August 2025 - Linux-kselftest-mirror

[PATCH v7 00/29] KVM: arm64: Implement support for SME

by Mark Brown

I've removed the RFC tag from this version of the series, but the items that I'm looking for feedback on remains the same: - The userspace ABI, in particular: - The vector length used for the SVE registers, access to the SVE registers and access to ZA and (if available) ZT0 depending on the current state of PSTATE.{SM,ZA}. - The use of a single finalisation for both SVE and SME. - The addition of control for enabling fine grained traps in a similar manner to FGU but without the UNDEF, I'm not clear if this is desired at all and at present this requires symmetric read and write traps like FGU. That seemed like it might be desired from an implementation point of view but we already have one case where we enable an asymmetric trap (for ARM64_WORKAROUND_AMPERE_AC03_CPU_38) and it seems generally useful to enable asymmetrically. This series implements support for SME use in non-protected KVM guests. Much of this is very similar to SVE, the main additional challenge that SME presents is that it introduces a new vector length similar to the SVE vector length and two new controls which change the registers seen by guests: - PSTATE.ZA enables the ZA matrix register and, if SME2 is supported, the ZT0 LUT register. - PSTATE.SM enables streaming mode, a new floating point mode which uses the SVE register set with the separately configured SME vector length. In streaming mode implementation of the FFR register is optional. It is also permitted to build systems which support SME without SVE, in this case when not in streaming mode no SVE registers or instructions are available. Further, there is no requirement that there be any overlap in the set of vector lengths supported by SVE and SME in a system, this is expected to be a common situation in practical systems. Since there is a new vector length to configure we introduce a new feature parallel to the existing SVE one with a new pseudo register for the streaming mode vector length. Due to the overlap with SVE caused by streaming mode rather than finalising SME as a separate feature we use the existing SVE finalisation to also finalise SME, a new define KVM_ARM_VCPU_VEC is provided to help make user code clearer. Finalising SVE and SME separately would introduce complication with register access since finalising SVE makes the SVE registers writeable by userspace and doing multiple finalisations results in an error being reported. Dealing with a state where the SVE registers are writeable due to one of SVE or SME being finalised but may have their VL changed by the other being finalised seems like needless complexity with minimal practical utility, it seems clearer to just express directly that only one finalisation can be done in the ABI. Access to the floating point registers follows the architecture: - When both SVE and SME are present: - If PSTATE.SM == 0 the vector length used for the Z and P registers is the SVE vector length. - If PSTATE.SM == 1 the vector length used for the Z and P registers is the SME vector length. - If only SME is present: - If PSTATE.SM == 0 the Z and P registers are inaccessible and the floating point state accessed via the encodings for the V registers. - If PSTATE.SM == 1 the vector length used for the Z and P registers - The SME specific ZA and ZT0 registers are only accessible if SVCR.ZA is 1. The VMM must understand this, in particular when loading state SVCR should be configured before other state. It should be noted that while the architecture refers to PSTATE.SM and PSTATE.ZA these PSTATE bits are not preserved in SPSR_ELx, they are only accessible via SVCR. There are a large number of subfeatures for SME, most of which only offer additional instructions but some of which (SME2 and FA64) add architectural state. These are configured via the ID registers as per usual. Protected KVM supported, with the implementation maintaining the existing restriction that the hypervisor will refuse to run if streaming mode or ZA is enabled. This both simplfies the code and avoids the need to allocate storage for host ZA and ZT0 state, there seems to be little practical use case for supporting this and the memory usage would be non-trivial. The new KVM_ARM_VCPU_VEC feature and ZA and ZT0 registers have not been added to the get-reg-list selftest, the idea of supporting additional features there without restructuring the program to generate all possible feature combinations has been rejected. I will post a separate series which does that restructuring. Signed-off-by: Mark Brown <broonie(a)kernel.org> --- Changes in v7: - Rebase onto v6.17-rc1. - Handle SMIDR_EL1 as a VM wide ID register and use this in feat_sme_smps(). - Expose affinity fields in SMIDR_EL1. - Remove SMPRI_EL1 from vcpu_sysreg, the value is always 0 currently. - Prevent userspace writes to SMPRIMAP_EL2. - Link to v6: https://lore.kernel.org/r/20250625-kvm-arm64-sme-v6-0-114cff4ffe04@kernel.o… Changes in v6: - Rebase onto v6.16-rc3. - Link to v5: https://lore.kernel.org/r/20250417-kvm-arm64-sme-v5-0-f469a2d5f574@kernel.o… Changes in v5: - Rebase onto v6.15-rc2. - Add pKVM guest support. - Always restore SVCR. - Link to v4: https://lore.kernel.org/r/20250214-kvm-arm64-sme-v4-0-d64a681adcc2@kernel.o… Changes in v4: - Rebase onto v6.14-rc2 and Mark Rutland's fixes. - Expose SME to nested guests. - Additional cleanups and test fixes following on from the rebase. - Flush register state on VMM PSTATE.{SM,ZA}. - Link to v3: https://lore.kernel.org/r/20241220-kvm-arm64-sme-v3-0-05b018c1ffeb@kernel.o… Changes in v3: - Rebase onto v6.12-rc2. - Link to v2: https://lore.kernel.org/r/20231222-kvm-arm64-sme-v2-0-da226cb180bb@kernel.o… Changes in v2: - Rebase onto v6.7-rc3. - Configure subfeatures based on host system only. - Complete nVHE support. - There was some snafu with sending v1 out, it didn't make it to the lists but in case it hit people's inboxes I'm sending as v2. --- Mark Brown (29): arm64/sysreg: Update SMIDR_EL1 to DDI0601 2025-06 arm64/fpsimd: Update FA64 and ZT0 enables when loading SME state arm64/fpsimd: Decide to save ZT0 and streaming mode FFR at bind time arm64/fpsimd: Check enable bit for FA64 when saving EFI state arm64/fpsimd: Determine maximum virtualisable SME vector length KVM: arm64: Introduce non-UNDEF FGT control KVM: arm64: Pay attention to FFR parameter in SVE save and load KVM: arm64: Pull ctxt_has_ helpers to start of sysreg-sr.h KVM: arm64: Move SVE state access macros after feature test macros KVM: arm64: Rename SVE finalization constants to be more general KVM: arm64: Document the KVM ABI for SME KVM: arm64: Define internal features for SME KVM: arm64: Rename sve_state_reg_region KVM: arm64: Store vector lengths in an array KVM: arm64: Implement SME vector length configuration KVM: arm64: Support SME control registers KVM: arm64: Support TPIDR2_EL0 KVM: arm64: Support SME identification registers for guests KVM: arm64: Support SME priority registers KVM: arm64: Provide assembly for SME register access KVM: arm64: Support userspace access to streaming mode Z and P registers KVM: arm64: Flush register state on writes to SVCR.SM and SVCR.ZA KVM: arm64: Expose SME specific state to userspace KVM: arm64: Context switch SME state for guests KVM: arm64: Handle SME exceptions KVM: arm64: Expose SME to nested guests KVM: arm64: Provide interface for configuring and enabling SME for guests KVM: arm64: selftests: Add SME system registers to get-reg-list KVM: arm64: selftests: Add SME to set_id_regs test Documentation/virt/kvm/api.rst | 117 +++++++---- arch/arm64/include/asm/fpsimd.h | 26 +++ arch/arm64/include/asm/kvm_emulate.h | 6 + arch/arm64/include/asm/kvm_host.h | 169 ++++++++++++--- arch/arm64/include/asm/kvm_hyp.h | 5 +- arch/arm64/include/asm/kvm_pkvm.h | 2 +- arch/arm64/include/asm/vncr_mapping.h | 2 + arch/arm64/include/uapi/asm/kvm.h | 33 +++ arch/arm64/kernel/cpufeature.c | 2 - arch/arm64/kernel/fpsimd.c | 89 ++++---- arch/arm64/kvm/arm.c | 10 + arch/arm64/kvm/config.c | 8 +- arch/arm64/kvm/fpsimd.c | 28 ++- arch/arm64/kvm/guest.c | 252 ++++++++++++++++++++--- arch/arm64/kvm/handle_exit.c | 14 ++ arch/arm64/kvm/hyp/fpsimd.S | 28 ++- arch/arm64/kvm/hyp/include/hyp/switch.h | 175 ++++++++++++++-- arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h | 110 ++++++---- arch/arm64/kvm/hyp/nvhe/hyp-main.c | 86 ++++++-- arch/arm64/kvm/hyp/nvhe/pkvm.c | 85 ++++++-- arch/arm64/kvm/hyp/nvhe/switch.c | 4 +- arch/arm64/kvm/hyp/nvhe/sys_regs.c | 6 + arch/arm64/kvm/hyp/vhe/switch.c | 17 +- arch/arm64/kvm/hyp/vhe/sysreg-sr.c | 7 + arch/arm64/kvm/nested.c | 3 +- arch/arm64/kvm/reset.c | 156 ++++++++++---- arch/arm64/kvm/sys_regs.c | 141 ++++++++++++- arch/arm64/tools/sysreg | 8 +- include/uapi/linux/kvm.h | 1 + tools/testing/selftests/kvm/arm64/get-reg-list.c | 15 +- tools/testing/selftests/kvm/arm64/set_id_regs.c | 27 ++- 31 files changed, 1328 insertions(+), 304 deletions(-) --- base-commit: 062b3e4a1f880f104a8d4b90b767788786aa7b78 change-id: 20230301-kvm-arm64-sme-06a1246d3636 Best regards, -- Mark Brown <broonie(a)kernel.org>

