- Linux-kselftest-mirror - lists.linaro.org

[PATCH v5 0/2] x86/fred: Prevent immediate repeat of single step trap on return from SIGTRAP handler

by Xin Li (Intel)

IDT event delivery has a debug hole in which it does not generate #DB upon returning to userspace before the first userspace instruction is executed if the Trap Flag (TF) is set. FRED closes this hole by introducing a software event flag, i.e., bit 17 of the augmented SS: if the bit is set and ERETU would result in RFLAGS.TF = 1, a single-step trap will be pending upon completion of ERETU. However I overlooked properly setting and clearing the bit in different situations. Thus when FRED is enabled, if the Trap Flag (TF) is set without an external debugger attached, it can lead to an infinite loop in the SIGTRAP handler. To avoid this, the software event flag in the augmented SS must be cleared, ensuring that no single-step trap remains pending when ERETU completes. This patch set combines the fix [1] and its corresponding selftest [2] (requested by Dave Hansen) into one patch set. [1] https://lore.kernel.org/lkml/20250523050153.3308237-1-xin@zytor.com/ [2] https://lore.kernel.org/lkml/20250530230707.2528916-1-xin@zytor.com/ This patch set is based on tip/x86/urgent branch as of today. Link to v4 of this patch set: https://lore.kernel.org/lkml/20250605181020.590459-1-xin@zytor.com/ Changes in v5: *) Accurately rephrase the shortlog (hpa). *) Do "sub $-128, %rsp" rather than "add $128, %rsp", which is more efficient in code size (hpa). *) Add TB from Sohil. *) Add Cc: stable(a)vger.kernel.org to all patches. Xin Li (Intel) (2): x86/fred/signal: Prevent immediate repeat of single step trap on return from SIGTRAP handler selftests/x86: Add a test to detect infinite sigtrap handler loop arch/x86/include/asm/sighandling.h | 22 +++++ arch/x86/kernel/signal_32.c | 4 + arch/x86/kernel/signal_64.c | 4 + tools/testing/selftests/x86/Makefile | 2 +- tools/testing/selftests/x86/sigtrap_loop.c | 98 ++++++++++++++++++++++ 5 files changed, 129 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/x86/sigtrap_loop.c base-commit: dd2922dcfaa3296846265e113309e5f7f138839f -- 2.49.0

2 weeks, 6 days

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[PATCH RFC bpf-next 0/4] bpf, arm64: support up to 12 arguments

by Alexis Lothoré (eBPF Foundation)

