July 2025 - Linux-kselftest-mirror

[PATCH v3 0/4] kselftest/arm64: Add coverage for the interaction of vfork() and GCS

by Mark Brown

I had cause to look at the vfork() support for GCS and realised that we don't have any direct test coverage, this series does so by adding vfork() to nolibc and then using that in basic-gcs to provide some simple vfork() coverage. Signed-off-by: Mark Brown <broonie(a)kernel.org> --- Changes in v3: - Stylistic nits in the GCS vfork() test. - SPARC has a non-standard vfork() ABI which needs handling. - Link to v2: https://lore.kernel.org/r/20250610-arm64-gcs-vfork-exit-v2-0-929443dfcf82@k… Changes in v2: - Add replacement of ifdef with if defined() in nolibc since the code doesn't reflect the coding style. - Remove check for arch specific vfork(). - Link to v1: https://lore.kernel.org/r/20250609-arm64-gcs-vfork-exit-v1-0-baad0f085747@k… --- Mark Brown (4): tools/nolibc: Replace ifdef with if defined() in sys.h tools/nolibc: Provide vfork() kselftest/arm64: Add a test for vfork() with GCS selftests/nolibc: Add coverage of vfork() tools/include/nolibc/arch-sparc.h | 16 +++++++ tools/include/nolibc/sys.h | 59 ++++++++++++++++++------- tools/testing/selftests/arm64/gcs/basic-gcs.c | 63 +++++++++++++++++++++++++++ tools/testing/selftests/nolibc/nolibc-test.c | 23 ++++++++-- 4 files changed, 142 insertions(+), 19 deletions(-) --- base-commit: 86731a2a651e58953fc949573895f2fa6d456841 change-id: 20250528-arm64-gcs-vfork-exit-4a7daf7652ee Best regards, -- Mark Brown <broonie(a)kernel.org>

2 weeks, 4 days

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[kvm-unit-tests PATCH] riscv: Use norvc over arch, -c

by Jesse Taube

The Linux kernel main tree uses "norvc" over "arch, -c" change to match this. GCC 15 started to add _zca_zcd to the assembler flags causing a bug which made "arch, -c" generate a compressed instruction. Link: https://sourceware.org/bugzilla/show_bug.cgi?id=33128 Cc: Clément Léger <cleger(a)rivosinc.com> Signed-off-by: Jesse Taube <jesse(a)rivosinc.com> --- riscv/isa-dbltrp.c | 2 +- riscv/sbi-dbtr.c | 2 +- riscv/sbi-fwft.c | 2 +- 3 files changed, 3 insertions(+), 3 deletions(-) diff --git a/riscv/isa-dbltrp.c b/riscv/isa-dbltrp.c index b7e21589..af12860c 100644 --- a/riscv/isa-dbltrp.c +++ b/riscv/isa-dbltrp.c @@ -26,7 +26,7 @@ do { \ unsigned long value = 0; \ asm volatile( \ " .option push\n" \ - " .option arch,-c\n" \ + " .option norvc\n" \ " sw %0, 0(%1)\n" \ " .option pop\n" \ : : "r" (value), "r" (ptr) : "memory"); \ diff --git a/riscv/sbi-dbtr.c b/riscv/sbi-dbtr.c index c4ccd81d..129f79b8 100644 --- a/riscv/sbi-dbtr.c +++ b/riscv/sbi-dbtr.c @@ -134,7 +134,7 @@ static __attribute__((naked)) void exec_call(void) { /* skip over nop when triggered instead of ret. */ asm volatile (".option push\n" - ".option arch, -c\n" + ".option norvc\n" "nop\n" "ret\n" ".option pop\n"); diff --git a/riscv/sbi-fwft.c b/riscv/sbi-fwft.c index 8920bcb5..fda7eb52 100644 --- a/riscv/sbi-fwft.c +++ b/riscv/sbi-fwft.c @@ -174,7 +174,7 @@ static void fwft_check_misaligned_exc_deleg(void) * Disable compression so the lw takes exactly 4 bytes and thus * can be skipped reliably from the exception handler. */ - ".option arch,-c\n" + ".option norvc\n" "lw %[val], 1(%[val_addr])\n" ".option pop\n" : [val] "+r" (ret.value) -- 2.43.0

2 weeks, 4 days

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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

