May 2025 - Linux-kselftest-mirror

[RFC PATCH 00/33] vfio: Introduce selftests for VFIO

by David Matlack

This series introduces VFIO selftests, located in tools/testing/selftests/vfio/. VFIO selftests aim to enable kernel developers to write and run tests that take the form of userspace programs that interact with VFIO and IOMMUFD uAPIs. VFIO selftests can be used to write functional tests for new features, regression tests for bugs, and performance tests for optimizations. These tests are designed to interact with real PCI devices, i.e. they do not rely on mocking out or faking any behavior in the kernel. This allows the tests to exercise not only VFIO but also IOMMUFD, the IOMMU driver, interrupt remapping, IRQ handling, etc. We chose selftests to host these tests primarily to enable integration with the existing KVM selftests. As explained in the next section, enabling KVM developers to test the interaction between VFIO and KVM is one of the motivators of this series. Motivation ----------------------------------------------------------------------- The main motivation for this series is upcoming development in the kernel to support Hypervisor Live Updates [1][2]. Live Update is a specialized reboot process where selected devices are kept operational and their kernel state is preserved and recreated across a kexec. For devices, DMA and interrupts may continue during the reboot. VFIO-bound devices are the main target, since the first usecase of Live Updates is to enable host kernel upgrades in a Cloud Computing environment without disrupting running customer VMs. To prepare for upcoming support for Live Updates in VFIO, IOMMUFD, IOMMU drivers, the PCI layer, etc., we'd like to first lay the ground work for exercising and testing VFIO from kernel selftests. This way when we eventually upstream support for Live Updates, we can also upstream tests for those changes, rather than purely relying on Live Update integration tests which would be hard to share and reproduce upstream. But even without Live Updates, VFIO and IOMMUFD are becoming an increasingly critical component of running KVM-based VMs in cloud environments. Virtualized networking and storage are increasingly being offloaded to smart NICs/cards, and demand for high performance networking, storage, and AI are also leading to NICs, SSDs, and GPUs being directly attached to VMs via VFIO. VFIO selftests increases our ability to test in several ways. - It enables developers sending VFIO, IOMMUFD, etc. commits upstream to test their changes against all existing VFIO selftests, reducing the probability of regressions. - It enables developers sending VFIO, IOMMUFD, etc. commits upstream to include tests alongside their changes, increasing the quality of the code that is merged. - It enables testing the interaction between VFIO and KVM. There are some paths in KVM that are only exercised through VFIO, such as IRQ bypass. VFIO selftests provides a helper library to enable KVM developers to write KVM selftests to test those interactions [3]. Design ----------------------------------------------------------------------- VFIO selftests are designed around interacting with with VFIO-managed PCI devices. As such, the core data struture is struct vfio_pci_device, which represents a single PCI device. struct vfio_pci_device *device; device = vfio_pci_device_init("0000:6a:01.0", iommu_mode); ... vfio_pci_device_cleanup(device); vfio_pci_device_init() sets up a container or iommufd, depending on the iommu_mode argument, to manage DMA mappings, fetches information about the device and what interrupts it supports from VFIO and caches it, and mmap()s all mappable BARs for the test to use. There are helper methods that operate on struct vfio_pci_device to do things like read and write to PCI config space, enable/disable IRQs, and map memory for DMA, struct vfio_pci_device and its methods do not care about what device they are actually interacting with. It can be a GPU, a NIC, an SSD, etc. To keep things simple initially, VFIO selftests only support a single device per group and per container/iommufd. But it should be possible to relax those restrictions in the future, e.g. to enable testing with multiple devices in the same container/iommufd. Driver Framework ----------------------------------------------------------------------- In order to support VFIO selftests where a device is generating DMA and interrupts on command, the VFIO selftests supports a driver framework. This framework abstracts away device-specific details allowing VFIO selftests to be written in a generic way, and then run against different devices depending on what hardware developers have access to. The framework also aims to support carrying drivers out-of-tree, e.g. so that companies can run VFIO selftests with custom/test hardware. Drivers must implement the following methods: - probe(): Check if the driver supports a given device. - init(): Initialize the driver. - remove(): Deinitialize the driver and reset the device. - memcpy_start(): Kick off a series of repeated memcpys (DMA reads and DMA writes). - memcpy_wait(): Wait for a memcpy operation to complete. - send_msi(): Make the device send an MSI interrupt. memcpy_start/wait() are for generating DMA. We separate the operation into 2 steps so that tests can trigger a long-running DMA operation. We expect to use this to stress test Live Updates by kicking off a long-running mempcy operation and then performing a Live Update. These methods are required to not generate any interrupts. send_msi() is used for testing MSI and MSI-x interrupts. The driver tells the test which MSI it will be using via device->driver.msi. It's the responsibility of the test to set up a region of memory and map it into the device for use by the driver, e.g. for in-memory descriptors, before calling init(). A demo of the driver framework can be found in tools/testing/selftests/vfio/vfio_pci_driver_test.c. In addition, this series introduces a new KVM selftest to demonstrate delivering a device MSI directly into a guest, which can be found in tools/testing/selftests/kvm/vfio_pci_device_irq_test.c. Tests ----------------------------------------------------------------------- There are 5 tests in this series, mostly to demonstrate as a proof-of-concept: - tools/testing/selftests/vfio/vfio_pci_device_test.c - tools/testing/selftests/vfio/vfio_pci_driver_test.c - tools/testing/selftests/vfio/vfio_iommufd_setup_test.c - tools/testing/selftests/vfio/vfio_dma_mapping_test.c - tools/testing/selftests/kvm/vfio_pci_device_irq_test.c Integrating with KVM selftests ----------------------------------------------------------------------- To support testing the interactions between VFIO and KVM, the VFIO selftests support sharing its library with the KVM selftest. The patches at the end of this series demonstrate how that works. Essentially, we allow the KVM selftests to build their own copy of tools/testing/selftests/vfio/lib/ and link it into KVM selftests binaries. This requires minimal changes to the KVM selftests Makefile. Future Areas of Development ----------------------------------------------------------------------- Library: - Driver support for devices that can be used on AMD, ARM, and other platforms. - Driver support for a device available in QEMU VMs. - Support for tests that use multiple devices. - Support for IOMMU groups with multiple devices. - Support for multiple devices sharing the same container/iommufd. - Sharing TEST_ASSERT() macros and other common code between KVM and VFIO selftests. Tests: - DMA mapping performance tests for BARs/HugeTLB/etc. - Live Update selftests. - Porting Sean's KVM selftest for posted interrupts to use the VFIO selftests library [3] This series can also be found on GitHub: https://github.com/dmatlack/linux/tree/vfio/selftests/rfc Cc: Alex Williamson <alex.williamson(a)redhat.com> Cc: Jason Gunthorpe <jgg(a)nvidia.com> Cc: Kevin Tian <kevin.tian(a)intel.com> Cc: Paolo Bonzini <pbonzini(a)redhat.com> Cc: Sean Christopherson <seanjc(a)google.com> Cc: Vipin Sharma <vipinsh(a)google.com> Cc: Josh Hilke <jrhilke(a)google.com> Cc: Pasha Tatashin <pasha.tatashin(a)soleen.com> Cc: Saeed Mahameed <saeedm(a)nvidia.com> Cc: Saeed Mahameed <saeedm(a)nvidia.com> Cc: Adithya Jayachandran <ajayachandra(a)nvidia.com> Cc: Parav Pandit <parav(a)nvidia.com> Cc: Leon Romanovsky <leonro(a)nvidia.com> Cc: Vinicius Costa Gomes <vinicius.gomes(a)intel.com> Cc: Dave Jiang <dave.jiang(a)intel.com> Cc: Dan Williams <dan.j.williams(a)intel.com> [1] https://lore.kernel.org/all/f35359d5-63e1-8390-619f-67961443bfe1@google.com/ [2] https://lore.kernel.org/all/20250515182322.117840-1-pasha.tatashin@soleen.c… [3] https://lore.kernel.org/kvm/20250404193923.1413163-68-seanjc@google.com/ David Matlack (28): selftests: Create tools/testing/selftests/vfio vfio: selftests: Add a helper library for VFIO selftests vfio: selftests: Introduce vfio_pci_device_test tools headers: Add stub definition for __iomem tools headers: Import asm-generic MMIO helpers tools headers: Import x86 MMIO helper overrides tools headers: Import iosubmit_cmds512() tools headers: Import drivers/dma/ioat/{hw.h,registers.h} tools headers: Import drivers/dma/idxd/registers.h tools headers: Import linux/pci_ids.h vfio: selftests: Keep track of DMA regions mapped into the device vfio: selftests: Enable asserting MSI eventfds not firing vfio: selftests: Add a helper for matching vendor+device IDs vfio: selftests: Add driver framework vfio: sefltests: Add vfio_pci_driver_test vfio: selftests: Add driver for Intel CBDMA vfio: selftests: Add driver for Intel DSA vfio: selftests: Move helper to get cdev path to libvfio vfio: selftests: Encapsulate IOMMU mode vfio: selftests: Add [-i iommu_mode] option to all tests vfio: selftests: Add vfio_type1v2_mode vfio: selftests: Add iommufd_compat_type1{,v2} modes vfio: selftests: Add iommufd mode vfio: selftests: Make iommufd the default iommu_mode vfio: selftests: Add a script to help with running VFIO selftests KVM: selftests: Build and link sefltests/vfio/lib into KVM selftests KVM: selftests: Test sending a vfio-pci device IRQ to a VM KVM: selftests: Use real device MSIs in vfio_pci_device_irq_test Josh Hilke (5): vfio: selftests: Test basic VFIO and IOMMUFD integration vfio: selftests: Move vfio dma mapping test to their own file vfio: selftests: Add test to reset vfio device. vfio: selftests: Use command line to set hugepage size for DMA mapping test vfio: selftests: Validate 2M/1G HugeTLB are mapped as 2M/1G in IOMMU MAINTAINERS | 7 + tools/arch/x86/include/asm/io.h | 101 + tools/arch/x86/include/asm/special_insns.h | 27 + tools/include/asm-generic/io.h | 482 +++ tools/include/asm/io.h | 11 + tools/include/drivers/dma/idxd/registers.h | 601 +++ tools/include/drivers/dma/ioat/hw.h | 270 ++ tools/include/drivers/dma/ioat/registers.h | 251 ++ tools/include/linux/compiler.h | 4 + tools/include/linux/io.h | 4 +- tools/include/linux/pci_ids.h | 3212 +++++++++++++++++ tools/testing/selftests/Makefile | 1 + tools/testing/selftests/kvm/Makefile.kvm | 6 +- .../testing/selftests/kvm/include/kvm_util.h | 4 + tools/testing/selftests/kvm/lib/kvm_util.c | 21 + .../selftests/kvm/vfio_pci_device_irq_test.c | 173 + tools/testing/selftests/vfio/.gitignore | 7 + tools/testing/selftests/vfio/Makefile | 20 + .../testing/selftests/vfio/lib/drivers/dsa.c | 416 +++ .../testing/selftests/vfio/lib/drivers/ioat.c | 235 ++ .../selftests/vfio/lib/include/vfio_util.h | 271 ++ tools/testing/selftests/vfio/lib/libvfio.mk | 26 + .../selftests/vfio/lib/vfio_pci_device.c | 573 +++ .../selftests/vfio/lib/vfio_pci_driver.c | 126 + tools/testing/selftests/vfio/run.sh | 110 + .../selftests/vfio/vfio_dma_mapping_test.c | 239 ++ .../selftests/vfio/vfio_iommufd_setup_test.c | 133 + .../selftests/vfio/vfio_pci_device_test.c | 195 + .../selftests/vfio/vfio_pci_driver_test.c | 256 ++ 29 files changed, 7780 insertions(+), 2 deletions(-) create mode 100644 tools/arch/x86/include/asm/io.h create mode 100644 tools/arch/x86/include/asm/special_insns.h create mode 100644 tools/include/asm-generic/io.h create mode 100644 tools/include/asm/io.h create mode 100644 tools/include/drivers/dma/idxd/registers.h create mode 100644 tools/include/drivers/dma/ioat/hw.h create mode 100644 tools/include/drivers/dma/ioat/registers.h create mode 100644 tools/include/linux/pci_ids.h create mode 100644 tools/testing/selftests/kvm/vfio_pci_device_irq_test.c create mode 100644 tools/testing/selftests/vfio/.gitignore create mode 100644 tools/testing/selftests/vfio/Makefile create mode 100644 tools/testing/selftests/vfio/lib/drivers/dsa.c create mode 100644 tools/testing/selftests/vfio/lib/drivers/ioat.c create mode 100644 tools/testing/selftests/vfio/lib/include/vfio_util.h create mode 100644 tools/testing/selftests/vfio/lib/libvfio.mk create mode 100644 tools/testing/selftests/vfio/lib/vfio_pci_device.c create mode 100644 tools/testing/selftests/vfio/lib/vfio_pci_driver.c create mode 100755 tools/testing/selftests/vfio/run.sh create mode 100644 tools/testing/selftests/vfio/vfio_dma_mapping_test.c create mode 100644 tools/testing/selftests/vfio/vfio_iommufd_setup_test.c create mode 100644 tools/testing/selftests/vfio/vfio_pci_device_test.c create mode 100644 tools/testing/selftests/vfio/vfio_pci_driver_test.c base-commit: a11a72229881d8ac1d52ea727101bc9c744189c1 prerequisite-patch-id: 3bae97c9e1093148763235f47a84fa040b512d04 -- 2.49.0.1151.ga128411c76-goog

