August 2025 - Linux-kselftest-mirror

[PATCH 0/8] riscv: add initial support for hardware breakpoints

by Jesse Taube

This patchset adds initial support for hardware breakpoints and watchpoints to the RISC-V architecture. The framework is built on top of perf subsystem and SBI debug trigger extension. Currently following features are not supported and are in works: - icount for single stepping - Virtualization of debug triggers - kernel space debug triggers The SBI debug trigger extension can be found at: https://github.com/riscv-non-isa/riscv-sbi-doc/blob/master/src/ext-debug-tr… The Sdtrig ISA is part of RISC-V debug specification which can be found at: https://github.com/riscv/riscv-debug-spec based off the original RFC by Himanshu Chauhan here: https://lore.kernel.org/lkml/20240222125059.13331-1-hchauhan@ventanamicro.c… Second RFC by Jesse Taube here: https://lore.kernel.org/lkml/20250722173829.984082-1-jesse@rivosinc.com/ Himanshu Chauhan (2): riscv: Add SBI debug trigger extension and function ids riscv: Introduce support for hardware break/watchpoints Jesse Taube (6): riscv: Add insn.c, consolidate instruction decoding riscv: insn: Add get_insn_nofault riscv: hw_breakpoint: Use icount for single stepping riscv: ptrace: Add hw breakpoint support riscv: ptrace: Add hw breakpoint regset selftests: riscv: Add test for hardware breakpoints arch/riscv/Kconfig | 13 + arch/riscv/include/asm/bug.h | 12 - arch/riscv/include/asm/hw_breakpoint.h | 59 ++ arch/riscv/include/asm/insn.h | 132 ++- arch/riscv/include/asm/kdebug.h | 3 +- arch/riscv/include/asm/processor.h | 4 + arch/riscv/include/asm/sbi.h | 33 +- arch/riscv/include/uapi/asm/ptrace.h | 9 + arch/riscv/kernel/Makefile | 2 + arch/riscv/kernel/hw_breakpoint.c | 769 ++++++++++++++++++ arch/riscv/kernel/insn.c | 165 ++++ arch/riscv/kernel/kgdb.c | 102 +-- arch/riscv/kernel/probes/kprobes.c | 1 + arch/riscv/kernel/process.c | 4 + arch/riscv/kernel/ptrace.c | 169 ++++ arch/riscv/kernel/traps.c | 11 +- arch/riscv/kernel/traps_misaligned.c | 93 +-- include/uapi/linux/elf.h | 2 + tools/include/uapi/linux/elf.h | 1 + tools/perf/tests/tests.h | 3 +- tools/testing/selftests/riscv/Makefile | 2 +- .../selftests/riscv/breakpoints/.gitignore | 1 + .../selftests/riscv/breakpoints/Makefile | 12 + .../riscv/breakpoints/breakpoint_test.c | 246 ++++++ 24 files changed, 1657 insertions(+), 191 deletions(-) create mode 100644 arch/riscv/include/asm/hw_breakpoint.h create mode 100644 arch/riscv/kernel/hw_breakpoint.c create mode 100644 arch/riscv/kernel/insn.c create mode 100644 tools/testing/selftests/riscv/breakpoints/.gitignore create mode 100644 tools/testing/selftests/riscv/breakpoints/Makefile create mode 100644 tools/testing/selftests/riscv/breakpoints/breakpoint_test.c -- 2.43.0

2 months, 4 weeks

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[PATCH v7 0/2] libbpf: fix USDT SIB argument handling causing unrecognized register error