2 months, 2 weeks

3
31
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[PATCH v1 00/36] mm: remove nth_page()

by David Hildenbrand

This is based on mm-unstable. I will only CC non-MM folks on the cover letter and the respective patch to not flood too many inboxes (the lists receive all patches). -- As discussed recently with Linus, nth_page() is just nasty and we would like to remove it. To recap, the reason we currently need nth_page() within a folio is because on some kernel configs (SPARSEMEM without SPARSEMEM_VMEMMAP), the memmap is allocated per memory section. While buddy allocations cannot cross memory section boundaries, hugetlb and dax folios can. So crossing a memory section means that "page++" could do the wrong thing. Instead, nth_page() on these problematic configs always goes from page->pfn, to the go from (++pfn)->page, which is rather nasty. Likely, many people have no idea when nth_page() is required and when it might be dropped. We refer to such problematic PFN ranges and "non-contiguous pages". If we only deal with "contiguous pages", there is not need for nth_page(). Besides that "obvious" folio case, we might end up using nth_page() within CMA allocations (again, could span memory sections), and in one corner case (kfence) when processing memblock allocations (again, could span memory sections). So let's handle all that, add sanity checks, and remove nth_page(). Patch #1 -> #5 : stop making SPARSEMEM_VMEMMAP user-selectable + cleanups Patch #6 -> #13 : disallow folios to have non-contiguous pages Patch #14 -> #20 : remove nth_page() usage within folios Patch #21 : disallow CMA allocations of non-contiguous pages Patch #22 -> #32 : sanity+check + remove nth_page() usage within SG entry Patch #33 : sanity-check + remove nth_page() usage in unpin_user_page_range_dirty_lock() Patch #34 : remove nth_page() in kfence Patch #35 : adjust stale comment regarding nth_page Patch #36 : mm: remove nth_page() A lot of this is inspired from the discussion at [1] between Linus, Jason and me, so cudos to them. [1] https://lore.kernel.org/all/CAHk-=wiCYfNp4AJLBORU-c7ZyRBUp66W2-Et6cdQ4REx-G… RFC -> v1: * "wireguard: selftests: remove CONFIG_SPARSEMEM_VMEMMAP=y from qemu kernel config" -> Mention that it was never really relevant for the test * "mm/mm_init: make memmap_init_compound() look more like prep_compound_page()" -> Mention the setup of page links * "mm: limit folio/compound page sizes in problematic kernel configs" -> Improve comment for PUD handling, mentioning hugetlb and dax * "mm: simplify folio_page() and folio_page_idx()" -> Call variable "n" * "mm/hugetlb: cleanup hugetlb_folio_init_tail_vmemmap()" -> Keep __init_single_page() and refer to the usage of memblock_reserved_mark_noinit() * "fs: hugetlbfs: cleanup folio in adjust_range_hwpoison()" * "fs: hugetlbfs: remove nth_page() usage within folio in adjust_range_hwpoison()" -> Separate nth_page() removal from cleanups -> Further improve cleanups * "io_uring/zcrx: remove nth_page() usage within folio" -> Keep the io_copy_cache for now and limit to nth_page() removal * "mm/gup: drop nth_page() usage within folio when recording subpages" -> Cleanup record_subpages as bit * "mm/cma: refuse handing out non-contiguous page ranges" -> Replace another instance of "pfn_to_page(pfn)" where we already have the page * "scatterlist: disallow non-contigous page ranges in a single SG entry" -> We have to EXPORT the symbol. I thought about moving it to mm_inline.h, but I really don't want to include that in include/linux/scatterlist.h * "ata: libata-eh: drop nth_page() usage within SG entry" * "mspro_block: drop nth_page() usage within SG entry" * "memstick: drop nth_page() usage within SG entry" * "mmc: drop nth_page() usage within SG entry" -> Keep PAGE_SHIFT * "scsi: scsi_lib: drop nth_page() usage within SG entry" * "scsi: sg: drop nth_page() usage within SG entry" -> Split patches, Keep PAGE_SHIFT * "crypto: remove nth_page() usage within SG entry" -> Keep PAGE_SHIFT * "kfence: drop nth_page() usage" -> Keep modifying i and use "start_pfn" only instead Cc: Andrew Morton <akpm(a)linux-foundation.org> Cc: Linus Torvalds <torvalds(a)linux-foundation.org> Cc: Jason Gunthorpe <jgg(a)nvidia.com> Cc: Lorenzo Stoakes <lorenzo.stoakes(a)oracle.com> Cc: "Liam R. Howlett" <Liam.Howlett(a)oracle.com> Cc: Vlastimil Babka <vbabka(a)suse.cz> Cc: Mike Rapoport <rppt(a)kernel.org> Cc: Suren Baghdasaryan <surenb(a)google.com> Cc: Michal Hocko <mhocko(a)suse.com> Cc: Jens Axboe <axboe(a)kernel.dk> Cc: Marek Szyprowski <m.szyprowski(a)samsung.com> Cc: Robin Murphy <robin.murphy(a)arm.com> Cc: John Hubbard <jhubbard(a)nvidia.com> Cc: Peter Xu <peterx(a)redhat.com> Cc: Alexander Potapenko <glider(a)google.com> Cc: Marco Elver <elver(a)google.com> Cc: Dmitry Vyukov <dvyukov(a)google.com> Cc: Brendan Jackman <jackmanb(a)google.com> Cc: Johannes Weiner <hannes(a)cmpxchg.org> Cc: Zi Yan <ziy(a)nvidia.com> Cc: Dennis Zhou <dennis(a)kernel.org> Cc: Tejun Heo <tj(a)kernel.org> Cc: Christoph Lameter <cl(a)gentwo.org> Cc: Muchun Song <muchun.song(a)linux.dev> Cc: Oscar Salvador <osalvador(a)suse.de> Cc: x86(a)kernel.org Cc: linux-arm-kernel(a)lists.infradead.org Cc: linux-mips(a)vger.kernel.org Cc: linux-s390(a)vger.kernel.org Cc: linux-crypto(a)vger.kernel.org Cc: linux-ide(a)vger.kernel.org Cc: intel-gfx(a)lists.freedesktop.org Cc: dri-devel(a)lists.freedesktop.org Cc: linux-mmc(a)vger.kernel.org Cc: linux-arm-kernel(a)axis.com Cc: linux-scsi(a)vger.kernel.org Cc: kvm(a)vger.kernel.org Cc: virtualization(a)lists.linux.dev Cc: linux-mm(a)kvack.org Cc: io-uring(a)vger.kernel.org Cc: iommu(a)lists.linux.dev Cc: kasan-dev(a)googlegroups.com Cc: wireguard(a)lists.zx2c4.com Cc: netdev(a)vger.kernel.org Cc: linux-kselftest(a)vger.kernel.org Cc: linux-riscv(a)lists.infradead.org David Hildenbrand (36): mm: stop making