Re: [PATCH v6 2/6] iommufd: Add IOMMU_HWPT_INVALIDATE

[Nicolin Chen]

On Wed, Nov 29, 2023 at 03:58:04PM -0400, Jason Gunthorpe wrote:
> On Tue, Nov 28, 2023 at 05:09:07PM -0800, Nicolin Chen wrote:
> 
> > > > With that being said, I think errno (-EIO) could do the job,
> > > > as you suggested too.
> > > 
> > > Do we have any idea what HW failures can be generated by the commands
> > > this will execture? IIRC I don't remember seeing any smmu specific
> > > codes related to invalid invalidation? Everything is a valid input?
> > 
> > "7.1 Command queue errors" has the info.
> 
> Hmm CERROR_ATC_INV_SYNC needs to be forwarded to the guest somehow

Oh, for sure. That's typically triggered with an asynchronous
timeout from the eventq, so we'd need the io page fault series
as you previously remarked. Though I also wonder if an invalid
vSID that doesn't link to a pSID should be CERROR_ATC_INV_SYNC
also v.s. CERROR_ILL.