by Jiawei Zhao

When using GCC on x86-64 to compile an usdt prog with -O1 or higher optimization, the compiler will generate SIB addressing mode for global array and PC-relative addressing mode for global variable, e.g. "1@-96(%rbp,%rax,8)" and "-1@4+t1(%rip)". The current USDT implementation in libbpf cannot parse these two formats, causing `bpf_program__attach_usdt()` to fail with -ENOENT (unrecognized register). This patch series adds support for SIB addressing mode in USDT probes. The main changes include: - add correct handling logic for SIB-addressed arguments in `parse_usdt_arg`. - add an usdt_o2 test case to cover SIB addressing mode. Testing shows that the SIB probe correctly generates 8@(%rcx,%rax,8) argument spec and passes all validation checks. The modification history of this patch series: Change since v1: - refactor the code to make it more readable - modify the commit message to explain why and how Change since v2: - fix the `scale` uninitialized error Change since v3: - force -O2 optimization for usdt.test.o to generate SIB addressing usdt and pass all test cases. Change since v4: - split the patch into two parts, one for the fix and the other for the test Change since v5: - Only enable optimization for x86 architecture to generate SIB addressing usdt argument spec. Change since v6: - Add an usdt_o2 test case to cover SIB addressing mode. - Reinstate the usdt.c test case. Do we need to add support for PC-relative USDT argument spec handling in libbpf? I have some interest in this question, but currently have no ideas. Getting offsets based on symbols requires dependency on the symbol table. However, once the binary file is stripped, the symtab will also be removed, which will cause this approach to fail. Does anyone have any thoughts on this? Jiawei Zhao (2): libbpf: fix USDT SIB argument handling causing unrecognized register error selftests/bpf: Force -O2 for USDT selftests to cover SIB handling logic tools/lib/bpf/usdt.bpf.h | 33 ++++++++- tools/lib/bpf/usdt.c | 43 +++++++++-- tools/testing/selftests/bpf/Makefile | 8 +++ .../selftests/bpf/prog_tests/usdt_o2.c | 71 +++++++++++++++++++ .../selftests/bpf/progs/test_usdt_o2.c | 37 ++++++++++ 5 files changed, 185 insertions(+), 7 deletions(-) create mode 100644 tools/testing/selftests/bpf/prog_tests/usdt_o2.c create mode 100644 tools/testing/selftests/bpf/progs/test_usdt_o2.c -- 2.43.0

2 months, 4 weeks

5
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[PATCH bpf-next v12 0/2] libbpf: fix USDT SIB argument handling causing unrecognized register error

by Jiawei Zhao

When using GCC on x86-64 to compile an usdt prog with -O1 or higher optimization, the compiler will generate SIB addressing mode for global array and PC-relative addressing mode for global variable, e.g. "1@-96(%rbp,%rax,8)" and "-1@4+t1(%rip)". The current USDT implementation in libbpf cannot parse these two formats, causing `bpf_program__attach_usdt()` to fail with -ENOENT (unrecognized register). This patch series adds support for SIB addressing mode in USDT probes. The main changes include: - add correct handling logic for SIB-addressed arguments in `parse_usdt_arg`. - add an usdt_o2 test case to cover SIB addressing mode. Testing shows that the SIB probe correctly generates 8@(%rcx,%rax,8) argument spec and passes all validation checks. The modification history of this patch series: Change since v1: - refactor the code to make it more readable - modify the commit message to explain why and how Change since v2: - fix the `scale` uninitialized error Change since v3: - force -O2 optimization for usdt.test.o to generate SIB addressing usdt and pass all test cases. Change since v4: - split the patch into two parts, one for the fix and the other for the test Change since v5: - Only enable optimization for x86 architecture to generate SIB addressing usdt argument spec. Change since v6: - Add an usdt_o2 test case to cover SIB addressing mode. - Reinstate the usdt.c test case. Change since v7: - Refactor modifications to __bpf_usdt_arg_spec to avoid increasing its size, achieving better compatibility - Fix some minor code style issues - Refactor the usdt_o2 test case, removing semaphore and adding GCC attribute to force -O2 optimization Change since v8: - Refactor the usdt_o2 test case, using assembly to force SIB addressing mode. Change since v9: - Only enable the usdt_o2 test case on x86_64 and i386 architectures since the SIB addressing mode is only supported on x86_64 and i386. Change since v10: - Replace `__attribute__((optimize("O2")))` with `#pragma GCC optimize("O1")` to fix the issue where the optimized compilation condition works improperly. - Renamed test case usdt_o2 and relevant files name to usdt_o1 in that O1 level optimization is enough to generate SIB addressing usdt argument spec. Change since v11: - Replace `STAP_PROBE1` with `STAP_PROBE_ASM` - Use bit fields instead of bit shifting operations - Merge the usdt_o1 test case into the usdt test case Jiawei Zhao (2): libbpf: fix USDT SIB argument handling causing unrecognized register error selftests/bpf: Enrich subtest_basic_usdt case in selftests to cover SIB handling logic tools/lib/bpf/usdt.bpf.h | 47 ++++++++++++++- tools/lib/bpf/usdt.c | 58 +++++++++++++++++-- tools/testing/selftests/bpf/prog_tests/usdt.c | 44 +++++++++++++- tools/testing/selftests/bpf/progs/test_usdt.c | 30 ++++++++++ 4 files changed, 170 insertions(+), 9 deletions(-) -- 2.43.0