2 weeks, 4 days

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[PATCH v3] selftests/futex: Convert 32bit timespec struct to 64bit version for 32bit compatibility mode

by Terry Tritton

Futex_waitv can not accept old_timespec32 struct, so userspace should convert it from 32bit to 64bit before syscall in 32bit compatible mode. This fix is based off [1] Link: https://lore.kernel.org/all/20231203235117.29677-1-wegao@suse.com/ [1] Originally-by: Wei Gao <wegao(a)suse.com> Signed-off-by: Terry Tritton <terry.tritton(a)linaro.org> --- Changes in v3: - Fix signed-off-by chain but for real this time Changes in v2: - Fix signed-off-by chain .../testing/selftests/futex/include/futex2test.h | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/tools/testing/selftests/futex/include/futex2test.h b/tools/testing/selftests/futex/include/futex2test.h index ea79662405bc..6780e51eb2d6 100644 --- a/tools/testing/selftests/futex/include/futex2test.h +++ b/tools/testing/selftests/futex/include/futex2test.h @@ -55,6 +55,13 @@ struct futex32_numa { futex_t numa; }; +#if !defined(__LP64__) +struct timespec64 { + int64_t tv_sec; + int64_t tv_nsec; +}; +#endif + /** * futex_waitv - Wait at multiple futexes, wake on any * @waiters: Array of waiters @@ -65,7 +72,15 @@ struct futex32_numa { static inline int futex_waitv(volatile struct futex_waitv *waiters, unsigned long nr_waiters, unsigned long flags, struct timespec *timo, clockid_t clockid) { +#if !defined(__LP64__) + struct timespec64 timo64 = {0}; + + timo64.tv_sec = timo->tv_sec; + timo64.tv_nsec = timo->tv_nsec; + return syscall(__NR_futex_waitv, waiters, nr_waiters, flags, &timo64, clockid); +#else return syscall(__NR_futex_waitv, waiters, nr_waiters, flags, timo, clockid); +#endif } /* -- 2.39.5

2 weeks, 5 days

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[PATCH] selftests: print installation complete message

by Shuah Khan

Add installation complete message to Makefile install logic. Signed-off-by: Shuah Khan <skhan(a)linuxfoundation.org> --- tools/testing/selftests/Makefile | 1 + 1 file changed, 1 insertion(+) diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile index 9dae84a74e7f..b95de208265a 100644 --- a/tools/testing/selftests/Makefile +++ b/tools/testing/selftests/Makefile @@ -300,6 +300,7 @@ ifdef INSTALL_PATH else \ printf "Unable to get version from git describe\n"; \ fi + @echo "**Kselftest Installation is complete: $(INSTALL_PATH)**" else $(error Error: set INSTALL_PATH to use install) endif -- 2.47.2

2 weeks, 5 days

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[PATCH net-next v3 7/7] selftests: net: extend SCM_PIDFD test to cover stale pidfds

