qemu/net/vhost-user.c
Adrian Moreno c6beefd674 vhost-user: save features if the char dev is closed
That way the state can be correctly restored when the device is opened
again. This might happen if the backend is restarted.

Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1738768
Reported-by: Pei Zhang <pezhang@redhat.com>
Fixes: 6ab79a20af ("do not call vhost_net_cleanup() on running net from char user event")
Cc: ddstreet@canonical.com
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: qemu-stable@nongnu.org
Signed-off-by: Adrian Moreno <amorenoz@redhat.com>
Message-Id: <20190924162044.11414-1-amorenoz@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2019-10-05 17:12:08 -04:00

442 lines
12 KiB
C

/*
* 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 "hw/virtio/vhost-user.h"
#include "chardev/char-fe.h"
#include "qapi/error.h"
#include "qapi/qapi-commands-net.h"
#include "qemu/config-file.h"
#include "qemu/error-report.h"
#include "qemu/option.h"
#include "trace.h"
typedef struct NetVhostUserState {
NetClientState nc;
CharBackend chr; /* only queue index 0 */
VhostUserState *vhost_user;
VHostNetState *vhost_net;
guint watch;
uint64_t acked_features;
bool started;
} NetVhostUserState;
VHostNetState *vhost_user_get_vhost_net(NetClientState *nc)
{
NetVhostUserState *s = DO_UPCAST(NetVhostUserState, nc, nc);
assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_USER);
return s->vhost_net;
}
uint64_t vhost_user_get_acked_features(NetClientState *nc)
{
NetVhostUserState *s = DO_UPCAST(NetVhostUserState, nc, nc);
assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_USER);
return s->acked_features;
}
static void vhost_user_stop(int queues, NetClientState *ncs[])
{
NetVhostUserState *s;
int i;
for (i = 0; i < queues; i++) {
assert(ncs[i]->info->type == NET_CLIENT_DRIVER_VHOST_USER);
s = DO_UPCAST(NetVhostUserState, nc, ncs[i]);
if (s->vhost_net) {
/* save acked features */
uint64_t features = vhost_net_get_acked_features(s->vhost_net);
if (features) {
s->acked_features = features;
}
vhost_net_cleanup(s->vhost_net);
}
}
}
static int vhost_user_start(int queues, NetClientState *ncs[],
VhostUserState *be)
{
VhostNetOptions options;
struct vhost_net *net = NULL;
NetVhostUserState *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_DRIVER_VHOST_USER);
s = DO_UPCAST(NetVhostUserState, nc, ncs[i]);
options.net_backend = ncs[i];
options.opaque = be;
options.busyloop_timeout = 0;
net = vhost_net_init(&options);
if (!net) {
error_report("failed to init vhost_net for queue %d", i);
goto err;
}
if (i == 0) {
max_queues = vhost_net_get_max_queues(net);
if (queues > max_queues) {
error_report("you are asking more queues than supported: %d",
max_queues);
goto err;
}
}
if (s->vhost_net) {
vhost_net_cleanup(s->vhost_net);
g_free(s->vhost_net);
}
s->vhost_net = net;
}
return 0;
err:
if (net) {
vhost_net_cleanup(net);
g_free(net);
}
vhost_user_stop(i, 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) {
NetVhostUserState *s = DO_UPCAST(NetVhostUserState, 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 net_vhost_user_cleanup(NetClientState *nc)
{
NetVhostUserState *s = DO_UPCAST(NetVhostUserState, nc, nc);
if (s->vhost_net) {
vhost_net_cleanup(s->vhost_net);
g_free(s->vhost_net);
s->vhost_net = NULL;
}
if (nc->queue_index == 0) {
if (s->watch) {
g_source_remove(s->watch);
s->watch = 0;
}
qemu_chr_fe_deinit(&s->chr, true);
if (s->vhost_user) {
vhost_user_cleanup(s->vhost_user);
g_free(s->vhost_user);
s->vhost_user = NULL;
}
}
qemu_purge_queued_packets(nc);
}
static int vhost_user_set_vnet_endianness(NetClientState *nc,
bool enable)
{
/* Nothing to do. If the server supports
* VHOST_USER_PROTOCOL_F_CROSS_ENDIAN, it will get the
* vnet header endianness from there. If it doesn't, negotiation
* fails.
*/
return 0;
}
static bool vhost_user_has_vnet_hdr(NetClientState *nc)
{
assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_USER);
return true;
}
static bool vhost_user_has_ufo(NetClientState *nc)
{
assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_USER);
return true;
}
static NetClientInfo net_vhost_user_info = {
.type = NET_CLIENT_DRIVER_VHOST_USER,
.size = sizeof(NetVhostUserState),
.receive = vhost_user_receive,
.cleanup = net_vhost_user_cleanup,
.has_vnet_hdr = vhost_user_has_vnet_hdr,
.has_ufo = vhost_user_has_ufo,
.set_vnet_be = vhost_user_set_vnet_endianness,
.set_vnet_le = vhost_user_set_vnet_endianness,