2 months, 4 weeks

3
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[PATCH] selftests: centralise maybe-unused definition in kselftest.h

by Bala-Vignesh-Reddy

Several selftests subdirectories duplicated the define __maybe_unused, leading to redundant code. Moved to kselftest.h header and removed other definition. This addresses the duplication noted in the proc-pid-vm warning fix Suggested-by: Andrew Morton <akpm(a)linux-foundation.org> Link:https://lore.kernel.org/lkml/20250820143954.33d95635e504e94df01930d0@l… Signed-off-by: Bala-Vignesh-Reddy <reddybalavignesh9979(a)gmail.com> --- tools/testing/selftests/kselftest.h | 4 ++++ tools/testing/selftests/landlock/audit.h | 6 ++---- tools/testing/selftests/landlock/common.h | 4 ---- tools/testing/selftests/mm/pkey-helpers.h | 3 --- tools/testing/selftests/net/psock_lib.h | 4 ---- tools/testing/selftests/perf_events/watermark_signal.c | 2 -- tools/testing/selftests/proc/proc-pid-vm.c | 4 ---- tools/testing/selftests/ublk/utils.h | 2 -- 8 files changed, 6 insertions(+), 23 deletions(-) diff --git a/tools/testing/selftests/kselftest.h b/tools/testing/selftests/kselftest.h index c3b6d2604b1e..661d31c4b558 100644 --- a/tools/testing/selftests/kselftest.h +++ b/tools/testing/selftests/kselftest.h @@ -92,6 +92,10 @@ #endif #define __printf(a, b) __attribute__((format(printf, a, b))) +#ifndef __maybe_unused +#define __maybe_unused __attribute__((__unused__)) +#endif + /* counters */ struct ksft_count { unsigned int ksft_pass; diff --git a/tools/testing/selftests/landlock/audit.h b/tools/testing/selftests/landlock/audit.h index b16986aa6442..02fd1393947a 100644 --- a/tools/testing/selftests/landlock/audit.h +++ b/tools/testing/selftests/landlock/audit.h @@ -20,14 +20,12 @@ #include <sys/time.h> #include <unistd.h> +#include "../kselftest.h" + #ifndef ARRAY_SIZE #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0])) #endif -#ifndef __maybe_unused -#define __maybe_unused __attribute__((__unused__)) -#endif - #define REGEX_LANDLOCK_PREFIX "^audit([0-9.:]\\+): domain=\$[0-9a-f]\\+\$" struct audit_filter { diff --git a/tools/testing/selftests/landlock/common.h b/tools/testing/selftests/landlock/common.h index 88a3c78f5d98..9acecae36f51 100644 --- a/tools/testing/selftests/landlock/common.h +++ b/tools/testing/selftests/landlock/common.h @@ -22,10 +22,6 @@ #define TMP_DIR "tmp" -#ifndef __maybe_unused -#define __maybe_unused __attribute__((__unused__)) -#endif - /* TEST_F_FORK() should not be used for new tests. */ #define TEST_F_FORK(fixture_name, test_name) TEST_F(fixture_name, test_name) diff --git a/tools/testing/selftests/mm/pkey-helpers.h b/tools/testing/selftests/mm/pkey-helpers.h index ea404f80e6cb..fa15f006fa68 100644 --- a/tools/testing/selftests/mm/pkey-helpers.h +++ b/tools/testing/selftests/mm/pkey-helpers.h @@ -84,9 +84,6 @@ extern void abort_hooks(void); #ifndef noinline # define noinline __attribute__((noinline)) #endif -#ifndef __maybe_unused -# define __maybe_unused __attribute__((__unused__)) -#endif int sys_pkey_alloc(unsigned long flags, unsigned long init_val); int sys_pkey_free(unsigned long pkey); diff --git a/tools/testing/selftests/net/psock_lib.h b/tools/testing/selftests/net/psock_lib.h index 6e4fef560873..067265b0a554 100644 --- a/tools/testing/selftests/net/psock_lib.h +++ b/tools/testing/selftests/net/psock_lib.h @@ -22,10 +22,6 @@ #define PORT_BASE 8000 -#ifndef __maybe_unused -# define __maybe_unused __attribute__ ((__unused__)) -#endif - static __maybe_unused void pair_udp_setfilter(int fd) { /* the filter below checks for all of the following conditions that diff --git a/tools/testing/selftests/perf_events/watermark_signal.c b/tools/testing/selftests/perf_events/watermark_signal.c index e03fe1b9bba2..b3a72f0ac522 100644 --- a/tools/testing/selftests/perf_events/watermark_signal.c +++ b/tools/testing/selftests/perf_events/watermark_signal.c @@ -17,8 +17,6 @@ #include "../kselftest_harness.h" -#define __maybe_unused __attribute__((__unused__)) - static int sigio_count; static void handle_sigio(int signum __maybe_unused, diff --git a/tools/testing/selftests/proc/proc-pid-vm.c b/tools/testing/selftests/proc/proc-pid-vm.c index 978cbcb3eb11..2a72d37ad008 100644 --- a/tools/testing/selftests/proc/proc-pid-vm.c +++ b/tools/testing/selftests/proc/proc-pid-vm.c @@ -47,10 +47,6 @@ #include <sys/resource.h> #include <linux/fs.h> -#ifndef __maybe_unused -#define __maybe_unused __attribute__((__unused__)) -#endif - #include "../kselftest.h" static inline long sys_execveat(int dirfd, const char *pathname, char **argv, char **envp, int flags) diff --git a/tools/testing/selftests/ublk/utils.h b/tools/testing/selftests/ublk/utils.h index 36545d1567f1..a852e0b7153e 100644 --- a/tools/testing/selftests/ublk/utils.h +++ b/tools/testing/selftests/ublk/utils.h @@ -2,8 +2,6 @@ #ifndef KUBLK_UTILS_H #define KUBLK_UTILS_H -#define __maybe_unused __attribute__((unused)) - #ifndef min #define min(a, b) ((a) < (b) ? (a) : (b)) #endif -- 2.43.0

