From patchwork Thu Jul 20 18:38:59 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Brown X-Patchwork-Id: 13320986 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3301FEB64DA for ; Thu, 20 Jul 2023 18:39:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230259AbjGTSjZ (ORCPT ); Thu, 20 Jul 2023 14:39:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41264 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232119AbjGTSjX (ORCPT ); Thu, 20 Jul 2023 14:39:23 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 583571995; Thu, 20 Jul 2023 11:39:15 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id DA5FB61A40; Thu, 20 Jul 2023 18:39:14 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 413BEC433CB; Thu, 20 Jul 2023 18:39:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1689878354; bh=pefhisUmRsg+2EzyXrIeOHRp6qKwWRumC3ginNtyGbg=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=p/oJ6uyxh3xofibC1pEqoM1PeEC5/+oMzPMezdcSijS3RdbpERHzTz5LwehzW8Vet SkBQdrctNCfcunPCiQ7idJY41da67z2cWB2d5x5d8QqJGYuuUyoPd2vFgjk+VzCoQd pt6bBi+PoZQ7W+E6JKFgVEkyag4ySlImLRcSR7gZYLn66vVausxBrhbcGO9UHw6AsW fkQvvGKFpJu+XFE8cxJ/aUErjgj8lNFV+394YWt5b9CdZptacC40p74U2yvpfnc9es sXUzmIf/PD8lqrZoN4lgRqKjqzAX5d7kiMBkNYJOb7w4KEFyLiq+Ve0hTqWevE0VDw woeprbJI/RYRQ== From: Mark Brown Date: Thu, 20 Jul 2023 19:38:59 +0100 Subject: [PATCH v2 2/3] kselftest/arm64: Add a test case for SVE VL changes with SME active MIME-Version: 1.0 Message-Id: <20230720-arm64-fix-sve-sme-vl-change-v2-2-8eea06b82d57@kernel.org> References: <20230720-arm64-fix-sve-sme-vl-change-v2-0-8eea06b82d57@kernel.org> In-Reply-To: <20230720-arm64-fix-sve-sme-vl-change-v2-0-8eea06b82d57@kernel.org> To: Catalin Marinas , Will Deacon , Shuah Khan Cc: David Spickett , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, Mark Brown X-Mailer: b4 0.13-dev-099c9 X-Developer-Signature: v=1; a=openpgp-sha256; l=4758; i=broonie@kernel.org; h=from:subject:message-id; bh=pefhisUmRsg+2EzyXrIeOHRp6qKwWRumC3ginNtyGbg=; b=owEBbQGS/pANAwAKASTWi3JdVIfQAcsmYgBkuX9IrtjQMya+hnrdUq/tdc/QlegceKFWcKxurFj5 FT9G+faJATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCZLl/SAAKCRAk1otyXVSH0NHrB/ 9bQANLHG6b9UnQm/WjRfWZOiAjyBfrksGMqOKKJr+/uNan8IR/2wuGJCJ8Rv/nMzUgIIyC8SF/XziY 983Mk6LYgev8A+0ZxyyLjR8r1HAAuJB6+Q5T4WI8Nx3xEgpKpLM7tPAqDkHkdkfMyONObCRYv0Qern jot3GNH19btOoM/v16hCL5wuYwWDXXtSaHtBrvVva+8SCl5GiVeBFTNYDm86PwAGNWZJca+Vl1Uc+6 TlpTOwbAwuCLg8qrRAe5uDtPJD+O3CLSMqBDxZGWN02ys0X1c55v4qAetgs7itHwyyKmdX5tQ7wXUb YJnDKspvNKrPW+ciek5wgmRjyikEs0 X-Developer-Key: i=broonie@kernel.org; a=openpgp; fpr=3F2568AAC26998F9E813A1C5C3F436CA30F5D8EB Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org We just fixed an issue where changing the SVE VL while SME was active could result in us attempting to save the streaming mode SVE vectors without any backing storage. Add a test case which provokes that issue, ideally we should also verify that the contents of ZA are unaffected by any of what we did. Note that since we need to keep streaming mode enabled we can't use any syscalls to trigger the issue, we have to sit in a loop in usersapce and hope to be preempted. The chosen numbers trigger with defconfig on all the virtual platforms for me, this won't be 100% on all systems but avoid an overcomplicated test implementation. Signed-off-by: Mark Brown --- tools/testing/selftests/arm64/fp/vec-syscfg.c | 105 +++++++++++++++++++++++++- 