Re: [PATCH 09/18] iommu/vt-d: Enlightened PASID allocation

Jacob Pan
2019-04-09T16:34:13Z

On Tue, 9 Apr 2019 13:08:59 +0300
Andriy Shevchenko <andriy.shevchenko@linux.intel.com> wrote:

> On Mon, Apr 08, 2019 at 04:59:24PM -0700, Jacob Pan wrote:
> > From: Lu Baolu <baolu.lu@linux.intel.com>
> >
> > If Intel IOMMU runs in caching mode, a.k.a. virtual IOMMU, the
> > IOMMU driver should rely on the emulation software to allocate
> > and free PASID IDs. The Intel vt-d spec revision 3.0 defines a
> > register set to support this. This includes a capability register,
> > a virtual command register and a virtual response register. Refer
> > to section 10.4.42, 10.4.43, 10.4.44 for more information.
> >
> > This patch adds the enlightened PASID allocation/free interfaces
> > via the virtual command register.
>
> > + pr_debug("vcmd alloc pasid\n");
>
> Perhaps tracepoints should be in use?
> OTOH we have function tracer, so, this message in any case is a noise.
> And this is applicable to other similar cases.
>

Agreed, I added that for debug purpose.

Thanks,

Jacob