by Alexander Mikhalitsyn

Extend SCM_PIDFD test scenarios to also cover dead task's pidfd retrieval and reading its exit info. Cc: linux-kselftest(a)vger.kernel.org Cc: linux-kernel(a)vger.kernel.org Cc: netdev(a)vger.kernel.org Cc: Shuah Khan <shuah(a)kernel.org> Cc: "David S. Miller" <davem(a)davemloft.net> Cc: Eric Dumazet <edumazet(a)google.com> Cc: Jakub Kicinski <kuba(a)kernel.org> Cc: Paolo Abeni <pabeni(a)redhat.com> Cc: Simon Horman <horms(a)kernel.org> Cc: Christian Brauner <brauner(a)kernel.org> Cc: Kuniyuki Iwashima <kuniyu(a)google.com> Cc: Lennart Poettering <mzxreary(a)0pointer.de> Cc: Luca Boccassi <bluca(a)debian.org> Cc: David Rheinsberg <david(a)readahead.eu> Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn(a)canonical.com> Reviewed-by: Christian Brauner <brauner(a)kernel.org> --- .../testing/selftests/net/af_unix/scm_pidfd.c | 217 ++++++++++++++---- 1 file changed, 173 insertions(+), 44 deletions(-) diff --git a/tools/testing/selftests/net/af_unix/scm_pidfd.c b/tools/testing/selftests/net/af_unix/scm_pidfd.c index 7e534594167e..37e034874034 100644 --- a/tools/testing/selftests/net/af_unix/scm_pidfd.c +++ b/tools/testing/selftests/net/af_unix/scm_pidfd.c @@ -15,6 +15,7 @@ #include <sys/types.h> #include <sys/wait.h> +#include "../../pidfd/pidfd.h" #include "../../kselftest_harness.h" #define clean_errno() (errno == 0 ? "None" : strerror(errno)) @@ -26,6 +27,8 @@ #define SCM_PIDFD 0x04 #endif +#define CHILD_EXIT_CODE_OK 123 + static void child_die() { exit(1); @@ -126,16 +129,65 @@ static pid_t get_pid_from_fdinfo_file(int pidfd, const char *key, size_t keylen) return result; } +struct cmsg_data { + struct ucred *ucred; + int *pidfd; +}; + +static int parse_cmsg(struct msghdr *msg, struct cmsg_data *res) +{ + struct cmsghdr *cmsg; + int data = 0; + + if (msg->msg_flags & (MSG_TRUNC | MSG_CTRUNC)) { + log_err("recvmsg: truncated"); + return 1; + } + + for (cmsg = CMSG_FIRSTHDR(msg); cmsg != NULL; + cmsg = CMSG_NXTHDR(msg, cmsg)) { + if (cmsg->cmsg_level == SOL_SOCKET && + cmsg->cmsg_type == SCM_PIDFD) { + if (cmsg->cmsg_len < sizeof(*res->pidfd)) { + log_err("CMSG parse: SCM_PIDFD wrong len"); + return 1; + } + + res->pidfd = (void *)CMSG_DATA(cmsg); + } + + if (cmsg->cmsg_level == SOL_SOCKET && + cmsg->cmsg_type == SCM_CREDENTIALS) { + if (cmsg->cmsg_len < sizeof(*res->ucred)) { + log_err("CMSG parse: SCM_CREDENTIALS wrong len"); + return 1; + } + + res->ucred = (void *)CMSG_DATA(cmsg); + } + } + + if (!res->pidfd) { + log_err("CMSG parse: SCM_PIDFD not found"); + return 1; + } + + if (!res->ucred) { + log_err("CMSG parse: SCM_CREDENTIALS not found"); + return 1; + } + + return 0; +} + static int cmsg_check(int fd) { struct msghdr msg = { 0 }; - struct cmsghdr *cmsg; + struct cmsg_data res; struct iovec iov; - struct ucred *ucred = NULL; int data = 0; char control[CMSG_SPACE(sizeof(struct ucred)) + CMSG_SPACE(sizeof(int))] = { 0 }; - int *pidfd = NULL; pid_t parent_pid; int err; @@ -158,53 +210,99 @@ static int cmsg_check(int fd) return 1; } - for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL; - cmsg = CMSG_NXTHDR(&msg, cmsg)) { - if (cmsg->cmsg_level == SOL_SOCKET && - cmsg->cmsg_type == SCM_PIDFD) { - if (cmsg->cmsg_len < sizeof(*pidfd)) { - log_err("CMSG parse: SCM_PIDFD wrong len"); - return 1; - } + /* send(pfd, "x", sizeof(char), 0) */ + if (data != 'x') { + log_err("recvmsg: data corruption"); + return 1; + } - pidfd = (void *)CMSG_DATA(cmsg); - } + if (parse_cmsg(&msg, &res)) { + log_err("CMSG parse: parse_cmsg() failed"); + return 1; + } - if (cmsg->cmsg_level == SOL_SOCKET && - cmsg->cmsg_type == SCM_CREDENTIALS) { - if (cmsg->cmsg_len < sizeof(*ucred)) { - log_err("CMSG parse: SCM_CREDENTIALS wrong len"); - return 1; - } + /* pidfd from SCM_PIDFD should point to the parent process PID */ + parent_pid = + get_pid_from_fdinfo_file(*res.pidfd, "Pid:", sizeof("Pid:") - 1); + if (parent_pid != getppid()) { + log_err("wrong SCM_PIDFD %d != %d", parent_pid, getppid()); + close(*res.pidfd); + return 1; + } - ucred = (void *)CMSG_DATA(cmsg); - } + close(*res.pidfd); + return 0; +} + +static int cmsg_check_dead(int fd, int expected_pid) +{ + int err; + struct msghdr msg = { 0 }; + struct cmsg_data res; + struct iovec iov; + int data = 0; + char control[CMSG_SPACE(sizeof(struct