From patchwork Wed Jul 28 16:33:17 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Brown X-Patchwork-Id: 12406347 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 910BCC4320A for ; Wed, 28 Jul 2021 16:34:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6815060F9B for ; Wed, 28 Jul 2021 16:34:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229729AbhG1QeS (ORCPT ); Wed, 28 Jul 2021 12:34:18 -0400 Received: from mail.kernel.org ([198.145.29.99]:37628 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230001AbhG1QeR (ORCPT ); Wed, 28 Jul 2021 12:34:17 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id A4BB061019; Wed, 28 Jul 2021 16:34:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1627490055; bh=EN820oZ5k8blUq0DCy4U6RFJp5l8AIsEi0JmwQjoCLg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jLH6UDP+TE5CNjQnASoc9d86h3CzHyHf0c38HinYlK4isKJ0xY1X8ihzEVWxChN+F BD/11sl6JkQ6TdU6psfeQieRQbmWYEbUsIzl3y7DNPNyP9yiB1Bwr3gBATjUew3CaW MJ51P9PBBmVMLROK7PoMSCTKhzEcC4FAMOtvYJuGR7TkkLFl7zReD8jFxIkKFHA7Kl J9yNJ0Z7qRJRvEGkDtvqL5XlWi21FbF3vB6Dq4uKPhV0BlnkjLnLQksrhCU88fOSl8 1hGBLqeJalNupWXzHkLd0xgwMBcQRs9j2u/fG0kPooev8yW0KBGFhzQPZvK9kU6RSi 6+y8BI6QD9MLQ== From: Mark Brown To: Catalin Marinas , Will Deacon , Shuah Khan Cc: Dave Martin , linux-arm-kernel@lists.infradead.org, linux-kselftest@vger.kernel.org, Mark Brown Subject: [PATCH v2 3/4] kselftest/arm64: Add tests for SVE vector configuration Date: Wed, 28 Jul 2021 17:33:17 +0100 Message-Id: <20210728163318.51492-4-broonie@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20210728163318.51492-1-broonie@kernel.org> References: <20210728163318.51492-1-broonie@kernel.org> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=17248; h=from:subject; bh=EN820oZ5k8blUq0DCy4U6RFJp5l8AIsEi0JmwQjoCLg=; b=owEBbQGS/pANAwAKASTWi3JdVIfQAcsmYgBhAYbK5LOb1vE1WFnF9eAbbZOLfUcO9qu6RG+jdCcz UVsXc9eJATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCYQGGygAKCRAk1otyXVSH0LGIB/ 4qTEvGo/Su/VYTT+Vb/3vQFLYE71F8m3GZqulFHbAC83eJwqnqEeuX0eNY/bd0By5kpvC+jSaP98bO I+cPUmgmpZbFY7VixWOjQ/0Xc8N2DrkoimeaHXxThHmgYGaG+ONF8VklHktQwMPZIj+Cd5Aq72D8r2 yM6hJVnlCWOe5fNVoifOZBW4ERa+GCv8WwC7jIM1henVZO1UmmVuNnYc0GQLAGapXjY4QczJrEahIx m9hZtSoOQgdfpmlvG3E0B5v4gSCYDZyEVXdQLnWq1LQ1IIkPlZqIA8zHnafBJIWOnXnfmRCR3ZBIXe zHqpRVl24kUGIVXHdskwYSNUapbQKu X-Developer-Key: i=broonie@kernel.org; a=openpgp; fpr=3F2568AAC26998F9E813A1C5C3F436CA30F5D8EB Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org We provide interfaces for configuring the SVE vector length seen by processes using prctl and also via /proc for configuring the default values. Provide tests that exercise all these interfaces and verify that they take effect as expected, though at present no test fully enumerates all the possible vector lengths. A subset of this is already tested via sve-probe-vls but the /proc interfaces are not currently covered at all. In preparation for the forthcoming support for SME, the Scalable Matrix Extension, which has separately but similarly configured vector lengths which we expect to offer similar userspace interfaces for, all the actual files and prctls used are parameterised and we don't validate that the architectural minimum vector length is the minimum we see. Signed-off-by: Mark Brown --- tools/testing/selftests/arm64/fp/.gitignore | 1 + tools/testing/selftests/arm64/fp/Makefile | 3 +- tools/testing/selftests/arm64/fp/vec-syscfg.c | 580 ++++++++++++++++++ 3 files changed, 583 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/arm64/fp/vec-syscfg.c diff --git a/tools/testing/selftests/arm64/fp/.gitignore