qemu-e2k/net/vhost-user.c
Marc-André Lureau a463215b08 vhost-net: save & restore vhost-user acked features
The initial vhost-user connection sets the features to be negotiated
with the driver. Renegotiation isn't possible without device reset.

To handle reconnection of vhost-user backend, ensure the same set of
features are provided, and reuse already acked features.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Tested-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Reviewed-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Reviewed-by: Victor Kaplansky <victork@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-06-17 03:28:03 +03:00

362 lines
9.5 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 "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;
int 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;
}
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);
}