Vhost-user will implement the multiqueueu support in a similar way to what
vhost already has - a separate thread for each queue.
To enable the multiqueue funcionality - a new command line parameter
"queues" is introduced for the vhost-user netdev.
Changes since v1:
- use s->nc.info_str when bringing up/down the backend
Signed-off-by: Nikolay Nikolaev <n.nikol...@virtualopensystems.com>
---
docs/specs/vhost-user.txt | 5 +++++
hw/virtio/vhost-user.c | 6 +++++-
net/vhost-user.c | 39 +++++++++++++++++++++++++--------------
qapi-schema.json | 6 +++++-
qemu-options.hx | 5 +++--
5 files changed, 43 insertions(+), 18 deletions(-)
diff --git a/docs/specs/vhost-user.txt b/docs/specs/vhost-user.txt
index 650bb18..d7b208c 100644
--- a/docs/specs/vhost-user.txt
+++ b/docs/specs/vhost-user.txt
@@ -127,6 +127,11 @@ in the ancillary data:
If Master is unable to send the full message or receives a wrong reply it will
close the connection. An optional reconnection mechanism can be implemented.
+Multi queue suport
+---------------------
+The protocol supports multiple queues by setting all index fields in the sent
+messages to a properly calculated value.
+
Message types
-------------
diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
index aefe0bb..83ebcaa 100644
--- a/hw/virtio/vhost-user.c
+++ b/hw/virtio/vhost-user.c
@@ -253,17 +253,20 @@ static int vhost_user_call(struct vhost_dev *dev,
unsigned long int request,
case VHOST_SET_VRING_NUM:
case VHOST_SET_VRING_BASE:
memcpy(&msg.state, arg, sizeof(struct vhost_vring_state));
+ msg.state.index += dev->vq_index;
msg.size = sizeof(m.state);
break;
case VHOST_GET_VRING_BASE:
memcpy(&msg.state, arg, sizeof(struct vhost_vring_state));
+ msg.state.index += dev->vq_index;
msg.size = sizeof(m.state);
need_reply = 1;
break;
case VHOST_SET_VRING_ADDR:
memcpy(&msg.addr, arg, sizeof(struct vhost_vring_addr));
+ msg.addr.index += dev->vq_index;
msg.size = sizeof(m.addr);
break;
@@ -271,7 +274,7 @@ static int vhost_user_call(struct vhost_dev *dev, unsigned
long int request,
case VHOST_SET_VRING_CALL:
case VHOST_SET_VRING_ERR:
file = arg;
- msg.u64 = file->index & VHOST_USER_VRING_IDX_MASK;
+ msg.u64 = (file->index + dev->vq_index) & VHOST_USER_VRING_IDX_MASK;
msg.size = sizeof(m.u64);
if (ioeventfd_enabled() && file->fd > 0) {
fds[fd_num++] = file->fd;
@@ -313,6 +316,7 @@ static int vhost_user_call(struct vhost_dev *dev, unsigned
long int request,
error_report("Received bad msg size.\n");
return -1;
}
+ msg.state.index -= dev->vq_index;
memcpy(arg, &msg.state, sizeof(struct vhost_vring_state));
break;
default:
diff --git a/net/vhost-user.c b/net/vhost-user.c
index 24e050c..a0b4af2 100644
--- a/net/vhost-user.c
+++ b/net/vhost-user.c
@@ -122,37 +122,39 @@ static void net_vhost_user_event(void *opaque, int event)
case CHR_EVENT_OPENED:
vhost_user_start(s);
net_vhost_link_down(s, false);
- error_report("chardev \"%s\" went up\n", s->chr->label);
+ error_report("chardev \"%s\" went up\n", s->nc.info_str);
break;
case CHR_EVENT_CLOSED:
net_vhost_link_down(s, true);
vhost_user_stop(s);
- error_report("chardev \"%s\" went down\n", s->chr->label);
+ error_report("chardev \"%s\" went down\n", s->nc.info_str);
break;
}
}
static int net_vhost_user_init(NetClientState *peer, const char *device,
const char *name, CharDriverState *chr,
- bool vhostforce)
+ bool vhostforce, uint32_t queues)
{
NetClientState *nc;
VhostUserState *s;
+ int i;
- nc = qemu_new_net_client(&net_vhost_user_info, peer, device, name);
+ 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 to %s",
- chr->label);
+ snprintf(nc->info_str, sizeof(nc->info_str), "vhost-user%d to %s",
+ i, chr->label);
- s = DO_UPCAST(VhostUserState, nc, nc);
+ s = DO_UPCAST(VhostUserState, nc, nc);
- /* We don't provide a receive callback */
- s->nc.receive_disabled = 1;
- s->chr = chr;
- s->vhostforce = vhostforce;
-
- qemu_chr_add_handlers(s->chr, NULL, NULL, net_vhost_user_event, s);
+ /* We don't provide a receive callback */
+ s->nc.receive_disabled = 1;
+ s->chr = chr;
+ s->vhostforce = vhostforce;
+ qemu_chr_add_handlers(s->chr, NULL, NULL, net_vhost_user_event, s);
+ }
return 0;
}
@@ -228,6 +230,7 @@ static int net_vhost_check_net(QemuOpts *opts, void *opaque)
int net_init_vhost_user(const NetClientOptions *opts, const char *name,
NetClientState *peer)
{
+ uint32_t queues;
const NetdevVhostUserOptions *vhost_user_opts;
CharDriverState *chr;
bool vhostforce;
@@ -254,5 +257,13 @@ int net_init_vhost_user(const NetClientOptions *opts,
const char *name,
vhostforce = false;
}
- return net_vhost_user_init(peer, "vhost_user", name, chr, vhostforce);
+ /* number of queues for multiqueue */
+ if (vhost_user_opts->has_queues) {
+ queues = vhost_user_opts->queues;
+ } else {
+ queues = 1;
+ }
+
+ return net_vhost_user_init(peer, "vhost_user", name, chr, vhostforce,
+ queues);
}
diff --git a/qapi-schema.json b/qapi-schema.json
index e16f8eb..c2cead0 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -2287,12 +2287,16 @@
#
# @vhostforce: #optional vhost on for non-MSIX virtio guests (default: false).
#
+# @queues: #optional number of queues to be created for multiqueue vhost-user
+# (Since 2.3)
+#
# Since 2.1
##
{ 'type': 'NetdevVhostUserOptions',
'data': {
'chardev': 'str',
- '*vhostforce': 'bool' } }
+ '*vhostforce': 'bool',
+ '*queues': 'uint32' } }
##
# @NetClientOptions
diff --git a/qemu-options.hx b/qemu-options.hx
index 85ca3ad..b5fa61f 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -1894,13 +1894,14 @@ The hubport netdev lets you connect a NIC to a QEMU
"vlan" instead of a single
netdev. @code{-net} and @code{-device} with parameter @option{vlan} create the
required hub automatically.
-@item -netdev vhost-user,chardev=@var{id}[,vhostforce=on|off]
+@item -netdev vhost-user,chardev=@var{id}[,vhostforce=on|off][,queues=n]
Establish a vhost-user netdev, backed by a chardev @var{id}. The chardev should
be a unix domain socket backed one. The vhost-user uses a specifically defined
protocol to pass vhost ioctl replacement messages to an application on the
other
end of the socket. On non-MSIX guests, the feature can be forced with
-@var{vhostforce}.
+@var{vhostforce}. Use 'queues=@var{n}' to specify the number of queues to
+be created for multiqueue vhost-user.
Example:
@example