SPARSEMEM_VMEMMAP user-selectable arm64: Kconfig: drop superfluous "select SPARSEMEM_VMEMMAP" s390/Kconfig: drop superfluous "select SPARSEMEM_VMEMMAP" x86/Kconfig: drop superfluous "select SPARSEMEM_VMEMMAP" wireguard: selftests: remove CONFIG_SPARSEMEM_VMEMMAP=y from qemu kernel config mm/page_alloc: reject unreasonable folio/compound page sizes in alloc_contig_range_noprof() mm/memremap: reject unreasonable folio/compound page sizes in memremap_pages() mm/hugetlb: check for unreasonable folio sizes when registering hstate mm/mm_init: make memmap_init_compound() look more like prep_compound_page() mm: sanity-check maximum folio size in folio_set_order() mm: limit folio/compound page sizes in problematic kernel configs mm: simplify folio_page() and folio_page_idx() mm/hugetlb: cleanup hugetlb_folio_init_tail_vmemmap() mm/mm/percpu-km: drop nth_page() usage within single allocation fs: hugetlbfs: remove nth_page() usage within folio in adjust_range_hwpoison() fs: hugetlbfs: cleanup folio in adjust_range_hwpoison() mm/pagewalk: drop nth_page() usage within folio in folio_walk_start() mm/gup: drop nth_page() usage within folio when recording subpages io_uring/zcrx: remove nth_page() usage within folio mips: mm: convert __flush_dcache_pages() to __flush_dcache_folio_pages() mm/cma: refuse handing out non-contiguous page ranges dma-remap: drop nth_page() in dma_common_contiguous_remap() scatterlist: disallow non-contigous page ranges in a single SG entry ata: libata-eh: drop nth_page() usage within SG entry drm/i915/gem: drop nth_page() usage within SG entry mspro_block: drop nth_page() usage within SG entry memstick: drop nth_page() usage within SG entry mmc: drop nth_page() usage within SG entry scsi: scsi_lib: drop nth_page() usage within SG entry scsi: sg: drop nth_page() usage within SG entry vfio/pci: drop nth_page() usage within SG entry crypto: remove nth_page() usage within SG entry mm/gup: drop nth_page() usage in unpin_user_page_range_dirty_lock() kfence: drop nth_page() usage block: update comment of "struct bio_vec" regarding nth_page() mm: remove nth_page() arch/arm64/Kconfig | 1 - arch/mips/include/asm/cacheflush.h | 11 +++-- arch/mips/mm/cache.c | 8 ++-- arch/s390/Kconfig | 1 - arch/x86/Kconfig | 1 - crypto/ahash.c | 4 +- crypto/scompress.c | 8 ++-- drivers/ata/libata-sff.c | 6 +-- drivers/gpu/drm/i915/gem/i915_gem_pages.c | 2 +- drivers/memstick/core/mspro_block.c | 3 +- drivers/memstick/host/jmb38x_ms.c | 3 +- drivers/memstick/host/tifm_ms.c | 3 +- drivers/mmc/host/tifm_sd.c | 4 +- drivers/mmc/host/usdhi6rol0.c | 4 +- drivers/scsi/scsi_lib.c | 3 +- drivers/scsi/sg.c | 3 +- drivers/vfio/pci/pds/lm.c | 3 +- drivers/vfio/pci/virtio/migrate.c | 3 +- fs/hugetlbfs/inode.c | 33 +++++-------- include/crypto/scatterwalk.h | 4 +- include/linux/bvec.h | 7 +-- include/linux/mm.h | 48 +++++++++++++++---- include/linux/page-flags.h | 5 +- include/linux/scatterlist.h | 3 +- io_uring/zcrx.c | 4 +- kernel/dma/remap.c | 2 +- mm/Kconfig | 3 +- mm/cma.c | 39 +++++++++------ mm/gup.c | 14 ++++-- mm/hugetlb.c | 22 +++++---- mm/internal.h | 1 + mm/kfence/core.c | 12 +++-- mm/memremap.c | 3 ++ mm/mm_init.c | 15 +++--- mm/page_alloc.c | 5 +- mm/pagewalk.c | 2 +- mm/percpu-km.c | 2 +- mm/util.c | 34 +++++++++++++ tools/testing/scatterlist/linux/mm.h | 1 - .../selftests/wireguard/qemu/kernel.config | 1 - 40 files changed, 202 insertions(+), 129 deletions(-) base-commit: efa7612003b44c220551fd02466bfbad5180fc83 -- 2.50.1

2 months, 2 weeks

14
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[PATCH v2 0/5] Add Zilsd/Zclsd support in hwprobe and KVM

by Pincheng Wang

Hi all, This is v2 of a short series that adds kernel support for the ratified Zilsd (Load/Store pair) and Zclsd (Compressed Load/Store pair) RISC-V ISA extensions. The series enables kernel-side exposure so user-space (for example glibc) can detect and use these extensions via hwprobe and runtime checks. Patches: - Patch 1：Add device tree bindings documentation for Zilsd and Zclsd. - Patch 2: Extend RISC-V ISA extension string parsing to recognize them. - Patch 3: Export Zilsd and Zclsd via riscv_hwprobe. - Patch 4: Allow KVM guests to use them. - Patch 5: Add KVM selftests. Changes in v2: - Device-tree schema: simplified the rv64 validation for Zilsd by removing a redundant `contais: const: zilsd` in the `if` clause; the simpler `if (riscv, isa-base contains rv64i) then (riscv, isa-extension not contains zilsd)` form is used instead. Behaviour is unchanged, and the logic is cleaner. - Device-tree schema: corrected Zclsd dependency to require both Zilsd and Zca (previous `anyOf` was incorrect; now both are enforced). - Commit message typo fixed: "dt-bidings" -> "dt-bindings" in the Patch 1 commit subject. The v2 changes are documentation/schema corrections in extensions.yaml. No functional changes were made to ISA parsing, hwprobe syscall, KVM guest support or the selftests beyond ensuring the binding correctly documents and validates the extension relationships. Please review v2 and advise if futher changes are needed. Thanks, Pincheng Wang Pincheng Wang (5): dt-bindings: riscv: add Zilsd and Zclsd extension descriptions riscv: add ISA extension parsing for Zilsd and Zclsd riscv: hwprobe: export Zilsd and Zclsd ISA extensions riscv: KVM: allow Zilsd and Zclsd extensions for Guest/VM KVM: riscv: selftests: add Zilsd and Zclsd extension to get-reg-list test Documentation/arch/riscv/hwprobe.rst | 8 +++++ .../devicetree/bindings/riscv/extensions.yaml | 36 +++++++++++++++++++ arch/riscv/include/asm/hwcap.h | 2 ++ arch/riscv/include/uapi/asm/hwprobe.h | 2 ++ arch/riscv/include/uapi/asm/kvm.h | 2 ++ arch/riscv/kernel/cpufeature.c | 24 +++++++++++++ arch/riscv/kernel/sys_hwprobe.c | 2 ++ arch/riscv/kvm/vcpu_onereg.c | 2 ++ .../selftests/kvm/riscv/get-reg-list.c | 6 ++++ 9 files changed, 84 insertions(+) -- 2.39.5