Hello, this series is a revival of Xu Kuhoai's work to enable larger arguments count for BPF programs on ARM64 ([1]). His initial series received some positive feedback, but lacked some specific case handling around arguments alignment (see AAPCS64 C.14 rule in section 6.8.2, [2]). There as been another attempt from Puranjay Mohan, which was unfortunately missing the same thing ([3]). Since there has been some time between those series and this new one, I chose to send it as a new series rather than a new revision of the existing series. To support the increased argument counts and arguments larger than registers size (eg: structures), the trampoline does the following: - for bpf programs: arguments are retrieved from both registers and the function stack, and pushed in the trampoline stack as an array of u64 to generate the programs context. It is then passed by pointer to the bpf programs - when the trampoline is in charge of calling the original function: it restores the registers content, and generates a new stack layout for the additional arguments that do not fit in registers. This new attempt is based on Xu's series and aims to handle the missing alignment concern raised in the reviews discussions. The main novelties are then around arguments alignments: - the first commit is exposing some new info in the BTF function model passed to the JIT compiler to allow it to deduce the needed alignment when configuring the trampoline stack - the second commit is taken from Xu's series, and received the following modifications: - the calc_aux_args computes an expected alignment for each argument - the calc_aux_args computes two different stack space sizes: the one needed to store the bpf programs context, and the original function stacked arguments (which needs alignment). Those stack sizes are in bytes instead of "slots" - when saving/restoring arguments for bpf program or for the original function, make sure to align the load/store accordingly, when relevant - a few typos fixes and some rewording, raised by the review on the original series - the last commit introduces some explicit tests that ensure that the needed alignment is enforced by the trampoline I marked the series as RFC because it appears that the new tests trigger some failures in CI on x86 and s390, despite the series not touching any code related to those architectures. Some very early investigation/gdb debugging on the x86 side seems to hint that it could be related to the same missing alignment too (based on section 3.2.3 in [4], and so the x86 trampoline would need the same alignment handling ?). For s390 it looks less clear, as all values captured from the bpf test program are set to 0 in the CI output, and I don't have the proper setup yet to check the low level details. I am tempted to isolate those new tests (which were actually useful to spot real issues while tuning the ARM64 trampoline) and add them to the relevant DENYLIST files for x86/s390, but I guess this is not the right direction, so I would gladly take a second opinion on this. [1] https://lore.kernel.org/all/20230917150752.69612-1-xukuohai@huaweicloud.com… [2] https://github.com/ARM-software/abi-aa/blob/main/aapcs64/aapcs64.rst#id82 [3] https://lore.kernel.org/bpf/20240705125336.46820-1-puranjay@kernel.org/ [4] https://refspecs.linuxbase.org/elf/x86_64-abi-0.99.pdf Signed-off-by: Alexis Lothoré (eBPF Foundation) <alexis.lothore(a)bootlin.com> --- Alexis Lothoré (eBPF Foundation) (3): bpf: add struct largest member size in func model bpf/selftests: add tests to validate proper arguments alignment on ARM64 bpf/selftests: enable tracing tests for ARM64 Xu Kuohai (1): bpf, arm64: Support up to 12 function arguments arch/arm64/net/bpf_jit_comp.c | 235 ++++++++++++++++----- include/linux/bpf.h | 1 + kernel/bpf/btf.c | 25 +++ tools/testing/selftests/bpf/DENYLIST.aarch64 | 3 - .../selftests/bpf/prog_tests/tracing_struct.c | 23 ++ tools/testing/selftests/bpf/progs/tracing_struct.c | 10 +- .../selftests/bpf/progs/tracing_struct_many_args.c | 67 ++++++ .../testing/selftests/bpf/test_kmods/bpf_testmod.c | 50 +++++ 8 files changed, 357 insertions(+), 57 deletions(-) --- base-commit: 91e7eb701b4bc389e7ddfd80ef6e82d1a6d2d368 change-id: 20250220-many_args_arm64-8bd3747e6948 Best regards, -- Alexis Lothoré, Bootlin Embedded Linux and Kernel engineering https://bootlin.com

2 weeks, 6 days

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[PATCH v2 00/15] Consolidate iommu page table implementations (AMD)

by Jason Gunthorpe

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 - VT-D second stage format - DART v1 & v2 format - Draft of a iommufd 'cut' operation to break down huge pages - Draft of support for a DMA incoherent HW page table walker - 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 - 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 v1: - AMD driver only, many code changes RFC: https://lore.kernel.org/all/0-v1-01fa10580981+1d-iommu_pt_jgg@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 | 105 ++ 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 | 493 ++++--- drivers/iommu/generic_pt/.kunitconfig | 13 + drivers/iommu/generic_pt/Kconfig | 72 ++ drivers/iommu/generic_pt/fmt/Makefile | 26 + drivers/iommu/generic_pt/fmt/amdv1.h | 407 ++++++ 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 | 12 + drivers/iommu/generic_pt/fmt/x86_64.h | 241 ++++ drivers/iommu/generic_pt/iommu_pt.h | 1146 +++++++++++++++++ drivers/iommu/generic_pt/kunit_generic_pt.h | 721 +++++++++++ drivers/iommu/generic_pt/kunit_iommu.h | 183 +++ drivers/iommu/generic_pt/kunit_iommu_pt.h | 451 +++++++ drivers/iommu/generic_pt/pt_common.h | 351 +++++ drivers/iommu/generic_pt/pt_defs.h | 312 +++++ drivers/iommu/generic_pt/pt_fmt_defaults.h | 193 +++ drivers/iommu/generic_pt/pt_iter.h | 638 +++++++++ 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 | 439 +++---- include/linux/generic_pt/common.h | 166 +++ include/linux/generic_pt/iommu.h | 264 ++++ include/linux/io-pgtable.h | 2 - tools/testing/selftests/iommu/iommufd.c | 60 +- tools/testing/selftests/iommu/iommufd_utils.h | 12 + 41 files changed, 6046 insertions(+), 1574 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: db37090502f67e46541e53b91f00bbd565c96bd0 -- 2.43.0

