From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by dpdk.org (Postfix) with ESMTP id 4553D19F5 for ; Wed, 28 Mar 2018 11:57:44 +0200 (CEST) Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id BFE0E4023155; Wed, 28 Mar 2018 09:57:43 +0000 (UTC) Received: from [10.36.112.44] (ovpn-112-44.ams2.redhat.com [10.36.112.44]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 03A482026985; Wed, 28 Mar 2018 09:57:41 +0000 (UTC) To: "Liu, Changpeng" , "Kulasek, TomaszX" , "yliu@fridaylinux.org" Cc: "Verkamp, Daniel" , "Harris, James R" , "Wodkowski, PawelX" , "dev@dpdk.org" , "Tan, Jianfeng" References: <20180327151737.6640-1-tomaszx.kulasek@intel.com> <20180327153500.10464-1-tomaszx.kulasek@intel.com> <6c556086-bccc-1e55-d490-c21bcc8a6c4b@redhat.com> From: Maxime Coquelin Message-ID: Date: Wed, 28 Mar 2018 11:57:40 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.78 on 10.11.54.4 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.6]); Wed, 28 Mar 2018 09:57:43 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.6]); Wed, 28 Mar 2018 09:57:43 +0000 (UTC) for IP:'10.11.54.4' DOMAIN:'int-mx04.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'maxime.coquelin@redhat.com' RCPT:'' Subject: Re: [dpdk-dev] [PATCH v2] vhost: add virtio configuration space messages X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 28 Mar 2018 09:57:44 -0000 On 03/28/2018 11:50 AM, Liu, Changpeng wrote: > > >> -----Original Message----- >> From: Maxime Coquelin [mailto:maxime.coquelin@redhat.com] >> Sent: Wednesday, March 28, 2018 5:12 PM >> To: Kulasek, TomaszX ; yliu@fridaylinux.org >> Cc: Verkamp, Daniel ; Harris, James R >> ; Wodkowski, PawelX >> ; dev@dpdk.org; Liu, Changpeng >> ; Tan, Jianfeng >> Subject: Re: [dpdk-dev] [PATCH v2] vhost: add virtio configuration space >> messages >> >> >> >> On 03/27/2018 05:35 PM, Tomasz Kulasek wrote: >>> This patch adds new vhost user messages GET_CONFIG and SET_CONFIG used >>> for get/set virtio device's configuration space. >>> >>> Signed-off-by: Changpeng Liu >>> Signed-off-by: Tomasz Kulasek >>> --- >>> Changes in v2: >>> - code cleanup >>> >>> lib/librte_vhost/rte_vhost.h | 4 ++++ >>> lib/librte_vhost/vhost_user.c | 22 ++++++++++++++++++++++ >>> lib/librte_vhost/vhost_user.h | 16 ++++++++++++++++ >>> 3 files changed, 42 insertions(+) >>> >>> diff --git a/lib/librte_vhost/rte_vhost.h b/lib/librte_vhost/rte_vhost.h >>> index d332069..fe30518 100644 >>> --- a/lib/librte_vhost/rte_vhost.h >>> +++ b/lib/librte_vhost/rte_vhost.h >>> @@ -84,6 +84,10 @@ struct vhost_device_ops { >>> int (*new_connection)(int vid); >>> void (*destroy_connection)(int vid); >>> >>> + int (*get_config)(int vid, uint8_t *config, uint32_t config_len); >>> + int (*set_config)(int vid, uint8_t *config, uint32_t offset, >>> + uint32_t len, uint32_t flags); >>> + >>> void *reserved[2]; /**< Reserved for future extension */ >> >> You are breaking the ABI, as you grow the size of the ops struct. >> >> Also, I'm wondering if we shouldn't have a different ops for external >> backends. Here these ops are more intended to the application, we could >> have a specific ops