2 months, 2 weeks

3
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[PATCH v5 0/7] Add support for FEAT_{LS64, LS64_V} and related tests

by Yicong Yang

From: Yicong Yang <yangyicong(a)hisilicon.com> Armv8.7 introduces single-copy atomic 64-byte loads and stores instructions and its variants named under FEAT_{LS64, LS64_V}. Add support for Armv8.7 FEAT_{LS64, LS64_V}: - Add identifying and enabling in the cpufeature list - Expose the support of these features to userspace through HWCAP3 and cpuinfo - Add related hwcap test - Handle the trap of unsupported memory (normal/uncacheable) access in a VM A real scenario for this feature is that the userspace driver can make use of this to implement direct WQE (workqueue entry) - a mechanism to fill WQE directly into the hardware. Picked Marc's 2 patches form [1] for handling the LS64 trap in a VM on emulated MMIO and the introduce of KVM_EXIT_ARM_LDST64B. [1] https://lore.kernel.org/linux-arm-kernel/20240815125959.2097734-1-maz@kerne… Tested with updated hwcap test: [root@localhost tmp]# dmesg | grep "All CPU(s) started" [ 14.789859] CPU: All CPU(s) started at EL2 [root@localhost tmp]# ./hwcap # LS64 present ok 217 cpuinfo_match_LS64 ok 218 sigill_LS64 ok 219 # SKIP sigbus_LS64_V # LS64_V present ok 220 cpuinfo_match_LS64_V ok 221 sigill_LS64_V ok 222 # SKIP sigbus_LS64_V # 115 skipped test(s) detected. Consider enabling relevant config options to improve coverage. # Totals: pass:107 fail:0 xfail:0 xpass:0 skip:115 error:0 root@localhost:/mnt# dmesg | grep "All CPU(s) started" [ 0.281152] CPU: All CPU(s) started at EL1 root@localhost:/mnt# ./hwcap # LS64 present ok 217 cpuinfo_match_LS64 ok 218 sigill_LS64 ok 219 # SKIP sigbus_LS64 # LS64_V present ok 220 cpuinfo_match_LS64_V ok 221 sigill_LS64_V ok 222 # SKIP sigbus_LS64_V # 115 skipped test(s) detected. Consider enabling relevant config options to improve coverage. # Totals: pass:107 fail:0 xfail:0 xpass:0 skip:115 error:0 Change since v4: - Rebase on v6.17-rc2 and fix the conflicts Link: https://lore.kernel.org/linux-arm-kernel/20250715081356.12442-1-yangyicong@… Change since v3: - Inject DABT fault for LS64 fault on unsupported memory but with valid memslot Link: https://lore.kernel.org/linux-arm-kernel/20250626080906.64230-1-yangyicong@… Change since v2: - Handle the LS64 fault to userspace and allow userspace to inject LS64 fault - Reorder the patches to make KVM handling prior to feature support Link: https://lore.kernel.org/linux-arm-kernel/20250331094320.35226-1-yangyicong@… Change since v1: - Drop the support for LS64_ACCDATA - handle the DABT of unsupported memory type after checking the memory attributes Link: https://lore.kernel.org/linux-arm-kernel/20241202135504.14252-1-yangyicong@… Marc Zyngier (2): KVM: arm64: Add exit to userspace on {LD,ST}64B* outside of memslots KVM: arm64: Add documentation for KVM_EXIT_ARM_LDST64B Yicong Yang (5): KVM: arm64: Handle DABT caused by LS64* instructions on unsupported memory arm64: Provide basic EL2 setup for FEAT_{LS64, LS64_V} usage at EL0/1 arm64: Add support for FEAT_{LS64, LS64_V} KVM: arm64: Enable FEAT_{LS64, LS64_V} in the supported guest kselftest/arm64: Add HWCAP test for FEAT_{LS64, LS64_V} Documentation/arch/arm64/booting.rst | 12 +++ Documentation/arch/arm64/elf_hwcaps.rst | 6 ++ Documentation/virt/kvm/api.rst | 43 +++++++++-- arch/arm64/include/asm/el2_setup.h | 12 ++- arch/arm64/include/asm/esr.h | 8 ++ arch/arm64/include/asm/hwcap.h | 2 + arch/arm64/include/asm/kvm_emulate.h | 7 ++ arch/arm64/include/uapi/asm/hwcap.h | 2 + arch/arm64/kernel/cpufeature.c | 51 +++++++++++++ arch/arm64/kernel/cpuinfo.c | 2 + arch/arm64/kvm/inject_fault.c | 22 ++++++ arch/arm64/kvm/mmio.c | 27 ++++++- arch/arm64/kvm/mmu.c | 14 +++- arch/arm64/tools/cpucaps | 2 + include/uapi/linux/kvm.h | 3 +- tools/testing/selftests/arm64/abi/hwcap.c | 90 +++++++++++++++++++++++ 16 files changed, 292 insertions(+), 11 deletions(-) -- 2.24.0

2 months, 2 weeks

1
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[PATCHSET V1 0/2] cpuidle, bpf: Introduce BPF-based extensible cpuidle policy via struct_ops

by Lin Yikai

Summary ---------- Hi, everyone, This patch set introduces an extensible cpuidle governor framework using BPF struct_ops, enabling dynamic implementation of idle-state selection policies via BPF programs. Motivation ---------- As is well-known, CPUs support multiple idle states (e.g., C0, C1, C2, ...), where deeper states reduce power consumption, but results in longer wakeup latency, potentially affecting performance. Existing generic cpuidle governors operate effectively in common scenarios but exhibit suboptimal behavior in specific Android phone's use cases. Our testing reveals that during low-utilization scenarios (e.g., screen-off background tasks like music playback with CPU utilization <10%), the C0 state occupies ~50% of idle time, causing significant energy inefficiency. Reducing C0 to ≤20% could yield ≥5% power savings on mobile phones. To address this, we expect: 1.Dynamic governor switching to power-saved policies for low cpu utilization scenarios (e.g., screen-off mode) 2.Dynamic switching to alternate governors for high-performance scenarios (e.g., gaming) OverView ---------- The BPF cpuidle ext governor registers at postcore_initcall() but remains disabled by default due to its low priority "rating" with value "1". Activation requires adjust higer "rating" than other governors within BPF. Core Components: 1.**struct cpuidle_gov_ext_ops** – BPF-overridable operations: - ops.enable()/ops.disable(): enable or disable callback - ops.select(): cpu Idle-state selection logic - ops.set_stop_tick(): Scheduler tick management after state selection - ops.reflect(): feedback info about previous idle state. - ops.init()/ops.deinit(): Initialization or cleanup. 2.**Critical kfuncs for kernel state access**: - bpf_cpuidle_ext_gov_update_rating(): Activate ext governor by raising rating must be called from "ops.init()" - bpf_cpuidle_ext_gov_latency_req(): get idle-state latency constraints - bpf_tick_nohz_get_sleep_length(): get CPU sleep duration in tickless mode Future work ---------- 1. Scenario detection: Identifying low-utilization states (e.g., screen-off + background music) 2. Policy optimization: Optimizing state-selection algorithms for specific scenarios Lin Yikai (2): Subject: [PATCH v1 1/2] cpuidle: Implement BPF extensible cpuidle class Subject: [PATCH v1 2/2] selftests/bpf: Add selftests drivers/cpuidle/Kconfig | 12 + drivers/cpuidle/governors/Makefile | 1 + drivers/cpuidle/governors/ext.c | 537 ++++++++++++++++++ .../bpf/prog_tests/test_cpuidle_gov_ext.c | 28 + .../selftests/bpf/progs/cpuidle_gov_ext.c | 208 +++++++ 5 files changed, 786 insertions(+) create mode 100644 drivers/cpuidle/governors/ext.c create mode 100644 tools/testing/selftests/bpf/prog_tests/test_cpuidle_gov_ext.c create mode 100644 tools/testing/selftests/bpf/progs/cpuidle_gov_ext.c -- 2.43.0

