Shared virtual address (SVA), a.k.a, Shared virtual memory (SVM) on Intel
platforms allow address space sharing between device DMA and applications.
SVA can reduce programming complexity and enhance security.
This series is intended to expose SVA capability to VMs. i.e. shared guest
application address space with passthru devices. The whole SVA virtualization
requires QEMU/VFIO/IOMMU changes. This series includes the VFIO changes, for
QEMU and IOMMU changes, they are in separate series (listed in the "Related
series").
The high-level architecture for SVA virtualization is as below:
.-------------. .---------------------------.
| vIOMMU | | Guest process CR3, FL only|
| | '---------------------------'
.----------------/
| PASID Entry |--- PASID cache flush -
'-------------' |
| | V
| | CR3 in GPA
'-------------'
Guest
------| Shadow |--------------------------|--------
v v v
Host
.-------------. .----------------------.
| pIOMMU | | Bind FL for GVA-GPA |
| | '----------------------'
.----------------/ |
| PASID Entry | V (Nested xlate)
'----------------\.------------------------------.
| | |SL for GPA-HPA, default domain|
| | '------------------------------'
'-------------'
Where:
- FL = First level/stage one page tables
- SL = Second level/stage two page tables
There are roughly three parts:
1. vfio support for PASID allocation and free from VMs
2. vfio support for guest PASID binding from VMs
3. vfio support for IOMMU cache invalidation from VMs
Related series:
[1] [PATCH v4 00/22] Shared virtual address IOMMU and VT-d support:
https://lwn.net/Articles/790820/
<My series is based on this kernel series from Jacob Pan>
[2] [RFC v1 00/18] intel_iommu: expose Shared Virtual Addressing to VM
from Yi Liu
This work is based on collaboration with other developers on the IOMMU
mailing list. Notably,
[1] [RFC PATCH 00/20] Qemu: Extend intel_iommu emulator to support
Shared Virtual Memory from Yi Liu
https://www.spinics.net/lists/kvm/msg148798.html
[2] [RFC PATCH 0/8] Shared Virtual Memory virtualization for VT-d from Yi Liu
https://lists.linuxfoundation.org/pipermail/iommu/2017-April/021475.html
[3] [PATCH v3 00/12] Introduce new iommu notifier framework for virt-SVA by Yi
https://lists.gnu.org/archive/html/qemu-devel/2018-03/msg00078.html
[4] [PATCH v6 00/22] SMMUv3 Nested Stage Setup by Eric Auger
https://lkml.org/lkml/2019/3/17/124
[5] [RFC v4 00/27] vSMMUv3/pSMMUv3 2 stage VFIO integration by Eric Auger
https://lists.sr.ht/~philmd/qemu/%3C20190527114203.2762-1-eric.auger%40redhat.com%3E
[6] [RFC PATCH 2/6] drivers core: Add I/O ASID allocator by Jean-Philippe
Brucker
https://www.spinics.net/lists/iommu/msg30639.html
Liu Yi L (4):
vfio: VFIO_IOMMU_ATTACH/DETACH_PASID_TABLE
vfio: VFIO_IOMMU_CACHE_INVALIDATE
vfio/type1: VFIO_IOMMU_PASID_REQUEST(alloc/free)
vfio/type1: bind guest pasid (guest page tables) to host
drivers/vfio/vfio_iommu_type1.c | 384 ++++++++++++++++++++++++++++++++++++++++
include/uapi/linux/vfio.h | 116 ++++++++++++
2 files changed, 500 insertions(+)
--
2.7.4