2 months, 4 weeks

5
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[PATCH net-next 0/3] selftests: Test XDP_TX for single-buffer

by Dimitri Daskalakis

Ensure single buffer XDP functions correctly by covering the following cases: 1) Zero size payload 2) Full MTU 3) Single buffer packets through a multi-buffer XDP program These changes were tested with netdevsim and fbnic. # ./ksft-net-drv/drivers/net/xdp.py TAP version 13 1..10 ok 1 xdp.test_xdp_native_pass_sb ok 2 xdp.test_xdp_native_pass_mb ok 3 xdp.test_xdp_native_drop_sb ok 4 xdp.test_xdp_native_drop_mb ok 5 xdp.test_xdp_native_tx_sb ok 6 xdp.test_xdp_native_tx_mb # Failed run: pkt_sz 2048, offset 1. Last successful run: pkt_sz 1024, offset 256. Reason: Adjustment failed ok 7 xdp.test_xdp_native_adjst_tail_grow_data ok 8 xdp.test_xdp_native_adjst_tail_shrnk_data # Failed run: pkt_sz 512, offset -256. Last successful run: pkt_sz 512, offset -128. Reason: Adjustment failed ok 9 xdp.test_xdp_native_adjst_head_grow_data # Failed run: pkt_sz (2048) > HDS threshold (1536) and offset 64 > 48 ok 10 xdp.test_xdp_native_adjst_head_shrnk_data # Totals: pass:10 fail:0 xfail:0 xpass:0 skip:0 error:0 Dimitri Daskalakis (3): selftests: drv-net: xdp: Extract common XDP_TX setup/validation. selftests: drv-net: xdp: Add a single-buffer XDP_TX test. selftests: drv-net: xdp: Validate single-buff XDP_TX in multi-buff mode tools/testing/selftests/drivers/net/xdp.py | 71 ++++++++++++++++++---- 1 file changed, 58 insertions(+), 13 deletions(-) -- 2.47.3