ucred)) + + CMSG_SPACE(sizeof(int))] = { 0 }; + pid_t client_pid; + struct pidfd_info info = { + .mask = PIDFD_INFO_EXIT, + }; + + iov.iov_base = &data; + iov.iov_len = sizeof(data); + + msg.msg_iov = &iov; + msg.msg_iovlen = 1; + msg.msg_control = control; + msg.msg_controllen = sizeof(control); + + err = recvmsg(fd, &msg, 0); + if (err < 0) { + log_err("recvmsg"); + return 1; } - /* send(pfd, "x", sizeof(char), 0) */ - if (data != 'x') { + if (msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC)) { + log_err("recvmsg: truncated"); + return 1; + } + + /* send(cfd, "y", sizeof(char), 0) */ + if (data != 'y') { log_err("recvmsg: data corruption"); return 1; } - if (!pidfd) { - log_err("CMSG parse: SCM_PIDFD not found"); + if (parse_cmsg(&msg, &res)) { + log_err("CMSG parse: parse_cmsg() failed"); return 1; } - if (!ucred) { - log_err("CMSG parse: SCM_CREDENTIALS not found"); + /* + * pidfd from SCM_PIDFD should point to the client_pid. + * Let's read exit information and check if it's what + * we expect to see. + */ + if (ioctl(*res.pidfd, PIDFD_GET_INFO, &info)) { + log_err("%s: ioctl(PIDFD_GET_INFO) failed", __func__); + close(*res.pidfd); return 1; } - /* pidfd from SCM_PIDFD should point to the parent process PID */ - parent_pid = - get_pid_from_fdinfo_file(*pidfd, "Pid:", sizeof("Pid:") - 1); - if (parent_pid != getppid()) { - log_err("wrong SCM_PIDFD %d != %d", parent_pid, getppid()); + if (!(info.mask & PIDFD_INFO_EXIT)) { + log_err("%s: No exit information from ioctl(PIDFD_GET_INFO)", __func__); + close(*res.pidfd); return 1; } + err = WIFEXITED(info.exit_code) ? WEXITSTATUS(info.exit_code) : 1; + if (err != CHILD_EXIT_CODE_OK) { + log_err("%s: wrong exit_code %d != %d", __func__, err, CHILD_EXIT_CODE_OK); + close(*res.pidfd); + return 1; + } + + close(*res.pidfd); return 0; } @@ -291,6 +389,24 @@ static void fill_sockaddr(struct sock_addr *addr, bool abstract) memcpy(sun_path_buf, addr->sock_name, strlen(addr->sock_name)); } +static int sk_enable_cred_pass(int sk) +{ + int on = 0; + + on = 1; + if (setsockopt(sk, SOL_SOCKET, SO_PASSCRED, &on, sizeof(on))) { + log_err("Failed to set SO_PASSCRED"); + return 1; + } + + if (setsockopt(sk, SOL_SOCKET, SO_PASSPIDFD, &on, sizeof(on))) { + log_err("Failed to set SO_PASSPIDFD"); + return 1; + } + + return 0; +} + static void client(FIXTURE_DATA(scm_pidfd) *self, const FIXTURE_VARIANT(scm_pidfd) *variant) { @@ -299,7 +415,6 @@ static void client(FIXTURE_DATA(scm_pidfd) *self, struct ucred peer_cred; int peer_pidfd; pid_t peer_pid; - int on = 0; cfd = socket(AF_UNIX, variant->type, 0); if (cfd < 0) { @@ -322,14 +437,8 @@ static void client(FIXTURE_DATA(scm_pidfd) *self, child_die(); } - on = 1; - if (setsockopt(cfd, SOL_SOCKET, SO_PASSCRED, &on, sizeof(on))) { - log_err("Failed to set SO_PASSCRED"); - child_die(); - } - - if (setsockopt(cfd, SOL_SOCKET, SO_PASSPIDFD, &on, sizeof(on))) { - log_err("Failed to set SO_PASSPIDFD"); + if (sk_enable_cred_pass(cfd)) { + log_err("sk_enable_cred_pass() failed"); child_die(); } @@ -340,6 +449,12 @@ static void client(FIXTURE_DATA(scm_pidfd) *self, child_die(); } + /* send something to the parent so it can receive SCM_PIDFD too and validate it */ + if (send(cfd, "y", sizeof(char), 0) == -1) { + log_err("Failed to send(cfd, \"y\", sizeof(char), 0)"); + child_die(); + } + /* skip further for SOCK_DGRAM as it's not applicable */ if (variant->type == SOCK_DGRAM) return; @@ -398,7 +513,13 @@ TEST_F(scm_pidfd, test) close(self->server); close(self->startup_pipe[0]); client(self, variant); - exit(0); + + /* + * It's a bit unusual, but in case of success we return non-zero + * exit code (CHILD_EXIT_CODE_OK) and then we expect to read it + * from ioctl(PIDFD_GET_INFO) in cmsg_check_dead(). + */ + exit(CHILD_EXIT_CODE_OK); } close(self->startup_pipe[1]); @@ -421,9 +542,17 @@ TEST_F(scm_pidfd, test) ASSERT_NE(-1, err); } - close(pfd); waitpid(self->client_pid, &child_status, 0); - ASSERT_EQ(0, WIFEXITED(child_status) ? WEXITSTATUS(child_status) : 1); + /* see comment before exit(CHILD_EXIT_CODE_OK) */ + ASSERT_EQ(CHILD_EXIT_CODE_OK, WIFEXITED(child_status) ? WEXITSTATUS(child_status) : 1); + + err = sk_enable_cred_pass(pfd); + ASSERT_EQ(0, err); + + err = cmsg_check_dead(pfd, self->client_pid); + ASSERT_EQ(0, err); + + close(pfd); } TEST_HARNESS_MAIN -- 2.43.0

