May 2025 - Linux-kselftest-mirror

[PATCH bpf-next v4 0/5] Replace CONFIG_DMABUF_SYSFS_STATS with BPF

by T.J. Mercier

Until CONFIG_DMABUF_SYSFS_STATS was added [1] it was only possible to perform per-buffer accounting with debugfs which is not suitable for production environments. Eventually we discovered the overhead with per-buffer sysfs file creation/removal was significantly impacting allocation and free times, and exacerbated kernfs lock contention. [2] dma_buf_stats_setup() is responsible for 39% of single-page buffer creation duration, or 74% of single-page dma_buf_export() duration when stressing dmabuf allocations and frees. I prototyped a change from per-buffer to per-exporter statistics with a RCU protected list of exporter allocations that accommodates most (but not all) of our use-cases and avoids almost all of the sysfs overhead. While that adds less overhead than per-buffer sysfs, and less even than the maintenance of the dmabuf debugfs_list, it's still *additional* overhead on top of the debugfs_list and doesn't give us per-buffer info. This series uses the existing dmabuf debugfs_list to implement a BPF dmabuf iterator, which adds no overhead to buffer allocation/free and provides per-buffer info. The list has been moved outside of CONFIG_DEBUG_FS scope so that it is always populated. The BPF program loaded by userspace that extracts per-buffer information gets to define its own interface which avoids the lack of ABI stability with debugfs. This will allow us to replace our use of CONFIG_DMABUF_SYSFS_STATS, and the plan is to remove it from the kernel after the next longterm stable release. [1] https://lore.kernel.org/linux-media/20201210044400.1080308-1-hridya@google.… [2] https://lore.kernel.org/all/20220516171315.2400578-1-tjmercier@google.com v1: https://lore.kernel.org/all/20250414225227.3642618-1-tjmercier@google.com v1 -> v2: Make the DMA buffer list independent of CONFIG_DEBUG_FS per Christian König Add CONFIG_DMA_SHARED_BUFFER check to kernel/bpf/Makefile per kernel test robot Use BTF_ID_LIST_SINGLE instead of BTF_ID_LIST_GLOBAL_SINGLE per Song Liu Fixup comment style, mixing code/declarations, and use ASSERT_OK_FD in selftest per Song Liu Add BPF_ITER_RESCHED feature to bpf_dmabuf_reg_info per Alexei Starovoitov Add open-coded iterator and selftest per Alexei Starovoitov Add a second test buffer from the system dmabuf heap to selftests Use the BPF program we'll use in production for selftest per Alexei Starovoitov https://r.android.com/c/platform/system/bpfprogs/+/3616123/2/dmabufIter.c https://r.android.com/c/platform/system/memory/libmeminfo/+/3614259/1/libdm… v2: https://lore.kernel.org/all/20250504224149.1033867-1-tjmercier@google.com v2 -> v3: Rebase onto bpf-next/master Move get_next_dmabuf() into drivers/dma-buf/dma-buf.c, along with the new get_first_dmabuf(). This avoids having to expose the dmabuf list and mutex to the rest of the kernel, and keeps the dmabuf mutex operations near each other in the same file. (Christian König) Add Christian's RB to dma-buf: Rename debugfs symbols Drop RFC: dma-buf: Remove DMA-BUF statistics v3: https://lore.kernel.org/all/20250507001036.2278781-1-tjmercier@google.com v3 -> v4: Fix selftest BPF program comment style (not kdoc) per Alexei Starovoitov Fix dma-buf.c kdoc comment style per Alexei Starovoitov Rename get_first_dmabuf / get_next_dmabuf to dma_buf_iter_begin / dma_buf_iter_next per Christian König Add Christian's RB to bpf: Add dmabuf iterator T.J. Mercier (5): dma-buf: Rename debugfs symbols bpf: Add dmabuf iterator bpf: Add open coded dmabuf iterator selftests/bpf: Add test for dmabuf_iter selftests/bpf: Add test for open coded dmabuf_iter drivers/dma-buf/dma-buf.c | 98 +++++-- include/linux/dma-buf.h | 4 +- kernel/bpf/Makefile | 3 + kernel/bpf/dmabuf_iter.c | 149 ++++++++++ kernel/bpf/helpers.c | 5 + .../testing/selftests/bpf/bpf_experimental.h | 5 + tools/testing/selftests/bpf/config | 3 + .../selftests/bpf/prog_tests/dmabuf_iter.c | 258 ++++++++++++++++++ .../testing/selftests/bpf/progs/dmabuf_iter.c | 91 ++++++ 9 files changed, 594 insertions(+), 22 deletions(-) create mode 100644 kernel/bpf/dmabuf_iter.c create mode 100644 tools/testing/selftests/bpf/prog_tests/dmabuf_iter.c create mode 100644 tools/testing/selftests/bpf/progs/dmabuf_iter.c base-commit: 43745d11bfd9683abdf08ad7a5cc403d6a9ffd15 -- 2.49.0.1015.ga840276032-goog

