Messages in this thread | | | Date | Wed, 18 Jul 2018 17:47:02 -0700 | From | Jacob Pan <> | Subject | Re: [PATCH 00/10] iommu/vt-d: Add scalable mode support |
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On Mon, 16 Jul 2018 11:51:57 +0100 Jean-Philippe Brucker <jean-philippe.brucker@arm.com> wrote:
> Hi, > > On 16/07/18 07:49, Lu Baolu wrote: > > Intel vt-d rev3.0 [1] introduces a new translation mode called > > 'scalable mode', which enables PASID-granular translations for > > first level, second level, nested and pass-through modes. The > > vt-d scalable mode is the key ingredient to enable Scalable I/O > > Virtualization (Scalable IOV) [2] [3], which allows sharing a > > device in minimal possible granularity (ADI - Assignable Device > > Interface). It also includes all the capabilities required to > > enable Shared Virtual Addressing (SVA). As a result, previous > > Extended Context (ECS) mode is deprecated (no production ever > > implements ECS). > > > > Each scalable mode pasid table entry is 64 bytes in length, with > > fields point to the first level page table and the second level > > page table. The PGTT (Pasid Granular Translation Type) field is > > used by hardware to determine the translation type. > > Looks promising! Since the 2nd level page tables are in the PASID > entry, the hypervisor traps guest accesses to the PASID tables > instead of passing through the whole PASID directory? Are you still > planning to use the VFIO BIND_PASID_TABLE interface in this mode, or > a slightly different one for individual PASIDs? > Since we deprecated ECS mode, there is no need for VT-d to bind guest pasid table in scalable mode. We are planning on adding another flag for bind guest pasid and guest CR3, Perhaps call it VFIO_IOMMU_BIND_GUEST_SVA. > Thanks, > Jean > _______________________________________________ > iommu mailing list > iommu@lists.linux-foundation.org > https://lists.linuxfoundation.org/mailman/listinfo/iommu
[Jacob Pan]
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