3 weeks

8
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[PATCH] selftests/mm: Skip failed memfd setups in gup_longterm

by Mark Brown

Unlike the other cases gup_longterm's memfd tests previously skipped the test when failing to set up the file descriptor to test, restore this behaviour. Signed-off-by: Mark Brown <broonie(a)kernel.org> --- tools/testing/selftests/mm/gup_longterm.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/mm/gup_longterm.c b/tools/testing/selftests/mm/gup_longterm.c index 8a97ac5176a4..29047d2e0c49 100644 --- a/tools/testing/selftests/mm/gup_longterm.c +++ b/tools/testing/selftests/mm/gup_longterm.c @@ -298,8 +298,11 @@ static void run_with_memfd(test_fn fn, const char *desc) log_test_start("%s ... with memfd", desc); fd = memfd_create("test", 0); - if (fd < 0) + if (fd < 0) { ksft_print_msg("memfd_create() failed (%s)\n", strerror(errno)); + log_test_result(KSFT_SKIP); + return; + } fn(fd, pagesize); close(fd); @@ -366,6 +369,8 @@ static void run_with_memfd_hugetlb(test_fn fn, const char *desc, fd = memfd_create("test", flags); if (fd < 0) { ksft_print_msg("memfd_create() failed (%s)\n", strerror(errno)); + log_test_result(KSFT_SKIP); + return; } fn(fd, hugetlbsize); --- base-commit: ec7714e4947909190ffb3041a03311a975350fe0 change-id: 20250603-selftest-mm-gup-longterm-tweaks-e685a8ae9751 Best regards, -- Mark Brown <broonie(a)kernel.org>

3 weeks

4
3
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[kvm-unit-tests PATCH v3 1/2] riscv: Add RV_INSN_LEN to processor.h

by Jesse Taube

When handeling traps and faults it is offten necessary to know the size of the instruction at epc. Add RV_INSN_LEN to calculate the instruction size. Signed-off-by: Jesse Taube <jesse(a)rivosinc.com> --- lib/riscv/asm/processor.h | 2 ++ 1 file changed, 2 insertions(+) diff --git a/lib/riscv/asm/processor.h b/lib/riscv/asm/processor.h index 40104272..631ce226 100644 --- a/lib/riscv/asm/processor.h +++ b/lib/riscv/asm/processor.h @@ -7,6 +7,8 @@ #define EXCEPTION_CAUSE_MAX 24 #define INTERRUPT_CAUSE_MAX 16 +#define RV_INSN_LEN(insn) ((((insn) & 0x3) < 0x3) ? 2 : 4) + typedef void (*exception_fn)(struct pt_regs *); struct thread_info { -- 2.43.0

3 weeks

2
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[PATCH v5 0/5] kunit: Add support for suppressing warning backtraces