6 months

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[PATCH v8 iproute2-next 0/1] DUALPI2 iproute2 patch

by chia-yu.chang＠nokia-bell-labs.com

From: Chia-Yu Chang <chia-yu.chang(a)nokia-bell-labs.com> Hello, Please find DUALPI2 iproute2 patch v8. v8 (09-May-25) - Update pkt_sched.h with the one in nex-next - Fix one typo of comment in pkt_sched.h (ALOK TIWARI <alok.a.tiwari(a)oracle.com>) - Update manual content in man/man8/tc-dualpi2.8 (ALOK TIWARI <alok.a.tiwari(a)oracle.com>) - Update tc/q_dualpi2.c to fix missing blank lines and add missing case (ALOK TIWARI <alok.a.tiwari(a)oracle.com>) v7 (05-May-25) - Align pkt_sched.h with the v14 version of net-next due to spec modificiaotn in tc.yaml - Reorganize dualpi2_print_opt() to match the order in tc.yaml - Remove credit-queue in PRINT_JSON v6 (26-Apr-25) - Update JSON file output due to spec modifiocation in tc.yaml of net-next v5 (25-Mar-25) - Use matches() to replace current strcmp() (Stephen Hemminger <stephen(a)networkplumber.org>) - Use general parse_percent() for handling scaled percentage values (Stephen Hemminger <stephen(a)networkplumber.org>) - Add print function for JSON of dualpi2 stats (Stephen Hemminger <stephen(a)networkplumber.org>) v4 (16-Mar-25) - Add min_qlen_step to dualpi2 attribute as the minimum queue length in number of packets in the L-queue to start step amrking. v3 (21-Feb-25) - Add memlimit to dualpi2 attribute, and add memory_used, max_memory_used, memory_limit in dualpi2 stats (Dave Taht <dave.taht(a)gmail.com>) - Update manual to align latest implementation and clarify the queue naming and default unit - Use common "get_scaled_alpha_beta" and clean print_opt for Dualpi2 v2 (23-Oct-24) - Rename get_float in dualpi2 to get_float_min_max in utils.c - Move get_float from iplink_can.c in utils.c (Stephen Hemminger <stephen(a)networkplumber.org>) - Add print function for JSON of dualpi2 (Stephen Hemminger <stephen(a)networkplumber.org>) For more details of DualPI2, plesae refer IETF RFC9332 (https://datatracker.ietf.org/doc/html/rfc9332). Best Regards, Chia-Yu Chia-Yu Chang (1): tc: add dualpi2 scheduler module bash-completion/tc | 11 +- include/uapi/linux/pkt_sched.h | 68 +++++ include/utils.h | 2 + ip/iplink_can.c | 14 - lib/utils.c | 30 ++ man/man8/tc-dualpi2.8 | 249 +++++++++++++++ tc/Makefile | 1 + tc/q_dualpi2.c | 534 +++++++++++++++++++++++++++++++++ 8 files changed, 894 insertions(+), 15 deletions(-) create mode 100644 man/man8/tc-dualpi2.8 create mode 100644 tc/q_dualpi2.c -- 2.34.1

6 months

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[PATCH] kunit: configs: Enable coverage of the bitfield packing library

by Mark Brown

There are KUnit tests for the bitfield packing library but these depend on CONFIG_PACKING which is not enabled by anything in either the existing KUnit all_tests.config or the base UML config it runs on as standard. Enable that in all_tests.config to improve coverage. Signed-off-by: Mark Brown <broonie(a)kernel.org> --- tools/testing/kunit/configs/all_tests.config | 2 ++ 1 file changed, 2 insertions(+) diff --git a/tools/testing/kunit/configs/all_tests.config b/tools/testing/kunit/configs/all_tests.config index cdd9782f9646..b0223b7aebde 100644 --- a/tools/testing/kunit/configs/all_tests.config +++ b/tools/testing/kunit/configs/all_tests.config @@ -51,3 +51,5 @@ CONFIG_SOUND=y CONFIG_SND=y CONFIG_SND_SOC=y CONFIG_SND_SOC_TOPOLOGY_BUILD=y + +CONFIG_PACKING=y --- base-commit: 8ffd015db85fea3e15a77027fda6c02ced4d2444 change-id: 20250422-kunit-enable-missing-tests-9189ee930cae Best regards, -- Mark Brown <broonie(a)kernel.org>