2 weeks, 5 days

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[PATCH v2] selftests/powerpc: fix "for a while" typo

by Ahelenia Ziemiańska

Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli(a)nabijaczleweli.xyz> --- v1: https://lore.kernel.org/lkml/h2ieddqja5jfrnuh3mvlxt6njrvp352t5rfzp2cvnrufop… tools/testing/selftests/powerpc/tm/tm-tmspr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/powerpc/tm/tm-tmspr.c b/tools/testing/selftests/powerpc/tm/tm-tmspr.c index dd5ddffa28b7..0d64988ffb40 100644 --- a/tools/testing/selftests/powerpc/tm/tm-tmspr.c +++ b/tools/testing/selftests/powerpc/tm/tm-tmspr.c @@ -14,7 +14,7 @@ * (1) create more threads than cpus * (2) in each thread: * (a) set TFIAR and TFHAR a unique value - * (b) loop for awhile, continually checking to see if + * (b) loop for a while, continually checking to see if * either register has been corrupted. * * (3) Loop: -- 2.39.5

2 weeks, 5 days

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[PATCH v6 00/28] KVM: arm64: Implement support for SME

by Mark Brown

I've removed the RFC tag from this version of the series, but the items that I'm looking for feedback on remains the same: - The userspace ABI, in particular: - The vector length used for the SVE registers, access to the SVE registers and access to ZA and (if available) ZT0 depending on the current state of PSTATE.{SM,ZA}. - The use of a single finalisation for both SVE and SME. - The addition of control for enabling fine grained traps in a similar manner to FGU but without the UNDEF, I'm not clear if this is desired at all and at present this requires symmetric read and write traps like FGU. That seemed like it might be desired from an implementation point of view but we already have one case where we enable an asymmetric trap (for ARM64_WORKAROUND_AMPERE_AC03_CPU_38) and it seems generally useful to enable asymmetrically. This series implements support for SME use in non-protected KVM guests. Much of this is very similar to SVE, the main additional challenge that SME presents is that it introduces a new vector length similar to the SVE vector length and two new controls which change the registers seen by guests: - PSTATE.ZA enables the ZA matrix register and, if SME2 is supported, the ZT0 LUT register. - PSTATE.SM enables streaming mode, a new floating point mode which uses the SVE register set with the separately configured SME vector length. In streaming mode implementation of the FFR register is optional. It is also permitted to build systems which support SME without SVE, in this case when not in streaming mode no SVE registers or instructions are available. Further, there is no requirement that there be any overlap in the set of vector lengths supported by SVE and SME in a system, this is expected to be a common situation in practical systems. Since there is a new vector length to configure we introduce a new feature parallel to the existing SVE one with a new pseudo register for the streaming mode vector length. Due to the overlap with SVE caused by streaming mode rather than finalising SME as a separate feature we use the existing SVE finalisation to also finalise SME, a new define KVM_ARM_VCPU_VEC is provided to help make user code clearer. Finalising SVE and SME separately would introduce complication with register access since finalising SVE makes the SVE registers writeable by userspace and doing multiple finalisations results in an error being reported. Dealing with a state where the SVE registers are writeable due to one of SVE or SME being finalised but may have their VL changed by the other being finalised seems like needless complexity with minimal practical utility, it seems clearer to just express directly that only one finalisation can be done in the ABI. Access to the floating point registers follows the architecture: - When both SVE and SME are present: - If PSTATE.SM == 0 the vector length used for the Z and P registers is the SVE vector length. - If PSTATE.SM == 1 the vector length used for the Z and P registers is the SME vector length. - If only SME is present: - If PSTATE.SM == 0 the Z and P registers are inaccessible and the floating point state accessed via the encodings for the V registers. - If PSTATE.SM == 1 the vector length used for the Z and P registers - The SME specific ZA and ZT0 registers are only accessible if SVCR.ZA is 1. The VMM must understand this, in particular when loading state SVCR should be configured before other state. It should be noted that while the architecture refers to PSTATE.SM and PSTATE.ZA these PSTATE bits are not preserved in SPSR_ELx, they are only accessible via SVCR. There are a large number of subfeatures for SME, most of which only offer additional instructions but some of which (SME2 and FA64) add