by Alessandro Carminati

Some unit tests intentionally trigger warning backtraces by passing bad parameters to kernel API functions. Such unit tests typically check the return value from such calls, not the existence of the warning backtrace. Such intentionally generated warning backtraces are neither desirable nor useful for a number of reasons: - They can result in overlooked real problems. - A warning that suddenly starts to show up in unit tests needs to be investigated and has to be marked to be ignored, for example by adjusting filter scripts. Such filters are ad hoc because there is no real standard format for warnings. On top of that, such filter scripts would require constant maintenance. One option to address the problem would be to add messages such as "expected warning backtraces start/end here" to the kernel log. However, that would again require filter scripts, might result in missing real problematic warning backtraces triggered while the test is running, and the irrelevant backtrace(s) would still clog the kernel log. Solve the problem by providing a means to identify and suppress specific warning backtraces while executing test code. Support suppressing multiple backtraces while at the same time limiting changes to generic code to the absolute minimum. Overview: Patch#1 Introduces the suppression infrastructure. Patch#2 Mitigate the impact at WARN*() sites. Patch#3 Adds selftests to validate the functionality. Patch#4 Demonstrates real-world usage in the DRM subsystem. Patch#5 Documents the new API and usage guidelines. Design Notes: The objective is to suppress unwanted WARN*() generated messages. Although most major architectures share common bug handling via `lib/bug.c` and `report_bug()`, some minor or legacy architectures still rely on their own platform-specific handling. This divergence must be considered in any such feature. Additionally, a key challenge in implementing this feature is the fragmentation of `WARN*()` messages emission: specific part in the macro, common with BUG*() part in the exception handler. As a result, any intervention to suppress the message must occur before the illegal instruction. Lessons from the Previous Attempt In earlier iterations, suppression logic was added inside the `__report_bug()` function to intercept WARN*() messages not producing messages in the macro. To implement the check in the check in the bug handler code, two strategies were considered: * Strategy #1: Use `kallsyms` to infer the originating functionid, namely a pointer to the function. Since in any case, the user interface relies on function names, they must be translated in addresses at suppression- time or at check-time. Assuming to translate at suppression-time, the `kallsyms` subsystem needs to be used to determine the symbol address from the name, and again to produce the functionid from `bugaddr`. This approach proved unreliable due to compiler-induced transformations such as inlining, cloning, and code fragmentation. Attempts to preventing them is also unconvenient because several `WARN()` sites are in functions intentionally declared as `__always_inline`. * Strategy #2: Store function name `__func__` in `struct bug_entry` in the `__bug_table`. This implementation was used in the previous version. However, `__func__` is a compiler-generated symbol, which complicates relocation and linking in position-independent code. Workarounds such as storing offsets from `.rodata` or embedding string literals directly into the table would have significantly either increased complexity or increase the __bug_table size. Additionally, architectures not using the unified `BUG()` path would still require ad-hoc handling. Because current WARN*() message production strategy, a few WARN*() macros still need a check to suppress the part of the message produced in the macro itself. Current Proposal: Check Directly in the `WARN()` Macros. This avoids the need for function symbol resolution or ELF section modification. Suppression is implemented directly in the `WARN*()` macros. A helper function, `__kunit_is_suppressed_warning()`, is used to determine whether suppression applies. It is marked as `noinstr`, since some `WARN*()` sites reside in non-instrumentable sections. As it uses `strcmp`, a `noinstr` version of `strcmp` was introduced. The implementation is deliberately simple and avoids architecture-specific optimizations to preserve portability. Since this mechanism compares function names and is intended for test usage only, performance is not a primary concern. This series is based on the RFC patch and subsequent discussion at https://patchwork.kernel.org/project/linux-kselftest/patch/02546e59-1afe-4b… and offers a more comprehensive solution of the problem discussed there. Changes since RFC: - Introduced CONFIG_KUNIT_SUPPRESS_BACKTRACE - Minor cleanups and bug fixes - Added support for all affected architectures - Added support for counting suppressed warnings - Added unit tests using those counters - Added patch to suppress warning backtraces in dev_addr_lists tests Changes since v1: - Rebased to v6.9-rc1 - Added Tested-by:, Acked-by:, and Reviewed-by: tags [I retained those tags since there have been no functional changes] - Introduced KUNIT_SUPPRESS_BACKTRACE configuration option, enabled by default. Changes since v2: - Rebased to v6.9-rc2 - Added comments to drm warning suppression explaining why it is needed. - Added patch to move conditional code in arch/sh/include/asm/bug.h to avoid kerneldoc warning - Added architecture maintainers to Cc: for architecture specific patches - No functional changes Changes since v3: - Rebased to v6.14-rc6 - Dropped net: "kunit: Suppress lock warning noise at end of dev_addr_lists tests" since 3db3b62955cd6d73afde05a17d7e8e106695c3b9 - Added __kunit_ and KUNIT_ prefixes. - Tested on interessed architectures. Changes since v4: - Rebased to v6.15-rc7 - Dropped all code in __report_bug() - Moved all checks in WARN*() macros. - Dropped all architecture specific code. - Made __kunit_is_suppressed_warning nice to noinstr functions. Alessandro Carminati (2): bug/kunit: Core support for suppressing warning backtraces bug/kunit: Suppressing warning backtraces reduced impact on WARN*() sites Guenter Roeck (3): Add unit tests to verify that warning backtrace suppression works. drm: Suppress intentional warning backtraces in scaling unit tests kunit: Add documentation for warning backtrace suppression API Documentation/dev-tools/kunit/usage.rst | 30 ++++++- drivers/gpu/drm/tests/drm_rect_test.c | 16 ++++ include/asm-generic/bug.h | 48 +++++++---- include/kunit/bug.h | 62 ++++++++++++++ include/kunit/test.h | 1 + lib/kunit/Kconfig | 9 ++ lib/kunit/Makefile | 9 +- lib/kunit/backtrace-suppression-test.c | 105 ++++++++++++++++++++++++ lib/kunit/bug.c | 54 ++++++++++++ 9 files changed, 316 insertions(+), 18 deletions(-) create mode 100644 include/kunit/bug.h create mode 100644 lib/kunit/backtrace-suppression-test.c create mode 100644 lib/kunit/bug.c -- 2.34.1