2 months, 2 weeks

4
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[PATCH net-next] selftests: net: add test for ipv6 fragmentation

by Brett A C Sheffield

Add selftest for the IPv6 fragmentation regression which affected several stable kernels. Commit a18dfa9925b9 ("ipv6: save dontfrag in cork") was backported to stable without some prerequisite commits. This caused a regression when sending IPv6 UDP packets by preventing fragmentation and instead returning -1 (EMSGSIZE). Add selftest to check for this issue by attempting to send a packet larger than the interface MTU. The packet will be fragmented on a working kernel, with sendmsg(2) correctly returning the expected number of bytes sent. When the regression is present, sendmsg returns -1 and sets errno to EMSGSIZE. Signed-off-by: Brett A C Sheffield <bacs(a)librecast.net> Link: https://lore.kernel.org/stable/aElivdUXqd1OqgMY@karahi.gladserv.com --- tools/testing/selftests/net/.gitignore | 1 + tools/testing/selftests/net/Makefile | 1 + .../selftests/net/ipv6_fragmentation.c | 204 ++++++++++++++++++ 3 files changed, 206 insertions(+) create mode 100644 tools/testing/selftests/net/ipv6_fragmentation.c diff --git a/tools/testing/selftests/net/.gitignore b/tools/testing/selftests/net/.gitignore index 47c293c2962f..3d4b4a53dfda 100644 --- a/tools/testing/selftests/net/.gitignore +++ b/tools/testing/selftests/net/.gitignore @@ -16,6 +16,7 @@ ip_local_port_range ipsec ipv6_flowlabel ipv6_flowlabel_mgr +ipv6_fragmentation log.txt msg_oob msg_zerocopy diff --git a/tools/testing/selftests/net/Makefile b/tools/testing/selftests/net/Makefile index b31a71f2b372..f83f91b758ae 100644 --- a/tools/testing/selftests/net/Makefile +++ b/tools/testing/selftests/net/Makefile @@ -117,6 +117,7 @@ TEST_GEN_FILES += tfo TEST_PROGS += tfo_passive.sh TEST_PROGS += broadcast_pmtu.sh TEST_PROGS += ipv6_force_forwarding.sh +TEST_GEN_PROGS += ipv6_fragmentation # YNL files, must be before "include ..lib.mk" YNL_GEN_FILES := busy_poller netlink-dumps diff --git a/tools/testing/selftests/net/ipv6_fragmentation.c b/tools/testing/selftests/net/ipv6_fragmentation.c new file mode 100644 index 000000000000..21e1a3cdc63d --- /dev/null +++ b/tools/testing/selftests/net/ipv6_fragmentation.c @@ -0,0 +1,204 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Author: Brett A C Sheffield <bacs(a)librecast.net> + * + * Kernel selftest for the IPv6 fragmentation regression which affected + * stable kernels: + * + * https://lore.kernel.org/stable/aElivdUXqd1OqgMY@karahi.gladserv.com + * + * Commit: + * a18dfa9925b9 ("ipv6: save dontfrag in cork") + * was backported to stable without some prerequisite commits. + * + * This caused a regression when sending IPv6 UDP packets by preventing + * fragmentation and instead returning -1 (EMSGSIZE). + * + * This selftest demonstrates the issue. sendmsg returns correctly (8192) + * on a working kernel, and returns -1 (EMSGSIZE) when the regression is + * present. + * + * The regression was not present in the mainline kernel, but add this test to + * catch similar breakage in future. + */ + +#define _GNU_SOURCE + +#include <fcntl.h> +#include <linux/if_tun.h> +#include <net/if.h> +#include <netinet/in.h> +#include <sched.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/ioctl.h> +#include <sys/socket.h> +#include <unistd.h> + +#define MTU 1500 +#define LARGER_THAN_MTU 8192 + +/* ensure MTU is smaller than what we plan to send */ +static int set_mtu(int ctl, char *ifname, struct ifreq *ifr) +{ + ifr->ifr_mtu = MTU; + return ioctl(ctl, SIOCSIFMTU, ifr); +} + +/* bring up interface */ +static int interface_up(int ctl, char *ifname, struct ifreq *ifr) +{ + if (ioctl(ctl, SIOCGIFFLAGS, ifr) == -1) { + perror("ioctl SIOCGIFFLAGS"); + return -1; + } + ifr->ifr_flags = ifr->ifr_flags | IFF_UP; + return ioctl(ctl, SIOCSIFFLAGS, ifr); +} + +/* no need to wait for DAD in our namespace */ +static int disable_dad(char *ifname) +{ + char sysvar[] = "/proc/sys/net/ipv6/conf/%s/accept_dad"; + char fname[IFNAMSIZ + sizeof(sysvar)]; + int fd; + + snprintf(fname, sizeof(fname), sysvar, ifname); + fd = open(fname, O_WRONLY); + if (fd == -1) { + perror("open accept_dad"); + return -1; + } + if (write(fd, "0", 1) != 1) { + perror("write"); + return -1; + } + return close(fd); +} + +/* create TAP interface that will be deleted when this process exits */ +static int create_interface(int ctl, char *ifname, struct ifreq *ifr) +{ + int fd; + + fd = open("/dev/net/tun", O_RDWR); + if (fd == -1) { + perror("open tun"); + return -1; + } + + ifr->ifr_flags = IFF_TAP | IFF_NO_PI; + if (ioctl(fd, TUNSETIFF, (void *)ifr) == -1) { + close(fd); + perror("ioctl: TUNSETIFF"); + return -1; + } + strcpy(ifname, ifr->ifr_name); + + return fd; +} + +/* we need to set MTU, so do this in a namespace to play nicely */ +static int create_namespace(void) +{ + const char *netns_path = "/proc/self/ns/net"; + int fd; + + if (unshare(CLONE_NEWNET) != 0) { + perror("unshare"); + return -1; + } + + fd = open(netns_path, O_RDONLY); + if (fd == -1) { + perror("open"); + return -1; + } + + if (setns(fd, CLONE_NEWNET)) { + perror("setns"); + return -1; + } + + return 0; +} + +static int setup(void) +{ + struct ifreq ifr = {0}; + char ifname[IFNAMSIZ]; + int fd = -1; + int ctl; + + if (create_namespace() == -1) + return -1; + + ctl = socket(AF_LOCAL, SOCK_STREAM, 0); + if (ctl == -1) + return -1; + + memset(ifname, 0, sizeof(ifname)); + fd = create_interface(ctl, ifname, &ifr); + if (fd == -1) + goto err_close_ctl; + if (disable_dad(ifname) == -1) + goto err_close_fd; + if (interface_up(ctl, ifname, &ifr) == -1) + goto err_close_fd; + if (set_mtu(ctl, ifname, &ifr) == -1) + goto err_close_fd; + usleep(10000); /* give interface a moment to wake up */ + goto err_close_ctl; +err_close_fd: + close(fd); + fd = -1; +err_close_ctl: + close(ctl); + return fd; +} + +int main(void) +{ + /* address doesn't matter, use an IPv6 multicast address for simplicity */ + struct in6_addr addr = { + .s6_addr[0] = 0xff, /* multicast */ + .s6_addr[1] = 0x12, /* set flags (T, link-local) */ + }; + struct sockaddr_in6 sa = { + .sin6_family = AF_INET6, + .sin6_addr = addr, + .sin6_port = 4242 + }; + char buf[LARGER_THAN_MTU] = {0}; + struct iovec iov = { .iov_base = buf, .iov_len = sizeof(buf)}; + struct msghdr msg = { + .msg_iov = &iov, + .msg_iovlen = 1, + .msg_name = (struct sockaddr *)&sa, + .msg_namelen = sizeof(sa), + }; + ssize_t rc; + int ns_fd; + int s; + + printf("Testing IPv6 fragmentation\n"); + ns_fd = setup(); + if (ns_fd == -1) + return 1; + s = socket(AF_INET6, SOCK_DGRAM, 0); + msg.msg_name = (struct sockaddr *)&sa; + msg.msg_namelen = sizeof(sa); + rc = sendmsg(s, &msg, 0); + if (rc == -1) { + perror("send"); + return 1; + } else if (rc != LARGER_THAN_MTU) { + fprintf(stderr, "send() returned %zi\n", rc); + return 1; + } + close(s); + close(ns_fd); + + return 0; +} -- 2.49.1