architectural state. These are configured via the ID registers as per usual. Protected KVM supported, with the implementation maintaining the existing restriction that the hypervisor will refuse to run if streaming mode or ZA is enabled. This both simplfies the code and avoids the need to allocate storage for host ZA and ZT0 state, there seems to be little practical use case for supporting this and the memory usage would be non-trivial. The new KVM_ARM_VCPU_VEC feature and ZA and ZT0 registers have not been added to the get-reg-list selftest, the idea of supporting additional features there without restructuring the program to generate all possible feature combinations has been rejected. I will post a separate series which does that restructuring. Signed-off-by: Mark Brown <broonie(a)kernel.org> --- Changes in v6: - Rebase onto v6.16-rc3. - Link to v5: https://lore.kernel.org/r/20250417-kvm-arm64-sme-v5-0-f469a2d5f574@kernel.o… Changes in v5: - Rebase onto v6.15-rc2. - Add pKVM guest support. - Always restore SVCR. - Link to v4: https://lore.kernel.org/r/20250214-kvm-arm64-sme-v4-0-d64a681adcc2@kernel.o… Changes in v4: - Rebase onto v6.14-rc2 and Mark Rutland's fixes. - Expose SME to nested guests. - Additional cleanups and test fixes following on from the rebase. - Flush register state on VMM PSTATE.{SM,ZA}. - Link to v3: https://lore.kernel.org/r/20241220-kvm-arm64-sme-v3-0-05b018c1ffeb@kernel.o… Changes in v3: - Rebase onto v6.12-rc2. - Link to v2: https://lore.kernel.org/r/20231222-kvm-arm64-sme-v2-0-da226cb180bb@kernel.o… Changes in v2: - Rebase onto v6.7-rc3. - Configure subfeatures based on host system only. - Complete nVHE support. - There was some snafu with sending v1 out, it didn't make it to the lists but in case it hit people's inboxes I'm sending as v2. --- Mark Brown (28): arm64/fpsimd: Update FA64 and ZT0 enables when loading SME state arm64/fpsimd: Decide to save ZT0 and streaming mode FFR at bind time arm64/fpsimd: Check enable bit for FA64 when saving EFI state arm64/fpsimd: Determine maximum virtualisable SME vector length KVM: arm64: Introduce non-UNDEF FGT control KVM: arm64: Pay attention to FFR parameter in SVE save and load KVM: arm64: Pull ctxt_has_ helpers to start of sysreg-sr.h KVM: arm64: Move SVE state access macros after feature test macros KVM: arm64: Rename SVE finalization constants to be more general KVM: arm64: Document the KVM ABI for SME KVM: arm64: Define internal features for SME KVM: arm64: Rename sve_state_reg_region KVM: arm64: Store vector lengths in an array KVM: arm64: Implement SME vector length configuration KVM: arm64: Support SME control registers KVM: arm64: Support TPIDR2_EL0 KVM: arm64: Support SME identification registers for guests KVM: arm64: Support SME priority registers KVM: arm64: Provide assembly for SME register access KVM: arm64: Support userspace access to streaming mode Z and P registers KVM: arm64: Flush register state on writes to SVCR.SM and SVCR.ZA KVM: arm64: Expose SME specific state to userspace KVM: arm64: Context switch SME state for guests KVM: arm64: Handle SME exceptions KVM: arm64: Expose SME to nested guests KVM: arm64: Provide interface for configuring and enabling SME for guests KVM: arm64: selftests: Add SME system registers to get-reg-list KVM: arm64: selftests: Add SME to set_id_regs test Documentation/virt/kvm/api.rst | 117 +++++++---- arch/arm64/include/asm/fpsimd.h | 26 +++ arch/arm64/include/asm/kvm_emulate.h | 6 + arch/arm64/include/asm/kvm_host.h | 168 ++++++++++++--- arch/arm64/include/asm/kvm_hyp.h | 5 +- arch/arm64/include/asm/kvm_pkvm.h | 2 +- arch/arm64/include/asm/vncr_mapping.h | 2 + arch/arm64/include/uapi/asm/kvm.h | 33 +++ arch/arm64/kernel/cpufeature.c | 2 - arch/arm64/kernel/fpsimd.c | 89 ++++---- arch/arm64/kvm/arm.c | 10 + arch/arm64/kvm/fpsimd.c | 28 ++- arch/arm64/kvm/guest.c | 252 ++++++++++++++++++++--- arch/arm64/kvm/handle_exit.c | 14 ++ arch/arm64/kvm/hyp/fpsimd.S | 28 ++- arch/arm64/kvm/hyp/include/hyp/switch.h | 175 ++++++++++++++-- arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h | 97 +++++---- arch/arm64/kvm/hyp/nvhe/hyp-main.c | 86 ++++++-- arch/arm64/kvm/hyp/nvhe/pkvm.c | 81 ++++++-- arch/arm64/kvm/hyp/nvhe/switch.c | 4 +- arch/arm64/kvm/hyp/nvhe/sys_regs.c | 6 + arch/arm64/kvm/hyp/vhe/switch.c | 17 +- arch/arm64/kvm/nested.c | 3 +- arch/arm64/kvm/reset.c | 156 ++++++++++---- arch/arm64/kvm/sys_regs.c | 140 ++++++++++++- include/uapi/linux/kvm.h | 1 + tools/testing/selftests/kvm/arm64/get-reg-list.c | 32 ++- tools/testing/selftests/kvm/arm64/set_id_regs.c | 29 ++- 28 files changed, 1315 insertions(+), 294 deletions(-) --- base-commit: 7204503c922cfdb4fcfce4a4ab61f4558a01a73b change-id: 20230301-kvm-arm64-sme-06a1246d3636 Best regards, -- Mark Brown <broonie(a)kernel.org>

