From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56913) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YxZjg-0001rf-Hd for qemu-devel@nongnu.org; Wed, 27 May 2015 07:43:02 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YxZjd-0003n9-8b for qemu-devel@nongnu.org; Wed, 27 May 2015 07:43:00 -0400 Received: from mx1.redhat.com ([209.132.183.28]:56866) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YxZjd-0003n3-0R for qemu-devel@nongnu.org; Wed, 27 May 2015 07:42:57 -0400 Date: Wed, 27 May 2015 13:42:49 +0200 From: "Michael S. Tsirkin" Message-ID: <20150527134016-mutt-send-email-mst@redhat.com> References: <1432274284-11814-1-git-send-email-changchun.ouyang@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1432274284-11814-1-git-send-email-changchun.ouyang@intel.com> Subject: Re: [Qemu-devel] [PATCH v4] vhost-user: add multi queue support List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Ouyang Changchun Cc: luke@snabb.co, snabb-devel@googlegroups.com, thomas.long@intel.com, qemu-devel@nongnu.org, n.nikolaev@virtualopensystems.com On Fri, May 22, 2015 at 01:58:04PM +0800, Ouyang Changchun wrote: > 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 functionality - a new command line parameter > "queues" is introduced for the vhost-user netdev. > > Signed-off-by: Nikolay Nikolaev > Signed-off-by: Changchun Ouyang Looks good to me, but I have a question, below. > --- > Changes since v3: > - fix one typo and wrap one long line > > 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 leads 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(-) > > diff --git a/docs/specs/vhost-user.txt b/docs/specs/vhost-user.txt > index 650bb18..2c8e934 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 support > +------------------- > +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/net/vhost_net.c b/hw/net/vhost_net.c > index 47f8b89..426b23e 100644 > --- a/hw/net/vhost_net.c > +++ b/hw/net/vhost_net.c > @@ -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); > } > } > diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c > index e7ab829..d6f2163 100644 > --- a/hw/virtio/vhost-user.c > +++ b/hw/virtio/vhost-user.c > @@ -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: > diff --git a/net/vhost-user.c b/net/vhost-user.c > index 1d86a2b..41c8a27 100644 > --- a/net/vhost-user.c > +++ b/net/vhost-user.c > @@ -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; > } > } > Hmm should the trailing \n be there? > 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); > } > diff --git a/qapi-schema.json b/qapi-schema.json > index f97ffa1..00791dd 100644 > --- a/qapi-schema.json > +++ b/qapi-schema.json > @@ -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 > diff --git a/qemu-options.hx b/qemu-options.hx > index ec356f6..dad035e 100644 > --- a/qemu-options.hx > +++ b/qemu-options.hx > @@ -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 > -- > 1.8.4.2 >