Hi Jacob On Mon, Sep 23, 2019 at 12:27:15PM -0700, Jacob Pan wrote: > > > > In VT-d 3.0, scalable mode is introduced, which offers two level > > translation page tables and nested translation mode. Regards to > > GIOVA support, it can be simplified by 1) moving the GIOVA support > > over 1st-level page table to store GIOVA->GPA mapping in vIOMMU, > > 2) binding vIOMMU 1st level page table to the pIOMMU, 3) using pIOMMU > > second level for GPA->HPA translation, and 4) enable nested (a.k.a. > > dual stage) translation in host. Compared with current shadow GIOVA > > support, the new approach is more secure and software is simplified > > as we only need to flush the pIOMMU IOTLB and possible device-IOTLB > > when an IOVA mapping in vIOMMU is torn down. > > > > .-----------. > > | vIOMMU | > > |-----------| .-----------. > > | |IOTLB flush trap | QEMU | > > .-----------. (unmap) |-----------| > > | GVA->GPA |---------------->| | > > '-----------' '-----------' > > | | | > > '-----------' | > > <------------------------------ > > | VFIO/IOMMU > > | cache invalidation and > > | guest gpd bind interfaces > > v > For vSVA, the guest PGD bind interface will mark the PASID as guest > PASID and will inject page request into the guest. In FL gIOVA case, I > guess we are assuming there is no page fault for GIOVA. I will need to > add a flag in the gpgd bind such that any PRS will be auto responded > with invalid. Is there real need to enforce this? I'm not sure if there is any limitation in the spec, and if so, can the guest check that instead? Also i believe the idea is to overcommit PASID#0 such uses. Thought we had a capability to expose this to the vIOMMU as well. Not sure if this is already documented, if not should be up in the next rev. > > Also, native use of IOVA FL map is not to be supported? i.e. IOMMU API > and DMA API for native usage will continue to be SL only? > > .-----------. > > | pIOMMU | > > |-----------| > > .-----------. > > | GVA->GPA |<---First level > > '-----------' > > | GPA->HPA |<---Scond level s/Scond/Second > > '-----------' > > '-----------' > > > > This patch series only aims to achieve the first goal, a.k.a using > > first level translation for IOVA mappings in vIOMMU. I am sending > > it out for your comments. Any comments, suggestions and concerns are > > welcomed. > > > > > > Based-on-idea-by: Ashok Raj <ashok.raj@xxxxxxxxx> > > Based-on-idea-by: Kevin Tian <kevin.tian@xxxxxxxxx> > > Based-on-idea-by: Liu Yi L <yi.l.liu@xxxxxxxxx> > > Based-on-idea-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx> > > Based-on-idea-by: Sanjay Kumar <sanjay.k.kumar@xxxxxxxxx> > > > > Lu Baolu (4): > > iommu/vt-d: Move domain_flush_cache helper into header > > iommu/vt-d: Add first level page table interfaces > > iommu/vt-d: Map/unmap domain with mmmap/mmunmap > > iommu/vt-d: Identify domains using first level page table > > > > drivers/iommu/Makefile | 2 +- > > drivers/iommu/intel-iommu.c | 142 ++++++++++-- > > drivers/iommu/intel-pgtable.c | 342 > > +++++++++++++++++++++++++++++ include/linux/intel-iommu.h | > > 31 ++- include/trace/events/intel_iommu.h | 60 +++++ > > 5 files changed, 553 insertions(+), 24 deletions(-) > > create mode 100644 drivers/iommu/intel-pgtable.c > > > > [Jacob Pan]