2 weeks, 5 days

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[PATCH v2 0/3] kselftest/arm64: Update sve-ptrace for ABI changes

by Mark Brown

Mark Rutland's recent SME fixes updated the SME ABI to reject any attempt to write FPSIMD register data via the streaming mode SVE register set but did not update the sve-ptrace test to take account of this, resulting in spurious failures. Update the test for this, and also fix another preexisting issue I noticed while looking at this. Signed-off-by: Mark Brown <broonie(a)kernel.org> --- Changes in v2: - Rebase onto v6.16-rc1. - Update fixes tag for patch 1. - Link to v1: https://lore.kernel.org/r/20250523-kselftest-arm64-ssve-fixups-v1-0-65069a2… --- Mark Brown (3): kselftest/arm64: Fix check for setting new VLs in sve-ptrace kselftest/arm64: Fix test for streaming FPSIMD write in sve-ptrace kselftest/arm64: Specify SVE data when testing VL set in sve-ptrace tools/testing/selftests/arm64/fp/sve-ptrace.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) --- base-commit: 19272b37aa4f83ca52bdf9c16d5d81bdd1354494 change-id: 20250523-kselftest-arm64-ssve-fixups-b68ae61c1ebf Best regards, -- Mark Brown <broonie(a)kernel.org>

2 weeks, 5 days

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[PATCH] kselftest/arm64: Convert tpidr2 test to use kselftest.h