2 months, 4 weeks

2
4
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[PATCH v2] kselftests: netfilter: fix spelling mistakes in nft_nat.sh

by Debanil Chowdhury

Changed a typo in an error message in nft_nat.sh : "cannnot" → "cannot". Signed-off-by: Debanil Chowdhury <kerneldev(a)debanilchowdhury.com> --- Changes in v2: - Added commit message tools/testing/selftests/net/netfilter/nft_nat.sh | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/net/netfilter/nft_nat.sh b/tools/testing/selftests/net/netfilter/nft_nat.sh index a954754b9..05a34c135 100755 --- a/tools/testing/selftests/net/netfilter/nft_nat.sh +++ b/tools/testing/selftests/net/netfilter/nft_nat.sh @@ -569,7 +569,7 @@ test_redirect6() ip netns exec "$ns0" sysctl net.ipv6.conf.all.forwarding=1 > /dev/null if ! ip netns exec "$ns2" ping -q -c 1 dead:1::99 > /dev/null;then - echo "ERROR: cannnot ping $ns1 from $ns2 via ipv6" + echo "ERROR: cannot ping $ns1 from $ns2 via ipv6" lret=1 fi -- 2.49.1

2 months, 4 weeks

1
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[PATCH v2] kselftests: ntb: fix spelling mistakes in ntb_test.sh

by Debanil Chowdhury

Changed a typo in the help text in ntb_test.sh: "maxmium" → "maximum". Signed-off-by: Debanil Chowdhury <kerneldev(a)debanilchowdhury.com> --- Changes in v2: - Added commit message (suggested by Greg KH) tools/testing/selftests/ntb/ntb_test.sh | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/ntb/ntb_test.sh b/tools/testing/selftests/ntb/ntb_test.sh index 020137b61..41ad97e34 100755 --- a/tools/testing/selftests/ntb/ntb_test.sh +++ b/tools/testing/selftests/ntb/ntb_test.sh @@ -39,7 +39,7 @@ function show_help() echo " -d run dma tests for ntb_perf" echo " -p ORDER total data order for ntb_perf" echo " (default: $PERF_RUN_ORDER)" - echo " -w MAX_MW_SIZE maxmium memory window size for ntb_perf" + echo " -w MAX_MW_SIZE maximum memory window size for ntb_perf" echo } -- 2.49.1

2 months, 4 weeks

1
0
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[PATCH] selftests/alsa: remove 0/NULL global variable assignment

by Nikola Z. Ivanov

Remove 0/NULL global variable assignment in mixer-test.c and pcm-test.c Signed-off-by: Nikola Z. Ivanov <zlatistiv(a)gmail.com> --- tools/testing/selftests/alsa/mixer-test.c | 8 ++++---- tools/testing/selftests/alsa/pcm-test.c | 8 ++++---- 2 files changed, 8 insertions(+), 8 deletions(-) diff --git a/tools/testing/selftests/alsa/mixer-test.c b/tools/testing/selftests/alsa/mixer-test.c index 2a4b2662035e..e113dafa5c24 100644 --- a/tools/testing/selftests/alsa/mixer-test.c +++ b/tools/testing/selftests/alsa/mixer-test.c @@ -53,10 +53,10 @@ struct ctl_data { struct ctl_data *next; }; -int num_cards = 0; -int num_controls = 0; -struct card_data *card_list = NULL; -struct ctl_data *ctl_list = NULL; +int num_cards; +int num_controls; +struct card_data *card_list; +struct ctl_data *ctl_list; static void find_controls(void) { diff --git a/tools/testing/selftests/alsa/pcm-test.c b/tools/testing/selftests/alsa/pcm-test.c index dbd7c222ce93..ce92548670c8 100644 --- a/tools/testing/selftests/alsa/pcm-test.c +++ b/tools/testing/selftests/alsa/pcm-test.c @@ -30,7 +30,7 @@ struct card_data { struct card_data *next; }; -struct card_data *card_list = NULL; +struct card_data *card_list; struct pcm_data { snd_pcm_t *handle; @@ -43,10 +43,10 @@ struct pcm_data { struct pcm_data *next; }; -struct pcm_data *pcm_list = NULL; +struct pcm_data *pcm_list; -int num_missing = 0; -struct pcm_data *pcm_missing = NULL; +int num_missing; +struct pcm_data *pcm_missing; snd_config_t *default_pcm_config; -- 2.50.1