22 hours, 2 minutes

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[PATCH 0/4] selftests/mm/uffd: refactor global variables

by Ujwal Kundur

This patchset refactors non-composite global variables into a common struct that can be initialized and passed around per-test instead of relying on the presence of global variables. This allows: - Better encapsulation - Debugging becomes easier -- local variable state can be viewed per stack frame, and we can more easily reason about the variable mutations Patch 1 needs to be applied first and can be followed by any of the other patches. I've ensured that the tests are passing locally (or atleast have the same output as the code on master). Ujwal Kundur (4): selftests/mm/uffd: Refactor non-composite global vars into struct selftests/mm/uffd: Swap global vars with global test options selftests/mm/uffd: Swap global variables with global test opts selftests/mm/uffd: Swap global variables with global test opts tools/testing/selftests/mm/uffd-common.c | 269 +++++----- tools/testing/selftests/mm/uffd-common.h | 78 +-- tools/testing/selftests/mm/uffd-stress.c | 226 ++++---- tools/testing/selftests/mm/uffd-unit-tests.c | 523 ++++++++++--------- tools/testing/selftests/mm/uffd-wp-mremap.c | 23 +- 5 files changed, 591 insertions(+), 528 deletions(-) -- 2.20.1

3 days, 23 hours

4
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[PATCH v3] kunit: fix longest symbol length test

by Sergio González Collado

The kunit test that checks the longests symbol length [1], has triggered warnings in some pilelines when symbol prefixes are used [2][3]. The test will to depend on !PREFIX_SYMBOLS and !CFI_CLANG as sujested in [4] and on !GCOV_KERNEL. [1] https://lore.kernel.org/rust-for-linux/CABVgOSm=5Q0fM6neBhxSbOUHBgNzmwf2V22… [2] https://lore.kernel.org/all/20250328112156.2614513-1-arnd@kernel.org/T/#u [3] https://lore.kernel.org/rust-for-linux/bbd03b37-c4d9-4a92-9be2-75aaf8c19815… [4] https://lore.kernel.org/linux-kselftest/20250427200916.GA1661412@ax162/T/#t Reviewed-by: Rae Moar <rmoar(a)google.com> Signed-off-by: Sergio González Collado <sergio.collado(a)gmail.com> --- v2 -> v3: added dependency on !GCOV_KERNEL (to avoid __gcov_ prefix) --- v1 -> v2: added dependency on !CFI_CLANG as suggested in [3], removed CONFIG_ prefix --- lib/Kconfig.debug | 1 + lib/tests/longest_symbol_kunit.c | 3 +-- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index f9051ab610d5..e55c761eae20 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -2886,6 +2886,7 @@ config FORTIFY_KUNIT_TEST config LONGEST_SYM_KUNIT_TEST tristate "Test the longest symbol possible" if !KUNIT_ALL_TESTS depends on KUNIT && KPROBES + depends on !PREFIX_SYMBOLS && !CFI_CLANG && !GCOV_KERNEL default KUNIT_ALL_TESTS help Tests the longest symbol possible diff --git a/lib/tests/longest_symbol_kunit.c b/lib/tests/longest_symbol_kunit.c index e3c28ff1807f..9b4de3050ba7 100644 --- a/lib/tests/longest_symbol_kunit.c +++ b/lib/tests/longest_symbol_kunit.c @@ -3,8 +3,7 @@ * Test the longest symbol length. Execute with: * ./tools/testing/kunit/kunit.py run longest-symbol * --arch=x86_64 --kconfig_add CONFIG_KPROBES=y --kconfig_add CONFIG_MODULES=y - * --kconfig_add CONFIG_RETPOLINE=n --kconfig_add CONFIG_CFI_CLANG=n - * --kconfig_add CONFIG_MITIGATION_RETPOLINE=n + * --kconfig_add CONFIG_CPU_MITIGATIONS=n --kconfig_add CONFIG_GCOV_KERNEL=n */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt base-commit: 1a80a098c606b285fb0a13aa992af4f86da1ff06 -- 2.39.2

