Hi Will, On 17/08/2017 18:34, Will Deacon wrote: > On Fri, Aug 11, 2017 at 03:45:28PM +0200, Eric Auger wrote: >> When running a virtual SMMU on a guest we sometimes need to trap >> all changes to the translation structures. This is especially useful >> to integrate with VFIO. This patch adds a new option that forces >> the IO_PGTABLE_QUIRK_TLBI_ON_MAP to be applied on LPAE page tables. >> >> TLBI commands then can be trapped. >> >> Signed-off-by: Eric Auger <eric.au...@redhat.com> >> >> --- >> v1 -> v2: >> - rebase on v4.13-rc2 >> --- >> Documentation/devicetree/bindings/iommu/arm,smmu-v3.txt | 4 ++++ >> drivers/iommu/arm-smmu-v3.c | 5 +++++ >> 2 files changed, 9 insertions(+) >> >> diff --git a/Documentation/devicetree/bindings/iommu/arm,smmu-v3.txt >> b/Documentation/devicetree/bindings/iommu/arm,smmu-v3.txt >> index c9abbf3..ebb85e9 100644 >> --- a/Documentation/devicetree/bindings/iommu/arm,smmu-v3.txt >> +++ b/Documentation/devicetree/bindings/iommu/arm,smmu-v3.txt >> @@ -52,6 +52,10 @@ the PCIe specification. >> devicetree/bindings/interrupt-controller/msi.txt >> for a description of the msi-parent property. >> >> +- tlbi-on-map : invalidate caches whenever there is an update of >> + any remapping structure (updates to not-present or >> + present entries). >> + > > My position on this hasn't changed, so NAK for this patch. If you want to > emulate something outside of the SMMUv3 architecture, please do so, but > don't pretend that it's an SMMUv3. OK understood. I wanted to go down the road and enable DPDK use case using the same solution as Intel.
So to me the approach is not adapted to SMMUv3 because - SMMUv3 does not expose anything similar to the Intel Caching Mode (when set, indicates the OS needs to invalidate TLB on map) - SMMUv3 does not expose any IOVA range TLB invalidation command. Do you agree with this conclusion? ACPI enablement was not a showstopper I think. I will see with Peter and other potential users in the community whether it is worth to pursue the efforts on upstreaming the QEMU vSMMUv3 device, considering the VFIO/VHOST integration is made impossible. Thanks Eric > > Will >
