Messages in this thread | | | Subject | Re: [PATCH v1 1/1] iommu/vt-d: Enable PRI only if the device enables PASID. | From | David Woodhouse <> | Date | Thu, 07 Feb 2019 20:08:06 +0000 |
| |
On Thu, 2019-02-07 at 10:44 -0800, sathyanarayanan.kuppuswamy@linux.intel.com wrote: > From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> > > Intel IOMMU Page Request Services (PRS) only works with devices which > supports/uses PASID. So enable PRI only if the device also enables > PASID support. For more details, Please check the implementation of PRQ > handler(prq_event_thread()) in intel-svm driver. > > Cc: Jacob Pan <jacob.jun.pan@linux.intel.com> > Cc: Ashok Raj <ashok.raj@intel.com> > Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Hm, that shouldn't be true. PRI and PASID support are orthogonal.
If we get a PRI request without PASID, we should currently report it as non-serviced which is the right thing to do. We can hook this up to KVM etc. to actually allow paging of guests with devices attached, *if* the devices attached to those guests support PRI.
Nothing fundamentally stops us using PRI without PASID support.
[unhandled content-type:application/x-pkcs7-signature] | |