2 months, 2 weeks

3
5
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[PATCH] kselftest/arm64: Don't open code SVE_PT_SIZE() in fp-ptrace

by Mark Brown

In fp-trace when allocating a buffer to write SVE register data we open code the addition of the header size to the VL depeendent register data size, which lead to an underallocation bug when we cut'n'pasted the code for FPSIMD format writes. Use the SVE_PT_SIZE() macro that the kernel UAPI provides for this. Fixes: b84d2b27954f ("kselftest/arm64: Test FPSIMD format data writes via NT_ARM_SVE in fp-ptrace") Signed-off-by: Mark Brown <broonie(a)kernel.org> --- tools/testing/selftests/arm64/fp/fp-ptrace.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/tools/testing/selftests/arm64/fp/fp-ptrace.c b/tools/testing/selftests/arm64/fp/fp-ptrace.c index 124bc883365e..cdd7a45c045d 100644 --- a/tools/testing/selftests/arm64/fp/fp-ptrace.c +++ b/tools/testing/selftests/arm64/fp/fp-ptrace.c @@ -1187,7 +1187,7 @@ static void sve_write_sve(pid_t child, struct test_config *config) if (!vl) return; - iov.iov_len = SVE_PT_SVE_OFFSET + SVE_PT_SVE_SIZE(vq, SVE_PT_REGS_SVE); + iov.iov_len = SVE_PT_SIZE(vq, SVE_PT_REGS_SVE); iov.iov_base = malloc(iov.iov_len); if (!iov.iov_base) { ksft_print_msg("Failed allocating %lu byte SVE write buffer\n", @@ -1234,8 +1234,7 @@ static void sve_write_fpsimd(pid_t child, struct test_config *config) if (!vl) return; - iov.iov_len = SVE_PT_SVE_OFFSET + SVE_PT_SVE_SIZE(vq, - SVE_PT_REGS_FPSIMD); + iov.iov_len = SVE_PT_SIZE(vq, SVE_PT_REGS_FPSIMD); iov.iov_base = malloc(iov.iov_len); if (!iov.iov_base) { ksft_print_msg("Failed allocating %lu byte SVE write buffer\n", --- base-commit: 8f5ae30d69d7543eee0d70083daf4de8fe15d585 change-id: 20250808-arm64-fp-trace-macro-02ede083da51 Best regards, -- Mark Brown <broonie(a)kernel.org>

2 months, 3 weeks

2
1
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[PATCHv4 iproute2-next] iplink: bond_slave: add support for actor_port_prio

by Hangbin Liu

Add support for the actor_port_prio option for bond slaves. This per-port priority can be used by the bonding driver in ad_select to choose the higher-priority aggregator during failover. Signed-off-by: Hangbin Liu <liuhangbin(a)gmail.com> --- v4: no update v3: rename ad_actor_port_prio to actor_port_prio v2: no update --- ip/iplink_bond.c | 1 + ip/iplink_bond_slave.c | 18 ++++++++++++++++-- man/man8/ip-link.8.in | 6 ++++++ 3 files changed, 23 insertions(+), 2 deletions(-) diff --git a/ip/iplink_bond.c b/ip/iplink_bond.c index d6960f6d9b03..1a2c1b3042a0 100644 --- a/ip/iplink_bond.c +++ b/ip/iplink_bond.c @@ -91,6 +91,7 @@ static const char *ad_select_tbl[] = { "stable", "bandwidth", "count", + "prio", NULL, }; diff --git a/ip/iplink_bond_slave.c b/ip/iplink_bond_slave.c index ad6875006950..c88100e248dd 100644 --- a/ip/iplink_bond_slave.c +++ b/ip/iplink_bond_slave.c @@ -15,7 +15,9 @@ static void print_explain(FILE *f) { - fprintf(f, "Usage: ... bond_slave [ queue_id ID ] [ prio PRIORITY ]\n"); + fprintf(f, "Usage: ... bond_slave [ queue_id ID ] [ prio PRIORITY ]\n" + " [ actor_port_prio PRIORITY ]\n" + ); } static void explain(void) @@ -145,12 +147,18 @@ static void bond_slave_print_opt(struct link_util *lu, FILE *f, struct rtattr *t state); print_slave_oper_state(f, "ad_partner_oper_port_state_str", state); } + + if (tb[IFLA_BOND_SLAVE_ACTOR_PORT_PRIO]) + print_int(PRINT_ANY, + "actor_port_prio", + "actor_port_prio %d ", + rta_getattr_u16(tb[IFLA_BOND_SLAVE_ACTOR_PORT_PRIO])); } static int bond_slave_parse_opt(struct link_util *lu, int argc, char **argv, struct nlmsghdr *n) { - __u16 queue_id; + __u16 queue_id, actor_port_prio; int prio; while (argc > 0) { @@ -164,6 +172,12 @@ static int bond_slave_parse_opt(struct link_util *lu, int argc, char **argv, if (get_s32(&prio, *argv, 0)) invarg("prio is invalid", *argv); addattr32(n, 1024, IFLA_BOND_SLAVE_PRIO, prio); + } else if (strcmp(*argv, "actor_port_prio") == 0) { + NEXT_ARG(); + if (get_u16(&actor_port_prio, *argv, 0)) + invarg("actor prio is invalid", *argv); + addattr16(n, 1024, IFLA_BOND_SLAVE_ACTOR_PORT_PRIO, + actor_port_prio); } else { if (matches(*argv, "help") != 0) fprintf(stderr, diff --git a/man/man8/ip-link.8.in b/man/man8/ip-link.8.in index e3297c577152..7995943ab11f 100644 --- a/man/man8/ip-link.8.in +++ b/man/man8/ip-link.8.in @@ -2846,6 +2846,12 @@ the following additional arguments are supported: (a 32bit signed value). This option only valid for active-backup(1), balance-tlb (5) and balance-alb (6) mode. +.sp +.BI actor_port_prio " PRIORITY" +- set the slave's ad actor port priority for 802.3ad aggregation selection +logic during failover (a 16bit unsigned value). This option only valid for +802.3ad (4) mode. + .in -8 .TP -- 2.50.1