6 months

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[PATCH] selftests/seccomp: fix negative_ENOSYS tracer tests on arm32

by Terry Tritton

TRACE_syscall.ptrace.negative_ENOSYS and TRACE_syscall.seccomp.negative_ENOSYS on arm32 are being reported as failures instead of skipping. The teardown_trace_fixture function sets the test to KSFT_FAIL in case of a non 0 return value from the tracer process. Due to _metadata now being shared between the forked processes the tracer is returning the KSFT_SKIP value set by the tracee which is non 0. Remove the setting of the _metadata.exit_code in teardown_trace_fixture. Fixes: 24cf65a62266 ("selftests/harness: Share _metadata between forked processes") Signed-off-by: Terry Tritton <terry.tritton(a)linaro.org> --- tools/testing/selftests/seccomp/seccomp_bpf.c | 6 ------ 1 file changed, 6 deletions(-) diff --git a/tools/testing/selftests/seccomp/seccomp_bpf.c b/tools/testing/selftests/seccomp/seccomp_bpf.c index b2f76a52215a..c43a6f8f8cd5 100644 --- a/tools/testing/selftests/seccomp/seccomp_bpf.c +++ b/tools/testing/selftests/seccomp/seccomp_bpf.c @@ -1629,14 +1629,8 @@ void teardown_trace_fixture(struct __test_metadata *_metadata, { if (tracer) { int status; - /* - * Extract the exit code from the other process and - * adopt it for ourselves in case its asserts failed. - */ ASSERT_EQ(0, kill(tracer, SIGUSR1)); ASSERT_EQ(tracer, waitpid(tracer, &status, 0)); - if (WEXITSTATUS(status)) - _metadata->exit_code = KSFT_FAIL; } } -- 2.39.5

6 months

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[PATCH 0/3] selftests/timens: Various small fixes

by Thomas Weißschuh

Fixes for various issues in the timens selftests. Signed-off-by: Thomas Weißschuh <thomas.weissschuh(a)linutronix.de> --- Thomas Weißschuh (3): selftests/timens: Print TAP headers selftests/timens: Make run_tests() functions static selftests/timens: timerfd: Use correct clockid type in tclock_gettime() tools/testing/selftests/timens/clock_nanosleep.c | 4 +++- tools/testing/selftests/timens/exec.c | 2 ++ tools/testing/selftests/timens/futex.c | 2 ++ tools/testing/selftests/timens/gettime_perf.c | 2 ++ tools/testing/selftests/timens/procfs.c | 2 ++ tools/testing/selftests/timens/timens.c | 2 ++ tools/testing/selftests/timens/timer.c | 4 +++- tools/testing/selftests/timens/timerfd.c | 6 ++++-- tools/testing/selftests/timens/vfork_exec.c | 2 ++ 9 files changed, 22 insertions(+), 4 deletions(-) --- base-commit: 0af2f6be1b4281385b618cb86ad946eded089ac8 change-id: 20250326-selftests-timens-fixes-97662bdb18b6 Best regards, -- Thomas Weißschuh <thomas.weissschuh(a)linutronix.de>

6 months

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[PATCH] KVM: SEV: Disable SEV-SNP support on initialization failure