b/tools/testing/selftests/arm64/fp/.gitignore index 6b53a7b60fee..b67395903b9b 100644 --- a/tools/testing/selftests/arm64/fp/.gitignore +++ b/tools/testing/selftests/arm64/fp/.gitignore @@ -3,4 +3,5 @@ rdvl-sve sve-probe-vls sve-ptrace sve-test +vec-syscfg vlset diff --git a/tools/testing/selftests/arm64/fp/Makefile b/tools/testing/selftests/arm64/fp/Makefile index fa3a0167db2d..f2abdd6ba12e 100644 --- a/tools/testing/selftests/arm64/fp/Makefile +++ b/tools/testing/selftests/arm64/fp/Makefile @@ -1,7 +1,7 @@ # SPDX-License-Identifier: GPL-2.0 CFLAGS += -I../../../../../usr/include/ -TEST_GEN_PROGS := sve-ptrace sve-probe-vls +TEST_GEN_PROGS := sve-ptrace sve-probe-vls vec-syscfg TEST_PROGS_EXTENDED := fpsimd-test fpsimd-stress \ rdvl-sve \ sve-test sve-stress \ @@ -16,6 +16,7 @@ sve-ptrace: sve-ptrace.o sve-ptrace-asm.o sve-probe-vls: sve-probe-vls.o rdvl.o sve-test: sve-test.o $(CC) -nostdlib $^ -o $@ +vec-syscfg: vec-syscfg.o rdvl.o vlset: vlset.o include ../../lib.mk diff --git a/tools/testing/selftests/arm64/fp/vec-syscfg.c b/tools/testing/selftests/arm64/fp/vec-syscfg.c new file mode 100644 index 000000000000..63d080537d21 --- /dev/null +++ b/tools/testing/selftests/arm64/fp/vec-syscfg.c @@ -0,0 +1,580 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2021 ARM Limited. + * Original author: Mark Brown + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "../../kselftest.h" +#include "rdvl.h" + +#define ARRAY_SIZE(a) (sizeof(a) / sizeof(a[0])) + +#define ARCH_MIN_VL SVE_VL_MIN + +struct vec_data { + const char *name; + unsigned long hwcap_type; + unsigned long hwcap; + const char *rdvl_binary; + int (*rdvl)(void); + + int prctl_get; + int prctl_set; + const char *default_vl_file; + + int default_vl; + int min_vl; + int max_vl; +}; + + +static struct vec_data vec_data[] = { + { + .name = "SVE", + .hwcap_type = AT_HWCAP, + .hwcap = HWCAP_SVE, + .rdvl = rdvl_sve, + .rdvl_binary = "./rdvl-sve", + .prctl_get = PR_SVE_GET_VL, + .prctl_set = PR_SVE_SET_VL, + .default_vl_file = "/proc/sys/abi/sve_default_vector_length", + }, +}; + +/* Start a new process and return the vector length it sees */ +int get_child_rdvl(struct vec_data *data) +{ + FILE *out; + int pipefd[2]; + pid_t pid, child; + int read_vl, ret; + + ret = pipe(pipefd); + if (ret == -1) { + ksft_print_msg("pipe() failed: %d (%s)\n", + errno, strerror(errno)); + return -1; + } + + fflush(stdout); + + child = fork(); + if (child == -1) { + ksft_print_msg("fork() failed: %d (%s)\n", + errno, strerror(errno)); + return -1; + } + + /* Child: put vector length on the pipe */ + if (child == 0) { + /* + * Replace stdout with the pipe, errors to stderr from + * here as kselftest prints to stdout. + */ + ret = dup2(pipefd[1], 1); + if (ret == -1) { + fprintf(stderr, "dup2() %d\n", errno); + exit(EXIT_FAILURE); + } + + /* exec() a new binary which puts the VL on stdout */ + ret = execl(data->rdvl_binary, data->rdvl_binary, NULL); + fprintf(stderr, "execl(%s) failed: %d\n", + data->rdvl_binary, errno, strerror(errno)); + + exit(EXIT_FAILURE); + } + + close(pipefd[1]); + + /* Parent; wait for the exit status from the child & verify it */ + while (1) { + pid = wait(&ret); + if (pid == -1) { + ksft_print_msg("wait() failed: %d (%s)\n", + errno, strerror(errno)); + return -1; + } + + if (pid != child) + continue; + + if (!WIFEXITED(ret)) { + ksft_print_msg("child exited abnormally\n"); + return -1; + } + + if (WEXITSTATUS(ret) != 0) { + ksft_print_msg("child returned error %d\n", + WEXITSTATUS(ret)); + return -1; + } + + out = fdopen(pipefd[0], "r"); + if (!out) { + ksft_print_msg("failed to open child