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![Yunjian Wang](/assets/img/avatar_default.png)
"nc" is freed after hotplug vhost-user, but the watcher is not removed. The QEMU crash when the watcher access the "nc" when socket disconnects. Program received signal SIGSEGV, Segmentation fault. #0 object_get_class (obj=obj@entry=0x2) at qom/object.c:750 #1 0x00007f9bb4180da1 in qemu_chr_fe_disconnect (be=<optimized out>) at chardev/char-fe.c:372 #2 0x00007f9bb40d1100 in net_vhost_user_watch (chan=<optimized out>, cond=<optimized out>, opaque=<optimized out>) at net/vhost-user.c:188 #3 0x00007f9baf97f99a in g_main_context_dispatch () from /usr/lib64/libglib-2.0.so.0 #4 0x00007f9bb41d7ebc in glib_pollfds_poll () at util/main-loop.c:213 #5 os_host_main_loop_wait (timeout=<optimized out>) at util/main-loop.c:261 #6 main_loop_wait (nonblocking=nonblocking@entry=0) at util/main-loop.c:515 #7 0x00007f9bb3e266a7 in main_loop () at vl.c:1917 #8 main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at vl.c:4786 Signed-off-by: Yunjian Wang <wangyunjian@huawei.com> Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
397 lines
11 KiB
C
397 lines
11 KiB
C
/*
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* vhost-user.c
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*
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* Copyright (c) 2013 Virtual Open Systems Sarl.
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*
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* This work is licensed under the terms of the GNU GPL, version 2 or later.
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* See the COPYING file in the top-level directory.
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*
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*/
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#include "qemu/osdep.h"
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#include "clients.h"
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#include "net/vhost_net.h"
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#include "net/vhost-user.h"
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#include "chardev/char-fe.h"
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#include "qemu/config-file.h"
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#include "qemu/error-report.h"
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#include "qmp-commands.h"
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#include "trace.h"
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typedef struct VhostUserState {
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NetClientState nc;
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CharBackend chr; /* only queue index 0 */
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VHostNetState *vhost_net;
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guint watch;
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uint64_t acked_features;
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bool started;
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} VhostUserState;
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VHostNetState *vhost_user_get_vhost_net(NetClientState *nc)
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{
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VhostUserState *s = DO_UPCAST(VhostUserState, nc, nc);
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assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_USER);
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return s->vhost_net;
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}
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uint64_t vhost_user_get_acked_features(NetClientState *nc)
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{
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VhostUserState *s = DO_UPCAST(VhostUserState, nc, nc);
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assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_USER);
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return s->acked_features;
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}
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static void vhost_user_stop(int queues, NetClientState *ncs[])
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{
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VhostUserState *s;
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int i;
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for (i = 0; i < queues; i++) {
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assert(ncs[i]->info->type == NET_CLIENT_DRIVER_VHOST_USER);
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s = DO_UPCAST(VhostUserState, nc, ncs[i]);
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if (s->vhost_net) {
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/* save acked features */
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uint64_t features = vhost_net_get_acked_features(s->vhost_net);
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if (features) {
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s->acked_features = features;
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}
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vhost_net_cleanup(s->vhost_net);
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}
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}
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}
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static int vhost_user_start(int queues, NetClientState *ncs[], CharBackend *be)
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{
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VhostNetOptions options;
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struct vhost_net *net = NULL;
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VhostUserState *s;
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int max_queues;
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int i;
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options.backend_type = VHOST_BACKEND_TYPE_USER;
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for (i = 0; i < queues; i++) {
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assert(ncs[i]->info->type == NET_CLIENT_DRIVER_VHOST_USER);
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s = DO_UPCAST(VhostUserState, nc, ncs[i]);
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options.net_backend = ncs[i];
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options.opaque = be;
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options.busyloop_timeout = 0;
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net = vhost_net_init(&options);
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if (!net) {
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error_report("failed to init vhost_net for queue %d", i);
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goto err;
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}
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if (i == 0) {
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max_queues = vhost_net_get_max_queues(net);
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if (queues > max_queues) {
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error_report("you are asking more queues than supported: %d",
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max_queues);
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goto err;
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}
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}
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if (s->vhost_net) {
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vhost_net_cleanup(s->vhost_net);
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g_free(s->vhost_net);
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}
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s->vhost_net = net;
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}
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return 0;
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err:
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if (net) {
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vhost_net_cleanup(net);
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}
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vhost_user_stop(i, ncs);
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return -1;
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}
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static ssize_t vhost_user_receive(NetClientState *nc, const uint8_t *buf,
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size_t size)
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{
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/* In case of RARP (message size is 60) notify backup to send a fake RARP.