by Mark Brown

Recent work by Thomas Weißschuh means that it is now possible to use kselftest.h with nolibc. Convert the tpidr2 test which is nolibc specific to use kselftest.h, making it look more standard and ensuring it gets the benefit of any work done on kselftest.h. Signed-off-by: Mark Brown <broonie(a)kernel.org> --- tools/testing/selftests/arm64/abi/Makefile | 2 +- tools/testing/selftests/arm64/abi/tpidr2.c | 140 ++++++++--------------------- 2 files changed, 38 insertions(+), 104 deletions(-) diff --git a/tools/testing/selftests/arm64/abi/Makefile b/tools/testing/selftests/arm64/abi/Makefile index a6d30c620908..483488f8c2ad 100644 --- a/tools/testing/selftests/arm64/abi/Makefile +++ b/tools/testing/selftests/arm64/abi/Makefile @@ -12,4 +12,4 @@ $(OUTPUT)/syscall-abi: syscall-abi.c syscall-abi-asm.S $(OUTPUT)/tpidr2: tpidr2.c $(CC) -fno-asynchronous-unwind-tables -fno-ident -s -Os -nostdlib \ -static -include ../../../../include/nolibc/nolibc.h \ - -ffreestanding -Wall $^ -o $@ -lgcc + -I../.. -ffreestanding -Wall $^ -o $@ -lgcc diff --git a/tools/testing/selftests/arm64/abi/tpidr2.c b/tools/testing/selftests/arm64/abi/tpidr2.c index eb19dcc37a75..f58a9f89b952 100644 --- a/tools/testing/selftests/arm64/abi/tpidr2.c +++ b/tools/testing/selftests/arm64/abi/tpidr2.c @@ -3,31 +3,12 @@ #include <linux/sched.h> #include <linux/wait.h> +#include "kselftest.h" + #define SYS_TPIDR2 "S3_3_C13_C0_5" #define EXPECTED_TESTS 5 -static void putstr(const char *str) -{ - write(1, str, strlen(str)); -} - -static void putnum(unsigned int num) -{ - char c; - - if (num / 10) - putnum(num / 10); - - c = '0' + (num % 10); - write(1, &c, 1); -} - -static int tests_run; -static int tests_passed; -static int tests_failed; -static int tests_skipped; - static void set_tpidr2(uint64_t val) { asm volatile ( @@ -50,20 +31,6 @@ static uint64_t get_tpidr2(void) return val; } -static void print_summary(void) -{ - if (tests_passed + tests_failed + tests_skipped != EXPECTED_TESTS) - putstr("# UNEXPECTED TEST COUNT: "); - - putstr("# Totals: pass:"); - putnum(tests_passed); - putstr(" fail:"); - putnum(tests_failed); - putstr(" xfail:0 xpass:0 skip:"); - putnum(tests_skipped); - putstr(" error:0\n"); -} - /* Processes should start with TPIDR2 == 0 */ static int default_value(void) { @@ -105,9 +72,8 @@ static int write_fork_read(void) if (newpid == 0) { /* In child */ if (get_tpidr2() != oldpid) { - putstr("# TPIDR2 changed in child: "); - putnum(get_tpidr2()); - putstr("\n"); + ksft_print_msg("TPIDR2 changed in child: %llx\n", + get_tpidr2()); exit(0); } @@ -115,14 +81,12 @@ static int write_fork_read(void) if (get_tpidr2() == getpid()) { exit(1); } else { - putstr("# Failed to set TPIDR2 in child\n"); + ksft_print_msg("Failed to set TPIDR2 in child\n"); exit(0); } } if (newpid < 0) { - putstr("# fork() failed: -"); - putnum(-newpid); - putstr("\n"); + ksft_print_msg("fork() failed: %d\n", newpid); return 0; } @@ -132,23 +96,22 @@ static int write_fork_read(void) if (waiting < 0) { if (errno == EINTR) continue; - putstr("# waitpid() failed: "); - putnum(errno); - putstr("\n"); + ksft_print_msg("waitpid() failed: %d\n", errno); return 0; } if (waiting != newpid) { - putstr("# waitpid() returned wrong PID\n"); + ksft_print_msg("waitpid() returned wrong PID: %d != %d\n", + waiting, newpid); return 0; } if (!WIFEXITED(status)) { - putstr("# child did not exit\n"); + ksft_print_msg("child did not exit\n"); return 0; } if (getpid() != get_tpidr2()) { - putstr("# TPIDR2 corrupted in parent\n"); + ksft_print_msg("TPIDR2 corrupted in parent\n"); return 0; } @@ -188,35 +151,32 @@ static int write_clone_read(void) stack = malloc(__STACK_SIZE); if (!stack) { - putstr("# malloc() failed\n"); + ksft_print_msg("malloc() failed\n"); return 0; } ret = sys_clone(CLONE_VM, (unsigned long)stack + __STACK_SIZE, &parent_tid, 0, &child_tid); if (ret == -1) { - putstr("# clone() failed\n"); - putnum(errno); - putstr("\n"); + ksft_print_msg("clone() failed: %d\n", errno); return 0; } if (ret == 0) { /* In child */ if (get_tpidr2() != 0) { - putstr("# TPIDR2 non-zero in child: "); - putnum(get_tpidr2()); - putstr("\n"); + ksft_print_msg("TPIDR2 non-zero in child: %llx\n", + get_tpidr2()); exit(0); } if (gettid() == 0) - putstr("# Child TID==0\n"); + ksft_print_msg("Child TID==0\n"); set_tpidr2(gettid()); if (get_tpidr2() == gettid()) { exit(1); } else { - putstr("# Failed to set TPIDR2 in child\n"); + ksft_print_msg("Failed to set TPIDR2 in child\n"); exit(0); } } @@ -227,25 +187,22 @@ static int write_clone_read(void) if (waiting < 0) { if (errno == EINTR) continue; - putstr("# wait4() failed: "); - putnum(errno); - putstr("\n"); + ksft_print_msg("wait4() failed: %d\n", errno); return 0; } if (waiting != ret) { - putstr("# wait4() returned wrong PID "); - putnum(waiting); - putstr("\n"); + ksft_print_msg("wait4() returned wrong PID %d\n", + waiting); return 0; } if (!WIFEXITED(status)) { - putstr("# child did not exit\n"); + ksft_print_msg("child did not exit\n"); return 0; } if (parent != get_tpidr2()) { - putstr("# TPIDR2 corrupted in parent\n"); + ksft_print_msg("TPIDR2 corrupted in parent\n"); return 0; } @@ -253,35 +210,14 @@ static int write_clone_read(void) } } -#define run_test(name) \ - if (name()) { \ - tests_passed++; \ - } else { \ - tests_failed++; \ - putstr("not "); \ - } \ - putstr("ok "); \ - putnum(++tests_run); \ - putstr(" " #name "\n"); - -#define skip_test(name) \ - tests_skipped++; \ - putstr("ok "); \ - putnum(++tests_run); \ - putstr(" # SKIP " #name "\n"); - int main(int argc, char **argv) { int ret; - putstr("TAP version 13\n"); - putstr("1.."); - putnum(EXPECTED_TESTS); - putstr("\n"); + ksft_print_header(); + ksft_set_plan(5); - putstr("# PID: "); - putnum(getpid()); - putstr("\n"); + ksft_print_msg("PID: %d\n", getpid()); /* * This test is run with nolibc which doesn't support hwcap and @@ -290,23 +226,21 @@ int main(int argc, char **argv) */ ret = open("/proc/sys/abi/sme_default_vector_length", O_RDONLY, 0); if (ret >= 0) { - run_test(default_value); - run_test(write_read); - run_test(write_sleep_read); - run_test(write_fork_read); - run_test(write_clone_read); + ksft_test_result(default_value(), "default_value\n"); + ksft_test_result(write_read, "write_read\n"); + ksft_test_result(write_sleep_read, "write_sleep_read\n"); + ksft_test_result(write_fork_read, "write_fork_read\n"); + ksft_test_result(write_clone_read, "write_clone_read\n"); } else { - putstr("# SME support not present\n"); + ksft_print_msg("SME support not present\n"); - skip_test(default_value); - skip_test(write_read); - skip_test(write_sleep_read); - skip_test(write_fork_read); - skip_test(write_clone_read); + ksft_test_result_skip("default_value\n"); + ksft_test_result_skip("write_read\n"); + ksft_test_result_skip("write_sleep_read\n"); + ksft_test_result_skip("write_fork_read\n"); + ksft_test_result_skip("write_clone_read\n"); } - print_summary(); - - return 0; + ksft_finished(); } --- base-commit: 19272b37aa4f83ca52bdf9c16d5d81bdd1354494 change-id: 20250527-kselftest-arm64-nolibc-header-b650a457f7f4 Best regards, -- Mark Brown <broonie(a)kernel.org>

2 weeks, 5 days

2
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