RE: Shouldn't VFIO virtualize the ATS capability?

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

 



I would virtualize the "ATS Control Register".

Regarding poor behavior, I couldn't really find what happens when ATS is misconfigured, but I would assume it can cause problems.
The scenarios I'm concerned about are:
	1. The guest enables translation caching, while the hypervisor thinks there are disabled -> Hypervisor won't issue invalidations.
	2. Smallest Translation Unit misconfiguration. Not sure if it will cause invalid access or only poor caching behavior.

Thanks,
Ilya

> -----Original Message-----
> From: Alex Williamson [mailto:alex.williamson@xxxxxxxxxx]
> Sent: Sunday, November 06, 2016 7:09 PM
> To: Ilya Lesokhin <ilyal@xxxxxxxxxxxx>
> Cc: linux-pci@xxxxxxxxxxxxxxx; kvm@xxxxxxxxxxxxxxx; bhelgaas@xxxxxxxxxx
> Subject: Re: Shouldn't VFIO virtualize the ATS capability?
> 
> On Sun, 6 Nov 2016 11:13:09 +0000
> Ilya Lesokhin <ilyal@xxxxxxxxxxxx> wrote:
> 
> > Hi
> > I've noticed that VFIO doesn't virtualize the ATS capability.
> > It seems to me that translation caching and Smallest Translation Unit is
> something you would want to control on the host. Am I wrong?
> 
> What about those fields would we virtualize?  Why does the host need to be
> an intermediary?  Can the user induce poor behavior with direct access to
> them?  Thanks,
> 
> Alex
--
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




[Index of Archives]     [DMA Engine]     [Linux Coverity]     [Linux USB]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [Greybus]

  Powered by Linux