From: Maxime Coquelin <maxime.coquelin@redhat.com>
To: "Liu, Changpeng" <changpeng.liu@intel.com>,
"Kulasek, TomaszX" <tomaszx.kulasek@intel.com>,
"yliu@fridaylinux.org" <yliu@fridaylinux.org>
Cc: "Verkamp, Daniel" <daniel.verkamp@intel.com>,
"Harris, James R" <james.r.harris@intel.com>,
"Wodkowski, PawelX" <pawelx.wodkowski@intel.com>,
"dev@dpdk.org" <dev@dpdk.org>,
"Tan, Jianfeng" <jianfeng.tan@intel.com>
Subject: Re: [dpdk-dev] [PATCH v2] vhost: add virtio configuration space messages
Date: Wed, 28 Mar 2018 11:57:40 +0200 [thread overview]
Message-ID: <fe5a4063-1848-11b3-85b6-6f1ba7db9f20@redhat.com> (raw)
In-Reply-To: <FF7FC980937D6342B9D289F5F3C7C2625B6252DD@SHSMSX103.ccr.corp.intel.com>
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 <tomaszx.kulasek@intel.com>; yliu@fridaylinux.org
>> Cc: Verkamp, Daniel <daniel.verkamp@intel.com>; Harris, James R
>> <james.r.harris@intel.com>; Wodkowski, PawelX
>> <pawelx.wodkowski@intel.com>; dev@dpdk.org; Liu, Changpeng
>> <changpeng.liu@intel.com>; Tan, Jianfeng <jianfeng.tan@intel.com>
>> 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 <changpeng.liu@intel.com>
>>> Signed-off-by: Tomasz Kulasek <tomaszx.kulasek@intel.com>
>>> ---
>>> 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
next prev parent reply other threads:[~2018-03-28 9:57 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-27 15:17 [dpdk-dev] [PATCH] " Tomasz Kulasek
2018-03-27 15:35 ` [dpdk-dev] [PATCH v2] " Tomasz Kulasek
2018-03-28 9:11 ` Maxime Coquelin
2018-03-28 9:19 ` Wodkowski, PawelX
2018-03-28 9:33 ` Maxime Coquelin
2018-03-28 9:48 ` Maxime Coquelin
2018-03-28 9:50 ` Liu, Changpeng
2018-03-28 9:57 ` Maxime Coquelin [this message]
2018-03-28 10:03 ` Liu, Changpeng
2018-03-28 10:11 ` Maxime Coquelin
2018-03-28 10:23 ` Liu, Changpeng
2018-03-28 10:56 ` Maxime Coquelin
2018-04-19 14:39 ` Maxime Coquelin
2018-04-20 0:32 ` Liu, Changpeng
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