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@xxxxxxxxxxxxxxxxxxx] On Behalf Of Learner Study Sent: Monday, April 21, 2014 8:34 PM To: Busch, Keith Cc: bhelgaas@xxxxxxxxxx; linux-pci@xxxxxxxxxxxxxxx; 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@xxxxxxxxx> 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@xxxxxxxxx> 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. _______________________________________________ Linux-nvme mailing list Linux-nvme@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/linux-nvme -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