4 days, 12 hours

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[RFC PATCH 0/7] platform/chrome: Add Kunit tests for protocol device drivers

by Tzung-Bi Shih

The protocol device drivers under drivers/platform/chrome/ are responsible to communicate to the ChromeOS EC (Embedded Controller). They need to pack the data in a pre-defined format and check if the EC responds accordingly. The series adds some fundamental unit tests for the protocol. It calls the .cmd_xfer() and .pkt_xfer() callbacks (which are the most crucial parts for the protocol), mocks the rest of the system, and checks if the interactions are all correct. The series isn't ready for landing. It's more like a PoC for the binary-level function redirection and its use cases. The 1st patch adds ftrace stub which is originally from [1][2]. There is no follow-up discussion about the ftrace stub. As a result, the patch is still on the mailing list. The 2nd patch adds Kunit tests for cros_ec_i2c. It relies on the ftrace stub for redirecting cros_ec_{un,}register(). The 3rd patch uses static stub instead (if ftrace stub isn't really an option). However, I'm not a big fan to change the production code (i.e. adding the prologue in cros_ec_{un,}register()) for testing. The 4th patch adds Kunit tests for cros_ec_spi. It relies on the ftrace stub for redirecting cros_ec_{un,}register() again. The 5th patch calls .probe() directly instead of forcing the driver probe needs to be synchronous. In comparison with the 4th patch, I don't think this is simpler. I'd prefer to the way in the 4th patch. After talked to Masami about the work, he suggested to use Kprobes for function redirection. The 6th patch adds kprobes stub. The 7th patch uses kprobes stub instead for cros_ec_spi. Questions: - Are we going to support ftrace stub so that tests can use it? - If ftrace stub isn't on the plate (e.g. due to too many dependencies), how about the kprobes stub? Is it something we could pursue? - (minor) I'm unsure if people would prefer 'kprobes stub' vs. 'kprobe stub'. [1]: https://kunit.dev/mocking.html#binary-level-ftrace-et-al [2]: https://lore.kernel.org/linux-kselftest/20220318021314.3225240-3-davidgow@g… Daniel Latypov (1): kunit: expose ftrace-based API for stubbing out functions during tests Tzung-Bi Shih (6): platform/chrome: kunit: cros_ec_i2c: Add tests with ftrace stub platform/chrome: kunit: cros_ec_i2c: Use static stub instead platform/chrome: kunit: cros_ec_spi: Add tests with ftrace stub platform/chrome: kunit: cros_ec_spi: Call .probe() directly kunit: Expose 'kprobes stub' API to redirect functions platform/chrome: kunit: cros_ec_spi: Use kprobes stub instead drivers/platform/chrome/Kconfig | 17 + drivers/platform/chrome/Makefile | 2 + drivers/platform/chrome/cros_ec.c | 6 + drivers/platform/chrome/cros_ec_i2c_test.c | 479 +++++++++++++++++++++ drivers/platform/chrome/cros_ec_spi_test.c | 355 +++++++++++++++ include/kunit/ftrace_stub.h | 84 ++++ include/kunit/kprobes_stub.h | 19 + kernel/trace/ftrace.c | 3 + lib/kunit/Kconfig | 18 + lib/kunit/Makefile | 8 + lib/kunit/ftrace_stub.c | 139 ++++++ lib/kunit/kprobes_stub.c | 113 +++++ lib/kunit/kunit-example-test.c | 27 +- lib/kunit/stubs_example.kunitconfig | 11 + 14 files changed, 1280 insertions(+), 1 deletion(-) create mode 100644 drivers/platform/chrome/cros_ec_i2c_test.c create mode 100644 drivers/platform/chrome/cros_ec_spi_test.c create mode 100644 include/kunit/ftrace_stub.h create mode 100644 include/kunit/kprobes_stub.h create mode 100644 lib/kunit/ftrace_stub.c create mode 100644 lib/kunit/kprobes_stub.c create mode 100644 lib/kunit/stubs_example.kunitconfig -- 2.49.0.1101.gccaa498523-goog

1 week

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[PATCH] selftests: futex: define SYS_futex on 32-bit architectures with 64-bit time_t

by Ben Zong-You Xie

glibc does not define SYS_futex for 32-bit architectures using 64-bit time_t e.g. riscv32, therefore this test fails to compile since it does not find SYS_futex in C library headers. Define SYS_futex as SYS_futex_time64 in this situation to ensure successful compilation and compatibility. Signed-off-by: Ben Zong-You Xie <ben717(a)andestech.com> Signed-off-by: Cynthia Huang <cynthia(a)andestech.com> --- tools/testing/selftests/futex/include/futextest.h | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/tools/testing/selftests/futex/include/futextest.h b/tools/testing/selftests/futex/include/futextest.h index ddbcfc9b7bac..7a5fd1d5355e 100644 --- a/tools/testing/selftests/futex/include/futextest.h +++ b/tools/testing/selftests/futex/include/futextest.h @@ -47,6 +47,17 @@ typedef volatile u_int32_t futex_t; FUTEX_PRIVATE_FLAG) #endif +/* + * SYS_futex is expected from system C library, in glibc some 32-bit + * architectures (e.g. RV32) are using 64-bit time_t, therefore it doesn't have + * SYS_futex defined but just SYS_futex_time64. Define SYS_futex as + * SYS_futex_time64 in this situation to ensure the compilation and the + * compatibility. + */ +#if !defined(SYS_futex) && defined(SYS_futex_time64) +#define SYS_futex SYS_futex_time64 +#endif + /** * futex() - SYS_futex syscall wrapper * @uaddr: address of first futex -- 2.34.1

1 week, 4 days

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[PATCH v2 00/14] stackleak: Support Clang stack depth tracking

