Messages in this thread | | | Subject | Re: [PATCH] uio/uio_pci_generic: Add SR-IOV support | From | Don Dutile <> | Date | Mon, 2 Oct 2017 14:52:31 -0400 |
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On 10/02/2017 08:35 AM, David Woodhouse wrote: > On Thu, 2017-09-28 at 12:56 -0400, Don Dutile wrote: >> Well, my point is more like: why put it in uio? >> why not make it available via pcie, setup while/if no driver attached? >> i.e., other non-uio users can use the mechanism.... like libvirt? ... >> if a PF driver isn't required. > > This would allow you to enable SR-IOV on a PF before its driver is > loaded, right? Even when that driver *is* going to need to perform > resource management for those VFs? > > Would existing drivers cope with SR-IOV being enabled, and VFs being > assigned to guests, before they're loaded? If so then sure, let's do it > generically. But I'm not sure that's the case. > No better than a uio driver/mgmt api that may have to configure a PF before a VF is enabled. Q: So what is better: provide a common hook in sysfs for all to use, potentially causing a kernel fault (during vf probe/config), or a user-level program/mgmt-app that does the equivalent?
> As it is, the UIO driver is all about "userspace knows best". So if > there's resource management to be done, then userspace needs to do that > before enabling SR-IOV. And that's consistent with the current driver- > based enabling model for SR-IOV. > I'm not seeing the UIO driver consistency here. IMO, it's a similar problem, moved to a different place. i.e., slightly different attack vector, but same endpoint.
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