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Message-Id: <20230511143844.22693-1-yi.l.liu@intel.com>
Date: Thu, 11 May 2023 07:38:33 -0700
From: Yi Liu <yi.l.liu@...el.com>
To: joro@...tes.org, alex.williamson@...hat.com, jgg@...dia.com,
kevin.tian@...el.com, robin.murphy@....com,
baolu.lu@...ux.intel.com
Cc: cohuck@...hat.com, eric.auger@...hat.com, nicolinc@...dia.com,
kvm@...r.kernel.org, mjrosato@...ux.ibm.com,
chao.p.peng@...ux.intel.com, yi.l.liu@...el.com,
yi.y.sun@...ux.intel.com, peterx@...hat.com, jasowang@...hat.com,
shameerali.kolothum.thodi@...wei.com, lulu@...hat.com,
suravee.suthikulpanit@....com, iommu@...ts.linux.dev,
linux-kernel@...r.kernel.org, linux-kselftest@...r.kernel.org,
zhenzhong.duan@...el.com
Subject: [PATCH v2 00/11] iommufd: Add nesting infrastructure
Nested translation is a hardware feature that is supported by many modern
IOMMU hardwares. It has two stages (stage-1, stage-2) address translation
to get access to the physical address. stage-1 translation table is owned
by userspace (e.g. by a guest OS), while stage-2 is owned by kernel. Changes
to stage-1 translation table should be followed by an IOTLB invalidation.
Take Intel VT-d as an example, the stage-1 translation table is I/O page
table. As the below diagram shows, guest I/O page table pointer in GPA
(guest physical address) is passed to host and be used to perform the stage-1
address translation. Along with it, modifications to present mappings in the
guest I/O page table should be followed with an IOTLB invalidation.
.-------------. .---------------------------.
| vIOMMU | | Guest I/O page table |
| | '---------------------------'
.----------------/
| PASID Entry |--- PASID cache flush --+
'-------------' |
| | V
| | I/O page table pointer in GPA
'-------------'
Guest
------| Shadow |--------------------------|--------
v v v
Host
.-------------. .------------------------.
| pIOMMU | | FS for GIOVA->GPA |
| | '------------------------'
.----------------/ |
| PASID Entry | V (Nested xlate)
'----------------\.----------------------------------.
| | | SS for GPA->HPA, unmanaged domain|
| | '----------------------------------'
'-------------'
Where:
- FS = First stage page tables
- SS = Second stage page tables
<Intel VT-d Nested translation>
In IOMMUFD, all the translation tables are tracked by hw_pagetable (hwpt)
and each has an iommu_domain allocated from iommu driver. So in this series
hw_pagetable and iommu_domain means the same thing if no special note.
IOMMUFD has already supported allocating hw_pagetable that is linked with
an IOAS. However, nesting requires IOMMUFD to allow allocating hw_pagetable
with driver specific parameters and interface to sync stage-1 IOTLB as user
owns the stage-1 translation table.
This series is based on the iommu hw info reporting series [1]. It first
introduces new iommu op for allocating domains with user data and the op
for syncing stage-1 IOTLB, and then extend the IOMMUFD internal infrastructure
to accept user_data and parent hwpt, then relay the data to iommu core to
allocate iommu_domain. After it, extend the ioctl IOMMU_HWPT_ALLOC to accept
user data and stage-2 hwpt ID to allocate hwpt. Along with it, ioctl
IOMMU_HWPT_INVALIDATE is added to invalidate stage-1 IOTLB. This is needed
for user-managed hwpts. Selftest is added as well to cover the new ioctls.
Complete code can be found in [2], QEMU could can be found in [3].
At last, this is a team work together with Nicolin Chen, Lu Baolu. Thanks
them for the help. ^_^. Look forward to your feedbacks.
base-commit: cf905391237ded2331388e75adb5afbabeddc852
[1] https://lore.kernel.org/linux-iommu/20230511143024.19542-1-yi.l.liu@intel.com/
[2] https://github.com/yiliu1765/iommufd/tree/iommufd_nesting
[3] https://github.com/yiliu1765/qemu/tree/wip/iommufd_rfcv4.mig.reset.v4_var3%2Bnesting
Change log:
v2:
- Add union iommu_domain_user_data to include all user data structures to avoid
passing void * in kernel APIs.
- Add iommu op to return user data length for user domain allocation
- Rename struct iommu_hwpt_alloc::data_type to be hwpt_type
- Store the invalidation data length in iommu_domain_ops::cache_invalidate_user_data_len
- Convert cache_invalidate_user op to be int instead of void
- Remove @data_type in struct iommu_hwpt_invalidate
- Remove out_hwpt_type_bitmap in struct iommu_hw_info hence drop patch 08 of v1
v1: https://lore.kernel.org/linux-iommu/20230309080910.607396-1-yi.l.liu@intel.com/
Thanks,
Yi Liu
Lu Baolu (2):
iommu: Add new iommu op to create domains owned by userspace
iommu: Add nested domain support
Nicolin Chen (5):
iommufd/hw_pagetable: Do not populate user-managed hw_pagetables
iommufd/selftest: Add domain_alloc_user() support in iommu mock
iommufd/selftest: Add coverage for IOMMU_HWPT_ALLOC with user data
iommufd/selftest: Add IOMMU_TEST_OP_MD_CHECK_IOTLB test op
iommufd/selftest: Add coverage for IOMMU_HWPT_INVALIDATE ioctl
Yi Liu (4):
iommufd/hw_pagetable: Use domain_alloc_user op for domain allocation
iommufd: Pass parent hwpt and user_data to
iommufd_hw_pagetable_alloc()
iommufd: IOMMU_HWPT_ALLOC allocation with user data
iommufd: Add IOMMU_HWPT_INVALIDATE
drivers/iommu/iommufd/device.c | 2 +-
drivers/iommu/iommufd/hw_pagetable.c | 191 +++++++++++++++++-
drivers/iommu/iommufd/iommufd_private.h | 16 +-
drivers/iommu/iommufd/iommufd_test.h | 30 +++
drivers/iommu/iommufd/main.c | 5 +-
drivers/iommu/iommufd/selftest.c | 119 ++++++++++-
include/linux/iommu.h | 36 ++++
include/uapi/linux/iommufd.h | 58 +++++-
tools/testing/selftests/iommu/iommufd.c | 126 +++++++++++-
tools/testing/selftests/iommu/iommufd_utils.h | 70 +++++++
10 files changed, 629 insertions(+), 24 deletions(-)
--
2.34.1
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