Re: [PATCH 2/4] iommu/amd: Use pci_ats_supported()

Jean-Philippe Brucker
2020-05-15T12:11:44Z

On Fri, May 15, 2020 at 02:01:50PM +0200, Joerg Roedel wrote:
> On Fri, May 15, 2020 at 12:44:00PM +0200, Jean-Philippe Brucker wrote:
> > The pci_ats_supported() function checks if a device supports ATS and is
> > allowed to use it. In addition to checking that the device has an ATS
> > capability and that the global pci=noats is not set
> > (pci_ats_disabled()), it also checks if a device is untrusted.
>
> Hmm, but per patch 1, pci_ats_supported() does not check
> pci_ats_disabled(), or do I miss something?

The commit message isn't clear. pci_ats_init() sets dev->ats_cap only if
!pci_ats_disabled(), so checking dev->ats_cap in pci_ats_supported()
takes pci_ats_disabled() into account.

Thanks,
Jean