by Ashish Kalra

From: Ashish Kalra <ashish.kalra(a)amd.com> During platform init, SNP initialization may fail for several reasons, such as firmware command failures and incompatible versions. However, the KVM capability may continue to advertise support for it. The platform may have SNP enabled but if SNP_INIT fails then SNP is not supported by KVM. During KVM module initialization query the SNP platform status to obtain the SNP initialization state and use it as an additional condition to determine support for SEV-SNP. Co-developed-by: Sean Christopherson <seanjc(a)google.com> Signed-off-by: Sean Christopherson <seanjc(a)google.com> Co-developed-by: Pratik R. Sampat <prsampat(a)amd.com> Signed-off-by: Pratik R. Sampat <prsampat(a)amd.com> Signed-off-by: Ashish Kalra <ashish.kalra(a)amd.com> --- arch/x86/kvm/svm/sev.c | 43 +++++++++++++++++++++++++++++++++--------- 1 file changed, 34 insertions(+), 9 deletions(-) diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index ada53f04158c..a6abdb26f877 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -2934,6 +2934,32 @@ void __init sev_set_cpu_caps(void) } } +static bool sev_is_snp_initialized(void) +{ + struct sev_user_data_snp_status *status; + struct sev_data_snp_addr buf; + bool initialized = false; + void *data; + int error; + + data = snp_alloc_firmware_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO); + if (!data) + return initialized; + + buf.address = __psp_pa(data); + if (sev_do_cmd(SEV_CMD_SNP_PLATFORM_STATUS, &buf, &error)) + goto out; + + status = (struct sev_user_data_snp_status *)data; + if (status->state) + initialized = true; + +out: + snp_free_firmware_page(data); + + return initialized; +} + void __init sev_hardware_setup(void) { unsigned int eax, ebx, ecx, edx, sev_asid_count, sev_es_asid_count; @@ -3038,6 +3064,14 @@ void __init sev_hardware_setup(void) sev_snp_supported = sev_snp_enabled && cc_platform_has(CC_ATTR_HOST_SEV_SNP); out: + if (sev_enabled) { + init_args.probe = true; + if (sev_platform_init(&init_args)) + sev_supported = sev_es_supported = sev_snp_supported = false; + else + sev_snp_supported &= sev_is_snp_initialized(); + } + if (boot_cpu_has(X86_FEATURE_SEV)) pr_info("SEV %s (ASIDs %u - %u)\n", sev_supported ? min_sev_asid <= max_sev_asid ? "enabled" : @@ -3064,15 +3098,6 @@ void __init sev_hardware_setup(void) sev_supported_vmsa_features = 0; if (sev_es_debug_swap_enabled) sev_supported_vmsa_features |= SVM_SEV_FEAT_DEBUG_SWAP; - - if (!sev_enabled) - return; - - /* - * Do both SNP and SEV initialization at KVM module load. - */ - init_args.probe = true; - sev_platform_init(&init_args); } void sev_hardware_unsetup(void) -- 2.34.1

6 months

4
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[PATCH v2] selftests/ftrace: Convert poll to a gen_file

by Ayush Jain

Poll program is a helper to ftracetest, thus make it a generic file and remove it from being run as a test. Currently when executing tests using $ make run_tests CC poll TAP version 13 1..2 # timeout set to 0 # selftests: ftrace: poll # Error: Polling file is not specified not ok 1 selftests: ftrace: poll # exit=255 Fix this by using TEST_GEN_FILES to build the 'poll' binary as a helper rather than as a test. Fixes: 80c3e28528ff ("selftests/tracing: Add hist poll() support test") Signed-off-by: Ayush Jain <Ayush.jain3(a)amd.com> --- tools/testing/selftests/ftrace/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/ftrace/Makefile b/tools/testing/selftests/ftrace/Makefile index 49d96bb16355..7c12263f8260 100644 --- a/tools/testing/selftests/ftrace/Makefile +++ b/tools/testing/selftests/ftrace/Makefile @@ -6,6 +6,6 @@ TEST_PROGS := ftracetest-ktap TEST_FILES := test.d settings EXTRA_CLEAN := $(OUTPUT)/logs/* -TEST_GEN_PROGS = poll +TEST_GEN_FILES := poll include ../lib.mk -- 2.34.1

6 months

3
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[PATCH] selftests/bpf: Fix bpf selftest build warning

by Saket Kumar Bhaskar

On linux-next, build for bpf selftest displays a warning: Warning: Kernel ABI header at 'tools/include/uapi/linux/if_xdp.h' differs from latest version at 'include/uapi/linux/if_xdp.h'. Commit 8066e388be48 ("net: add UAPI to the header guard in various network headers") changed the header guard from _LINUX_IF_XDP_H to _UAPI_LINUX_IF_XDP_H in include/uapi/linux/if_xdp.h. To resolve the warning, update tools/include/uapi/linux/if_xdp.h to align with the changes in include/uapi/linux/if_xdp.h Reported-by: Venkat Rao Bagalkote <venkat88(a)linux.ibm.com> Closes: https://lore.kernel.org/all/c2bc466d-dff2-4d0d-a797-9af7f676c065@linux.ibm.… Signed-off-by: Saket Kumar Bhaskar <skb99(a)linux.ibm.com> --- tools/include/uapi/linux/if_xdp.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/tools/include/uapi/linux/if_xdp.h b/tools/include/uapi/linux/if_xdp.h index 42869770776e..44f2bb93e7e6 100644 --- a/tools/include/uapi/linux/if_xdp.h +++ b/tools/include/uapi/linux/if_xdp.h @@ -7,8 +7,8 @@ * Magnus Karlsson <magnus.karlsson(a)intel.com> */ -#ifndef _LINUX_IF_XDP_H -#define _LINUX_IF_XDP_H +#ifndef _UAPI_LINUX_IF_XDP_H +#define _UAPI_LINUX_IF_XDP_H #include <linux/types.h> @@ -180,4 +180,4 @@ struct xdp_desc { /* TX packet carries valid metadata. */ #define XDP_TX_METADATA (1 << 1) -#endif /* _LINUX_IF_XDP_H */ +#endif /* _UAPI_LINUX_IF_XDP_H */ -- 2.43.5