by Kees Cook

v2: - rename stackleak to kstack_erase (mingo) - address __init vs inline with KCOV changes v1: https://lore.kernel.org/lkml/20250507180852.work.231-kees@kernel.org/ RFC: https://lore.kernel.org/lkml/20250502185834.work.560-kees@kernel.org/ Hi, As part of looking at what GCC plugins could be replaced with Clang implementations, this series uses the recently landed stack depth tracking callback in Clang[1] to implement the stackleak feature. Since the Clang feature is now landed, I'm moving this out of RFC to a v1. Since this touches a lot of arch-specific Makefiles, I tried to trim the CC list down to just mailing lists in those cases, otherwise the CC was giant. Thanks! -Kees [1] https://clang.llvm.org/docs/SanitizerCoverage.html#tracing-stack-depth Kees Cook (14): stackleak: Rename STACKLEAK to KSTACK_ERASE stackleak: Rename stackleak_track_stack to __sanitizer_cov_stack_depth stackleak: Split KSTACK_ERASE_CFLAGS from GCC_PLUGINS_CFLAGS x86: Handle KCOV __init vs inline mismatches arm: Handle KCOV __init vs inline mismatches arm64: Handle KCOV __init vs inline mismatches s390: Handle KCOV __init vs inline mismatches powerpc: Handle KCOV __init vs inline mismatches mips: Handle KCOV __init vs inline mismatches loongarch: Handle KCOV __init vs inline mismatches init.h: Disable sanitizer coverage for __init and __head kstack_erase: Support Clang stack depth tracking configs/hardening: Enable CONFIG_KSTACK_ERASE configs/hardening: Enable CONFIG_INIT_ON_FREE_DEFAULT_ON arch/Kconfig | 4 +- arch/arm/Kconfig | 2 +- arch/arm64/Kconfig | 2 +- arch/riscv/Kconfig | 2 +- arch/s390/Kconfig | 2 +- arch/x86/Kconfig | 2 +- security/Kconfig.hardening | 45 +++++++++------- Makefile | 1 + arch/arm/boot/compressed/Makefile | 2 +- arch/arm/vdso/Makefile | 2 +- arch/arm64/kernel/pi/Makefile | 2 +- arch/arm64/kernel/vdso/Makefile | 3 +- arch/arm64/kvm/hyp/nvhe/Makefile | 2 +- arch/riscv/kernel/pi/Makefile | 2 +- arch/riscv/purgatory/Makefile | 2 +- arch/sparc/vdso/Makefile | 3 +- arch/x86/entry/vdso/Makefile | 3 +- arch/x86/purgatory/Makefile | 2 +- drivers/firmware/efi/libstub/Makefile | 8 +-- drivers/misc/lkdtm/Makefile | 2 +- kernel/Makefile | 10 ++-- lib/Makefile | 2 +- scripts/Makefile.gcc-plugins | 16 +----- scripts/Makefile.kstack_erase | 21 ++++++++ scripts/gcc-plugins/stackleak_plugin.c | 52 +++++++++---------- Documentation/admin-guide/sysctl/kernel.rst | 4 +- Documentation/arch/x86/x86_64/mm.rst | 2 +- Documentation/security/self-protection.rst | 2 +- .../zh_CN/security/self-protection.rst | 2 +- arch/arm64/include/asm/acpi.h | 2 +- arch/loongarch/include/asm/smp.h | 2 +- arch/mips/include/asm/time.h | 2 +- arch/s390/hypfs/hypfs.h | 2 +- arch/s390/hypfs/hypfs_diag.h | 2 +- arch/x86/entry/calling.h | 4 +- arch/x86/include/asm/acpi.h | 4 +- arch/x86/include/asm/init.h | 2 +- arch/x86/include/asm/realmode.h | 2 +- include/linux/acpi.h | 4 +- include/linux/bootconfig.h | 2 +- include/linux/efi.h | 2 +- include/linux/init.h | 4 +- include/linux/{stackleak.h => kstack_erase.h} | 20 +++---- include/linux/memblock.h | 2 +- include/linux/mfd/dbx500-prcmu.h | 2 +- include/linux/sched.h | 4 +- arch/arm/kernel/entry-common.S | 2 +- arch/arm64/kernel/entry.S | 2 +- arch/riscv/kernel/entry.S | 2 +- arch/s390/kernel/entry.S | 2 +- arch/arm/mm/cache-feroceon-l2.c | 2 +- arch/arm/mm/cache-tauros2.c | 2 +- arch/loongarch/kernel/time.c | 2 +- arch/loongarch/mm/ioremap.c | 4 +- arch/powerpc/mm/book3s64/hash_utils.c | 2 +- arch/powerpc/mm/book3s64/radix_pgtable.c | 2 +- arch/s390/mm/init.c | 2 +- arch/x86/kernel/kvm.c | 2 +- drivers/clocksource/timer-orion.c | 2 +- .../lkdtm/{stackleak.c => kstack_erase.c} | 26 +++++----- drivers/platform/x86/thinkpad_acpi.c | 4 +- drivers/soc/ti/pm33xx.c | 2 +- fs/proc/base.c | 6 +-- kernel/fork.c | 2 +- kernel/{stackleak.c => kstack_erase.c} | 22 ++++---- tools/objtool/check.c | 4 +- tools/testing/selftests/lkdtm/config | 2 +- MAINTAINERS | 6 ++- kernel/configs/hardening.config | 6 +++ 69 files changed, 203 insertions(+), 171 deletions(-) create mode 100644 scripts/Makefile.kstack_erase rename include/linux/{stackleak.h => kstack_erase.h} (81%) rename drivers/misc/lkdtm/{stackleak.c => kstack_erase.c} (89%) rename kernel/{stackleak.c => kstack_erase.c} (87%) -- 2.34.1

1 week, 6 days

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[PATCH] selftests: kvm: Fix spelling of 'occurrences' in sparsebit.c comments

by Rahul Kumar

Corrected two instances of the misspelled word 'occurences' to 'occurrences' in comments explaining node invariants in sparsebit.c. These comments describe core behavior of the data structure and should be clear. Signed-off-by: Rahul Kumar <rk0006818(a)gmail.com> --- tools/testing/selftests/kvm/lib/sparsebit.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/kvm/lib/sparsebit.c b/tools/testing/selftests/kvm/lib/sparsebit.c index cfed9d26cc71..a99188f87a38 100644 --- a/tools/testing/selftests/kvm/lib/sparsebit.c +++ b/tools/testing/selftests/kvm/lib/sparsebit.c @@ -116,7 +116,7 @@ * * + A node with all mask bits set only occurs when the last bit * described by the previous node is not equal to this nodes - * starting index - 1. All such occurences of this condition are + * starting index - 1. All such occurrences of this condition are * avoided by moving the setting of the nodes mask bits into * the previous nodes num_after setting. * @@ -592,7 +592,7 @@ static struct node *node_split(struct sparsebit *s, sparsebit_idx_t idx) * * + A node with all mask bits set only occurs when the last bit * described by the previous node is not equal to this nodes - * starting index - 1. All such occurences of this condition are + * starting index - 1. All such occurrences of this condition are * avoided by moving the setting of the nodes mask bits into * the previous nodes num_after setting. */ -- 2.43.0 This patch fixes two misspellings of the word 'occurrences' in comments within sparsebit.c used by the KVM selftests. Fixing the spelling improves readability and clarity of the documented behavior. Only comment text has been changed — there are no modifications to the functional logic of the tests. I would appreciate your review and any feedback you may have. Thank you for your time and support. Best regards, Rahul Kumar

1 week, 6 days

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[PATCH v3 00/13] KVM: Make irqfd registration globally unique

by Sean Christopherson

Non-KVM folks, I am hoping to route this through the KVM tree (6.17 or later), as the non-KVM changes should be glorified nops. Please holler if you object to that idea. Hyper-V folks in particular, let me know if you want a stable topic branch/tag, e.g. on the off chance you want to make similar changes to the Hyper-V code, and I'll make sure that happens. As for what this series actually does... Rework KVM's irqfd registration to require that an eventfd is bound to at most one irqfd throughout the entire system. KVM currently disallows binding an eventfd to multiple irqfds for a single VM, but doesn't reject attempts to bind an eventfd to multiple VMs. This is obviously an ABI change, but I'm fairly confident that it won't break userspace, because binding an eventfd to multiple irqfds hasn't truly worked since commit e8dbf19508a1 ("kvm/eventfd: Use priority waitqueue to catch events before userspace"). A somewhat undocumented, and perhaps even unintentional, side effect of suppressing eventfd notifications for userspace is that the priority+exclusive behavior also suppresses eventfd notifications for any subsequent waiters, even if they are priority waiters. I.e. only the first VM with an irqfd+eventfd binding will get notifications. And for IRQ bypass, a.k.a. device posted interrupts, globally unique bindings are a hard requirement (at least on x86; I assume other archs are the same). KVM and the IRQ bypass manager kinda sorta handle this, but in the absolute worst way possible (IMO). Instead of surfacing an error to userspace, KVM silently ignores IRQ bypass registration errors. The motivation for this series is to harden against userspace goofs. AFAIK, we (Google) have never actually had a bug where userspace tries to assign an eventfd to multiple VMs, but the possibility has come up in more than one bug investigation (our intra-host, a.k.a. copyless, migration scheme transfers eventfds from the old to the new VM when updating the host VMM). v3: - Retain WQ_FLAG_EXCLUSIVE in mshv_eventfd.c, which snuck in between v1 and v2. [Peter] - Use EXPORT_SYMBOL_GPL. [Peter] - Move WQ_FLAG_EXCLUSIVE out of add_wait_queue_priority() in a prep patch so that the affected subsystems are more explicitly documented (and then immediately drop the flag from drivers/xen/privcmd.c, which amusingly hides that file from the diff stats). v2: - https://lore.kernel.org/all/20250519185514.2678456-1-seanjc@google.com - Use guard(spinlock_irqsave). [Prateek] v1: https://lore.kernel.org/all/20250401204425.904001-1-seanjc@google.com Sean Christopherson (13): KVM: Use a local struct to do the initial vfs_poll() on an irqfd KVM: Acquire SCRU lock outside of irqfds.lock during assignment KVM: Initialize irqfd waitqueue callback when adding to the queue KVM: Add irqfd to KVM's list via the vfs_poll() callback KVM: Add irqfd to eventfd's waitqueue while holding irqfds.lock sched/wait: Drop WQ_FLAG_EXCLUSIVE from add_wait_queue_priority() xen: privcmd: Don't mark eventfd waiter as EXCLUSIVE sched/wait: Add a waitqueue helper for fully exclusive priority waiters KVM: Disallow binding multiple irqfds to an eventfd with a priority waiter KVM: Drop sanity check that per-VM list of irqfds is unique KVM: selftests: Assert that eventfd() succeeds in Xen shinfo test KVM: selftests: Add utilities to create eventfds and do KVM_IRQFD KVM: selftests: Add a KVM_IRQFD test to verify uniqueness requirements drivers/hv/mshv_eventfd.c | 8 ++ include/linux/kvm_irqfd.h | 1 - include/linux/wait.h | 2 + kernel/sched/wait.c | 22 ++- tools/testing/selftests/kvm/Makefile.kvm | 1 + tools/testing/selftests/kvm/arm64/vgic_irq.c | 12 +- .../testing/selftests/kvm/include/kvm_util.h | 40 ++++++ tools/testing/selftests/kvm/irqfd_test.c | 130 ++++++++++++++++++ .../selftests/kvm/x86/xen_shinfo_test.c | 21 +-- virt/kvm/eventfd.c | 130 +++++++++++++----- 10 files changed, 302 insertions(+), 65 deletions(-) create mode 100644 tools/testing/selftests/kvm/irqfd_test.c base-commit: 45eb29140e68ffe8e93a5471006858a018480a45 -- 2.49.0.1151.ga128411c76-goog

