On 26.02.2019 15:32, Maxime Coquelin wrote: > > > On 2/26/19 9:42 AM, Ilya Maximets wrote: >> On 26.02.2019 11:13, Liu, Changpeng wrote: >>> >>> >>>> -----Original Message----- >>>> From: Ilya Maximets [mailto:i.maxim...@samsung.com] >>>> Sent: Tuesday, February 26, 2019 3:39 PM >>>> To: Liu, Changpeng <changpeng....@intel.com>; dev@dpdk.org >>>> Cc: Stojaczyk, Dariusz <dariusz.stojac...@intel.com>; >>>> maxime.coque...@redhat.com; Bie, Tiwei <tiwei....@intel.com>; Wang, >>>> Zhihong <zhihong.w...@intel.com>; Jason Wang <jasow...@redhat.com> >>>> Subject: Re: vhost: add virtio configuration space access socket messages >>>> >>>> On 26.02.2019 10:01, Liu, Changpeng wrote: >>>>> >>>>> >>>>>> -----Original Message----- >>>>>> From: Ilya Maximets [mailto:i.maxim...@samsung.com] >>>>>> Sent: Monday, February 25, 2019 9:20 PM >>>>>> To: Liu, Changpeng <changpeng....@intel.com>; dev@dpdk.org >>>>>> Cc: Stojaczyk, Dariusz <dariusz.stojac...@intel.com>; >>>>>> maxime.coque...@redhat.com; Bie, Tiwei <tiwei....@intel.com>; Wang, >>>>>> Zhihong <zhihong.w...@intel.com>; Jason Wang <jasow...@redhat.com> >>>>>> Subject: Re: vhost: add virtio configuration space access socket messages >>>>>> >>>>>> On 25.02.2019 10:51, Changpeng Liu wrote: >>>>>>> This patch adds new vhost user messages GET_CONFIG and SET_CONFIG >>>>>>> used to get/set virtio device's PCI configuration space. >>>>>> >>>>>> Beside the fact that some additional description and reasoning required, >>>>>> I do not see the usage of this feature. You're defining the flag >>>>>> VHOST_USER_PROTOCOL_F_CONFIG, but it's never used. So, none of dpdk >>>> vhost >>>>>> backends (vdpa, vhost-user) will use this feature. >>>>>> You, probably, missed adding it to VHOST_USER_PROTOCOL_FEATURES or >>>>>> VDPA_SUPPORTED_PROTOCOL_FEATURES. >>>>>> >>>>>> From the other side, current implementation forces application to >>>>>> properly >>>>>> implement the get/set_config callbacks. Otherwise, receiving of the >>>>>> messages >>>>>> will result in RTE_VHOST_MSG_RESULT_ERR and subsequent vhost >>>>>> disconnection. >>>>>> This looks strange, because supported protocol features normally enabled >>>>>> by >>>>>> default. Am I misunderstood something ? >>>>> QEMU will not send the messages if VHOST_USER_PROTOCOL_F_CONFIG >>>> wasn't enabled. >>>> >>>> So, you're going to enable it only by explicit call to >>>> 'rte_vhost_driver_set_features' ? >>>> >>>> In this case I'm assuming that you're implementing your own vhost backend. >>>> But why you're not using 'dev->extern_ops' and corresponding >>>> 'pre_msg_handle' >>>> or 'post_msg_handle' to handle your GET/SET_CONFIG messages like it does >>>> 'vhost_crypto' backend ? >>> The patch was developed one year ago, while DPDK didn't have external ops. >> >> So, maybe it's time to reconsider the implementation. > > +1 > >>> The get_config/set_config was defined for all the virtio devices, so I >>> think it makes >>> more sense adding here. >> >> VHOST_USER_*_CRYPTO_SESSION messages are defined for all the virtio devices >> too, however they makes sense for vhost_crypto backend only. These messages >> (GET/SET_CONFIG) makes sense only when callbacks (get/set_config) are >> implemented, so IMHO it's better to implement their handlers along with the >> callbacks, i.e. inside the implementation of your vhost backend. >> >> Maxime, Tiwei, what do you think ? > > I would prefer it to be implemented in SPDK directly as a pre_handler > callback, as I don't foresee a need for it for other backends, and it > would avoid breaking the API. > > It would imply fixing the beginning of vhost_user_msg_handler() to accept > requests > VHOST_USER_MAX and add necessary check before doing > the debug logs.
VHOST_USER_MAX is 31 and both new requests are defined in the same enum VhostUserRequest: VHOST_USER_GET_CONFIG = 24, VHOST_USER_SET_CONFIG = 25 I don't think that any change is needed here. > > With above change we would also be able to remove VHOST_CRYPTO requests > from vhost_user.c, Maybe you're looking at the different git HEAD ? I don't see any crypto related code in vhost_user.c. Only name definition in vhost_message_str. > and we could then work on moving vhost-net bits > out of this file too. > > Regards, > Maxime > > >