Re: [PATCH v2 0/4] vfio-pci support pasid attach/detach

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]


On Tue, Apr 23, 2024 at 07:43:27AM +0000, Tian, Kevin wrote:
> I'm not sure how userspace can fully handle this w/o certain assistance
> from the kernel.
> So I kind of agree that emulated PASID capability is probably the only
> contract which the kernel should provide:
>   - mapped 1:1 at the physical location, or
>   - constructed at an offset according to DVSEC, or
>   - constructed at an offset according to a look-up table
> The VMM always scans the vfio pci config space to expose vPASID.
> Then the remaining open is what VMM could do when a VF supports
> PASID but unfortunately it's not reported by vfio. W/o the capability
> of inspecting the PASID state of PF, probably the only feasible option
> is to maintain a look-up table in VMM itself and assumes the kernel
> always enables the PASID cap on PF.

I'm still not sure I like doing this in the kernel - we need to do the
same sort of thing for ATS too, right?

It feels simpler if the indicates if PASID and ATS can be supported
and userspace builds the capability blocks.

There are migration considerations too - the blocks need to be
migrated over and end up in the same place as well..


[Index of Archives]     [KVM ARM]     [KVM ia64]     [KVM ppc]     [Virtualization Tools]     [Spice Development]     [Libvirt]     [Libvirt Users]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite Questions]     [Linux Kernel]     [Linux SCSI]     [XFree86]

  Powered by Linux