1 week, 6 days

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[PATCH v3] selftests: riscv: add misaligned access testing

by Clément Léger

This selftest tests all the currently emulated instructions (except for the RV32 compressed ones which are left as a future exercise for a RV32 user). For the FPU instructions, all the FPU registers are tested. Signed-off-by: Clément Léger <cleger(a)rivosinc.com> --- Note: This test can be executed with the FWFT series [1] or using an SBI firmware that delegates misaligned traps by default. If using QEMU, you will need the patches mentioned at [2] so that misaligned accesses will generate a trap. Note: This commit was part of a series [3] that was partially merged. Note: the remaining checkpatch errors are not applicable to this tests which is a user-space one and does not use the kernel headers. Macros with complex values can not be enclosed in do while loop since they are generating functions. Link: https://lore.kernel.org/all/20250424173204.1948385-1-cleger@rivosinc.com/ [1] Link: https://lore.kernel.org/all/20241211211933.198792-1-fkonrad@amd.com/ [2] Link: https://lore.kernel.org/linux-riscv/20250422162324.956065-1-cleger@rivosinc… [3] V3: - Fixed a segfault and a sign extension error found when compiling with -O<x>, x != 0 (Alex) - Use inline assembly to generate the sigbus and avoid GCC optimizations V2: - Fix commit description - Fix a few errors reported by checkpatch.pl tools/testing/selftests/riscv/Makefile | 2 +- .../selftests/riscv/misaligned/.gitignore | 1 + .../selftests/riscv/misaligned/Makefile | 12 + .../selftests/riscv/misaligned/common.S | 33 +++ .../testing/selftests/riscv/misaligned/fpu.S | 180 +++++++++++++ tools/testing/selftests/riscv/misaligned/gp.S | 103 +++++++ .../selftests/riscv/misaligned/misaligned.c | 253 ++++++++++++++++++ 7 files changed, 583 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/riscv/misaligned/.gitignore create mode 100644 tools/testing/selftests/riscv/misaligned/Makefile create mode 100644 tools/testing/selftests/riscv/misaligned/common.S create mode 100644 tools/testing/selftests/riscv/misaligned/fpu.S create mode 100644 tools/testing/selftests/riscv/misaligned/gp.S create mode 100644 tools/testing/selftests/riscv/misaligned/misaligned.c diff --git a/tools/testing/selftests/riscv/Makefile b/tools/testing/selftests/riscv/Makefile index 099b8c1f46f8..95a98ceeb3b3 100644 --- a/tools/testing/selftests/riscv/Makefile +++ b/tools/testing/selftests/riscv/Makefile @@ -5,7 +5,7 @@ ARCH ?= $(shell uname -m 2>/dev/null || echo not) ifneq (,$(filter $(ARCH),riscv)) -RISCV_SUBTARGETS ?= abi hwprobe mm sigreturn vector +RISCV_SUBTARGETS ?= abi hwprobe mm sigreturn vector misaligned else RISCV_SUBTARGETS := endif diff --git a/tools/testing/selftests/riscv/misaligned/.gitignore b/tools/testing/selftests/riscv/misaligned/.gitignore new file mode 100644 index 000000000000..5eff15a1f981 --- /dev/null +++ b/tools/testing/selftests/riscv/misaligned/.gitignore @@ -0,0 +1 @@ +misaligned diff --git a/tools/testing/selftests/riscv/misaligned/Makefile b/tools/testing/selftests/riscv/misaligned/Makefile new file mode 100644 index 000000000000..1aa40110c50d --- /dev/null +++ b/tools/testing/selftests/riscv/misaligned/Makefile @@ -0,0 +1,12 @@ +# SPDX-License-Identifier: GPL-2.0 +# Copyright (C) 2021 ARM Limited +# Originally tools/testing/arm64/abi/Makefile + +CFLAGS += -I$(top_srcdir)/tools/include + +TEST_GEN_PROGS := misaligned + +include ../../lib.mk + +$(OUTPUT)/misaligned: misaligned.c fpu.S gp.S + $(CC) -g3 -static -o$@ -march=rv64imafdc $(CFLAGS) $(LDFLAGS) $^ diff --git a/tools/testing/selftests/riscv/misaligned/common.S b/tools/testing/selftests/riscv/misaligned/common.S new file mode 100644 index 000000000000..8fa00035bd5d --- /dev/null +++ b/tools/testing/selftests/riscv/misaligned/common.S @@ -0,0 +1,33 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (c) 2025 Rivos Inc. + * + * Authors: + * Clément Léger <cleger(a)rivosinc.com> + */ + +.macro lb_sb temp, offset, src, dst + lb \temp, \offset(\src) + sb \temp, \offset(\dst) +.endm + +.macro copy_long_to temp, src, dst + lb_sb \temp, 0, \src, \dst, + lb_sb \temp, 1, \src, \dst, + lb_sb \temp, 2, \src, \dst, + lb_sb \temp, 3, \src, \dst, + lb_sb \temp, 4, \src, \dst, + lb_sb \temp, 5, \src, \dst, + lb_sb \temp, 6, \src, \dst, + lb_sb \temp, 7, \src, \dst, +.endm + +.macro sp_stack_prologue offset + addi sp, sp, -8 + sub sp, sp, \offset +.endm + +.macro sp_stack_epilogue offset + add sp, sp, \offset + addi sp, sp, 8 +.endm diff --git a/tools/testing/selftests/riscv/misaligned/fpu.S b/tools/testing/selftests/riscv/misaligned/fpu.S new file mode 100644 index 000000000000..a7ad4430a424 --- /dev/null +++ b/tools/testing/selftests/riscv/misaligned/fpu.S @@ -0,0 +1,180 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (c) 2025 Rivos Inc. + * + * Authors: + * Clément Léger <cleger(a)rivosinc.com> + */ + +#include "common.S" + +#define CASE_ALIGN 4 + +.macro fpu_load_inst fpreg, inst, precision, load_reg +.align CASE_ALIGN + \inst \fpreg, 0(\load_reg) + fmv.\precision fa0, \fpreg + j 2f +.endm + +#define flw(__fpreg) fpu_load_inst __fpreg, flw, s, a4 +#define fld(__fpreg) fpu_load_inst __fpreg, fld, d, a4 +#define c_flw(__fpreg) fpu_load_inst __fpreg, c.flw, s, a4 +#define c_fld(__fpreg) fpu_load_inst __fpreg, c.fld, d, a4 +#define c_fldsp(__fpreg) fpu_load_inst __fpreg, c.fldsp, d, sp + +.macro fpu_store_inst fpreg, inst, precision, store_reg +.align CASE_ALIGN + fmv.