2 months, 3 weeks

2
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[PATCH 1/9] KVM: selftests: Add pidfd_open syscall number fallback

by Aqib Faruqui

The kselftest-harness uses pidfd_open() for test timeout handling, but non-glibc C library headers may not define this syscall number. Add architecture-specific fallback definitions to pidfd.h, including support for Alpha (544) and other architectures (434). Update kselftest_harness.h to include pidfd.h for the syscall definitions. Signed-off-by: Aqib Faruqui <aqibaf(a)amazon.com> --- tools/testing/selftests/kselftest_harness.h | 1 + tools/testing/selftests/pidfd/pidfd.h | 4 ++++ 2 files changed, 5 insertions(+) diff --git a/tools/testing/selftests/kselftest_harness.h b/tools/testing/selftests/kselftest_harness.h index 2925e47db..1dd3e5a1b 100644 --- a/tools/testing/selftests/kselftest_harness.h +++ b/tools/testing/selftests/kselftest_harness.h @@ -69,6 +69,7 @@ #include <unistd.h> #include "kselftest.h" +#include "pidfd/pidfd.h" #define TEST_TIMEOUT_DEFAULT 30 diff --git a/tools/testing/selftests/pidfd/pidfd.h b/tools/testing/selftests/pidfd/pidfd.h index f87993def..c373ff18e 100644 --- a/tools/testing/selftests/pidfd/pidfd.h +++ b/tools/testing/selftests/pidfd/pidfd.h @@ -45,8 +45,12 @@ #endif #ifndef __NR_pidfd_open +#ifdef __alpha__ +#define __NR_pidfd_open 544 +#else #define __NR_pidfd_open 434 #endif +#endif #ifndef __NR_pidfd_send_signal #define __NR_pidfd_send_signal 424 -- 2.47.3

2 months, 3 weeks

2
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[PATCH v4 00/15] Consolidate iommu page table implementations (AMD)