6 months

2
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[PATCH v3 00/23] iommufd: Add vIOMMU infrastructure (Part-4 vQUEUE)

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. A vQUEUE 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 is an IOMMU HW feature to directly access the virtual queue in the guest address space, to avoid VM Exits to improve the performance. As an initial use case, it adds support for guest-owned HW virtual queues that VMM can allocate per request from a guest OS writing the VM register. Introduce IOMMUFD_OBJ_VQUEUE and its allocator IOMMUFD_CMD_VQUEUE_ALLOC, allowing VMM to forward the IOMMU-specific queue info, such as queue base address, size, and etc. Meanwhile, a guest-owned virtual queue needs the kernel (a virtual queue driver) to control the queue by reading/writing its consumer and producer indexes, which means the virtual queue HW allows the guest kernel to get a direct R/W access to those registers. Introduce an mmap infrastructure to the iommufd core so as to support pass through a piece of MMIO region from the host physical address space to the guest physical address space. The VMA info (vm_pgoff/size) used by an mmap must be pre-allocated during the IOMMUFD_CMD_VQUEUE_ALLOC and returned to the user space as an output driver-data carried via the IOMMUFD_CMD_VQUEUE_ALLOC. So, this requires a driver-specific user data support in the vIOMMU allocation flow. As a real-world use case, this series implements a vQUEUE support to 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_vqueue-v3 Paring QEMU branch for testing: https://github.com/nicolinc/qemu/commits/wip/for_iommufd_vqueue-v3 Changelog v3 * 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 (23): iommufd/viommu: Add driver-allocated vDEVICE support iommu: Pass in a driver-level user data structure to viommu_alloc op iommufd/viommu: Allow driver-specific user data for a vIOMMU object iommu: Add iommu_copy_struct_to_user helper iommufd/driver: Let iommufd_viommu_alloc helper save ictx to viommu->ictx iommufd/driver: Add iommufd_struct_destroy to revert iommufd_viommu_alloc iommufd/selftest: Support user_data in mock_viommu_alloc iommufd/selftest: Add covearge for viommu data iommufd: Abstract iopt_pin_pages and iopt_unpin_pages helpers iommufd/viommu: Introduce IOMMUFD_OBJ_VQUEUE and its related struct iommufd/viommu: Add IOMMUFD_CMD_VQUEUE_ALLOC ioctl iommufd/driver: Add iommufd_vqueue_depend/undepend() helpers iommufd/selftest: Add coverage for IOMMUFD_CMD_VQUEUE_ALLOC iommufd: Add mmap interface iommufd/selftest: Add coverage for the new mmap interface Documentation: userspace-api: iommufd: Update vQUEUE iommu/arm-smmu-v3-iommufd: Add vsmmu_alloc impl op iommu/arm-smmu-v3-iommufd: Support implementation-defined hw_info 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 | 25 +- drivers/iommu/iommufd/io_pagetable.h | 8 + drivers/iommu/iommufd/iommufd_private.h | 28 +- drivers/iommu/iommufd/iommufd_test.h | 20 + include/linux/iommu.h | 43 +- include/linux/iommufd.h | 184 ++++++- include/uapi/linux/iommufd.h | 117 ++++- tools/testing/selftests/iommu/iommufd_utils.h | 52 +- .../arm/arm-smmu-v3/arm-smmu-v3-iommufd.c | 42 +- .../iommu/arm/arm-smmu-v3/tegra241-cmdqv.c | 481 +++++++++++++++++- drivers/iommu/iommufd/device.c | 117 +---- drivers/iommu/iommufd/driver.c | 88 ++++ drivers/iommu/iommufd/io_pagetable.c | 95 ++++ drivers/iommu/iommufd/main.c | 84 ++- drivers/iommu/iommufd/selftest.c | 126 ++++- drivers/iommu/iommufd/viommu.c | 116 ++++- tools/testing/selftests/iommu/iommufd.c | 96 +++- .../selftests/iommu/iommufd_fail_nth.c | 11 +- Documentation/userspace-api/iommufd.rst | 15 + 19 files changed, 1555 insertions(+), 193 deletions(-) -- 2.43.0