2 months, 4 weeks

4
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[PATCH v2 0/8] selftests/mm: Add compiler flags and fix found warnings

by Muhammad Usama Anjum

Recently, I reviewed a patch on the mm/kselftest mailing list about a test which had obvious type mismatch fix in it. It was strange why that wasn't caught during development and when patch was accepted. This led me to discover that those extra compiler options to catch these warnings aren't being used. When I added them, I found tens of warnings in just mm suite. In this series, I'm adding these flags and fixing those warnings. In the last try several months ago [1], I'd patches for individual tests. I've made patches better by grouping the same type of fixes together. Hence there is no changelog for individual patches. The changes have been build tested on x86_64, arm64, powerpc64 and partially on riscv64. The test run with and without this series has been done on x86_64. --- Changes since v1: - Drop test harness patch which isn't needed anymore - Revamp how patches are written per same kind of failure Muhammad Usama Anjum (8): selftests/mm: Add -Wunreachable-code and fix warnings selftests/mm: protection_keys: Fix dead code selftests: kselftest.h: Add __unused macro selftests/mm: Add -Wunused family of flags selftests/mm: Remove unused parameters selftests/mm: Mark unused arguments with __unused selftests/mm: Mark unused arguments with __unused selftests/mm: Fix unused parameter warnings for different architectures tools/testing/selftests/kselftest.h | 4 ++ tools/testing/selftests/mm/Makefile | 3 +- tools/testing/selftests/mm/compaction_test.c | 2 +- tools/testing/selftests/mm/cow.c | 22 +++++------ tools/testing/selftests/mm/droppable.c | 2 +- tools/testing/selftests/mm/gup_longterm.c | 2 +- tools/testing/selftests/mm/hmm-tests.c | 5 +-- tools/testing/selftests/mm/hugepage-vmemmap.c | 2 +- tools/testing/selftests/mm/hugetlb-madvise.c | 2 +- .../selftests/mm/hugetlb-soft-offline.c | 2 +- .../selftests/mm/hugetlb_fault_after_madv.c | 4 +- .../selftests/mm/hugetlb_madv_vs_map.c | 6 +-- tools/testing/selftests/mm/ksm_tests.c | 17 ++++----- tools/testing/selftests/mm/madv_populate.c | 2 +- tools/testing/selftests/mm/map_populate.c | 2 +- tools/testing/selftests/mm/memfd_secret.c | 6 +-- .../testing/selftests/mm/mlock-random-test.c | 2 +- tools/testing/selftests/mm/mlock2-tests.c | 2 +- tools/testing/selftests/mm/mseal_test.c | 8 +++- tools/testing/selftests/mm/on-fault-limit.c | 2 +- tools/testing/selftests/mm/pfnmap.c | 2 +- tools/testing/selftests/mm/pkey-arm64.h | 5 ++- tools/testing/selftests/mm/pkey-powerpc.h | 2 +- tools/testing/selftests/mm/pkey-x86.h | 3 +- .../selftests/mm/pkey_sighandler_tests.c | 35 ++++++++++++----- tools/testing/selftests/mm/protection_keys.c | 22 +++++------ tools/testing/selftests/mm/soft-dirty.c | 6 +-- .../selftests/mm/split_huge_page_test.c | 8 ++-- tools/testing/selftests/mm/uffd-common.c | 15 ++++---- tools/testing/selftests/mm/uffd-common.h | 2 +- tools/testing/selftests/mm/uffd-stress.c | 2 +- tools/testing/selftests/mm/uffd-unit-tests.c | 38 +++++++++---------- tools/testing/selftests/mm/uffd-wp-mremap.c | 2 +- .../selftests/mm/virtual_address_range.c | 2 +- 34 files changed, 130 insertions(+), 111 deletions(-) -- 2.39.5