struct for external backends IMHO. >> >>> }; >>> >>> diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c >>> index 90ed211..0ed6a5a 100644 >>> --- a/lib/librte_vhost/vhost_user.c >>> +++ b/lib/librte_vhost/vhost_user.c >>> @@ -50,6 +50,8 @@ static const char *vhost_message_str[VHOST_USER_MAX] >> = { >>> [VHOST_USER_NET_SET_MTU] = "VHOST_USER_NET_SET_MTU", >>> [VHOST_USER_SET_SLAVE_REQ_FD] = >> "VHOST_USER_SET_SLAVE_REQ_FD", >>> [VHOST_USER_IOTLB_MSG] = "VHOST_USER_IOTLB_MSG", >>> + [VHOST_USER_GET_CONFIG] = "VHOST_USER_GET_CONFIG", >>> + [VHOST_USER_SET_CONFIG] = "VHOST_USER_SET_CONFIG", >>> }; >>> >>> static uint64_t >>> @@ -1355,6 +1357,7 @@ vhost_user_msg_handler(int vid, int fd) >>> * would cause a dead lock. >>> */ >>> switch (msg.request.master) { >>> + case VHOST_USER_SET_CONFIG: >> >> It seems VHOST_USER_GET_CONFIG is missing here. >> >>> case VHOST_USER_SET_FEATURES: >>> case VHOST_USER_SET_PROTOCOL_FEATURES: >>> case VHOST_USER_SET_OWNER: >>> @@ -1380,6 +1383,25 @@ vhost_user_msg_handler(int vid, int fd) >>> } >>> >>> switch (msg.request.master) { >>> + case VHOST_USER_GET_CONFIG: >>> + if (dev->notify_ops->get_config(dev->vid, >> Please check ->get_config is set before calling it. >> >>> + msg.payload.config.region, >>> + msg.payload.config.size) != 0) { >>> + msg.size = sizeof(uint64_t); >>> + } >>> + send_vhost_reply(fd, &msg); >>> + break; >>> + case VHOST_USER_SET_CONFIG: >>> + if ((dev->notify_ops->set_config(dev->vid, >> Ditto. >> >>> + msg.payload.config.region, >>> + msg.payload.config.offset, >>> + msg.payload.config.size, >>> + msg.payload.config.flags)) != 0) { >>> + ret = 1; >>> + } else { >>> + ret = 0; >>> + } >> >> ret = dev->notify_ops->set_config instead? >>> + break; >>> case VHOST_USER_GET_FEATURES: >>> msg.payload.u64 = vhost_user_get_features(dev); >>> msg.size = sizeof(msg.payload.u64); >>> diff --git a/lib/librte_vhost/vhost_user.h b/lib/librte_vhost/vhost_user.h >>> index d4bd604..25cc026 100644 >>> --- a/lib/librte_vhost/vhost_user.h >>> +++ b/lib/librte_vhost/vhost_user.h >>> @@ -14,6 +14,11 @@ >>> >>> #define VHOST_MEMORY_MAX_NREGIONS 8 >>> >>> +/* >>> + * Maximum size of virtio device config space >>> + */ >>> +#define VHOST_USER_MAX_CONFIG_SIZE 256 >>> + >>> #define VHOST_USER_PROTOCOL_F_MQ 0 >>> #define VHOST_USER_PROTOCOL_F_LOG_SHMFD 1 >>> #define VHOST_USER_PROTOCOL_F_RARP 2 >> >> Shouldn't there be a protocol feature associated to these new messages? >> Else how QEMU knows the backend supports it or not? >> >> I looked at QEMU code and indeed no protocol feature associated, that's >> strange... > Nice to have, for now not all the QEMU host driver need to get this configuration space from slave backend > when getting start. This message can be used for migration of vhost-user devices. So if QEMU sends this message but the DPDK version does not support it yet, vhost_user_msg_handler() will return an error ("vhost read incorrect message") and the socket will be closed. How do we overcome this? I think we really need a spec update ASAP, before QEMU v2.12 is out (-rc1 already). Do you have time to take care of this? Thanks, Maxime