stdout\n"); + return -1; + } + + ret = fscanf(out, "%d", &read_vl); + fclose(out); + if (ret != 1) { + ksft_print_msg("failed to parse VL from '%s'\n", + data->rdvl_binary); + return -1; + } + + return read_vl; + } +} + +int file_read_integer(const char *name, int *val) +{ + FILE *f; + int ret; + + f = fopen(name, "r"); + if (!f) { + ksft_test_result_fail("Unable to open %s: %d (%s)\n", + name, errno, + strerror(errno)); + return -1; + } + + ret = fscanf(f, "%d", val); + fclose(f); + if (ret != 1) { + ksft_test_result_fail("Failed to parse %s\n", name); + return -1; + } + + return 0; +} + +int file_write_integer(const char *name, int val) +{ + FILE *f; + int ret; + + f = fopen(name, "w"); + if (!f) { + ksft_test_result_fail("Unable to open %s: %d (%s)\n", + name, errno, + strerror(errno)); + return -1; + } + + fprintf(f, "%d", val); + fclose(f); + if (ret < 0) { + ksft_test_result_fail("Error writing %d to %s\n", + val, name); + return -1; + } + + return 0; +} + +/* + * Verify that we can read the default VL via proc, checking that it + * is set in a freshly spawned child. + */ +void proc_read_default(struct vec_data *data) +{ + int default_vl, child_vl, ret; + + ret = file_read_integer(data->default_vl_file, &default_vl); + if (ret != 0) + return; + + /* Is this the actual default seen by new processes? */ + child_vl = get_child_rdvl(data); + if (child_vl != default_vl) { + ksft_test_result_fail("%s is %d but child VL is %d\n", + data->default_vl_file, + default_vl, child_vl); + return; + } + + ksft_test_result_pass("%s default vector length %d\n", data->name, + default_vl); + data->default_vl = default_vl; +} + +/* Verify that we can write a minimum value and have it take effect */ +void proc_write_min(struct vec_data *data) +{ + int ret, new_default, child_vl; + + if (geteuid() != 0) { + ksft_test_result_skip("Need to be root to write to /proc\n"); + return; + } + + ret = file_write_integer(data->default_vl_file, ARCH_MIN_VL); + if (ret != 0) + return; + + /* What was the new value? */ + ret = file_read_integer(data->default_vl_file, &new_default); + if (ret != 0) + return; + + /* Did it take effect in a new process? */ + child_vl = get_child_rdvl(data); + if (child_vl != new_default) { + ksft_test_result_fail("%s is %d but child VL is %d\n", + data->default_vl_file, + new_default, child_vl); + return; + } + + ksft_test_result_pass("%s minimum vector length %d\n", data->name, + new_default); + data->min_vl = new_default; + + file_write_integer(data->default_vl_file, data->default_vl); +} + +/* Verify that we can write a maximum value and have it take effect */ +void proc_write_max(struct vec_data *data) +{ + int ret, new_default, child_vl; + + if (geteuid() != 0) { + ksft_test_result_skip("Need to be root to write to /proc\n"); + return; + } + + /* -1 is accepted by the /proc interface as the maximum VL */ + ret = file_write_integer(data->default_vl_file, -1); + if (ret != 0) + return; + + /* What was the new value? */ + ret = file_read_integer(data->default_vl_file, &new_default); + if (ret != 0) + return; + + /* Did it take effect in a new process? */ + child_vl = get_child_rdvl(data); + if (child_vl != new_default) { + ksft_test_result_fail("%s is %d but child VL is %d\n", + data->default_vl_file, + new_default, child_vl); + return; + } + + ksft_test_result_pass("%s maximum vector length %d\n", data->name, + new_default); + data->max_vl = new_default; + + file_write_integer(data->default_vl_file, data->default_vl); +} + +/* Can we read back a VL from prctl? */ +void prctl_get(struct vec_data *data) +{ + int ret; + + ret = prctl(data->prctl_get); + if (ret == -1) { + ksft_test_result_fail("%s prctl() read failed: %d (%s)\n", + data->name, errno, strerror(errno)); + return; + } + + /* Mask out any flags */ + ret &= PR_SVE_VL_LEN_MASK; + + /* Is that what we can read back directly? */ + if (ret == data->rdvl()) + ksft_test_result_pass("%s current VL is %d\n", + data->name, ret); + else + ksft_test_result_fail("%s prctl() VL %d but RDVL is %d\n", + data->name, ret, data->rdvl()); +} + +/* Does the prctl let us set the VL we already have? */ +void prctl_set_same(struct vec_data *data) +{ + int cur_vl = data->rdvl(); + int ret; + + ret = prctl(data->prctl_set, cur_vl); + if (ret < 0) { + ksft_test_result_fail("%s prctl set failed: %d (%s)\n", + data->name, errno, strerror(errno)); + return; + } + + if (cur_vl != data->rdvl()) + ksft_test_result_pass("%s current VL is %d\n", + data->name, ret); + else + ksft_test_result_fail("%s prctl() VL %d but RDVL is %d\n", + data->name, ret, data->rdvl()); +} + +/* Can we set a new VL for this process? */ +void prctl_set(struct vec_data *data) +{ + int ret; + + if (data->min_vl == data->max_vl) { + ksft_test_result_skip("%s only one VL supported\n", + data->name); + return; + } + + /* Try to set the minimum VL */ + ret = prctl(data->prctl_set, data->min_vl); + if (ret < 0) { + ksft_test_result_fail("%s prctl set failed for %d: %d (%s)\n", + data->name, data->min_vl, + errno, strerror(errno)); + return; + } + + if ((ret & PR_SVE_VL_LEN_MASK) != data->min_vl) { + ksft_test_result_fail("%s prctl set %d but return value is %d\n", + data->name, data->min_vl, data->rdvl()); + return; + } + + if (data->rdvl() != data->min_vl) { + ksft_test_result_fail("%s set %d but RDVL is %d\n", + data->name, data->min_vl, data->rdvl()); + return; + } + + /* Try to set the maximum VL */ + ret = prctl(data->prctl_set, data->max_vl); + if (ret < 0) { + ksft_test_result_fail("%s prctl set failed for %d: %d (%s)\n", + data->name, data->max_vl, + errno, strerror(errno)); + return; + } + + if ((ret & PR_SVE_VL_LEN_MASK) != data->max_vl) { + ksft_test_result_fail("%s prctl() set %d but return value is %d\n", + data->name, data->max_vl, data->rdvl()); + return; + } + + /* The _INHERIT flag should not be present when we read the VL */ + ret = prctl(data->prctl_get); + if (ret == -1) { + ksft_test_result_fail("%s prctl() read failed: %d (%s)\n", + data->name, errno, strerror(errno)); + return; + } + + if (ret & PR_SVE_VL_INHERIT) { + ksft_test_result_fail("%s prctl() reports _INHERIT\n", + data->name); + return; + } + + ksft_test_result_pass("%s prctl() set min/max\n", data->name); +} + +/* If we didn't request it a new VL shouldn't affect the child */ +void prctl_set_no_child(struct vec_data *data) +{ + int ret, child_vl; + + if (data->min_vl == data->max_vl) { + ksft_test_result_skip("%s only one VL supported\n", + data->name); + return; + } + + ret = prctl(data->prctl_set, data->min_vl); + if (ret < 0) { + ksft_test_result_fail("%s prctl set failed for %d: %d (%s)\n", + data->name, data->min_vl, + errno, strerror(errno)); + return; + } + + /* Ensure the default VL is different */ + ret = file_write_integer(data->default_vl_file, data->max_vl); + if (ret != 0) + return; + + /* Check that the child has the default we just set */ + child_vl = get_child_rdvl(data); + if (child_vl != data->max_vl) { + ksft_test_result_fail("%s is %d but child VL is %d\n", + data->default_vl_file, + data->max_vl, child_vl); + return; + } + + ksft_test_result_pass("%s vector length used default\n", data->name); + + file_write_integer(data->default_vl_file, data->default_vl); +} + +/* If