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This fake RARP will be sent by backend only for guest
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without GUEST_ANNOUNCE capability.
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*/
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if (size == 60) {
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VhostUserState *s = DO_UPCAST(VhostUserState, nc, nc);
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int r;
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static int display_rarp_failure = 1;
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char mac_addr[6];
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/* extract guest mac address from the RARP message */
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memcpy(mac_addr, &buf[6], 6);
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r = vhost_net_notify_migration_done(s->vhost_net, mac_addr);
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if ((r != 0) && (display_rarp_failure)) {
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fprintf(stderr,
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"Vhost user backend fails to broadcast fake RARP\n");
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fflush(stderr);
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display_rarp_failure = 0;
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}
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}
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return size;
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}
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static void vhost_user_cleanup(NetClientState *nc)
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{
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VhostUserState *s = DO_UPCAST(VhostUserState, nc, nc);
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if (s->vhost_net) {
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vhost_net_cleanup(s->vhost_net);
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g_free(s->vhost_net);
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s->vhost_net = NULL;
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}
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if (nc->queue_index == 0) {
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if (s->watch) {
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g_source_remove(s->watch);
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s->watch = 0;
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}
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qemu_chr_fe_deinit(&s->chr, true);
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}
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qemu_purge_queued_packets(nc);
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}
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static bool vhost_user_has_vnet_hdr(NetClientState *nc)
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{
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assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_USER);
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return true;
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}
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static bool vhost_user_has_ufo(NetClientState *nc)
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{
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assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_USER);
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return true;
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}
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static NetClientInfo net_vhost_user_info = {
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.type = NET_CLIENT_DRIVER_VHOST_USER,
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.size = sizeof(VhostUserState),
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.receive = vhost_user_receive,
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.cleanup = vhost_user_cleanup,
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.has_vnet_hdr = vhost_user_has_vnet_hdr,
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.has_ufo = vhost_user_has_ufo,
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};
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static gboolean net_vhost_user_watch(GIOChannel *chan, GIOCondition cond,
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void *opaque)
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{
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VhostUserState *s = opaque;
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qemu_chr_fe_disconnect(&s->chr);
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return TRUE;
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}
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static void net_vhost_user_event(void *opaque, int event);
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static void chr_closed_bh(void *opaque)
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{
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const char *name = opaque;
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NetClientState *ncs[MAX_QUEUE_NUM];
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VhostUserState *s;
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Error *err = NULL;
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int queues;
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queues = qemu_find_net_clients_except(name, ncs,
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NET_CLIENT_DRIVER_NIC,
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MAX_QUEUE_NUM);
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assert(queues < MAX_QUEUE_NUM);
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s = DO_UPCAST(VhostUserState, nc, ncs[0]);
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qmp_set_link(name, false, &err);
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vhost_user_stop(queues, ncs);
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qemu_chr_fe_set_handlers(&s->chr, NULL, NULL, net_vhost_user_event,
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NULL, opaque, NULL, true);
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if (err) {
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error_report_err(err);
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}
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}
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static void net_vhost_user_event(void *opaque, int event)
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{
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const char *name = opaque;
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NetClientState *ncs[MAX_QUEUE_NUM];
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VhostUserState *s;
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Chardev *chr;
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Error *err = NULL;
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int queues;
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queues = qemu_find_net_clients_except(name, ncs,
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NET_CLIENT_DRIVER_NIC,
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MAX_QUEUE_NUM);
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assert(queues < MAX_QUEUE_NUM);
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s = DO_UPCAST(VhostUserState, nc, ncs[0]);
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chr = qemu_chr_fe_get_driver(&s->chr);
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trace_vhost_user_event(chr->label, event);
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switch (event) {
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case CHR_EVENT_OPENED:
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if (vhost_user_start(queues, ncs, &s->chr) < 0) {
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qemu_chr_fe_disconnect(&s->chr);
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return;
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}
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s->watch = qemu_chr_fe_add_watch(&s->chr, G_IO_HUP,
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net_vhost_user_watch, s);
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qmp_set_link(name, true, &err);
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s->started = true;
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break;
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case CHR_EVENT_CLOSED:
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/* a close event may happen during a read/write, but vhost
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* code assumes the vhost_dev remains setup, so delay the
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* stop & clear to idle.
