linux-kernel - Re: [PATCH 3/5] vDPA: introduce vDPA bus

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Mon, 20 Jan 2020 15:50:01 +0800
From:   Jason Wang <jasowang@...hat.com>
To:     Jason Gunthorpe <jgg@...lanox.com>
Cc:     "mst@...hat.com" <mst@...hat.com>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "kvm@...r.kernel.org" <kvm@...r.kernel.org>,
        "virtualization@...ts.linux-foundation.org" 
        <virtualization@...ts.linux-foundation.org>,
        "netdev@...r.kernel.org" <netdev@...r.kernel.org>,
        "tiwei.bie@...el.com" <tiwei.bie@...el.com>,
        "maxime.coquelin@...hat.com" <maxime.coquelin@...hat.com>,
        "cunming.liang@...el.com" <cunming.liang@...el.com>,
        "zhihong.wang@...el.com" <zhihong.wang@...el.com>,
        "rob.miller@...adcom.com" <rob.miller@...adcom.com>,
        "xiao.w.wang@...el.com" <xiao.w.wang@...el.com>,
        "haotian.wang@...ive.com" <haotian.wang@...ive.com>,
        "lingshan.zhu@...el.com" <lingshan.zhu@...el.com>,
        "eperezma@...hat.com" <eperezma@...hat.com>,
        "lulu@...hat.com" <lulu@...hat.com>,
        Parav Pandit <parav@...lanox.com>,
        "kevin.tian@...el.com" <kevin.tian@...el.com>,
        "stefanha@...hat.com" <stefanha@...hat.com>,
        "rdunlap@...radead.org" <rdunlap@...radead.org>,
        "hch@...radead.org" <hch@...radead.org>,
        "aadam@...hat.com" <aadam@...hat.com>,
        "jakub.kicinski@...ronome.com" <jakub.kicinski@...ronome.com>,
        Jiri Pirko <jiri@...lanox.com>,
        Shahaf Shuler <shahafs@...lanox.com>,
        "hanand@...inx.com" <hanand@...inx.com>,
        "mhabets@...arflare.com" <mhabets@...arflare.com>
Subject: Re: [PATCH 3/5] vDPA: introduce vDPA bus


On 2020/1/17 下午9:54, Jason Gunthorpe wrote:
> On Fri, Jan 17, 2020 at 11:03:12AM +0800, Jason Wang wrote:
>> On 2020/1/16 下午11:22, Jason Gunthorpe wrote:
>>> On Thu, Jan 16, 2020 at 08:42:29PM +0800, Jason Wang wrote:
>>>> vDPA device is a device that uses a datapath which complies with the
>>>> virtio specifications with vendor specific control path. vDPA devices
>>>> can be both physically located on the hardware or emulated by
>>>> software. vDPA hardware devices are usually implemented through PCIE
>>>> with the following types:
>>>>
>>>> - PF (Physical Function) - A single Physical Function
>>>> - VF (Virtual Function) - Device that supports single root I/O
>>>>     virtualization (SR-IOV). Its Virtual Function (VF) represents a
>>>>     virtualized instance of the device that can be assigned to different
>>>>     partitions
>>>> - VDEV (Virtual Device) - With technologies such as Intel Scalable
>>>>     IOV, a virtual device composed by host OS utilizing one or more
>>>>     ADIs.
>>>> - SF (Sub function) - Vendor specific interface to slice the Physical
>>>>     Function to multiple sub functions that can be assigned to different
>>>>     partitions as virtual devices.
>>> I really hope we don't end up with two different ways to spell this
>>> same thing.
>> I think you meant ADI vs SF. It looks to me that ADI is limited to the scope
>> of scalable IOV but SF not.
> I think if one looks carefully you'd find that SF and ADI are using
> very similar techiniques. For instance we'd also like to use the code
> reorg of the MSIX vector setup with SFs that Intel is calling IMS.
>
> Really SIOV is simply a bundle of pre-existing stuff under a tidy
> name, whatever code skeleton we come up with for SFs should be re-used
> for ADI.


Ok, but do you prefer to mention ADI only for the next version?


>
>>> Shouldn't there be a device/driver matching process of some kind?
>>
>> The question is what do we want do match here.
>>
>> 1) "virtio" vs "vhost", I implemented matching method for this in mdev
>> series, but it looks unnecessary for vDPA device driver to know about this.
>> Anyway we can use sysfs driver bind/unbind to switch drivers
>> 2) virtio device id and vendor id. I'm not sure we need this consider the
>> two drivers so far (virtio/vhost) are all bus drivers.
> As we seem to be contemplating some dynamic creation of vdpa devices I
> think upon creation time it should be specified what mode they should
> run it and then all driver binding and autoloading should happen
> automatically. Telling the user to bind/unbind is a very poor
> experience.
>
> Jason


Ok, I will add the type (virtio vs vhost) and driver matching method back.

Thanks