3 weeks

7
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[PATCH v5 00/29] iommufd: Add vIOMMU infrastructure (Part-4 HW QUEUE)

by Nicolin Chen

The vIOMMU object is designed to represent a slice of an IOMMU HW for its virtualization features shared with or passed to user space (a VM mostly) in a way of HW acceleration. This extended the HWPT-based design for more advanced virtualization feature. HW QUEUE introduced by this series as a part of the vIOMMU infrastructure represents a HW accelerated queue/buffer for VM to use exclusively, e.g. - NVIDIA's Virtual Command Queue - AMD vIOMMU's Command Buffer, Event Log Buffer, and PPR Log Buffer each of which allows its IOMMU HW to directly access a queue memory owned by a guest VM and allows a guest OS to control the HW queue direclty, to avoid VM Exit overheads to improve the performance. Introduce IOMMUFD_OBJ_HW_QUEUE and its pairing IOMMUFD_CMD_HW_QUEUE_ALLOC allowing VMM to forward the IOMMU-specific queue info, such as queue base address, size, and etc. Meanwhile, a guest-owned queue needs the guest kernel to control the queue by reading/writing its consumer and producer indexes, via MMIO acceses to the hardware MMIO registers. Introduce an mmap infrastructure for iommufd to support passing through a piece of MMIO region from the host physical address space to the guest physical address space. The mmap info (offset/ length) used by an mmap syscall must be pre-allocated and returned to the user space via an output driver-data during an IOMMUFD_CMD_HW_QUEUE_ALLOC call. Thus, it requires a driver-specific user data support in the vIOMMU allocation flow. As a real-world use case, this series implements a HW QUEUE support in the tegra241-cmdqv driver for VCMDQs on NVIDIA Grace CPU. In another word, it is also the Tegra CMDQV series Part-2 (user-space support), reworked from Previous RFCv1: https://lore.kernel.org/all/cover.1712978212.git.nicolinc@nvidia.com/ This enables the HW accelerated feature for NVIDIA Grace CPU. Compared to the standard SMMUv3 operating in the nested translation mode trapping CMDQ for TLBI and ATC_INV commands, this gives a huge performance improvement: 70% to 90% reductions of invalidation time were measured by various DMA unmap tests running in a guest OS. // Unmap latencies from "dma_map_benchmark -g @granule -t @threads", // by toggling "/sys/kernel/debug/iommu/tegra241_cmdqv/bypass_vcmdq" @granule | @threads | bypass_vcmdq=1 | bypass_vcmdq=0 4KB 1 35.7 us 5.3 us 16KB 1 41.8 us 6.8 us 64KB 1 68.9 us 9.9 us 128KB 1 109.0 us 12.6 us 256KB 1 187.1 us 18.0 us 4KB 2 96.9 us 6.8 us 16KB 2 97.8 us 7.5 us 64KB 2 151.5 us 10.7 us 128KB 2 257.8 us 12.7 us 256KB 2 443.0 us 17.9 us This is on Github: https://github.com/nicolinc/iommufd/commits/iommufd_hw_queue-v5 Paring QEMU branch for testing: https://github.com/nicolinc/qemu/commits/wip/for_iommufd_hw_queue-v5 Changelog v5 * Rebase on v6.15-rc6 * Add Reviewed-by from Jason and Kevin * Correct typos in kdoc and update commit logs * [iommufd] Add a cosmetic fix * [iommufd] Drop unused num_pfns * [iommufd] Drop unnecessary check * [iommufd] Reorder patch sequence * [iommufd] Use io_remap_pfn_range() * [iommufd] Use success oriented flow * [iommufd] Fix max_npages calculation * [iommufd] Add more selftest coverage * [iommufd] Drop redundant static_assert * [iommufd] Fix mmap pfn range validation * [iommufd] Reject unmap on pinned iovas * [iommufd] Drop redundant vm_flags_set() * [iommufd] Drop iommufd_struct_destroy() * [iommufd] Drop redundant queue iova test * [iommufd] Use "mmio_addr" and "mmio_pfn" * [iommufd] Rename to "nesting_parent_iova" * [iommufd] Make iopt_pin_pages call option * [iommufd] Add ictx comparison in depend() * [iommufd] Add iommufd_object_alloc_ucmd() * [iommufd] Move kcalloc() after validations * [iommufd] Replace ictx setting with WARN_ON * [iommufd] Make hw_info's type bidirectional * [smmu] Add supported_vsmmu_type in impl_ops * [smmu] Drop impl report in smmu vendor struct * [tegra] Add IOMMU_HW_INFO_TYPE_TEGRA241_CMDQV * [tegra] Replace "number of VINTFs" with a note * [tegra] Drop the redundant lvcmdq pointer setting * [tegra] Flag IOMMUFD_VIOMMU_FLAG_HW_QUEUE_READS_PA * [tegra] Use "vintf_alloc_vsid" for vdevice_alloc op v4 https://lore.kernel.org/all/cover.1746757630.git.nicolinc@nvidia.com/ * Rebase on v6.15-rc5 * Add Reviewed-by from Vasant * Rename "vQUEUE" to "HW QUEUE" * Use "offset" and "length" for all mmap-related variables * [iommufd] Use u64 for guest PA * [iommufd] Fix typo in uAPI doc * [iommufd] Rename immap_id to offset * [iommufd] Drop the partial-size mmap support * [iommufd] Do not replace WARN_ON with WARN_ON_ONCE * [iommufd] Use "u64 base_addr" for queue base address * [iommufd] Use u64 base_pfn/num_pfns for immap structure * [iommufd] Correct the size passed in to mtree_alloc_range() * [iommufd] Add IOMMUFD_VIOMMU_FLAG_HW_QUEUE_READS_PA