From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51251) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YECuz-0004jW-4l for qemu-devel@nongnu.org; Thu, 22 Jan 2015 03:15:11 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YECuq-0001mM-ME for qemu-devel@nongnu.org; Thu, 22 Jan 2015 03:15:09 -0500 Received: from mail-qa0-f48.google.com ([209.85.216.48]:41901) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YECuq-0001mC-Ge for qemu-devel@nongnu.org; Thu, 22 Jan 2015 03:15:00 -0500 Received: by mail-qa0-f48.google.com with SMTP id v8so135121qal.7 for ; Thu, 22 Jan 2015 00:14:59 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <20150121142548.GA16545@redhat.com> References: <20141206165241.4064.61867.stgit@i3820> <20150121142548.GA16545@redhat.com> From: Nikolay Nikolaev Date: Thu, 22 Jan 2015 10:14:39 +0200 Message-ID: Content-Type: text/plain; charset=UTF-8 Subject: Re: [Qemu-devel] [snabb-devel] Re: [PATCH] vhost-user: multiqueue support List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "snabb-devel@googlegroups.com" Cc: VirtualOpenSystems Technical Team , "Long, Thomas" , qemu-devel On Wed, Jan 21, 2015 at 4:25 PM, Michael S. Tsirkin wrote: > > On Sat, Dec 06, 2014 at 06:52:56PM +0200, Nikolay Nikolaev wrote: > > Vhost-user will implement the multiqueueu support in a similar way to what > > vhost already has - a separate thread for each queue. > > > > To enable multiquue funcionality - a new command line parameter > > "queues" is introduced for the vhost-user netdev. > > > > Signed-off-by: Nikolay Nikolaev > > Nikolay - plan to repost addressing comments? I can send v2 with the small polishing fixes. However we currently don't have he resources to fix sending VHOST_USER_SET_OWNER, VHOST_USER_SET_FEATURES, VHOST_SET_MEM_TABLE messages per virtq. It work like this as it follows the tap backend behavior, which AFAIK assigns a different tap device per virtq and initializes them separately. At least I don't see an obvious and quick patch around this. > > > > --- > > docs/specs/vhost-user.txt | 7 +++++++ > > hw/virtio/vhost-user.c | 6 +++++- > > net/vhost-user.c | 35 +++++++++++++++++++++++------------ > > qapi-schema.json | 5 ++++- > > qemu-options.hx | 5 +++-- > > 5 files changed, 42 insertions(+), 16 deletions(-) > > > > diff --git a/docs/specs/vhost-user.txt b/docs/specs/vhost-user.txt > > index 650bb18..d3857f5 100644 > > --- a/docs/specs/vhost-user.txt > > +++ b/docs/specs/vhost-user.txt > > @@ -127,6 +127,13 @@ 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 value calculated by the following formula: > > + + > > +The is increased by 2. > > + > > Message types > > ------------- > > > > How is the support negotiated though? Not negotiated. Will a version bump be enough ? > What if I set queues=N with a legacy backend that > does not support multiqueue? It is supposed that the device that does not support MQ won't advertise VIRTIO_NET_F_MQ, thus not utilising more than 1 queue. Still the initialisation of the multiple virtqs will happen. regards, Nikolay Nikolaev > > > 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..1ea2f98 100644 > > --- a/net/vhost-user.c > > +++ b/net/vhost-user.c > > @@ -134,25 +134,27 @@ static void net_vhost_user_event(void *opaque, int event) > > > > 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 9ffdcf8..aa3bb6f 100644 > > --- a/qapi-schema.json > > +++ b/qapi-schema.json > > @@ -2208,12 +2208,15 @@ > > # > > # @vhostforce: #optional vhost on for non-MSIX virtio guests (default: false). > > # > > +# @queues: #optional number of queues to be created for multiqueue vhost-user > > +# > > # Since 2.1 > > ## > > { 'type': 'NetdevVhostUserOptions', > > 'data': { > > 'chardev': 'str', > > - '*vhostforce': 'bool' } } > > + '*vhostforce': 'bool', > > + '*queues': 'uint32' } } > > > > ## > > # @NetClientOptions > > diff --git a/qemu-options.hx b/qemu-options.hx > > index 64af16d..23f010f 100644 > > --- a/qemu-options.hx > > +++ b/qemu-options.hx > > @@ -1893,13 +1893,14 @@ 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 > > > > -- > 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 snabb-devel+unsubscribe@googlegroups.com. > To post to this group, send an email to snabb-devel@googlegroups.com. > Visit this group at http://groups.google.com/group/snabb-devel.