Re: [PATCH v2 0/8] Initial support for SMMUv3 nested translation

[Nicolin Chen <nicolinc@nvidia.com>]

Hi Shameer,

On Wed, Aug 28, 2024 at 04:31:36PM +0000, Shameerali Kolothum Thodi wrote:
> Hi Nicolin,
> 
> > -----Original Message-----
> > From: Nicolin Chen <nicolinc@nvidia.com>
> > Sent: Tuesday, August 27, 2024 10:31 PM
> > To: Jason Gunthorpe <jgg@nvidia.com>
> > Cc: acpica-devel@lists.linux.dev; Guohanjun (Hanjun Guo)
> > <guohanjun@huawei.com>; iommu@lists.linux.dev; Joerg Roedel
> > <joro@8bytes.org>; Kevin Tian <kevin.tian@intel.com>;
> > kvm@vger.kernel.org; Len Brown <lenb@kernel.org>; linux-
> > acpi@vger.kernel.org; linux-arm-kernel@lists.infradead.org; Lorenzo Pieralisi
> > <lpieralisi@kernel.org>; Rafael J. Wysocki <rafael@kernel.org>; Robert
> > Moore <robert.moore@intel.com>; Robin Murphy
> > <robin.murphy@arm.com>; Sudeep Holla <sudeep.holla@arm.com>; Will
> > Deacon <will@kernel.org>; Alex Williamson <alex.williamson@redhat.com>;
> > Eric Auger <eric.auger@redhat.com>; Jean-Philippe Brucker <jean-
> > philippe@linaro.org>; Moritz Fischer <mdf@kernel.org>; Michael Shavit
> > <mshavit@google.com>; patches@lists.linux.dev; Shameerali Kolothum
> > Thodi <shameerali.kolothum.thodi@huawei.com>; Mostafa Saleh
> > <smostafa@google.com>
> > Subject: Re: [PATCH v2 0/8] Initial support for SMMUv3 nested translation
> >
> 
> > As mentioned above, the VIOMMU series would be required to test the
> > entire nesting feature, which now has a v2 rebasing on this series. I tested it
> > with a paring QEMU branch. Please refer to:
> > https://lore.kernel.org/linux-
> > iommu/cover.1724776335.git.nicolinc@nvidia.com/
> 
> Thanks for this. I haven't gone through the viommu and its Qemu branch
> yet.  The way we present nested-smmuv3/iommufd to the Qemu seems to
> have changed  with the above Qemu branch(multiple nested SMMUs).
> The old Qemu command line for nested setup doesn't work anymore.
> 
> Could you please share an example Qemu command line  to verify this
> series(Sorry, if I missed it in the links/git).

My bad. I updated those two "for_iommufd_" QEMU branches with a
README commit on top of each for the reference command.

By the way, I wonder how many SMMUv3 instances there are on the
platforms that SMMUv3 developers here are running on -- if some
one is also working on a chip that has multiple instances?

Thanks
Nicolin