Skip to contentSkip to conversation

vhost-user: add multi queue support

PATCH In review Nikolay Nikolaev 4 participants 7 messages Jan 24, 2015 – May 21, 2015 Networking

lore
Share & tools
lore

Nikolay Nikolaev

author
#0 lore raw

PATCH v2 1/1 vhost-user: add multi queue support

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 <[email protected]>
---
 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(-)
docs/specs/vhost-user.txt +5 -0
index 650bb18..d7b208c 100644
@@ -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
 -------------
hw/virtio/vhost-user.c +5 -1
index aefe0bb..83ebcaa 100644
@@ -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:
net/vhost-user.c +25 -14
index 24e050c..a0b4af2 100644
@@ -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);
 }
qapi-schema.json +5 -1
index e16f8eb..c2cead0 100644
@@ -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
qemu-options.hx +3 -2
index 85ca3ad..b5fa61f 100644
@@ -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
#1 lore raw
Quoted 1 line · Nikolay Nikolaev

Vhost-user will implement the multiqueueu support in a similar way to what

s/multiqueueu/multiqueue/

Also, you probably want to be consistent - is it two words (subject line) or one word (this sentence)? I could go either way.

Quoted 3 lines

vhost already has - a separate thread for each queue.

To enable the multiqueue funcionality - a new command line parameter

s/funcionality/functionality/

Quoted 4 lines

"queues" is introduced for the vhost-user netdev.

Changes since v1:
- use s->nc.info_str when bringing up/down the backend

This paragraph about path versioning belongs...

Quoted 3 lines
Signed-off-by Nikolay Nikolaev <[email protected]>

---

...here, after the --- separator. It is useful to reviewers, but makes no sense in the final qemu.git repository (a year from now, we only care about the one version that got committed, not how many tries it took to get to that one version).

Quoted 12 lines
 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(-)
docs/specs/vhost-user.txt +0 -0
index 650bb18..d7b208c 100644

docs/specs/vhost-user.txt in the ancillary data: · line 130

Quoted 4 lines
docs/specs/vhost-user.txt +1 -0
@@ -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

s/suport/support/

docs/specs/vhost-user.txt in the ancillary data: · line 131

Quoted 1 line
docs/specs/vhost-user.txt +1 -0
+---------------------

Make the length of this separator match the text it is underlining (too long, even after the typo fix)

docs/specs/vhost-user.txt line 2291

Quoted 7 lines
docs/specs/vhost-user.txt +3 -0
+++ 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)

Might be worth mentioning that the default is 1.

Signature · 2 lines
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org
#2 lore raw
In reply to Nikolay Nikolaev
Quoted 1 line · Nikolay Nikolaev

Vhost-user will implement the multiqueueu support in a similar way to what

multiqueue

docs/specs/vhost-user.txt

Quoted 21 lines

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 <[email protected]>
---
 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(-)
docs/specs/vhost-user.txt +0 -0
index 650bb18..d7b208c 100644

I've been thinking that the protocol might be a useful addition to the virtio spec. For this, as a minimum you would have to submit this document as a comment to virtio TC with a proposal to include it in the virtio spec.
See
https://www.oasis-open.org/committees/comments/index.php?wg_abbrev=virtio

Can you do this?

We can take it from there, though I would encourage your company to join as a contributor.

docs/specs/vhost-user.txt in the ancillary data: · line 134

Quoted 9 lines
docs/specs/vhost-user.txt +5 -0
@@ -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.
+

Something that's not clear from this document is what happens with control VQ. Can you clarify please?

Quoted 168 lines
docs/specs/vhost-user.txt +0 -0
 Message types
 -------------
hw/virtio/vhost-user.c +5 -1
index aefe0bb..83ebcaa 100644
@@ -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:
net/vhost-user.c +25 -14
index 24e050c..a0b4af2 100644
@@ -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);
 }
qapi-schema.json +5 -1
index e16f8eb..c2cead0 100644
@@ -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
qemu-options.hx +3 -2
index 85ca3ad..b5fa61f 100644
@@ -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
author
#3 lore raw
Quoted 35 lines · Michael S. Tsirkin
Quoted 1 line · Nikolay Nikolaev

Vhost-user will implement the multiqueueu support in a similar way to what

multiqueue

docs/specs/vhost-user.txt

Quoted 21 lines

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 <[email protected]>
---
 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(-)
docs/specs/vhost-user.txt +0 -0
index 650bb18..d7b208c 100644

I've been thinking that the protocol might be a useful addition to the virtio spec. For this, as a minimum you would have to submit this document as a comment to virtio TC with a proposal to include it in the virtio spec.
See
https://www.oasis-open.org/committees/comments/index.php?wg_abbrev=virtio

Quoted 1 line

Can you do this?

