Re: [Xen-devel] PCIe IOMMU ACS support

[Roger Pau Monné <roger.pau@xxxxxxxxxx>]

Adding the PCI and IOMMU maintainers.

On Mon, Mar 23, 2020 at 01:55:01PM -0700, Roman Shaposhnik wrote:
> Hi!
> 
> I was going through how Xen support PCIe IOMMU ACS and
> all I could find is this:
>     
> https://github.com/xen-project/xen/blob/master/xen/drivers/passthrough/pci.c#L608
> which looks to me as an attempt of enabling ACS opportunistically,
> but still proceeding forward even if it fails.

That's correct AFAICT. Xen will try to enable some features, but will
proceed normally if ACS is not available, or if some of the features
are not implemented.

Are you looking to ensure that all devices on the system have a
certain feature enabled?

Can you provide some more details about what you expect of ACS
handling?

Thanks, Roger.