we didn't request it a new VL shouldn't affect the child */ +void prctl_set_for_child(struct vec_data *data) +{ + int ret, child_vl; + + if (data->min_vl == data->max_vl) { + ksft_test_result_skip("%s only one VL supported\n", + data->name); + return; + } + + ret = prctl(data->prctl_set, data->min_vl | PR_SVE_VL_INHERIT); + if (ret < 0) { + ksft_test_result_fail("%s prctl set failed for %d: %d (%s)\n", + data->name, data->min_vl, + errno, strerror(errno)); + return; + } + + /* The _INHERIT flag should be present when we read the VL */ + ret = prctl(data->prctl_get); + if (ret == -1) { + ksft_test_result_fail("%s prctl() read failed: %d (%s)\n", + data->name, errno, strerror(errno)); + return; + } + if (!(ret & PR_SVE_VL_INHERIT)) { + ksft_test_result_fail("%s prctl() does not report _INHERIT\n", + data->name); + return; + } + + /* Ensure the default VL is different */ + ret = file_write_integer(data->default_vl_file, data->max_vl); + if (ret != 0) + return; + + /* Check that the child inherited our VL */ + child_vl = get_child_rdvl(data); + if (child_vl != data->min_vl) { + ksft_test_result_fail("%s is %d but child VL is %d\n", + data->default_vl_file, + data->min_vl, child_vl); + return; + } + + ksft_test_result_pass("%s vector length was inherited\n", data->name); + + file_write_integer(data->default_vl_file, data->default_vl); +} + +/* _ONEXEC takes effect only in the child process */ +void prctl_set_onexec(struct vec_data *data) +{ + int ret, child_vl; + + if (data->min_vl == data->max_vl) { + ksft_test_result_skip("%s only one VL supported\n", + data->name); + return; + } + + /* Set a known value for the default and our current VL */ + ret = file_write_integer(data->default_vl_file, data->max_vl); + if (ret != 0) + return; + + ret = prctl(data->prctl_set, data->max_vl); + if (ret < 0) { + ksft_test_result_fail("%s prctl set failed for %d: %d (%s)\n", + data->name, data->min_vl, + errno, strerror(errno)); + return; + } + + /* Set a different value for the child to have on exec */ + ret = prctl(data->prctl_set, data->min_vl | PR_SVE_SET_VL_ONEXEC); + if (ret < 0) { + ksft_test_result_fail("%s prctl set failed for %d: %d (%s)\n", + data->name, data->min_vl, + errno, strerror(errno)); + return; + } + + /* Our current VL should stay the same */ + if (data->rdvl() != data->max_vl) { + ksft_test_result_fail("%s VL changed by _ONEXEC prctl()\n", + data->name); + return; + } + + /* Check that the child inherited our VL */ + child_vl = get_child_rdvl(data); + if (child_vl != data->min_vl) { + ksft_test_result_fail("%s is %d but child VL is %d\n", + data->default_vl_file, + data->min_vl, child_vl); + return; + } + + ksft_test_result_pass("%s vector length set on exec\n", data->name); + + file_write_integer(data->default_vl_file, data->default_vl); +} + +typedef void (*test_type)(struct vec_data *); + +test_type tests[] = { + /* + * The default/min/max tests must be first and in this order + * to provide data for other tests. + */ + proc_read_default, + proc_write_min, + proc_write_max, + + prctl_get, + prctl_set, + prctl_set_no_child, + prctl_set_for_child, + prctl_set_onexec, +}; + +int main(void) +{ + int i, j; + + ksft_print_header(); + ksft_set_plan(ARRAY_SIZE(tests) * ARRAY_SIZE(vec_data)); + + for (i = 0; i < ARRAY_SIZE(vec_data); i++) { + struct vec_data *data = &vec_data[i]; + int supported = getauxval(data->hwcap_type) & data->hwcap; + + for (j = 0; j < ARRAY_SIZE(tests); j++) { + if (supported) + tests[j](data); + else + ksft_test_result_skip("%s not supported\n", + data->name); + } + } + + ksft_exit_pass(); +}