\precision \fpreg, fa0 + \inst \fpreg, 0(\store_reg) + j 2f +.endm + +#define fsw(__fpreg) fpu_store_inst __fpreg, fsw, s, a4 +#define fsd(__fpreg) fpu_store_inst __fpreg, fsd, d, a4 +#define c_fsw(__fpreg) fpu_store_inst __fpreg, c.fsw, s, a4 +#define c_fsd(__fpreg) fpu_store_inst __fpreg, c.fsd, d, a4 +#define c_fsdsp(__fpreg) fpu_store_inst __fpreg, c.fsdsp, d, sp + +.macro fp_test_prologue + move a4, a1 + /* + * Compute jump offset to store the correct FP register since we don't + * have indirect FP register access (or at least we don't use this + * extension so that works on all archs) + */ + sll t0, a0, CASE_ALIGN + la t2, 1f + add t0, t0, t2 + jr t0 +.align CASE_ALIGN +1: +.endm + +.macro fp_test_prologue_compressed + /* FP registers for compressed instructions starts from 8 to 16 */ + addi a0, a0, -8 + fp_test_prologue +.endm + +#define fp_test_body_compressed(__inst_func) \ + __inst_func(f8); \ + __inst_func(f9); \ + __inst_func(f10); \ + __inst_func(f11); \ + __inst_func(f12); \ + __inst_func(f13); \ + __inst_func(f14); \ + __inst_func(f15); \ +2: + +#define fp_test_body(__inst_func) \ + __inst_func(f0); \ + __inst_func(f1); \ + __inst_func(f2); \ + __inst_func(f3); \ + __inst_func(f4); \ + __inst_func(f5); \ + __inst_func(f6); \ + __inst_func(f7); \ + __inst_func(f8); \ + __inst_func(f9); \ + __inst_func(f10); \ + __inst_func(f11); \ + __inst_func(f12); \ + __inst_func(f13); \ + __inst_func(f14); \ + __inst_func(f15); \ + __inst_func(f16); \ + __inst_func(f17); \ + __inst_func(f18); \ + __inst_func(f19); \ + __inst_func(f20); \ + __inst_func(f21); \ + __inst_func(f22); \ + __inst_func(f23); \ + __inst_func(f24); \ + __inst_func(f25); \ + __inst_func(f26); \ + __inst_func(f27); \ + __inst_func(f28); \ + __inst_func(f29); \ + __inst_func(f30); \ + __inst_func(f31); \ +2: +.text + +#define __gen_test_inst(__inst, __suffix) \ +.global test_ ## __inst; \ +test_ ## __inst:; \ + fp_test_prologue ## __suffix; \ + fp_test_body ## __suffix(__inst); \ + ret + +#define gen_test_inst_compressed(__inst) \ + .option arch,+c; \ + __gen_test_inst(c_ ## __inst, _compressed) + +#define gen_test_inst(__inst) \ + .balign 16; \ + .option push; \ + .option arch,-c; \ + __gen_test_inst(__inst, ); \ + .option pop + +.macro fp_test_prologue_load_compressed_sp + copy_long_to t0, a1, sp +.endm + +.macro fp_test_epilogue_load_compressed_sp +.endm + +.macro fp_test_prologue_store_compressed_sp +.endm + +.macro fp_test_epilogue_store_compressed_sp + copy_long_to t0, sp, a1 +.endm + +#define gen_inst_compressed_sp(__inst, __type) \ + .global test_c_ ## __inst ## sp; \ + test_c_ ## __inst ## sp:; \ + sp_stack_prologue a2; \ + fp_test_prologue_## __type ## _compressed_sp; \ + fp_test_prologue_compressed; \ + fp_test_body_compressed(c_ ## __inst ## sp); \ + fp_test_epilogue_## __type ## _compressed_sp; \ + sp_stack_epilogue a2; \ + ret + +#define gen_test_load_compressed_sp(__inst) gen_inst_compressed_sp(__inst, load) +#define gen_test_store_compressed_sp(__inst) gen_inst_compressed_sp(__inst, store) + +/* + * float_fsw_reg - Set a FP register from a register containing the value + * a0 = FP register index to be set + * a1 = addr where to store register value + * a2 = address offset + * a3 = value to be store + */ +gen_test_inst(fsw) + +/* + * float_flw_reg - Get a FP register value and return it + * a0 = FP register index to be retrieved + * a1 = addr to load register from + * a2 = address offset + */ +gen_test_inst(flw) + +gen_test_inst(fsd) +#ifdef __riscv_compressed +gen_test_inst_compressed(fsd) +gen_test_store_compressed_sp(fsd) +#endif + +gen_test_inst(fld) +#ifdef __riscv_compressed +gen_test_inst_compressed(fld) +gen_test_load_compressed_sp(fld) +#endif diff --git a/tools/testing/selftests/riscv/misaligned/gp.S b/tools/testing/selftests/riscv/misaligned/gp.S new file mode 100644 index 000000000000..f53f4c6d81dd --- /dev/null +++ b/tools/testing/selftests/riscv/misaligned/gp.S @@ -0,0 +1,103 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (c) 2025 Rivos Inc. + * + * Authors: + * Clément Léger <cleger(a)rivosinc.com> + */ + +#include "common.S" + +.text + +.macro __gen_test_inst inst, src_reg + \inst a2, 0(\src_reg) + move a0, a2 +.endm + +.macro gen_func_header func_name, rvc + .option arch,\rvc + .global test_\func_name + test_\func_name: +.endm + +.macro gen_test_inst inst + .option push + gen_func_header \inst, -c + __gen_test_inst \inst, a0 + .option pop + ret +.endm + +.macro __gen_test_inst_c name, src_reg + .option push + gen_func_header c_\name, +c + __gen_test_inst c.\name, \src_reg + .option pop + ret +.endm + +.macro gen_test_inst_c name + __gen_test_inst_c \name, a0 +.endm + + +.macro gen_test_inst_load_c_sp name + .option push + gen_func_header c_\name\()sp, +c + sp_stack_prologue a1 + copy_long_to t0, a0, sp + c.ldsp a0, 0(sp) + sp_stack_epilogue a1 + .option pop + ret +.endm + +.macro lb_sp_sb_a0 reg, offset + lb_sb \reg, \offset, sp, a0 +.endm + +.macro gen_test_inst_store_c_sp inst_name + .option push + gen_func_header c_\inst_name\()sp, +c + /* Misalign stack pointer */ + sp_stack_prologue a1 + /* Misalign access */ + c.sdsp a2, 0(sp) + copy_long_to t0, sp, a0 + sp_stack_epilogue a1 + .option pop + ret +.endm + + + /* + * a0 = addr to load from + * a1 = address offset + * a2 = value to be loaded + */ +gen_test_inst lh +gen_test_inst lhu +gen_test_inst lw +gen_test_inst lwu +gen_test_inst ld +#ifdef __riscv_compressed +gen_test_inst_c lw +gen_test_inst_c ld +gen_test_inst_load_c_sp ld +#endif + +/* + * a0 = addr where to store value + * a1 = address offset + * a2 = value to be stored + */ +gen_test_inst sh +gen_test_inst sw +gen_test_inst sd +#ifdef __riscv_compressed +gen_test_inst_c sw +gen_test_inst_c sd +gen_test_inst_store_c_sp sd +#endif + diff --git a/tools/testing/selftests/riscv/misaligned/misaligned.c b/tools/testing/selftests/riscv/misaligned/misaligned.c new file mode 100644 index 000000000000..50cd8f5ece94 --- /dev/null +++ b/tools/testing/selftests/riscv/misaligned/misaligned.c @@ -0,0 +1,253 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2025 Rivos Inc. + * + * Authors: + * Clément Léger <cleger(a)rivosinc.com> + */ +#include <signal.h> +#include <stdio.h> +#include <stdlib.h> +#include <linux/ptrace.h> +#include "../../kselftest_harness.h" + +#include <stdlib.h> +#include <stdio.h> +#include <stdint.h> +#include <float.h> +#include <errno.h> +#include <math.h> +#include <string.h> +#include <signal.h> +#include <stdbool.h> +#include <unistd.h> +#include <inttypes.h> +#include <ucontext.h> + +#include <sys/prctl.h> + +#define stringify(s) __stringify(s) +#define __stringify(s) #s + +#define VAL16 0x1234U +#define VAL32 