This is actually a great idea. I'll post the document to the comment's list. Do you prefer the upstream version or this one with the MQ additions?

I believe we have to go for the feature negotiation you're proposing and then add MQ,
reconnections etc. as negotiable features on top. So for the first version in virtio spec
we can go with this v1.0 of the vhost-user protocol.

Quoted 3 lines

We can take it from there, though I would encourage your company to join as a contributor.

We'll refrain from joining the TC for the time being, but we may consider it in the future.

Quoted 6 lines
Quoted 6 lines
docs/specs/vhost-user.txt +0 -0
@@ -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.
Quoted 8 lines

docs/specs/vhost-user.txt in the ancillary data: · line 134

Quoted 5 lines
docs/specs/vhost-user.txt +5 -0
+Multi queue suport
+---------------------
+The protocol supports multiple queues by setting all index fields in the sent
+messages to a properly calculated value.
+

Something that's not clear from this document is what happens with control VQ. Can you clarify please?

Well, the control VQ is a property of the virtio net device. The vhost-user protocol operates
at the generic virtio level. It has not defined specifics for the different device types.

It is true that the current implementation handles the control VQ in QEMU itself. This is
because vhost-user was modeled over the 'tap' backend which exposes only the Rx/Tx queues to the
vhost-net kernel module.

I believe this doc should stay as generic as possible, but still we can add a note about the
current implementation. Something like:

NOTE: the current vhost-user implementation has no virtio device specifics. In that sense
the net device handles the cotrolq in QEMU and this it is not exposed to the slave.

regards,
Nikolay Nikolaev

Quoted 176 lines
Quoted 160 lines
docs/specs/vhost-user.txt +0 -0
 Message types
 -------------
hw/virtio/vhost-user.c +5 -1
index aefe0bb..83ebcaa 100644
@@ -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:
net/vhost-user.c +25 -14
index 24e050c..a0b4af2 100644
@@ -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);
 }
qapi-schema.json +5 -1
index e16f8eb..c2cead0 100644
@@ -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
qemu-options.hx +1 -1
index 85ca3ad..b5fa61f 100644
@@ -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]

qemu-options.hx The hubport netdev lets you connect a NIC to a QEMU "vlan" instead of a single · line 1907

Quoted 10 lines
qemu-options.hx +2 -1
 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

--
You received this message because you are subscribed to the Google Groups "Snabb Switch development" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send an email to [email protected].
Visit this group at http://groups.google.com/group/snabb-devel.

#4 lore raw
In reply to Michael S. Tsirkin

Hi guys,

Quoted 89 lines

-----Original Message-----
From: [email protected] [mailto:snabb- [email protected]] On Behalf Of Michael S. Tsirkin
Sent: Monday, April 6, 2015 11:07 PM
To: Nikolay Nikolaev
Cc: Long, Thomas; [email protected]; [email protected]; [email protected]; [email protected]
Subject: [snabb-devel] Re: [PATCH v2] vhost-user: add multi queue support

Quoted 2 lines · Nikolay Nikolaev

Vhost-user will implement the multiqueueu support in a similar way to what

multiqueue

docs/specs/vhost-user.txt

Quoted 21 lines

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 <[email protected]>
---
 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(-)
docs/specs/vhost-user.txt +0 -0
index 650bb18..d7b208c 100644

I've been thinking that the protocol might be a useful addition to the virtio spec. For this, as a minimum you would have to submit this document as a comment to virtio TC with a proposal to include it in the virtio spec. See
https://www.oasis-
open.org/committees/comments/index.php?wg_abbrev=virtio

Can you do this?

