From: "Mayes, Barrett N" <barrett.n.mayes@intel.com>
To: Learner Study <learner.study@gmail.com>,
"Busch, Keith" <keith.busch@intel.com>
Cc: "bhelgaas@google.com" <bhelgaas@google.com>,
"linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>,
linux-nvme <linux-nvme@lists.infradead.org>
Subject: RE: [PATCH 2/2] NVMe: Implement PCI-e reset notification callback
Date: Tue, 22 Apr 2014 05:02:02 +0000 [thread overview]
Message-ID: <B8DB29EA17EB2742AC3405C31A9B9EE961457B96@ORSMSX111.amr.corp.intel.com> (raw)
In-Reply-To: <CAP8+hKUEygoeEv=LvY2ccp6cepnXEpi4WGVSaCnRw+zN7BUE_Q@mail.gmail.com>
Section 8.5 of the NVMe 1.1 spec contains the following: "While the details associated with implementing a controller that supports SR-IOV are outside the scope of this specification, such a controller shall implement fully compliant NVM Express Virtual Functions (VFs). This ensures that the same host software developed for non-virtualized environments is capable of running unmodified within an SI. No such requirement exists for the Physical Function (PF)."
If a VF is a fully NVMe compliant device then it must at least act like it implements NVMe subsystem reset. How the SR-IOV-capable controller actually implements this is left up to the vendor. But the spec does not require that a reset of one VF initiate a reset of other VF.
-----Original Message-----
From: Linux-nvme [mailto:linux-nvme-bounces@lists.infradead.org] On Behalf Of Learner Study
Sent: Monday, April 21, 2014 8:34 PM
To: Busch, Keith
Cc: bhelgaas@google.com; linux-pci@vger.kernel.org; linux-nvme
Subject: Re: [PATCH 2/2] NVMe: Implement PCI-e reset notification callback
Per the spec, "When an NVM Subsystem Reset occurs, the entire NVM subsystem is reset"....so all VFs would get impacted, if a VF does a Reset. So, I think Reset kind of control should be in PF mode only.
On Mon, Apr 21, 2014 at 7:45 PM, Learner <learner.study@gmail.com> wrote:
> But Won't resetting from a VF impact functionality of other VFs?
>
> On Apr 21, 2014, at 6:57 PM, Keith Busch <keith.busch@intel.com> wrote:
>
>> On Mon, 21 Apr 2014, Learner Study wrote:
>>> Hi Keith,
>>>
>>> I think NVMe Reset should apply to PF mode driver only, and not to
>>> VF mode driver.
>>> Is that understanding correct? Does the NVMe driver know which mode
>>> its running in?
>>
>> Oh, this driver doesn't enable SR-IOV and has no PF/VF awareness.
>> Shame on us, I'll add it to my list unless someone beats me to it.
>>
>> Still, I think we'd like to be able to reset a VF if only because it
>> gets the queues back to a pristine state. A VF reset should not
>> affect any of the other functions.
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next prev parent reply other threads:[~2014-04-22 5:02 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-04-08 23:42 [PATCH 1/2] PCI: Device driver function reset notification Keith Busch
2014-04-08 23:42 ` [PATCH 2/2] NVMe: Implement PCI-e reset notification callback Keith Busch
2014-04-22 1:34 ` Learner Study
2014-04-22 1:57 ` Keith Busch
2014-04-22 2:45 ` Learner
2014-04-22 3:34 ` Learner Study
2014-04-22 5:02 ` Mayes, Barrett N [this message]
2014-04-22 10:07 ` Learner Study
[not found] ` <7174f4a8.23ad7.14589360cb2.Coremail.liaohengquan1986@163.com>
2014-04-22 15:57 ` Wheather the NVMe driver has been tried on the IBM or Lenovo server? Bjorn Helgaas
2014-04-22 16:08 ` Learner Study
2014-04-22 14:22 ` [PATCH 2/2] NVMe: Implement PCI-e reset notification callback Keith Busch
2014-04-22 15:00 ` Learner Study
2014-04-30 22:46 ` [PATCH 1/2] PCI: Device driver function reset notification Bjorn Helgaas
2014-05-01 19:57 ` Keith Busch
2014-05-01 20:10 ` Bjorn Helgaas
2014-05-01 20:20 ` Keith Busch
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