0x5EADBEEFUL +#define VAL64 0x45674321D00DF789ULL + +#define VAL_float 78951.234375 +#define VAL_double 567890.512396965789589290 + +static bool float_equal(float a, float b) +{ + float scaled_epsilon; + float difference = fabsf(a - b); + + // Scale to the largest value. + a = fabsf(a); + b = fabsf(b); + if (a > b) + scaled_epsilon = FLT_EPSILON * a; + else + scaled_epsilon = FLT_EPSILON * b; + + return difference <= scaled_epsilon; +} + +static bool double_equal(double a, double b) +{ + double scaled_epsilon; + double difference = fabsl(a - b); + + // Scale to the largest value. + a = fabs(a); + b = fabs(b); + if (a > b) + scaled_epsilon = DBL_EPSILON * a; + else + scaled_epsilon = DBL_EPSILON * b; + + return difference <= scaled_epsilon; +} + +#define fpu_load_proto(__inst, __type) \ +extern __type test_ ## __inst(unsigned long fp_reg, void *addr, unsigned long offset, __type value) + +fpu_load_proto(flw, float); +fpu_load_proto(fld, double); +fpu_load_proto(c_flw, float); +fpu_load_proto(c_fld, double); +fpu_load_proto(c_fldsp, double); + +#define fpu_store_proto(__inst, __type) \ +extern void test_ ## __inst(unsigned long fp_reg, void *addr, unsigned long offset, __type value) + +fpu_store_proto(fsw, float); +fpu_store_proto(fsd, double); +fpu_store_proto(c_fsw, float); +fpu_store_proto(c_fsd, double); +fpu_store_proto(c_fsdsp, double); + +#define gp_load_proto(__inst, __type) \ +extern __type test_ ## __inst(void *addr, unsigned long offset, __type value) + +gp_load_proto(lh, uint16_t); +gp_load_proto(lhu, uint16_t); +gp_load_proto(lw, uint32_t); +gp_load_proto(lwu, uint32_t); +gp_load_proto(ld, uint64_t); +gp_load_proto(c_lw, uint32_t); +gp_load_proto(c_ld, uint64_t); +gp_load_proto(c_ldsp, uint64_t); + +#define gp_store_proto(__inst, __type) \ +extern void test_ ## __inst(void *addr, unsigned long offset, __type value) + +gp_store_proto(sh, uint16_t); +gp_store_proto(sw, uint32_t); +gp_store_proto(sd, uint64_t); +gp_store_proto(c_sw, uint32_t); +gp_store_proto(c_sd, uint64_t); +gp_store_proto(c_sdsp, uint64_t); + +#define TEST_GP_LOAD(__inst, __type_size) \ +TEST(gp_load_ ## __inst) \ +{ \ + int offset, ret; \ + uint8_t buf[16] __attribute__((aligned(16))); \ + \ + ret = prctl(PR_SET_UNALIGN, PR_UNALIGN_NOPRINT); \ + ASSERT_EQ(ret, 0); \ + \ + for (offset = 1; offset < (__type_size) / 8; offset++) { \ + uint ## __type_size ## _t val = VAL ## __type_size; \ + uint ## __type_size ## _t *ptr = (uint ## __type_size ## _t *)(buf + offset); \ + memcpy(ptr, &val, sizeof(val)); \ + val = test_ ## __inst(ptr, offset, val); \ + EXPECT_EQ(VAL ## __type_size, val); \ + } \ +} + +TEST_GP_LOAD(lh, 16); +TEST_GP_LOAD(lhu, 16); +TEST_GP_LOAD(lw, 32); +TEST_GP_LOAD(lwu, 32); +TEST_GP_LOAD(ld, 64); +#ifdef __riscv_compressed +TEST_GP_LOAD(c_lw, 32); +TEST_GP_LOAD(c_ld, 64); +TEST_GP_LOAD(c_ldsp, 64); +#endif + +#define TEST_GP_STORE(__inst, __type_size) \ +TEST(gp_load_ ## __inst) \ +{ \ + int offset, ret; \ + uint8_t buf[16] __attribute__((aligned(16))); \ + \ + ret = prctl(PR_SET_UNALIGN, PR_UNALIGN_NOPRINT); \ + ASSERT_EQ(ret, 0); \ + \ + for (offset = 1; offset < (__type_size) / 8; offset++) { \ + uint ## __type_size ## _t val = VAL ## __type_size; \ + uint ## __type_size ## _t *ptr = (uint ## __type_size ## _t *)(buf + offset); \ + memset(ptr, 0, sizeof(val)); \ + test_ ## __inst(ptr, offset, val); \ + memcpy(&val, ptr, sizeof(val)); \ + EXPECT_EQ(VAL ## __type_size, val); \ + } \ +} +TEST_GP_STORE(sh, 16); +TEST_GP_STORE(sw, 32); +TEST_GP_STORE(sd, 64); +#ifdef __riscv_compressed +TEST_GP_STORE(c_sw, 32); +TEST_GP_STORE(c_sd, 64); +TEST_GP_STORE(c_sdsp, 64); +#endif + +#define __TEST_FPU_LOAD(__type, __inst, __reg_start, __reg_end) \ +TEST(fpu_load_ ## __inst) \ +{ \ + int ret, offset, fp_reg; \ + uint8_t buf[16] __attribute__((aligned(16))); \ + \ + ret = prctl(PR_SET_UNALIGN, PR_UNALIGN_NOPRINT); \ + ASSERT_EQ(ret, 0); \ + \ + for (fp_reg = __reg_start; fp_reg < __reg_end; fp_reg++) { \ + for (offset = 1; offset < 4; offset++) { \ + void *load_addr = (buf + offset); \ + __type val = VAL_ ## __type ; \ + \ + memcpy(load_addr, &val, sizeof(val)); \ + val = test_ ## __inst(fp_reg, load_addr, offset, val); \ + EXPECT_TRUE(__type ##_equal(val, VAL_## __type)); \ + } \ + } \ +} +#define TEST_FPU_LOAD(__type, __inst) \ + __TEST_FPU_LOAD(__type, __inst, 0, 32) +#define TEST_FPU_LOAD_COMPRESSED(__type, __inst) \ + __TEST_FPU_LOAD(__type, __inst, 8, 16) + +TEST_FPU_LOAD(float, flw) +TEST_FPU_LOAD(double, fld) +#ifdef __riscv_compressed +TEST_FPU_LOAD_COMPRESSED(double, c_fld) +TEST_FPU_LOAD_COMPRESSED(double, c_fldsp) +#endif + +#define __TEST_FPU_STORE(__type, __inst, __reg_start, __reg_end) \ +TEST(fpu_store_ ## __inst) \ +{ \ + int ret, offset, fp_reg; \ + uint8_t buf[16] __attribute__((aligned(16))); \ + \ + ret = prctl(PR_SET_UNALIGN, PR_UNALIGN_NOPRINT); \ + ASSERT_EQ(ret, 0); \ + \ + for (fp_reg = __reg_start; fp_reg < __reg_end; fp_reg++) { \ + for (offset = 1; offset < 4; offset++) { \ + \ + void *store_addr = (buf + offset); \ + __type val = VAL_ ## __type ; \ + \ + test_ ## __inst(fp_reg, store_addr, offset, val); \ + memcpy(&val, store_addr, sizeof(val)); \ + EXPECT_TRUE(__type ## _equal(val, VAL_## __type)); \ + } \ + } \ +} +#define TEST_FPU_STORE(__type, __inst) \ + __TEST_FPU_STORE(__type, __inst, 0, 32) +#define TEST_FPU_STORE_COMPRESSED(__type, __inst) \ + __TEST_FPU_STORE(__type, __inst, 8, 16) + +TEST_FPU_STORE(float, fsw) +TEST_FPU_STORE(double, fsd) +#ifdef __riscv_compressed +TEST_FPU_STORE_COMPRESSED(double, c_fsd) +TEST_FPU_STORE_COMPRESSED(double, c_fsdsp) +#endif + +TEST_SIGNAL(gen_sigbus, SIGBUS) +{ + uint32_t val = VAL32; + uint8_t buf[16] __attribute__((aligned(16))); + int ret; + + ret = prctl(PR_SET_UNALIGN, PR_UNALIGN_SIGBUS); + ASSERT_EQ(ret, 0); + + asm volatile("sw %0, 1(%1)" : : "r"(val), "r"(buf) : "memory"); +} + +int main(int argc, char **argv) +{ + int ret, val; + + ret = prctl(PR_GET_UNALIGN, &val); + if (ret == -1 && errno == EINVAL) + ksft_exit_skip("SKIP GET_UNALIGN_CTL not supported\n"); + + exit(test_harness_run(argc, argv)); +} -- 2.49.0

