Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
MIME-Version: 1.0
In-Reply-To: <5fc62d10-790f-2356-c2f6-fd49f542dd3c@infradead.org>
References: <20180420162633.46077.49012.stgit@ahduyck-green-test.jf.intel.com> <5fc62d10-790f-2356-c2f6-fd49f542dd3c@infradead.org>
From:   Alexander Duyck <alexander.duyck@gmail.com>
Date:   Fri, 20 Apr 2018 13:01:07 -0700
Message-ID: <CAKgT0UewuO7LWc8wkHPTv2cksF39-8+5nFfEP_DmXVRQtgOWdg@mail.gmail.com>
Subject: Re: [pci PATCH v8 0/4] Add support for unmanaged SR-IOV
To:     Randy Dunlap <rdunlap@infradead.org>
Cc:     Alexander Duyck <alexander.h.duyck@intel.com>,
        Bjorn Helgaas <bhelgaas@google.com>, linux-pci@vger.kernel.org,
        virtio-dev@lists.oasis-open.org, kvm@vger.kernel.org,
        Netdev <netdev@vger.kernel.org>,
        "Daly, Dan" <dan.daly@intel.com>,
        LKML <linux-kernel@vger.kernel.org>,
        linux-nvme@lists.infradead.org,
        Keith Busch <keith.busch@intel.com>, netanel@amazon.com,
        Don Dutile <ddutile@redhat.com>,
        Maximilian Heyne <mheyne@amazon.de>,
        "Wang, Liang-min" <liang-min.wang@intel.com>,
        "Rustad, Mark D" <mark.d.rustad@intel.com>,
        David Woodhouse <dwmw2@infradead.org>,
        Christoph Hellwig <hch@lst.de>, dwmw@amazon.co.uk
Content-Type: text/plain; charset="UTF-8"
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Fri, Apr 20, 2018 at 10:23 AM, Randy Dunlap <rdunlap@infradead.org> wrote:
> On 04/20/18 09:28, Alexander Duyck wrote:
>> This series is meant to add support for SR-IOV on devices when the VFs are
>> not managed by the kernel. Examples of recent patches attempting to do this
>> include:
>> virto - https://patchwork.kernel.org/patch/10241225/
>> pci-stub - https://patchwork.kernel.org/patch/10109935/
>> vfio - https://patchwork.kernel.org/patch/10103353/
>> uio - https://patchwork.kernel.org/patch/9974031/
>
> Hi,
>
> Somewhere in this patch series it would be nice to tell us what the heck
> a "PF" is.  :)
>
> Thanks.

Sorry, I was kind of operating on the assumption of everyone
understanding SR-IOV nomenclature.

A "PF" is a PCIe Physical Function. When you bring up a PCIe device
that supports SR-IOV it is the device that is there to begin with.

A "VF" is a PCIe Virtual Function. You could think of as a logical
device that is spawned from the physical function using a combination
of hardware configuration via the SR-IOV block in the PCIe extended
configuration space and kernel/driver features.

There are also a number of online resources you could use to research
SR-IOV further. Hope that helps to clarify some of this.

Thanks.

Alex