};
static gboolean net_vhost_user_watch(GIOChannel *chan, GIOCondition cond,
void *opaque)
{
NetVhostUserState *s = opaque;
qemu_chr_fe_disconnect(&s->chr);
return TRUE;
}
static void net_vhost_user_event(void *opaque, int event);
static void chr_closed_bh(void *opaque)
{
const char *name = opaque;
NetClientState *ncs[MAX_QUEUE_NUM];
NetVhostUserState *s;
Error *err = NULL;
int queues;
queues = qemu_find_net_clients_except(name, ncs,
NET_CLIENT_DRIVER_NIC,
MAX_QUEUE_NUM);
assert(queues < MAX_QUEUE_NUM);
s = DO_UPCAST(NetVhostUserState, nc, ncs[0]);
if (s->vhost_net) {
s->acked_features = vhost_net_get_acked_features(s->vhost_net);
}
qmp_set_link(name, false, &err);
qemu_chr_fe_set_handlers(&s->chr, NULL, NULL, net_vhost_user_event,
NULL, opaque, NULL, true);
if (err) {
error_report_err(err);
}
}
static void net_vhost_user_event(void *opaque, int event)
{
const char *name = opaque;
NetClientState *ncs[MAX_QUEUE_NUM];
NetVhostUserState *s;
Chardev *chr;
Error *err = NULL;
int queues;
queues = qemu_find_net_clients_except(name, ncs,
NET_CLIENT_DRIVER_NIC,
MAX_QUEUE_NUM);
assert(queues < MAX_QUEUE_NUM);
s = DO_UPCAST(NetVhostUserState, nc, ncs[0]);
chr = qemu_chr_fe_get_driver(&s->chr);
trace_vhost_user_event(chr->label, event);
switch (event) {
case CHR_EVENT_OPENED:
if (vhost_user_start(queues, ncs, s->vhost_user) < 0) {
qemu_chr_fe_disconnect(&s->chr);
return;
}
s->watch = qemu_chr_fe_add_watch(&s->chr, G_IO_HUP,
net_vhost_user_watch, s);
qmp_set_link(name, true, &err);
s->started = true;
break;
case CHR_EVENT_CLOSED:
/* a close event may happen during a read/write, but vhost
* code assumes the vhost_dev remains setup, so delay the
* stop & clear to idle.
* FIXME: better handle failure in vhost code, remove bh
*/
if (s->watch) {
AioContext *ctx = qemu_get_current_aio_context();
g_source_remove(s->watch);
s->watch = 0;
qemu_chr_fe_set_handlers(&s->chr, NULL, NULL, NULL, NULL,
NULL, NULL, false);
aio_bh_schedule_oneshot(ctx, chr_closed_bh, opaque);
}
break;
}
if (err) {
error_report_err(err);
}
}
static int net_vhost_user_init(NetClientState *peer, const char *device,
const char *name, Chardev *chr,
int queues)
{
Error *err = NULL;
NetClientState *nc, *nc0 = NULL;
NetVhostUserState *s = NULL;
VhostUserState *user;
int i;
assert(name);
assert(queues > 0);
user = g_new0(struct VhostUserState, 1);
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;
if (!nc0) {
nc0 = nc;
s = DO_UPCAST(NetVhostUserState, nc, nc);
if (!qemu_chr_fe_init(&s->chr, chr, &err) ||
!vhost_user_init(user, &s->chr, &err)) {
error_report_err(err);
goto err;
}
}
s = DO_UPCAST(NetVhostUserState, nc, nc);
s->vhost_user = user;
}
s = DO_UPCAST(NetVhostUserState, nc, nc0);
do {
if (qemu_chr_fe_wait_connected(&s->chr, &err) < 0) {
error_report_err(err);
goto err;
}
qemu_chr_fe_set_handlers(&s->chr, NULL, NULL,
net_vhost_user_event, NULL, nc0->name, NULL,
true);
} while (!s->started);
assert(s->vhost_net);
return 0;
err:
if (user) {
vhost_user_cleanup(user);
g_free(user);
if (s) {
s->vhost_user = NULL;
}
}
if (nc0) {
qemu_del_net_client(nc0);
}
return -1;
}
static Chardev *net_vhost_claim_chardev(
const NetdevVhostUserOptions *opts, Error **errp)
{
Chardev *chr = qemu_chr_find(opts->chardev);
if (chr == NULL) {
error_setg(errp, "chardev \"%s\" not found", opts->chardev);
return NULL;
}
if (!qemu_chr_has_feature(chr, QEMU_CHAR_FEATURE_RECONNECTABLE)) {
error_setg(errp, "chardev \"%s\" is not reconnectable",
opts->chardev);
return NULL;
}
if (!qemu_chr_has_feature(chr, QEMU_CHAR_FEATURE_FD_PASS)) {
error_setg(errp, "chardev \"%s\" does not support FD passing",
opts->chardev);
return NULL;
}
return chr;
}
static int net_vhost_check_net(void *opaque, QemuOpts *opts, Error **errp)
{
const char *name = opaque;
const char *driver, *netdev;
driver = qemu_opt_get(opts, "driver");
netdev = qemu_opt_get(opts, "netdev");
if (!driver || !netdev) {
return 0;
}
if (strcmp(netdev, name) == 0 &&
!g_str_has_prefix(driver, "virtio-net-")) {
error_setg(errp, "vhost-user requires frontend driver virtio-net-*");
return -1;
}
return 0;
}
int net_init_vhost_user(const Netdev *netdev, const char *name,
NetClientState *peer, Error **errp)
{
int queues;
const NetdevVhostUserOptions *vhost_user_opts;
Chardev *chr;
assert(netdev->type == NET_CLIENT_DRIVER_VHOST_USER);
vhost_user_opts = &netdev->u.vhost_user;
chr = net_vhost_claim_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);
}