)
	{
	/* In case of RARP (message size is 60) notify backup to send a fake RARP.
	This fake RARP will be sent by backend only for guest
	without GUEST_ANNOUNCE capability.
	*/
	if (size == 60) {
	VhostUserState *s = DO_UPCAST(VhostUserState, nc, nc);
	int r;
	static int display_rarp_failure = 1;
	char mac_addr[6];

	/* extract guest mac address from the RARP message */
	memcpy(mac_addr, &buf[6], 6);

	r = vhost_net_notify_migration_done(s->vhost_net, mac_addr);

	if ((r != 0) && (display_rarp_failure)) {
	fprintf(stderr,
	"Vhost user backend fails to broadcast fake RARP\n");
	fflush(stderr);
	display_rarp_failure = 0;
	}
	}

	return size;
	}

	static void vhost_user_cleanup(NetClientState *nc)
	{
	VhostUserState *s = DO_UPCAST(VhostUserState, nc, nc);

	if (s->vhost_net) {
	vhost_net_cleanup(s->vhost_net);
	s->vhost_net = NULL;
	}
	if (s->chr) {
	qemu_chr_add_handlers(s->chr, NULL, NULL, NULL, NULL);
	qemu_chr_fe_release(s->chr);
	s->chr = NULL;
	}

	qemu_purge_queued_packets(nc);
	}

	static bool vhost_user_has_vnet_hdr(NetClientState *nc)
	{
	assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER);

	return true;
	}

	static bool vhost_user_has_ufo(NetClientState *nc)
	{
	assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER);

	return true;
	}

	static NetClientInfo net_vhost_user_info = {
	.type = NET_CLIENT_OPTIONS_KIND_VHOST_USER,
	.size = sizeof(VhostUserState),
	.receive = vhost_user_receive,
	.cleanup = vhost_user_cleanup,
	.has_vnet_hdr = vhost_user_has_vnet_hdr,
	.has_ufo = vhost_user_has_ufo,
	};

	static gboolean net_vhost_user_watch(GIOChannel *chan, GIOCondition cond,
	void *opaque)
	{
	VhostUserState *s = opaque;
	uint8_t buf[1];

	/* We don't actually want to read anything, but CHR_EVENT_CLOSED will be
	* raised as a side-effect of the read.
	*/
	qemu_chr_fe_read_all(s->chr, buf, sizeof(buf));

	return FALSE;
	}

	static void net_vhost_user_event(void *opaque, int event)
	{
	const char *name = opaque;
	NetClientState *ncs[MAX_QUEUE_NUM];
	VhostUserState *s;
	Error *err = NULL;
	int queues;

	queues = qemu_find_net_clients_except(name, ncs,
	NET_CLIENT_OPTIONS_KIND_NIC,
	MAX_QUEUE_NUM);
	assert(queues < MAX_QUEUE_NUM);

	s = DO_UPCAST(VhostUserState, nc, ncs[0]);
	trace_vhost_user_event(s->chr->label, event);
	switch (event) {
	case CHR_EVENT_OPENED:
	s->watch = qemu_chr_fe_add_watch(s->chr, G_IO_HUP,
	net_vhost_user_watch, s);
	if (vhost_user_start(queues, ncs) < 0) {
	qemu_chr_disconnect(s->chr);
	return;
	}
	qmp_set_link(name, true, &err);
	break;
	case CHR_EVENT_CLOSED:
	qmp_set_link(name, false, &err);
	vhost_user_stop(queues, ncs);
	g_source_remove(s->watch);
	s->watch = 0;
	break;
	}

	if (err) {
	error_report_err(err);
	}
	}

	static int net_vhost_user_init(NetClientState peer, const char device,
	const char name, CharDriverState chr,
	int queues)
	{
	NetClientState *nc;
	VhostUserState *s;
	int i;

	assert(name);
	assert(queues > 0);

	for (i = 0; i < queues; i++) {
	nc = qemu_new_net_client(&net_vhost_user_info, peer, device, name);

	snprintf(nc->info_str, sizeof(nc->info_str), "vhost-user%d to %s",
	i, chr->label);

	nc->queue_index = i;

	s = DO_UPCAST(VhostUserState, nc, nc);
	s->chr = chr;
	}

	qemu_chr_add_handlers(chr, NULL, NULL, net_vhost_user_event, nc[0].name);

	return 0;
	}

	static int net_vhost_chardev_opts(void *opaque,
	const char name, const char value,
	Error **errp)
	{
	VhostUserChardevProps *props = opaque;

	if (strcmp(name, "backend") == 0 && strcmp(value, "socket") == 0) {
	props->is_socket = true;
	} else if (strcmp(name, "path") == 0) {
	props->is_unix = true;
	} else if (strcmp(name, "server") == 0) {
	} else {
	error_setg(errp,
	"vhost-user does not support a chardev with option %s=%s",
	name, value);
	return -1;
	}
	return 0;
	}

	static CharDriverState *net_vhost_parse_chardev(
	const NetdevVhostUserOptions opts, Error *errp)
	{
	CharDriverState *chr = qemu_chr_find(opts->chardev);
	VhostUserChardevProps props;

	if (chr == NULL) {
	error_setg(errp, "chardev \"%s\" not found", opts->chardev);
	return NULL;
	}

	/* inspect chardev opts */
	memset(&props, 0, sizeof(props));
	if (qemu_opt_foreach(chr->opts, net_vhost_chardev_opts, &props, errp)) {
	return NULL;
	}

	if (!props.is_socket \|\| !props.is_unix) {
	error_setg(errp, "chardev \"%s\" is not a unix socket",
	opts->chardev);
	return NULL;
	}

	qemu_chr_fe_claim_no_fail(chr);

	return chr;
	}

	static int net_vhost_check_net(void opaque, QemuOpts opts, Error **errp)
	{
	const char *name = opaque;
	const char driver, netdev;
	const char virtio_name[] = "virtio-net-";

	driver = qemu_opt_get(opts, "driver");
	netdev = qemu_opt_get(opts, "netdev");

	if (!driver \|\| !netdev) {
	return 0;
	}

	if (strcmp(netdev, name) == 0 &&
	strncmp(driver, virtio_name, strlen(virtio_name)) != 0) {
	error_setg(errp, "vhost-user requires frontend driver virtio-net-*");
	return -1;
	}

	return 0;
	}

	int net_init_vhost_user(const NetClientOptions opts, const char name,
	NetClientState peer, Error *errp)
	{
	int queues;
	const NetdevVhostUserOptions *vhost_user_opts;
	CharDriverState *chr;

	assert(opts->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER);
	vhost_user_opts = opts->u.vhost_user.data;

	chr = net_vhost_parse_chardev(vhost_user_opts, errp);
	if (!chr) {
	return -1;
	}

	/* verify net frontend */
	if (qemu_opts_foreach(qemu_find_opts("device"), net_vhost_check_net,
	(char *)name, errp)) {
	return -1;
	}

	queues = vhost_user_opts->has_queues ? vhost_user_opts->queues : 1;
	if (queues < 1 \|\| queues > MAX_QUEUE_NUM) {
	error_setg(errp,
	"vhost-user number of queues must be in range [1, %d]",
	MAX_QUEUE_NUM);
	return -1;
	}

	return net_vhost_user_init(peer, "vhost_user", name, chr, queues);
	}