From: Jason Gunthorpe <jgg@nvidia.com>
To: Mostafa Saleh <smostafa@google.com>
Cc: acpica-devel@lists.linux.dev,
Alex Williamson <alex.williamson@redhat.com>,
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>, Eric Auger <eric.auger@redhat.com>,
Jean-Philippe Brucker <jean-philippe@linaro.org>,
Moritz Fischer <mdf@kernel.org>,
Michael Shavit <mshavit@google.com>,
Nicolin Chen <nicolinc@nvidia.com>,
patches@lists.linux.dev,
Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>
Subject: Re: [PATCH 2/8] iommu/arm-smmu-v3: Use S2FWB when available
Date: Tue, 20 Aug 2024 10:01:55 -0300 [thread overview]
Message-ID: <20240820130155.GD3773488@nvidia.com> (raw)
In-Reply-To: <20240820120102.GB3773488@nvidia.com>
On Tue, Aug 20, 2024 at 09:01:02AM -0300, Jason Gunthorpe wrote:
> Also bear in mind VFIO won't run unless ARM_SMMU_FEAT_COHERENCY is set
> so we won't even get a chance to ask for a S2 domain.
And I should also say that without iommufd something like the DMA API
could select a S2 with S2FWB enabled, but all that does is change the
encoding of the memattr bits. Requests for !IOMMU_CACHE will still map
to non-cacheble IO PTEs like before - just with a different encoding.
The only thing at issue is nesting which will end up in the guest as
forced cachable - however since VFIO doesn't support non-DMA-coherent
devices at all this is not a problem.
Jason
next prev parent reply other threads:[~2024-08-20 13:03 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-08-06 23:41 [PATCH 0/8] Initial support for SMMUv3 nested translation Jason Gunthorpe
2024-08-06 23:41 ` [PATCH 1/8] vfio: Remove VFIO_TYPE1_NESTING_IOMMU Jason Gunthorpe
2024-08-07 17:52 ` Alex Williamson
2024-08-20 8:23 ` Mostafa Saleh
2024-08-06 23:41 ` [PATCH 2/8] iommu/arm-smmu-v3: Use S2FWB when available Jason Gunthorpe
2024-08-09 14:26 ` Shameerali Kolothum Thodi
2024-08-09 15:12 ` Jason Gunthorpe
2024-08-15 16:14 ` Shameerali Kolothum Thodi
2024-08-15 16:18 ` Jason Gunthorpe
2024-08-20 8:30 ` Mostafa Saleh
2024-08-20 12:01 ` Jason Gunthorpe
2024-08-20 13:01 ` Jason Gunthorpe [this message]
2024-08-20 19:52 ` Mostafa Saleh
2024-08-20 20:21 ` Jason Gunthorpe
2024-08-21 9:53 ` Mostafa Saleh
2024-08-21 12:06 ` Jason Gunthorpe
2024-08-06 23:41 ` [PATCH 3/8] ACPI/IORT: Support CANWBS memory access flag Jason Gunthorpe
2024-08-09 14:36 ` Shameerali Kolothum Thodi
2024-08-09 14:59 ` Jason Gunthorpe
2024-08-09 15:15 ` Shameerali Kolothum Thodi
2024-08-09 20:14 ` Nicolin Chen
2024-08-06 23:41 ` [PATCH 4/8] iommu/arm-smmu-v3: Report IOMMU_CAP_ENFORCE_CACHE_COHERENCY for CANWBS Jason Gunthorpe
2024-08-06 23:41 ` [PATCH 5/8] iommu/arm-smmu-v3: Support IOMMU_GET_HW_INFO via struct arm_smmu_hw_info Jason Gunthorpe
2024-08-06 23:41 ` [PATCH 6/8] iommu/arm-smmu-v3: Implement IOMMU_HWPT_ALLOC_NEST_PARENT Jason Gunthorpe
2024-08-09 15:06 ` Robin Murphy
2024-08-09 16:09 ` Jason Gunthorpe
2024-08-09 18:34 ` Robin Murphy
2024-08-13 14:35 ` Jason Gunthorpe
2024-08-06 23:41 ` [PATCH 7/8] iommu/arm-smmu-v3: Support IOMMU_DOMAIN_NESTED Jason Gunthorpe
2024-08-09 16:05 ` Robin Murphy
2024-08-09 18:03 ` Jason Gunthorpe
2024-08-06 23:41 ` [PATCH 8/8] iommu/arm-smmu-v3: Add arm_smmu_cache_invalidate_user Jason Gunthorpe
2024-08-20 8:20 ` [PATCH 0/8] Initial support for SMMUv3 nested translation Mostafa Saleh
2024-08-20 15:24 ` Nicolin Chen
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