We can take it from there, though I would encourage your company to join as a contributor.

Quoted 3 lines
docs/specs/vhost-user.txt +0 -0
@@ -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.

docs/specs/vhost-user.txt

Quoted 6 lines
docs/specs/vhost-user.txt +5 -0
+Multi queue suport
+---------------------
+The protocol supports multiple queues by setting all index fields in
+the sent messages to a properly calculated value.
+

Something that's not clear from this document is what happens with control VQ.
Can you clarify please?

hw/virtio/vhost-user.c static int vhost_user_call(struct vhost_dev *dev,

Quoted 8 lines

Message types
-------------

hw/virtio/vhost-user.c index renamed from hw/virtio/vhost-user.c +0 -0

aefe0bb..83ebcaa 100644

hw/virtio/vhost-user.c +0 -0
@@ -253,17 +253,20 @@ static int vhost_user_call(struct vhost_dev *dev,

unsigned long int request,

Quoted 14 lines
hw/virtio/vhost-user.c +2 -0
     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;
Quoted 14 lines

hw/virtio/vhost-user.c static int vhost_user_call(struct vhost_dev *dev,

Quoted 7 lines
hw/virtio/vhost-user.c +1 -0
     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,

Quoted 6 lines
hw/virtio/vhost-user.c +2 -1
     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;

I identify one vq_index issue here when it is the case of VHOST_SET_VRING_CALL,
The vq_index is not initialized before it is used here, so it could be a random value.
It leads to error in vhost, when this random value is passed to vhost and vhost use this random value to set the vring call.

I have a quick fix for this, code changes as the following:

hw/net/vhost_net.c +1 -0
index 4e3a061..2fbdb93 100644
@@ -157,6 +157,7 @@ struct vhost_net *vhost_net_init(VhostNetOptions *options)
 
     net->dev.nvqs = 2;
     net->dev.vqs = net->vqs;
+    net->dev.vq_index = net->nc->queue_index;
 
     r = vhost_dev_init(&net->dev, options->opaque,
                        options->backend_type, options->force);
net/vhost-user.c +1 -0
index a0b4af2..b27190f 100644
@@ -152,6 +152,7 @@ static int net_vhost_user_init(NetClientState *peer, const char *device,
         s->nc.receive_disabled = 1;
         s->chr = chr;
         s->vhostforce = vhostforce;
+        s->nc.queue_index = i;
 
         qemu_chr_add_handlers(s->chr, NULL, NULL, net_vhost_user_event, s);
     }

Would you guys have a look at this issue?
And I also met other issues when I try to run with 2 virtio ports, each one has 2 queues But not root cause yet, need further investigate,
So I think it may have more issues in qemu for vhost user multiple queues enabling.

Quoted 144 lines

net/vhost-user.c static void net_vhost_user_event(void *opaque,

Quoted 16 lines
hw/virtio/vhost-user.c +0 -0
         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;
             }
hw/virtio/vhost-user.c +1 -0
+            msg.state.index -= dev->vq_index;
             memcpy(arg, &msg.state, sizeof(struct vhost_vring_state));
             break;
         default:
net/vhost-user.c index renamed from net/vhost-user.c +0 -0

24e050c..a0b4af2 100644

net/vhost-user.c +0 -0
@@ -122,37 +122,39 @@ static void net_vhost_user_event(void *opaque,

int event)

Quoted 15 lines
net/vhost-user.c +2 -2
     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;
     }
 }

net/vhost-user.c static void net_vhost_user_event(void *opaque, · line 142

Quoted 10 lines
net/vhost-user.c +2 -2
 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);

Quoted 8 lines
net/vhost-user.c +5 -2
+    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);

net/vhost-user.c static void net_vhost_user_event(void *opaque, · line 154

Quoted 10 lines
net/vhost-user.c +1 -7
 
-    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);

net/vhost-user.c static void net_vhost_user_event(void *opaque, · line 157

Quoted 6 lines
net/vhost-user.c +5 -0
+        /* 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);

net/vhost-user.c static int net_vhost_check_net(QemuOpts *opts, · line 230

Quoted 6 lines
net/vhost-user.c +1 -0
+    }
     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,

net/vhost-user.c int net_init_vhost_user(const NetClientOptions

Quoted 6 lines
net/vhost-user.c +1 -0
                         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,