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[PATCH net-next v12 00/10] tun: Introduce virtio-net hashing feature

by Akihiko Odaki

NOTE: I'm leaving Daynix Computing Ltd., for which I worked on this patch series, by the end of this month. While net-next is closed, this is the last chance for me to send another version so let me send the local changes now. Please contact Yuri Benditovich, who is CCed on this email, for anything about this series. virtio-net have two usage of hashes: one is RSS and another is hash reporting. Conventionally the hash calculation was done by the VMM. However, computing the hash after the queue was chosen defeats the purpose of RSS. Another approach is to use eBPF steering program. This approach has another downside: it cannot report the calculated hash due to the restrictive nature of eBPF. Introduce the code to compute hashes to the kernel in order to overcome thse challenges. An alternative solution is to extend the eBPF steering program so that it will be able to report to the userspace, but it is based on context rewrites, which is in feature freeze. We can adopt kfuncs, but they will not be UAPIs. We opt to ioctl to align with other relevant UAPIs (KVM and vhost_net). The patches for QEMU to use this new feature was submitted as RFC and is available at: https://patchew.org/QEMU/20250530-hash-v5-0-343d7d7a8200@daynix.com/ This work was presented at LPC 2024: https://lpc.events/event/18/contributions/1963/ V1 -> V2: Changed to introduce a new BPF program type. Signed-off-by: Akihiko Odaki <akihiko.odaki(a)daynix.com> --- Changes in v12: - Updated tools/testing/selftests/net/config. - Split TUNSETVNETHASH. - Link to v11: https://lore.kernel.org/r/20250317-rss-v11-0-4cacca92f31f@daynix.com Changes in v11: - Added the missing code to free vnet_hash in patch "tap: Introduce virtio-net hash feature". - Link to v10: https://lore.kernel.org/r/20250313-rss-v10-0-3185d73a9af0@daynix.com Changes in v10: - Split common code and TUN/TAP-specific code into separate patches. - Reverted a spurious style change in patch "tun: Introduce virtio-net hash feature". - Added a comment explaining disable_ipv6 in tests. - Used AF_PACKET for patch "selftest: tun: Add tests for virtio-net hashing". I also added the usage of FIXTURE_VARIANT() as the testing function now needs access to more variant-specific variables. - Corrected the message of patch "selftest: tun: Add tests for virtio-net hashing"; it mentioned validation of configuration but it is not scope of this patch. - Expanded the description of patch "selftest: tun: Add tests for virtio-net hashing". - Added patch "tun: Allow steering eBPF program to fall back". - Changed to handle TUNGETVNETHASHCAP before taking the rtnl lock. - Removed redundant tests for tun_vnet_ioctl(). - Added patch "selftest: tap: Add tests for virtio-net ioctls". - Added a design explanation of ioctls for extensibility and migration. - Removed a few branches in patch "vhost/net: Support VIRTIO_NET_F_HASH_REPORT". - Link to v9: https://lore.kernel.org/r/20250307-rss-v9-0-df76624025eb@daynix.com Changes in v9: - Added a missing return statement in patch "tun: Introduce virtio-net hash feature". - Link to v8: https://lore.kernel.org/r/20250306-rss-v8-0-7ab4f56ff423@daynix.com Changes in v8: - Disabled IPv6 to eliminate noises in tests. - Added a branch in tap to avoid unnecessary dissection when hash reporting is disabled. - Removed unnecessary rtnl_lock(). - Extracted code to handle new ioctls into separate functions to avoid adding extra NULL checks to the code handling other ioctls. - Introduced variable named "fd" to __tun_chr_ioctl(). - s/-/=/g in a patch message to avoid confusing Git. - Link to v7: https://lore.kernel.org/r/20250228-rss-v7-0-844205cbbdd6@daynix.com Changes in v7: - Ensured to set hash_report to VIRTIO_NET_HASH_REPORT_NONE for VHOST_NET_F_VIRTIO_NET_HDR. - s/4/sizeof(u32)/ in patch "virtio_net: Add functions for hashing". - Added tap_skb_cb type. - Rebased. - Link to v6: https://lore.kernel.org/r/20250109-rss-v6-0-b1c90ad708f6@daynix.com Changes in v6: - Extracted changes to fill vnet header holes into another series. - Squashed patches "skbuff: Introduce SKB_EXT_TUN_VNET_HASH", "tun: Introduce virtio-net hash reporting feature", and "tun: Introduce virtio-net RSS" into patch "tun: Introduce virtio-net hash feature". - Dropped the RFC tag. - Link to v5: https://lore.kernel.org/r/20241008-rss-v5-0-f3cf68df005d@daynix.com Changes in v5: - Fixed a compilation error with CONFIG_TUN_VNET_CROSS_LE. - Optimized the calculation of the hash value according to: https://git.dpdk.org/dpdk/commit/?id=3fb1ea032bd6ff8317af5dac9af901f1f324ca… - Added patch "tun: Unify vnet implementation". - Dropped patch "tap: Pad virtio header with zero". - Added patch "selftest: tun: Test vnet ioctls without device". - Reworked selftests to skip for older kernels. - Documented the case when the underlying device is deleted and packets have queue_mapping set by TC. - Reordered test harness arguments. - Added code to handle fragmented packets. - Link to v4: https://lore.kernel.org/r/20240924-rss-v4-0-84e932ec0e6c@daynix.com Changes in v4: - Moved tun_vnet_hash_ext to if_tun.h. - Renamed virtio_net_toeplitz() to virtio_net_toeplitz_calc(). - Replaced htons() with cpu_to_be16(). - Changed virtio_net_hash_rss() to return void. - Reordered variable declarations in virtio_net_hash_rss(). - Removed virtio_net_hdr_v1_hash_from_skb(). - Updated messages of "tap: Pad virtio header with zero" and "tun: Pad virtio header with zero". - Fixed vnet_hash allocation size. - Ensured to free vnet_hash when destructing tun_struct. - Link to v3: https://lore.kernel.org/r/20240915-rss-v3-0-c630015db082@daynix.com Changes in v3: - Reverted back to add ioctl. - Split patch "tun: Introduce virtio-net hashing feature" into "tun: Introduce virtio-net hash reporting feature" and "tun: Introduce virtio-net RSS". - Changed to reuse hash values computed for automq instead of performing RSS hashing when hash reporting is requested but RSS is not. - Extracted relevant data from struct tun_struct to keep it minimal. - Added kernel-doc. - Changed to allow calling TUNGETVNETHASHCAP before TUNSETIFF. - Initialized num_buffers with 1. - Added a test case for unclassified packets. - Fixed error handling in tests. - Changed tests to verify that the queue index will not overflow. - Rebased. - Link to v2: https://lore.kernel.org/r/20231015141644.260646-1-akihiko.odaki@daynix.com --- Akihiko Odaki (10): virtio_net: Add functions for hashing net: flow_dissector: Export flow_keys_dissector_symmetric tun: Allow steering eBPF program to fall back tun: Add common virtio-net hash feature code tun: Introduce virtio-net hash feature tap: Introduce virtio-net hash feature selftest: tun: Test vnet ioctls without device selftest: tun: Add tests for virtio-net hashing selftest: tap: Add tests for virtio-net ioctls vhost/net: Support VIRTIO_NET_F_HASH_REPORT Documentation/networking/tuntap.rst | 7 + drivers/net/Kconfig | 1 + drivers/net/ipvlan/ipvtap.c | 2 +- drivers/net/macvtap.c | 2 +- drivers/net/tap.c | 80 +++++- drivers/net/tun.c | 92 +++++-- drivers/net/tun_vnet.h | 165 +++++++++++- drivers/vhost/net.c | 68 ++--- include/linux/if_tap.h | 4 +- include/linux/skbuff.h | 3 + include/linux/virtio_net.h | 188 ++++++++++++++ include/net/flow_dissector.h | 1 + include/uapi/linux/if_tun.h | 80 ++++++ net/core/flow_dissector.c | 3 +- net/core/skbuff.c | 4 + tools/testing/selftests/net/Makefile | 2 +- tools/testing/selftests/net/config | 1 + tools/testing/selftests/net/tap.c | 131 +++++++++- tools/testing/selftests/net/tun.c | 485 ++++++++++++++++++++++++++++++++++- 19 files changed, 1234 insertions(+), 85 deletions(-) --- base-commit: 5cb8274d66c611b7889565c418a8158517810f9b change-id: 20240403-rss-e737d89efa77 Best regards, -- Akihiko Odaki <akihiko.odaki(a)daynix.com>

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