by Jason Gunthorpe

[All the precursor patches are merged now and AMD/RISCV/VTD conversions are written] Currently each of the iommu page table formats duplicates all of the logic to maintain the page table and perform map/unmap/etc operations. There are several different versions of the algorithms between all the different formats. The io-pgtable system provides an interface to help isolate the page table code from the iommu driver, but doesn't provide tools to implement the common algorithms. This makes it very hard to improve the state of the pagetable code under the iommu domains as any proposed improvement needs to alter a large number of different driver code paths. Combined with a lack of software based testing this makes improvement in this area very hard. iommufd wants several new page table operations: - More efficient map/unmap operations, using iommufd's batching logic - unmap that returns the physical addresses into a batch as it progresses - cut that allows splitting areas so large pages can have holes poked in them dynamically (ie guestmemfd hitless shared/private transitions) - More agressive freeing of table memory to avoid waste - Fragmenting large pages so that dirty tracking can be more granular - Reassembling large pages so that VMs can run at full IO performance in migration/dirty tracking error flows - KHO integration for kernel live upgrade Together these are algorithmically complex enough to be a very significant task to go and implement in all the page table formats we support. Just the "server" focused drivers use almost all the formats (ARMv8 S1&S2 / x86 PAE / AMDv1 / VT-D SS / RISCV) Instead of doing the duplicated work, this series takes the first step to consolidate the algorithms into one places. In spirit it is similar to the work Christoph did a few years back to pull the redundant get_user_pages() implementations out of the arch code into core MM. This unlocked a great deal of improvement in that space in the following years. I would like to see the same benefit in iommu as well. My first RFC showed a bigger picture with all most all formats and more algorithms. This series reorganizes that to be narrowly focused on just enough to convert the AMD driver to use the new mechanism. kunit tests are provided that allow good testing of the algorithms and all formats on x86, nothing is arch specific. AMD is one of the simpler options as the HW is quite uniform with few different options/bugs while still requiring the complicated contiguous pages support. The HW also has a very simple range based invalidation approach that is easy to implement. The AMD v1 and AMD v2 page table formats are implemented bit for bit identical to the current code, tested using a compare kunit test that checks against the io-pgtable version (on github, see below). Updating the AMD driver to replace the io-pgtable layer with the new stuff is fairly straightforward now. The layering is fixed up in the new version so that all the invalidation goes through function pointers. Several small fixing patches have come out of this as I've been fixing the problems that the test suite uncovers in the current code, and implementing the fixed version in iommupt. On performance, there is a quite wide variety of implementation designs across all the drivers. Looking at some key performance across the main formats: iommu_map(): pgsz ,avg new,old ns, min new,old ns , min % (+ve is better) 2^12, 53,66 , 51,63 , 19.19 (AMDV1) 256*2^12, 386,1909 , 367,1795 , 79.79 256*2^21, 362,1633 , 355,1556 , 77.77 2^12, 56,62 , 52,59 , 11.11 (AMDv2) 256*2^12, 405,1355 , 357,1292 , 72.72 256*2^21, 393,1160 , 358,1114 , 67.67 2^12, 55,65 , 53,62 , 14.14 (VTD second stage) 256*2^12, 391,518 , 332,512 , 35.35 256*2^21, 383,635 , 336,624 , 46.46 2^12, 57,65 , 55,63 , 12.12 (ARM 64 bit) 256*2^12, 380,389 , 361,369 , 2.02 256*2^21, 358,419 , 345,400 , 13.13 iommu_unmap(): pgsz ,avg new,old ns, min new,old ns , min % (+ve is better) 2^12, 69,88 , 65,85 , 23.23 (AMDv1) 256*2^12, 353,6498 , 331,6029 , 94.94 256*2^21, 373,6014 , 360,5706 , 93.93 2^12, 71,72 , 66,69 , 4.04 (AMDv2) 256*2^12, 228,891 , 206,871 , 76.76 256*2^21, 254,721 , 245,711 , 65.65 2^12, 69,87 , 65,82 , 20.20 (VTD second stage) 256*2^12, 210,321 , 200,315 , 36.36 256*2^21, 255,349 , 238,342 , 30.30 2^12, 72,77 , 68,74 , 8.08 (ARM 64 bit) 256*2^12, 521,357 , 447,346 , -29.29 256*2^21, 489,358 , 433,345 , -25.25 * Above numbers include additional patches to remove the iommu_pgsize() overheads. gcc 13.3.0, i7-12700 This version provides fairly consistent performance across formats. ARM unmap performance is quite different because this version supports contiguous pages and uses a very different algorithm for unmapping. Though why it is so worse compared to AMDv1 I haven't figured out yet. The per-format commits include a more detailed chart. There is a second branch: https://github.com/jgunthorpe/linux/commits/iommu_pt_all Containing supporting work and future steps: - ARM short descriptor (32 bit), ARM long descriptor (64 bit) formats - RISCV format and RISCV conversion https://github.com/jgunthorpe/linux/commits/iommu_pt_riscv - Support for a DMA incoherent HW page table walker - VT-D second stage format and VT-D conversion https://github.com/jgunthorpe/linux/commits/iommu_pt_vtd - DART v1 & v2 format - Draft of a iommufd 'cut' operation to break down huge pages - A compare test that checks the iommupt formats against the iopgtable interface, including updating AMD to have a working iopgtable and patches to make VT-D have an iopgtable for testing. - A performance test to micro-benchmark map and unmap against iogptable My strategy is to go one by one for the drivers: - AMD driver conversion - RISCV page table and driver - Intel VT-D driver and VTDSS page table - Flushing improvements for RISCV - ARM SMMUv3 And concurrently work on the algorithm side: - debugfs content dump, like VT-D has - Cut support - Increase/Decrease page size support - map/unmap batching - KHO As we make more algorithm improvements the value to convert the drivers increases. This is on github: https://github.com/jgunthorpe/linux/commits/iommu_pt v3: - Rebase on v6.16-rc3 - Integrate the HATS/HATDis changes - Remove 'default n' from kconfig - Remove unused 'PT_FIXED_TOP_LEVEL' - Improve comments and coumentation - Fix some compile warnings from kbuild robots v2: https://patch.msgid.link/r/0-v3-a93aab628dbc+521-iommu_pt_jgg@nvidia.com - Rebase on v6.16-rc2 - s/PT_ENTRY_WORD_SIZE/PT_ITEM_WORD_SIZE/s to follow the language better - Comment and documentation updates - Add PT_TOP_PHYS_MASK to help manage alignment restrictions on the top pointer - Add missed force_aperture = true - Make pt_iommu_deinit() take care of the not-yet-inited error case internally as AMD/RISCV/VTD all shared this logic - Change gather_range() into gather_range_pages() so it also deals with the page list. This makes the following cache flushing series simpler - Fix missed update of unmap->unmapped in some error cases - Change clear_contig() to order the gather more logically - Remove goto from the error handling in __map_range_leaf() - s/log2_/oalog2_/ in places where the argument is an oaddr_t - Pass the pts to pt_table_install64/32() - Do not use SIGN_EXTEND for the AMDv2 page table because of Vasant's information on how PASID 0 works. v1: https://patch.msgid.link/r/0-v2-5c26bde5c22d+58b-iommu_pt_jgg@nvidia.com - AMD driver only, many code changes RFC: https://lore.kernel.org/all/0-v1-01fa10580981+1d-iommu_pt_jgg@nvidia.com/ Cc: Michael Roth <michael.roth(a)amd.com> Cc: Alexey Kardashevskiy <aik(a)amd.com> Cc: Pasha Tatashin <pasha.tatashin(a)soleen.com> Cc: James Gowans <jgowans(a)amazon.com> Signed-off-by: Jason Gunthorpe <jgg(a)nvidia.com> Alejandro Jimenez (1): iommu/amd: Use the generic iommu page table Jason Gunthorpe (14): genpt: Generic Page Table base API genpt: Add Documentation/ files iommupt: Add the basic structure of the iommu implementation iommupt: Add the AMD IOMMU v1 page table format iommupt: Add iova_to_phys op iommupt: Add unmap_pages op iommupt: Add map_pages op iommupt: Add read_and_clear_dirty op iommupt: Add a kunit test for Generic Page Table iommupt: Add a mock pagetable format for iommufd selftest to use iommufd: Change the selftest to use iommupt instead of xarray iommupt: Add the x86 64 bit page table format iommu/amd: Remove AMD io_pgtable support iommupt: Add a kunit test for the IOMMU implementation .clang-format | 1 + Documentation/driver-api/generic_pt.rst | 140 ++ Documentation/driver-api/index.rst | 1 + drivers/iommu/Kconfig | 2 + drivers/iommu/Makefile | 1 + drivers/iommu/amd/Kconfig | 5 +- drivers/iommu/amd/Makefile | 2 +- drivers/iommu/amd/amd_iommu.h | 1 - drivers/iommu/amd/amd_iommu_types.h | 109 +- drivers/iommu/amd/io_pgtable.c | 560 -------- drivers/iommu/amd/io_pgtable_v2.c | 370 ------ drivers/iommu/amd/iommu.c | 538 ++++---- drivers/iommu/generic_pt/.kunitconfig | 13 + drivers/iommu/generic_pt/Kconfig | 67 + drivers/iommu/generic_pt/fmt/Makefile | 26 + drivers/iommu/generic_pt/fmt/amdv1.h | 409 ++++++ drivers/iommu/generic_pt/fmt/defs_amdv1.h | 21 + drivers/iommu/generic_pt/fmt/defs_x86_64.h | 21 + drivers/iommu/generic_pt/fmt/iommu_amdv1.c | 15 + drivers/iommu/generic_pt/fmt/iommu_mock.c | 10 + drivers/iommu/generic_pt/fmt/iommu_template.h | 48 + drivers/iommu/generic_pt/fmt/iommu_x86_64.c | 11 + drivers/iommu/generic_pt/fmt/x86_64.h | 248 ++++ drivers/iommu/generic_pt/iommu_pt.h | 1146 +++++++++++++++++ drivers/iommu/generic_pt/kunit_generic_pt.h | 717 +++++++++++ drivers/iommu/generic_pt/kunit_iommu.h | 183 +++ drivers/iommu/generic_pt/kunit_iommu_pt.h | 451 +++++++ drivers/iommu/generic_pt/pt_common.h | 354 +++++ drivers/iommu/generic_pt/pt_defs.h | 323 +++++ drivers/iommu/generic_pt/pt_fmt_defaults.h | 193 +++ drivers/iommu/generic_pt/pt_iter.h | 636 +++++++++ drivers/iommu/generic_pt/pt_log2.h | 130 ++ drivers/iommu/io-pgtable.c | 4 - drivers/iommu/iommufd/Kconfig | 1 + drivers/iommu/iommufd/iommufd_test.h | 11 +- drivers/iommu/iommufd/selftest.c | 438 +++---- include/linux/generic_pt/common.h | 166 +++ include/linux/generic_pt/iommu.h | 270 ++++ include/linux/io-pgtable.h | 2 - tools/testing/selftests/iommu/iommufd.c | 60 +- tools/testing/selftests/iommu/iommufd_utils.h | 12 + 41 files changed, 6124 insertions(+), 1592 deletions(-) create mode 100644 Documentation/driver-api/generic_pt.rst delete mode 100644 drivers/iommu/amd/io_pgtable.c delete mode 100644 drivers/iommu/amd/io_pgtable_v2.c create mode 100644 drivers/iommu/generic_pt/.kunitconfig create mode 100644 drivers/iommu/generic_pt/Kconfig create mode 100644 drivers/iommu/generic_pt/fmt/Makefile create mode 100644 drivers/iommu/generic_pt/fmt/amdv1.h create mode 100644 drivers/iommu/generic_pt/fmt/defs_amdv1.h create mode 100644 drivers/iommu/generic_pt/fmt/defs_x86_64.h create mode 100644 drivers/iommu/generic_pt/fmt/iommu_amdv1.c create mode 100644 drivers/iommu/generic_pt/fmt/iommu_mock.c create mode 100644 drivers/iommu/generic_pt/fmt/iommu_template.h create mode 100644 drivers/iommu/generic_pt/fmt/iommu_x86_64.c create mode 100644 drivers/iommu/generic_pt/fmt/x86_64.h create mode 100644 drivers/iommu/generic_pt/iommu_pt.h create mode 100644 drivers/iommu/generic_pt/kunit_generic_pt.h create mode 100644 drivers/iommu/generic_pt/kunit_iommu.h create mode 100644 drivers/iommu/generic_pt/kunit_iommu_pt.h create mode 100644 drivers/iommu/generic_pt/pt_common.h create mode 100644 drivers/iommu/generic_pt/pt_defs.h create mode 100644 drivers/iommu/generic_pt/pt_fmt_defaults.h create mode 100644 drivers/iommu/generic_pt/pt_iter.h create mode 100644 drivers/iommu/generic_pt/pt_log2.h create mode 100644 include/linux/generic_pt/common.h create mode 100644 include/linux/generic_pt/iommu.h base-commit: 8da0d63bd5726ff656bfa1eacb45d6f5cce65616 -- 2.43.0

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