2 months, 4 weeks

5
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[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. For more background on the motivation and design of this series, please see the RFC: https://lore.kernel.org/kvm/20250523233018.1702151-1-dmatlack@google.com/ This series can also be found on GitHub: https://github.com/dmatlack/linux/tree/vfio/selftests/v1 Changelog ----------------------------------------------------------------------- RFC: https://lore.kernel.org/kvm/20250523233018.1702151-1-dmatlack@google.com/ - Add symlink to linux/pci_ids.h instead of copying (Jason) - Add symlinks to drivers/dma/*/*.h instead of copying (Jason) - Automatically replicate vfio_dma_mapping_test across backing sources using fixture variants (Jason) - Automatically replicate vfio_dma_mapping_test and vfio_pci_driver_test across all iommu_modes using fixture variants (Jason) - Invert access() check in vfio_dma_mapping_test (me) - Use driver_override instead of add/remove_id (Alex) - Allow tests to get BDF from env var (Alex) - Use KSFT_FAIL instead of 1 to exit with failure (Alex) - Unconditionally create $(LIBVFIO_O_DIRS) to avoid target conflict with ../cgroup/lib/libcgroup.mk when building KVM selftests (me) - Allow VFIO selftests to run automatically by switching from TEST_GEN_PROGS_EXTENDED to TEST_GEN_PROGS. Automatically run selftests will use $VFIO_SELFTESTS_BDF environment variable to know which device to use (Alex) - Replace hardcoded SZ_4K with getpagesize() in vfio_dma_mapping_test to support platforms with other page sizes (me) - Make all global variables static where possible (me) - Pass argc and argv to test_harness_main() so that users can pass flags to the kselftest harness (me) Instructions ----------------------------------------------------------------------- Running VFIO selftests requires at a PCI device bound to vfio-pci for the tests to use. The address of this device is passed to the test as a segment:bus:device.function string, which must match the path to the device in /sys/bus/pci/devices/ (e.g. 0000:00:04.0). Once you have chosen a device, there is a helper script provided to unbind the device from its current driver, bind it to vfio-pci, export the environment variable $VFIO_SELFTESTS_BDF, and launch a shell: $ tools/testing/selftests/vfio/run.sh -d 0000:00:04.0 -s The -d option tells the script which device to use and the -s option tells the script to launch a shell. Additionally, the VFIO selftest vfio_dma_mapping_test has test cases that rely on HugeTLB pages being available, otherwise they are skipped. To enable those tests make sure at least 1 2MB and 1 1GB HugeTLB pages are available. $ echo 1 > /sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages $ echo 1 > /sys/kernel/mm/hugepages/hugepages-1048576kB/nr_hugepages To run all VFIO selftests using make: $ make -C tools/testing/selftests/vfio run_tests To run individual tests: $ tools/testing/selftests/vfio/vfio_dma_mapping_test $ tools/testing/selftests/vfio/vfio_dma_mapping_test -v iommufd_anonymous_hugetlb_2mb $ tools/testing/selftests/vfio/vfio_dma_mapping_test -r vfio_dma_mapping_test.iommufd_anonymous_hugetlb_2mb.dma_map_unmap The environment variable $VFIO_SELFTESTS_BDF can be overridden for a specific test by passing in the BDF on the command line as the last positional argument. $ tools/testing/selftests/vfio/vfio_dma_mapping_test 0000:00:04.0 $ tools/testing/selftests/vfio/vfio_dma_mapping_test -v iommufd_anonymous_hugetlb_2mb 0000:00:04.0 $ tools/testing/selftests/vfio/vfio_dma_mapping_test -r vfio_dma_mapping_test.iommufd_anonymous_hugetlb_2mb.dma_map_unmap 0000:00:04.0 When you are done, free the HugeTLB pages and exit the shell started by run.sh. Exiting the shell will cause the device to be unbound from vfio-pci and bound back to its original driver. $ echo 0 > /sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages $ echo 0 > /sys/kernel/mm/hugepages/hugepages-1048576kB/nr_hugepages $ exit It's also possible to use run.sh to run just a single test hermetically, rather than dropping into a shell: $ tools/testing/selftests/vfio/run.sh -d 0000:00:04.0 -- tools/testing/selftests/vfio/vfio_dma_mapping_test -v iommufd_anonymous 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 Future Areas of Development ----------------------------------------------------------------------- Library: - Driver support for devices that can be used on AMD, ARM, and other platforms (e.g. mlx5). - Driver support for a device available in QEMU VMs (e.g. pcie-ats-testdev [1]) - 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. - Porting tests from https://github.com/awilliam/tests/commits/for-clg/ to selftests. - Live Update selftests. - Porting Sean's KVM selftest for posted interrupts to use the VFIO selftests library [2] 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: Aaron Lewis <aaronlewis(a)google.com> Cc: Pasha Tatashin <pasha.tatashin(a)soleen.com> Cc: Saeed Mahameed <saeedm(a)nvidia.com> Cc: Adithya Jayachandran <ajayachandra(a)nvidia.com> Cc: Joel Granados <joel.granados(a)kernel.org> [1] https://github.com/Joelgranados/qemu/blob/pcie-testdev/hw/misc/pcie-ats-tes… [2] 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: Add symlink to 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 dmaengine: ioat: Move system_has_dca_enabled() to dma.h vfio: selftests: Add driver for Intel CBDMA dmaengine: idxd: Allow registers.h to be included from tools/ vfio: selftests: Add driver for Intel DSA vfio: selftests: Move helper to get cdev path to libvfio vfio: selftests: Encapsulate IOMMU mode vfio: selftests: Replicate tests across all iommu_modes 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: Add -d option to vfio_pci_device_irq_test for device-sent MSIs 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: Add DMA mapping tests for 2M and 1G HugeTLB vfio: selftests: Validate 2M/1G HugeTLB are mapped as 2M/1G in IOMMU MAINTAINERS | 7 + drivers/dma/idxd/registers.h | 4 + drivers/dma/ioat/dma.h | 2 + drivers/dma/ioat/hw.h | 3 - 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/linux/compiler.h | 4 + tools/include/linux/io.h | 4 +- tools/include/linux/pci_ids.h | 1 + tools/testing/selftests/Makefile | 1 + tools/testing/selftests/kvm/Makefile.kvm | 4 + .../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 | 172 +++++ tools/testing/selftests/vfio/.gitignore | 7 + tools/testing/selftests/vfio/Makefile | 21 + .../selftests/vfio/lib/drivers/dsa/dsa.c | 416 ++++++++++++ .../vfio/lib/drivers/dsa/registers.h | 1 + .../selftests/vfio/lib/drivers/ioat/hw.h | 1 + .../selftests/vfio/lib/drivers/ioat/ioat.c | 235 +++++++ .../vfio/lib/drivers/ioat/registers.h | 1 + .../selftests/vfio/lib/include/vfio_util.h | 295 +++++++++ tools/testing/selftests/vfio/lib/libvfio.mk | 24 + .../selftests/vfio/lib/vfio_pci_device.c | 594 ++++++++++++++++++ .../selftests/vfio/lib/vfio_pci_driver.c | 126 ++++ tools/testing/selftests/vfio/run.sh | 109 ++++ .../selftests/vfio/vfio_dma_mapping_test.c | 199 ++++++ .../selftests/vfio/vfio_iommufd_setup_test.c | 127 ++++ .../selftests/vfio/vfio_pci_device_test.c | 176 ++++++ .../selftests/vfio/vfio_pci_driver_test.c | 247 ++++++++ 32 files changed, 3423 insertions(+), 4 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 120000 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/dsa.c create mode 120000 tools/testing/selftests/vfio/lib/drivers/dsa/registers.h create mode 120000 tools/testing/selftests/vfio/lib/drivers/ioat/hw.h create mode 100644 tools/testing/selftests/vfio/lib/drivers/ioat/ioat.c create mode 120000 tools/testing/selftests/vfio/lib/drivers/ioat/registers.h 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: e271ed52b344ac02d4581286961d0c40acc54c03 prerequisite-patch-id: c1decca4653262d3d2451e6fd4422ebff9c0b589 -- 2.50.0.rc2.701.gf1e915cc24-goog

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