6 months

5
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[PATCH v1] selftests/mm: add simple VM_PFNMAP tests based on mmap'ing /dev/mem

by David Hildenbrand

Let's test some basic functionality using /dev/mem. These tests will implicitly cover some PAT (Page Attribute Handling) handling on x86. These tests will only run when /dev/mem access to the first two pages in physical address space is possible and allowed; otherwise, the tests are skipped. On current x86-64 with PAT inside a VM, all tests pass: TAP version 13 1..19 ok 1 madvise(MADV_DONTNEED) should be disallowed ok 2 madvise(MADV_DONTNEED_LOCKED) should be disallowed ok 3 madvise(MADV_FREE) should be disallowed ok 4 madvise(MADV_WIPEONFORK) should be disallowed ok 5 madvise(MADV_COLD) should be disallowed ok 6 madvise(MADV_PAGEOUT) should be disallowed ok 7 madvise(MADV_POPULATE_READ) should be disallowed ok 8 madvise(MADV_POPULATE_WRITE) should be disallowed ok 9 munmap() splitting ok 10 mmap() after splitting ok 11 mremap(MREMAP_FIXED) ok 12 mremap() shrinking ok 13 mremap() growing should be disallowed ok 14 mprotect(PROT_NONE) ok 15 SIGSEGV expected ok 16 mprotect(PROT_READ) ok 17 SIGSEGV not expected ok 18 fork() ok 19 SIGSEGV in child not expected # Totals: pass:19 fail:0 xfail:0 xpass:0 skip:0 error:0 However, we are able to trigger: [ 27.888251] x86/PAT: pfnmap:1790 freeing invalid memtype [mem 0x00000000-0x00000fff] There are probably more things worth testing in the future, such as MAP_PRIVATE handling. But this set of tests is sufficient to cover most of the things we will rework regarding PAT handling. Cc: Andrew Morton <akpm(a)linux-foundation.org> Cc: Shuah Khan <shuah(a)kernel.org> Cc: Lorenzo Stoakes <lorenzo.stoakes(a)oracle.com> Cc: Ingo Molnar <mingo(a)redhat.com> Cc: Peter Xu <peterx(a)redhat.com> Signed-off-by: David Hildenbrand <david(a)redhat.com> --- On current mm-unstable, the MADV_POPULATE_READ test fails because mm-unstable contains a patch [1] that must be dropped. [1] https://lore.kernel.org/all/20250507154105.763088-2-p.antoniou@partner.sams… --- tools/testing/selftests/mm/Makefile | 1 + tools/testing/selftests/mm/pfnmap.c | 278 ++++++++++++++++++++++++++++ 2 files changed, 279 insertions(+) create mode 100644 tools/testing/selftests/mm/pfnmap.c diff --git a/tools/testing/selftests/mm/Makefile b/tools/testing/selftests/mm/Makefile index ad4d6043a60f0..ae6f994d3add7 100644 --- a/tools/testing/selftests/mm/Makefile +++ b/tools/testing/selftests/mm/Makefile @@ -84,6 +84,7 @@ TEST_GEN_FILES += mremap_test TEST_GEN_FILES += mseal_test TEST_GEN_FILES += on-fault-limit TEST_GEN_FILES += pagemap_ioctl +TEST_GEN_FILES += pfnmap TEST_GEN_FILES += thuge-gen TEST_GEN_FILES += transhuge-stress TEST_GEN_FILES += uffd-stress diff --git a/tools/testing/selftests/mm/pfnmap.c b/tools/testing/selftests/mm/pfnmap.c new file mode 100644 index 0000000000000..59be2f3221124 --- /dev/null +++ b/tools/testing/selftests/mm/pfnmap.c @@ -0,0 +1,278 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Basic VM_PFNMAP tests relying on mmap() of '/dev/mem' + * + * Copyright 2025, Red Hat, Inc. + * + * Author(s): David Hildenbrand <david(a)redhat.com> + */ +#define _GNU_SOURCE +#include <stdlib.h> +#include <string.h> +#include <stdint.h> +#include <unistd.h> +#include <errno.h> +#include <fcntl.h> +#include <signal.h> +#include <setjmp.h> +#include <linux/mman.h> +#include <sys/mman.h> +#include <sys/wait.h> + +#include "../kselftest.h" +#include "vm_util.h" + +static size_t pagesize; +static int pagemap_fd; +static int dev_mem_fd; +static sigjmp_buf env; + +static void signal_handler(int sig) +{ + if (sig == SIGSEGV) + siglongjmp(env, 1); + siglongjmp(env, 2); +} + +static void sense_support(void) +{ + char *addr, tmp; + int ret; + + dev_mem_fd = open("/dev/mem", O_RDONLY); + if (dev_mem_fd < 0) + ksft_exit_skip("Cannot open '/dev/mem': %s\n", strerror(errno)); + + /* We'll require the first two pages throughout our tests ... */ + addr = mmap(0, pagesize * 2, PROT_READ, MAP_SHARED, dev_mem_fd, 0); + if (addr == MAP_FAILED) + ksft_exit_skip("Cannot mmap '/dev/mem'"); + + /* ... and want to be able to read from them. */ + ret = sigsetjmp(env, 1); + if (!ret) { + tmp = *addr + *(addr + pagesize); + asm volatile("" : "+r" (tmp)); + } + if (ret) + ksft_exit_skip("Cannot read-access mmap'ed '/dev/mem'"); + + munmap(addr, pagesize * 2); +} + +static void test_madvise(void) +{ +#define INIT_ADVICE(nr) { nr, #nr} + const struct { + int nr; + const char *name; + } advices[] = { + INIT_ADVICE(MADV_DONTNEED), + INIT_ADVICE(MADV_DONTNEED_LOCKED), + INIT_ADVICE(MADV_FREE), + INIT_ADVICE(MADV_WIPEONFORK), + INIT_ADVICE(MADV_COLD), + INIT_ADVICE(MADV_PAGEOUT), + INIT_ADVICE(MADV_POPULATE_READ), + INIT_ADVICE(MADV_POPULATE_WRITE), + }; + char *addr; + int ret, i; + + addr = mmap(0, pagesize, PROT_READ, MAP_SHARED, dev_mem_fd, 0); + if (addr == MAP_FAILED) + ksft_exit_fail_msg("mmap() failed: %s\n", strerror(errno)); + + /* All these advices must be rejected. */ + for (i = 0; i < ARRAY_SIZE(advices); i++) { + ret = madvise(addr, pagesize, advices[i].nr); + ksft_test_result(ret && errno == EINVAL, + "madvise(%s) should be disallowed\n", + advices[i].name); + } + + munmap(addr, pagesize); +} + +static void test_munmap_splitting(void) +{ + char *addr1, *addr2; + int ret; + + addr1 = mmap(0, pagesize * 2, PROT_READ, MAP_SHARED, dev_mem_fd, 0); + if (addr1 == MAP_FAILED) + ksft_exit_fail_msg("mmap() failed: %s\n", strerror(errno)); + + /* Unmap the first pages. */ + ret = munmap(addr1, pagesize); + ksft_test_result(!ret, "munmap() splitting\n"); + + /* Remap the first page while the second page is still mapped. */ + addr2 = mmap(0, pagesize, PROT_READ, MAP_SHARED, dev_mem_fd, 0); + ksft_test_result(addr2 != MAP_FAILED, "mmap() after splitting\n"); + + if (addr2 != MAP_FAILED) + munmap(addr2, pagesize); + if (!ret) + munmap(addr1 + pagesize, pagesize); + else + munmap(addr1, pagesize * 2); +} + +static void test_mremap_fixed(void) +{ + char *addr, *new_addr, *ret; + + addr = mmap(0, pagesize * 2, PROT_READ, MAP_SHARED, dev_mem_fd, 0); + if (addr == MAP_FAILED) + ksft_exit_fail_msg("mmap() failed: %s\n", strerror(errno)); + + /* Reserve a destination area. */ + new_addr = mmap(0, pagesize * 2, PROT_READ, MAP_ANON | MAP_PRIVATE, -1, 0); + if (new_addr == MAP_FAILED) + ksft_exit_fail_msg("mmap() failed: %s\n", strerror(errno)); + + /* mremap() over our destination. */ + ret = mremap(addr, pagesize * 2, pagesize * 2, + MREMAP_FIXED | MREMAP_MAYMOVE, new_addr); + ksft_test_result(ret == new_addr, "mremap(MREMAP_FIXED)\n"); + if (ret != new_addr) + munmap(new_addr, pagesize * 2); + munmap(addr, pagesize * 2); +} + +static void