to viommu_ops v3 https://lore.kernel.org/all/cover.1746139811.git.nicolinc@nvidia.com/ * Add Reviewed-by from Baolu, Pranjal, and Alok * Revise kdocs, uAPI docs, and commit logs * Rename "vCMDQ" back to "vQUEUE" for AMD cases * [tegra] Add tegra241_vcmdq_hw_flush_timeout() * [tegra] Rename vsmmu_alloc to alloc_vintf_user * [tegra] Use writel for SID replacement registers * [tegra] Move mmap removal call to vsmmu_destroy op * [tegra] Fix revert in tegra241_vintf_alloc_lvcmdq_user() * [iommufd] Replace "& ~PAGE_MASK" with PAGE_ALIGNED() * [iommufd] Add an object-type "owner" to immap structure * [iommufd] Drop the ictx input in the new for-driver APIs * [iommufd] Add iommufd_vma_ops to keep track of mmap lifecycle * [iommufd] Add viommu-based iommufd_viommu_alloc/destroy_mmap helpers * [iommufd] Rename iommufd_ctx_alloc/free_mmap to _iommufd_alloc/destroy_mmap v2 https://lore.kernel.org/all/cover.1745646960.git.nicolinc@nvidia.com/ * Add Reviewed-by from Jason * [smmu] Fix vsmmu initial value * [smmu] Support impl for hw_info * [tegra] Rename "slot" to "vsid" * [tegra] Update kdocs and commit logs * [tegra] Map/unmap LVCMDQ dynamically * [tegra] Refcount the previous LVCMDQ * [tegra] Return -EEXIST if LVCMDQ exists * [tegra] Simplify VINTF cleanup routine * [tegra] Use vmid and s2_domain in vsmmu * [tegra] Rename "mmap_pgoff" to "immap_id" * [tegra] Add more addr and length validation * [iommufd] Add more narrative to mmap's kdoc * [iommufd] Add iommufd_struct_depend/undepend() * [iommufd] Rename vcmdq_free op to vcmdq_destroy * [iommufd] Fix bug in iommu_copy_struct_to_user() * [iommufd] Drop is_io from iommufd_ctx_alloc_mmap() * [iommufd] Test the queue memory for its contiguity * [iommufd] Return -ENXIO if address or length fails * [iommufd] Do not change @min_last in mock_viommu_alloc() * [iommufd] Generalize TEGRA241_VCMDQ data in core structure * [iommufd] Add selftest coverage for IOMMUFD_CMD_VCMDQ_ALLOC * [iommufd] Add iopt_pin_pages() to prevent queue memory from unmapping v1 https://lore.kernel.org/all/cover.1744353300.git.nicolinc@nvidia.com/ Thanks Nicolin Nicolin Chen (29): iommufd: Apply obvious cosmetic fixes iommufd: Introduce iommufd_object_alloc_ucmd helper iommu: Apply the new iommufd_object_alloc_ucmd helper iommu: Add iommu_copy_struct_to_user helper iommu: Pass in a driver-level user data structure to viommu_alloc op iommufd/viommu: Allow driver-specific user data for a vIOMMU object iommufd/selftest: Support user_data in mock_viommu_alloc iommufd/selftest: Add coverage for viommu data iommufd: Do not unmap an owned iopt_area iommufd: Abstract iopt_pin_pages and iopt_unpin_pages helpers iommufd/driver: Let iommufd_viommu_alloc helper save ictx to viommu->ictx iommufd/viommu: Add driver-allocated vDEVICE support iommufd/viommu: Introduce IOMMUFD_OBJ_HW_QUEUE and its related struct iommufd/viommu: Add IOMMUFD_CMD_HW_QUEUE_ALLOC ioctl iommufd/driver: Add iommufd_hw_queue_depend/undepend() helpers iommufd/selftest: Add coverage for IOMMUFD_CMD_HW_QUEUE_ALLOC iommufd: Add mmap interface iommufd/selftest: Add coverage for the new mmap interface Documentation: userspace-api: iommufd: Update HW QUEUE iommu: Allow an input type in hw_info op iommufd: Allow an input data_type via iommu_hw_info iommufd/selftest: Update hw_info coverage for an input data_type iommu/arm-smmu-v3-iommufd: Add vsmmu_alloc impl op iommu/arm-smmu-v3-iommufd: Add hw_info to impl_ops iommu/tegra241-cmdqv: Use request_threaded_irq iommu/tegra241-cmdqv: Simplify deinit flow in tegra241_cmdqv_remove_vintf() iommu/tegra241-cmdqv: Do not statically map LVCMDQs iommu/tegra241-cmdqv: Add user-space use support iommu/tegra241-cmdqv: Add IOMMU_VEVENTQ_TYPE_TEGRA241_CMDQV support drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 28 +- drivers/iommu/iommufd/io_pagetable.h | 15 +- drivers/iommu/iommufd/iommufd_private.h | 41 +- drivers/iommu/iommufd/iommufd_test.h | 20 + include/linux/iommu.h | 53 +- include/linux/iommufd.h | 221 +++++++- include/uapi/linux/iommufd.h | 150 +++++- tools/testing/selftests/iommu/iommufd_utils.h | 91 +++- .../arm/arm-smmu-v3/arm-smmu-v3-iommufd.c | 33 +- .../iommu/arm/arm-smmu-v3/tegra241-cmdqv.c | 496 +++++++++++++++++- drivers/iommu/intel/iommu.c | 4 + drivers/iommu/iommufd/device.c | 137 +---- drivers/iommu/iommufd/driver.c | 97 ++++ drivers/iommu/iommufd/eventq.c | 14 +- drivers/iommu/iommufd/hw_pagetable.c | 6 +- drivers/iommu/iommufd/io_pagetable.c | 106 +++- drivers/iommu/iommufd/iova_bitmap.c | 1 - drivers/iommu/iommufd/main.c | 80 ++- drivers/iommu/iommufd/pages.c | 19 +- drivers/iommu/iommufd/selftest.c | 158 +++++- drivers/iommu/iommufd/viommu.c | 146 +++++- tools/testing/selftests/iommu/iommufd.c | 146 +++++- .../selftests/iommu/iommufd_fail_nth.c | 15 +- Documentation/userspace-api/iommufd.rst | 12 + 24 files changed, 1794 insertions(+), 295 deletions(-) -- 2.43.0