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* FIXME: better handle failure in vhost code, remove bh
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*/
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if (s->watch) {
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AioContext *ctx = qemu_get_current_aio_context();
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g_source_remove(s->watch);
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s->watch = 0;
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qemu_chr_fe_set_handlers(&s->chr, NULL, NULL, NULL, NULL,
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NULL, NULL, false);
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aio_bh_schedule_oneshot(ctx, chr_closed_bh, opaque);
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}
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break;
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}
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if (err) {
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error_report_err(err);
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}
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}
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static int net_vhost_user_init(NetClientState *peer, const char *device,
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const char *name, Chardev *chr,
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int queues)
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{
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Error *err = NULL;
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NetClientState *nc, *nc0 = NULL;
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VhostUserState *s;
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int i;
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assert(name);
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assert(queues > 0);
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for (i = 0; i < queues; i++) {
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nc = qemu_new_net_client(&net_vhost_user_info, peer, device, name);
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snprintf(nc->info_str, sizeof(nc->info_str), "vhost-user%d to %s",
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i, chr->label);
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nc->queue_index = i;
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if (!nc0) {
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nc0 = nc;
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s = DO_UPCAST(VhostUserState, nc, nc);
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if (!qemu_chr_fe_init(&s->chr, chr, &err)) {
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error_report_err(err);
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return -1;
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}
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}
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}
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s = DO_UPCAST(VhostUserState, nc, nc0);
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do {
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if (qemu_chr_fe_wait_connected(&s->chr, &err) < 0) {
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error_report_err(err);
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return -1;
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}
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qemu_chr_fe_set_handlers(&s->chr, NULL, NULL,
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net_vhost_user_event, NULL, nc0->name, NULL,
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true);
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} while (!s->started);
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assert(s->vhost_net);
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return 0;
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}
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static Chardev *net_vhost_claim_chardev(
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const NetdevVhostUserOptions *opts, Error **errp)
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{
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Chardev *chr = qemu_chr_find(opts->chardev);
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if (chr == NULL) {
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error_setg(errp, "chardev \"%s\" not found", opts->chardev);
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return NULL;
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}
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if (!qemu_chr_has_feature(chr, QEMU_CHAR_FEATURE_RECONNECTABLE)) {
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error_setg(errp, "chardev \"%s\" is not reconnectable",
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opts->chardev);
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return NULL;
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}
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if (!qemu_chr_has_feature(chr, QEMU_CHAR_FEATURE_FD_PASS)) {
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error_setg(errp, "chardev \"%s\" does not support FD passing",
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opts->chardev);
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return NULL;
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}
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return chr;
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}
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static int net_vhost_check_net(void *opaque, QemuOpts *opts, Error **errp)
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{
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const char *name = opaque;
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const char *driver, *netdev;
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driver = qemu_opt_get(opts, "driver");
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netdev = qemu_opt_get(opts, "netdev");
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if (!driver || !netdev) {
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return 0;
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}
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if (strcmp(netdev, name) == 0 &&
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!g_str_has_prefix(driver, "virtio-net-")) {
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error_setg(errp, "vhost-user requires frontend driver virtio-net-*");
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return -1;
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}
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return 0;
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}
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int net_init_vhost_user(const Netdev *netdev, const char *name,
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NetClientState *peer, Error **errp)
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{
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int queues;
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const NetdevVhostUserOptions *vhost_user_opts;
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Chardev *chr;
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assert(netdev->type == NET_CLIENT_DRIVER_VHOST_USER);
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vhost_user_opts = &netdev->u.vhost_user;
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chr = net_vhost_claim_chardev(vhost_user_opts, errp);
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if (!chr) {
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return -1;
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}
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/* verify net frontend */
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if (qemu_opts_foreach(qemu_find_opts("device"), net_vhost_check_net,
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(char *)name, errp)) {
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return -1;
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}
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queues = vhost_user_opts->has_queues ? vhost_user_opts->queues : 1;
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if (queues < 1 || queues > MAX_QUEUE_NUM) {
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error_setg(errp,
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"vhost-user number of queues must be in range [1, %d]",
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MAX_QUEUE_NUM);
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return -1;
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}
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return net_vhost_user_init(peer, "vhost_user", name, chr, queues);
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}
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