test_mremap_shrinking(void) +{ + char *addr, *ret; + + addr = mmap(0, pagesize * 2, PROT_READ, MAP_SHARED, dev_mem_fd, 0); + if (addr == MAP_FAILED) + ksft_exit_fail_msg("mmap() failed: %s\n", strerror(errno)); + + /* Shrinking is expected to work. */ + ret = mremap(addr, pagesize * 2, pagesize, 0); + ksft_test_result(ret == addr, "mremap() shrinking\n"); + if (ret != addr) + munmap(addr, pagesize * 2); + else + munmap(addr, pagesize); +} + +static void test_mremap_growing(void) +{ + char *addr, *ret; + + addr = mmap(0, pagesize, PROT_READ, MAP_SHARED, dev_mem_fd, 0); + if (addr == MAP_FAILED) + ksft_exit_fail_msg("mmap() failed: %s\n", strerror(errno)); + + /* Growing is not expected to work. */ + ret = mremap(addr, pagesize, pagesize * 2, MREMAP_MAYMOVE); + ksft_test_result(ret == MAP_FAILED, + "mremap() growing should be disallowed\n"); + if (ret == MAP_FAILED) + munmap(addr, pagesize); + else + munmap(ret, pagesize * 2); +} + +static void test_mprotect(void) +{ + char *addr, tmp; + int ret; + + addr = mmap(0, pagesize, PROT_READ, MAP_SHARED, dev_mem_fd, 0); + if (addr == MAP_FAILED) + ksft_exit_fail_msg("mmap() failed: %s\n", strerror(errno)); + + /* With PROT_NONE, read access must result in SIGSEGV. */ + ret = mprotect(addr, pagesize, PROT_NONE); + ksft_test_result(!ret, "mprotect(PROT_NONE)\n"); + + ret = sigsetjmp(env, 1); + if (!ret) { + tmp = *addr; + asm volatile("" : "+r" (tmp)); + } + ksft_test_result(ret == 1, "SIGSEGV expected\n"); + + /* With PROT_READ, read access must again succeed. */ + ret = mprotect(addr, pagesize, PROT_READ); + ksft_test_result(!ret, "mprotect(PROT_READ)\n"); + + ret = sigsetjmp(env, 1); + if (!ret) { + tmp = *addr; + asm volatile("" : "+r" (tmp)); + } + ksft_test_result(!ret, "SIGSEGV not expected\n"); + + munmap(addr, pagesize); +} + +static void test_fork(void) +{ + char *addr, tmp; + int ret; + + addr = mmap(0, pagesize, PROT_READ, MAP_SHARED, dev_mem_fd, 0); + if (addr == MAP_FAILED) + ksft_exit_fail_msg("mmap() failed: %s\n", strerror(errno)); + + /* fork() a child and test if the child can access the page. */ + ret = fork(); + if (ret < 0) { + ksft_test_result_fail("fork()\n"); + goto out; + } else if (!ret) { + ret = sigsetjmp(env, 1); + if (!ret) { + tmp = *addr; + asm volatile("" : "+r" (tmp)); + } + /* Return the result to the parent. */ + exit(ret); + } + ksft_test_result_pass("fork()\n"); + + /* Wait for our child and obtain the result. */ + wait(&ret); + if (WIFEXITED(ret)) + ret = WEXITSTATUS(ret); + else + ret = -EINVAL; + + ksft_test_result(!ret, "SIGSEGV in child not expected\n"); +out: + munmap(addr, pagesize); +} + +int main(int argc, char **argv) +{ + int err; + + ksft_print_header(); + ksft_set_plan(19); + + pagesize = getpagesize(); + pagemap_fd = open("/proc/self/pagemap", O_RDONLY); + if (pagemap_fd < 0) + ksft_exit_fail_msg("opening pagemap failed\n"); + if (signal(SIGSEGV, signal_handler) == SIG_ERR) + ksft_exit_fail_msg("signal() failed: %s\n", strerror(errno)); + + sense_support(); + test_madvise(); + test_munmap_splitting(); + test_mremap_fixed(); + test_mremap_shrinking(); + test_mremap_growing(); + test_mprotect(); + test_fork(); + + err = ksft_get_fail_cnt(); + if (err) + ksft_exit_fail_msg("%d out of %d tests failed\n", + err, ksft_test_num()); + ksft_exit_pass(); +} -- 2.49.0

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