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[PATCH bpf-next] selftests/bpf: rbtree: Fix incorrect global variable usage

by Rong Tao

From: Rong Tao <rongtao(a)cestc.cn> Within __add_three() function, should use function parameters instead of global variables. So that the variables groot_nested.inner.root and groot_nested.inner.glock in rbtree_add_nodes_nested() are tested correctly. Signed-off-by: Rong Tao <rongtao(a)cestc.cn> --- tools/testing/selftests/bpf/progs/rbtree.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/tools/testing/selftests/bpf/progs/rbtree.c b/tools/testing/selftests/bpf/progs/rbtree.c index a3620c15c136..49fe93d7e059 100644 --- a/tools/testing/selftests/bpf/progs/rbtree.c +++ b/tools/testing/selftests/bpf/progs/rbtree.c @@ -61,19 +61,19 @@ static long __add_three(struct bpf_rb_root *root, struct bpf_spin_lock *lock) } m->key = 1; - bpf_spin_lock(&glock); - bpf_rbtree_add(&groot, &n->node, less); - bpf_rbtree_add(&groot, &m->node, less); - bpf_spin_unlock(&glock); + bpf_spin_lock(lock); + bpf_rbtree_add(root, &n->node, less); + bpf_rbtree_add(root, &m->node, less); + bpf_spin_unlock(lock); n = bpf_obj_new(typeof(*n)); if (!n) return 3; n->key = 3; - bpf_spin_lock(&glock); - bpf_rbtree_add(&groot, &n->node, less); - bpf_spin_unlock(&glock); + bpf_spin_lock(lock); + bpf_rbtree_add(root, &n->node, less); + bpf_spin_unlock(lock); return 0; } -- 2.49.0

