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 58EDE1F28 for ; Wed, 28 Mar 2018 12:11:17 +0200 (CEST) Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id A8E844068053; Wed, 28 Mar 2018 10:11:16 +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 CB144946A2; Wed, 28 Mar 2018 10:11:13 +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 12:11:12 +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 2.79 on 10.11.54.5 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.5]); Wed, 28 Mar 2018 10:11:16 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.5]); Wed, 28 Mar 2018 10:11:16 +0000 (UTC) for IP:'10.11.54.5' DOMAIN:'int-mx05.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 10:11:17 -0000 On 03/28/2018 12:03 PM, Liu, Changpeng wrote: > > >> -----Original Message----- >> From: Maxime Coquelin [mailto:maxime.coquelin@redhat.com] >> Sent: Wednesday, March 28, 2018 5:58 PM >> To: Liu, Changpeng ; Kulasek, TomaszX >> ; yliu@fridaylinux.org >> Cc: Verkamp, Daniel ; Harris, James R >> ; Wodkowski, PawelX >> ; dev@dpdk.org; Tan, Jianfeng >> >> Subject: Re: [dpdk-dev] [PATCH v2] vhost: add virtio configuration space >> messages >> >> >> >> 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? > For now there are no other users except us care about this message, :), it's no hurry. > I can take this after QEMU 2.12 release adding a new protocol feature bit. Are you sure? If I understand the code correctly, as the guest writes in config regs of a virtio-blk device, .set_config callback will be called. If you have a vhost-user backend, it will receive the SET_CONFIG request, no? Cheers, Maxime >> >> Thanks, >> Maxime