Quoted 19 lines
net/vhost-user.c +9 -1
         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);
 }
qapi-schema.json index renamed from qapi-schema.json +0 -0

e16f8eb..c2cead0 100644

qapi-schema.json line 2288

Quoted 2 lines
qapi-schema.json +0 -0
@@ -2287,12 +2287,16 @@
 #
 # @vhostforce: #optional vhost on for non-MSIX virtio guests (default:

false).

qapi-schema.json line 2290

Quoted 2 lines
qapi-schema.json +1 -0
 #
+# @queues: #optional number of queues to be created for multiqueue

vhost-user

Quoted 18 lines
qapi-schema.json +4 -1
+#          (Since 2.3)
+#
 # Since 2.1
 ##
 { 'type': 'NetdevVhostUserOptions',
   'data': {
     'chardev':        'str',
-    '*vhostforce':    'bool' } }
+    '*vhostforce':    'bool',
+    '*queues':        'uint32' } }
 
 ##
 # @NetClientOptions
qemu-options.hx index 85ca3ad..b5fa61f renamed from qemu-options.hx +0 -0

100644

qemu-options.hx +0 -0
@@ -1894,13 +1894,14 @@ The hubport netdev lets you connect a NIC to a
Quoted 2 lines

QEMU "vlan" instead of a single netdev. @code{-net} and @code{-device} with parameter @option{vlan} create the required hub

automatically.

Quoted 15 lines

-@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

#5 lore raw

PATCH v3 1/1 vhost-user: add multi queue support

In reply to Nikolay Nikolaev

From: Changchun Ouyang <[email protected]>

Based on patch by Nikolay Nikolaev:
Vhost-user will implement the multi queue support in a similar way to what vhost already has - a separate thread for each queue. To enable the multi queue funcionality - a new command line parameter "queues" is introduced for the vhost-user netdev.

Signed-off-by Nikolay Nikolaev <[email protected]>
Signed-off-by Changchun Ouyang <[email protected]>

---
Changes since v2:
- fix vq index issue for set_vring_call
When it is the case of VHOST_SET_VRING_CALL, The vq_index is not initialized before it is used, thus it could be a random value. The random value lead to crash in vhost after passing down to vhost, as vhost use this random value to index an array index.
- fix the typo in the doc and description
- address vq index for reset_owner

Changes since v1:
- use s->nc.info_str when bringing up/down the backend

 docs/specs/vhost-user.txt |  5 +++++
 hw/net/vhost_net.c        |  3 ++-
 hw/virtio/vhost-user.c    | 11 ++++++++++-
 net/vhost-user.c          | 37 ++++++++++++++++++++++++-------------
 qapi-schema.json          |  6 +++++-
 qemu-options.hx           |  5 +++--
 6 files changed, 49 insertions(+), 18 deletions(-)
docs/specs/vhost-user.txt +5 -0
index 650bb18..2c8e934 100644
@@ -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 support
+-------------------
+The protocol supports multiple queues by setting all index fields in the sent
+messages to a properly calculated value.
+
 Message types
 -------------
hw/net/vhost_net.c +2 -1
index 47f8b89..426b23e 100644
@@ -157,6 +157,7 @@ struct vhost_net *vhost_net_init(VhostNetOptions *options)
 
     net->dev.nvqs = 2;
     net->dev.vqs = net->vqs;
+    net->dev.vq_index = net->nc->queue_index;
 
     r = vhost_dev_init(&net->dev, options->opaque,
                        options->backend_type, options->force);

@@ -267,7 +268,7 @@ static void vhost_net_stop_one(struct vhost_net *net,
         for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
             const VhostOps *vhost_ops = net->dev.vhost_ops;
             int r = vhost_ops->vhost_call(&net->dev, VHOST_RESET_OWNER,
-                                          NULL);
+                                          &file);
             assert(r >= 0);
         }
     }
hw/virtio/vhost-user.c +10 -1
index e7ab829..d6f2163 100644
@@ -210,7 +210,12 @@ static int vhost_user_call(struct vhost_dev *dev, unsigned long int request,
         break;
 
     case VHOST_SET_OWNER:
+        break;
+
     case VHOST_RESET_OWNER:
+        memcpy(&msg.state, arg, sizeof(struct vhost_vring_state));
+        msg.state.index += dev->vq_index;
+        msg.size = sizeof(m.state);
         break;
 
     case VHOST_SET_MEM_TABLE:

@@ -253,17 +258,20 @@ 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 +279,7 @@ 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 +321,7 @@ static int vhost_user_call(struct vhost_dev *dev, unsigned long int request,
                 error_report("Received bad msg size.");
                 return -1;
             }
+            msg.state.index -= dev->vq_index;
             memcpy(arg, &msg.state, sizeof(struct vhost_vring_state));
             break;
         default:
net/vhost-user.c +24 -13
index 1d86a2b..41c8a27 100644
@@ -121,35 +121,39 @@ 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", 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", 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)
+                               const char *name, CharDriverState *chr,
+                               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;
-
-    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->nc.queue_index = i;
 
+        qemu_chr_add_handlers(s->chr, NULL, NULL, net_vhost_user_event, s);
+    }
     return 0;
 }
 

@@ -225,6 +229,7 @@ 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;
 

@@ -243,6 +248,12 @@ int net_init_vhost_user(const NetClientOptions *opts, const char *name,
         return -1;
     }
 
+    /* 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);
+    return net_vhost_user_init(peer, "vhost_user", name, chr, queues);
 }
qapi-schema.json +5 -1
index f97ffa1..53c7839 100644
@@ -2444,12 +2444,16 @@
 #
 # @vhostforce: #optional vhost on for non-MSIX virtio guests (default: false).
 #
+# @queues: #optional number of queues to be created for multiqueue vhost-user (default: 1).
+#          (Since 2.4)
+#
 # Since 2.1
 ##
 { 'struct': 'NetdevVhostUserOptions',
   'data': {
     'chardev':        'str',
-    '*vhostforce':    'bool' } }
+    '*vhostforce':    'bool',
+    '*queues':        'uint32' } }
 
 ##
 # @NetClientOptions
qemu-options.hx +3 -2
index ec356f6..dad035e 100644
@@ -1942,13 +1942,14 @@ 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
Signature · 1 line
1.8.4.2
#6 lore raw
Quoted 2 lines · Ouyang Changchun

From: Changchun Ouyang <[email protected]>

It's better to post a v3 patch as a new top-level thread, rather than in-reply-to an existing thread.

Quoted 4 lines

Based on patch by Nikolay Nikolaev:
Vhost-user will implement the multi queue support in a similar way to what vhost already has - a separate thread for each queue. To enable the multi queue funcionality - a new command line parameter

s/funcionality/functionality/

Quoted 15 lines

"queues" is introduced for the vhost-user netdev.

Signed-off-by Nikolay Nikolaev <[email protected]>
Signed-off-by Changchun Ouyang <[email protected]>

---
Changes since v2:
- fix vq index issue for set_vring_call
When it is the case of VHOST_SET_VRING_CALL, The vq_index is not initialized before it is used, thus it could be a random value. The random value lead to crash in vhost after passing down to vhost, as vhost use this random value to index an array index.
- fix the typo in the doc and description
- address vq index for reset_owner

+++ b/qapi-schema.json

qapi-schema.json line 2447

Quoted 4 lines
qapi-schema.json +1 -0
@@ -2444,12 +2444,16 @@
 #
 # @vhostforce: #optional vhost on for non-MSIX virtio guests (default: false).
 #
+# @queues: #optional number of queues to be created for multiqueue vhost-user (default: 1).

Long line; please wrap to fit under 80 columns.

Quoted 10 lines
qapi-schema.json +4 -1
+#          (Since 2.4)
+#
 # Since 2.1
 ##
 { 'struct': 'NetdevVhostUserOptions',
   'data': {
     'chardev':        'str',
-    '*vhostforce':    'bool' } }
+    '*vhostforce':    'bool',
+    '*queues':        'uint32' } }
Signature · 2 lines
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org