3 weeks

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[PATCH v2 0/4] selftests/mm: cow and gup_longterm cleanups

by Mark Brown

The bulk of these changes modify the cow and gup_longterm tests to report unique and stable names for each test, bringing them into line with the expectations of tooling that works with kselftest. The string reported as a test result is used by tooling to both deduplicate tests and track tests between test runs, using the same string for multiple tests or changing the string depending on test result causes problems for user interfaces and automation such as bisection. It was suggested that converting to use kselftest_harness.h would be a good way of addressing this, however that really wants the set of tests to run to be known at compile time but both test programs dynamically enumarate the set of huge page sizes the system supports and test each. Refactoring to handle this would be even more invasive than these changes which are large but straightforward and repetitive. A version of the main gup_longterm cleanup was previously sent separately, this version factors out the helpers for logging the start of the test since the cow test looks very similar. Signed-off-by: Mark Brown <broonie(a)kernel.org> --- Changes in v2: - Typo fixes. - Link to v1: https://lore.kernel.org/r/20250522-selftests-mm-cow-dedupe-v1-0-713cee2fdd6… --- Mark Brown (4): selftests/mm: Use standard ksft_finished() in cow and gup_longterm selftests/mm: Add helper for logging test start and results selftests/mm: Report unique test names for each cow test selftests/mm: Fix test result reporting in gup_longterm tools/testing/selftests/mm/cow.c | 340 +++++++++++++++++++----------- tools/testing/selftests/mm/gup_longterm.c | 158 ++++++++------ tools/testing/selftests/mm/vm_util.h | 20 ++ 3 files changed, 334 insertions(+), 184 deletions(-) --- base-commit: a5806cd506af5a7c19bcd596e4708b5c464bfd21 change-id: 20250521-selftests-mm-cow-dedupe-33dcab034558 Best regards, -- Mark Brown <broonie(a)kernel.org>

3 weeks

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[PATCH bpf-next] selftests/bpf: Fix compile error of bin_attribute::read/write()

by Rong Tao

From: Rong Tao <rongtao(a)cestc.cn> Since commit 97d06802d10a ("sysfs: constify bin_attribute argument of bin_attribute::read/write()"), make bin_attribute parameter of bin_attribute::read/write() const. Signed-off-by: Rong Tao <rongtao(a)cestc.cn> --- tools/testing/selftests/bpf/test_kmods/bpf_testmod.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/tools/testing/selftests/bpf/test_kmods/bpf_testmod.c b/tools/testing/selftests/bpf/test_kmods/bpf_testmod.c index e6c248e3ae54..e9e918cdf31f 100644 --- a/tools/testing/selftests/bpf/test_kmods/bpf_testmod.c +++ b/tools/testing/selftests/bpf/test_kmods/bpf_testmod.c @@ -385,7 +385,7 @@ int bpf_testmod_fentry_ok; noinline ssize_t bpf_testmod_test_read(struct file *file, struct kobject *kobj, - struct bin_attribute *bin_attr, + const struct bin_attribute *bin_attr, char *buf, loff_t off, size_t len) { struct bpf_testmod_test_read_ctx ctx = { @@ -465,7 +465,7 @@ ALLOW_ERROR_INJECTION(bpf_testmod_test_read, ERRNO); noinline ssize_t bpf_testmod_test_write(struct file *file, struct kobject *kobj, - struct bin_attribute *bin_attr, + const struct bin_attribute *bin_attr, char *buf, loff_t off, size_t len) { struct bpf_testmod_test_write_ctx ctx = { @@ -567,7 +567,7 @@ static void testmod_unregister_uprobe(void) static ssize_t bpf_testmod_uprobe_write(struct file *file, struct kobject *kobj, - struct bin_attribute *bin_attr, + const struct bin_attribute *bin_attr, char *buf, loff_t off, size_t len) { unsigned long offset = 0; -- 2.49.0

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