On Tue, Dec 19, 2023 at 05:26:21PM +0800, Yi Liu wrote: > On 2023/12/17 19:21, Joel Granados wrote: > > Hey Yi > > > > I have been working with https://protect2.fireeye.com/v1/url?k=b58750ce-ea1c9eaa-b586db81-000babda0201-365207d33731a099&q=1&e=ee73b69d-5c35-49ef-9e62-2355fb797f21&u=https%3A%2F%2Fgithub.com%2Fyiliu1765%2Fqemu%2Ftree%2Fzhenzhong%2Fwip%2Fiommufd_nesting_rfcv1 > > good to know about it. > > > and have some questions regarding one of the commits in that series. > > I however cannot find it in lore.kernel.org. Can you please direct me to > > where the rfc was posted? If it has not been posted yet, do you have an > > alternate place for discussion? > > the qemu series has not been posted yet as kernel side is still changing. > It still needs some time to be ready for public review. Zhenzhong Duan > is going to post it when it's ready. If you have questions to discuss, > you can post your questions to Zhenzhong and me first. I guess it may be > fine to cc Alex Williamson, Eric Auger, Nicolin Chen, Cédric Le Goater, > Kevin Tian, Jason Gunthorpe and qemu mail list as this is discussion > something that is going to be posted in public. Thx for getting back to me. I'll direct my questions to these recipients. Best > > > > > Best > > > > On Fri, Nov 17, 2023 at 05:07:11AM -0800, Yi Liu wrote: > > > 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> > > > > > > This series adds the cache invalidation path for the userspace to invalidate > > > cache after modifying the stage-1 page table. This is based on the first part > > > of nesting [1] > > > > > > 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. > > > > > > [1] https://lore.kernel.org/linux-iommu/20231026044216.64964-1-yi.l.liu@xxxxxxxxx/ - merged > > > [2] https://protect2.fireeye.com/v1/url?k=38b56f01-672ea165-38b4e44e-000babda0201-469ae350f21411ca&q=1&e=ee73b69d-5c35-49ef-9e62-2355fb797f21&u=https%3A%2F%2Fgithub.com%2Fyiliu1765%2Fiommufd%2Ftree%2Fiommufd_nesting > > > [3] https://protect2.fireeye.com/v1/url?k=d6e01ed1-897bd0b5-d6e1959e-000babda0201-bcf2b26a8dc8b34d&q=1&e=ee73b69d-5c35-49ef-9e62-2355fb797f21&u=https%3A%2F%2Fgithub.com%2Fyiliu1765%2Fqemu%2Ftree%2Fzhenzhong%2Fwip%2Fiommufd_nesting_rfcv1 > > > > > > Change log: > > > > > > v6: > > > - No much change, just rebase on top of 6.7-rc1 as part 1/2 is merged > > > > > > v5: https://lore.kernel.org/linux-iommu/20231020092426.13907-1-yi.l.liu@xxxxxxxxx/#t > > > - Split the iommufd nesting series into two parts of alloc_user and > > > invalidation (Jason) > > > - Split IOMMUFD_OBJ_HW_PAGETABLE to IOMMUFD_OBJ_HWPT_PAGING/_NESTED, and > > > do the same with the structures/alloc()/abort()/destroy(). Reworked the > > > selftest accordingly too. (Jason) > > > - Move hwpt/data_type into struct iommu_user_data from standalone op > > > arguments. (Jason) > > > - Rename hwpt_type to be data_type, the HWPT_TYPE to be HWPT_ALLOC_DATA, > > > _TYPE_DEFAULT to be _ALLOC_DATA_NONE (Jason, Kevin) > > > - Rename iommu_copy_user_data() to iommu_copy_struct_from_user() (Kevin) > > > - Add macro to the iommu_copy_struct_from_user() to calculate min_size > > > (Jason) > > > - Fix two bugs spotted by ZhaoYan > > > > > > v4: https://lore.kernel.org/linux-iommu/20230921075138.124099-1-yi.l.liu@xxxxxxxxx/ > > > - Separate HWPT alloc/destroy/abort functions between user-managed HWPTs > > > and kernel-managed HWPTs > > > - Rework invalidate uAPI to be a multi-request array-based design > > > - Add a struct iommu_user_data_array and a helper for driver to sanitize > > > and copy the entry data from user space invalidation array > > > - Add a patch fixing TEST_LENGTH() in selftest program > > > - Drop IOMMU_RESV_IOVA_RANGES patches > > > - Update kdoc and inline comments > > > - Drop the code to add IOMMU_RESV_SW_MSI to kernel-managed HWPT in nested translation, > > > this does not change the rule that resv regions should only be added to the > > > kernel-managed HWPT. The IOMMU_RESV_SW_MSI stuff will be added in later series > > > as it is needed only by SMMU so far. > > > > > > v3: https://lore.kernel.org/linux-iommu/20230724110406.107212-1-yi.l.liu@xxxxxxxxx/ > > > - Add new uAPI things in alphabetical order > > > - Pass in "enum iommu_hwpt_type hwpt_type" to op->domain_alloc_user for > > > sanity, replacing the previous op->domain_alloc_user_data_len solution > > > - Return ERR_PTR from domain_alloc_user instead of NULL > > > - Only add IOMMU_RESV_SW_MSI to kernel-managed HWPT in nested translation (Kevin) > > > - Add IOMMU_RESV_IOVA_RANGES to report resv iova ranges to userspace hence > > > userspace is able to exclude the ranges in the stage-1 HWPT (e.g. guest I/O > > > page table). (Kevin) > > > - Add selftest coverage for the new IOMMU_RESV_IOVA_RANGES ioctl > > > - Minor changes per Kevin's inputs > > > > > > v2: https://lore.kernel.org/linux-iommu/20230511143844.22693-1-yi.l.liu@xxxxxxxxx/ > > > - 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@xxxxxxxxx/ > > > > > > Thanks, > > > Yi Liu > > > > > > Lu Baolu (1): > > > iommu: Add cache_invalidate_user op > > > > > > Nicolin Chen (4): > > > iommu: Add iommu_copy_struct_from_user_array helper > > > iommufd/selftest: Add mock_domain_cache_invalidate_user support > > > iommufd/selftest: Add IOMMU_TEST_OP_MD_CHECK_IOTLB test op > > > iommufd/selftest: Add coverage for IOMMU_HWPT_INVALIDATE ioctl > > > > > > Yi Liu (1): > > > iommufd: Add IOMMU_HWPT_INVALIDATE > > > > > > drivers/iommu/iommufd/hw_pagetable.c | 35 ++++++++ > > > drivers/iommu/iommufd/iommufd_private.h | 9 ++ > > > drivers/iommu/iommufd/iommufd_test.h | 22 +++++ > > > drivers/iommu/iommufd/main.c | 3 + > > > drivers/iommu/iommufd/selftest.c | 69 +++++++++++++++ > > > include/linux/iommu.h | 84 +++++++++++++++++++ > > > include/uapi/linux/iommufd.h | 35 ++++++++ > > > tools/testing/selftests/iommu/iommufd.c | 75 +++++++++++++++++ > > > tools/testing/selftests/iommu/iommufd_utils.h | 63 ++++++++++++++ > > > 9 files changed, 395 insertions(+) > > > > > > -- > > > 2.34.1 > > > > > > > -- > Regards, > Yi Liu -- Joel Granados
Attachment:
signature.asc
Description: PGP signature
