Re: [PATCH v5 09/11] iommu/vt-d: Add iotlb flush for nested domain

[Yi Liu]

On 2023/9/27 14:53, Tian, Kevin wrote:
> > From: Liu, Yi L <yi.l.liu@xxxxxxxxx>
> > Sent: Thursday, September 21, 2023 3:54 PM
> > +
> > +	/* REVISIT:
> > +	 * VT-d has defined ITE, ICE, IQE for invalidation failure per hardware,
> > +	 * but no error code yet, so just set the error code to be 0.
> > +	 */
> > +	*cerror_idx = 0;
> > +
>
> Is it "hardware doesn't provide error code now though it's defined in
> spec" or "intel-iommu driver doesn't retrieve the error code though
> it's provided by the hardware"?

I didn't see vtd spec defines error code for cache invalidation. :(

> Is there guarantee that '0' isn't used for an existing error code or
> won't be used for any new error code later?

may need to check it.

--
Regards,
Yi Liu