1 file changed, 102 insertions(+), 3 deletions(-) diff --git a/tools/testing/selftests/arm64/fp/vec-syscfg.c b/tools/testing/selftests/arm64/fp/vec-syscfg.c index 9bcfcdc34ee9..58ea4bde5be7 100644 --- a/tools/testing/selftests/arm64/fp/vec-syscfg.c +++ b/tools/testing/selftests/arm64/fp/vec-syscfg.c @@ -6,6 +6,7 @@ #include #include #include +#include #include #include #include @@ -39,9 +40,11 @@ struct vec_data { int max_vl; }; +#define VEC_SVE 0 +#define VEC_SME 1 static struct vec_data vec_data[] = { - { + [VEC_SVE] = { .name = "SVE", .hwcap_type = AT_HWCAP, .hwcap = HWCAP_SVE, @@ -51,7 +54,7 @@ static struct vec_data vec_data[] = { .prctl_set = PR_SVE_SET_VL, .default_vl_file = "/proc/sys/abi/sve_default_vector_length", }, - { + [VEC_SME] = { .name = "SME", .hwcap_type = AT_HWCAP2, .hwcap = HWCAP2_SME, @@ -644,18 +647,107 @@ static const test_type tests[] = { prctl_set_all_vqs, }; +static inline void smstart(void) +{ + asm volatile("msr S0_3_C4_C7_3, xzr"); +} + +static inline void smstart_sm(void) +{ + asm volatile("msr S0_3_C4_C3_3, xzr"); +} + +static inline void smstop(void) +{ + asm volatile("msr S0_3_C4_C6_3, xzr"); +} + + +/* + * Verify we can change the SVE vector length while SME is active and + * continue to use SME afterwards. + */ +static void change_sve_with_za(void) +{ + struct vec_data *sve_data = &vec_data[VEC_SVE]; + bool pass = true; + int ret, i; + + if (sve_data->min_vl == sve_data->max_vl) { + ksft_print_msg("Only one SVE VL supported, can't change\n"); + ksft_test_result_skip("change_sve_while_sme\n"); + return; + } + + /* Ensure we will trigger a change when we set the maximum */ + ret = prctl(sve_data->prctl_set, sve_data->min_vl); + if (ret != sve_data->min_vl) { + ksft_print_msg("Failed to set SVE VL %d: %d\n", + sve_data->min_vl, ret); + pass = false; + } + + /* Enable SM and ZA */ + smstart(); + + /* Trigger another VL change */ + ret = prctl(sve_data->prctl_set, sve_data->max_vl); + if (ret != sve_data->max_vl) { + ksft_print_msg("Failed to set SVE VL %d: %d\n", + sve_data->max_vl, ret); + pass = false; + } + + /* + * Spin for a bit with SM enabled to try to trigger another + * save/restore. We can't use syscalls without exiting + * streaming mode. + */ + for (i = 0; i < 100000000; i++) + smstart_sm(); + + /* + * TODO: Verify that ZA was preserved over the VL change and + * spin. + */ + + /* Clean up after ourselves */ + smstop(); + ret = prctl(sve_data->prctl_set, sve_data->default_vl); + if (ret != sve_data->default_vl) { + ksft_print_msg("Failed to restore SVE VL %d: %d\n", + sve_data->default_vl, ret); + pass = false; + } + + ksft_test_result(pass, "change_sve_with_za\n"); +} + +typedef void (*test_all_type)(void); + +static const struct { + const char *name; + test_all_type test; +} all_types_tests[] = { + { "change_sve_with_za", change_sve_with_za }, +}; + int main(void) { + bool all_supported = true; int i, j; ksft_print_header(); - ksft_set_plan(ARRAY_SIZE(tests) * ARRAY_SIZE(vec_data)); + ksft_set_plan(ARRAY_SIZE(tests) * ARRAY_SIZE(vec_data) + + ARRAY_SIZE(all_types_tests)); for (i = 0; i < ARRAY_SIZE(vec_data); i++) { struct vec_data *data = &vec_data[i]; unsigned long supported; supported = getauxval(data->hwcap_type) & data->hwcap; + if (!supported) + all_supported = false; for (j = 0; j < ARRAY_SIZE(tests); j++) { if (supported) @@ -666,5 +758,12 @@ int main(void) } } + for (i = 0; i < ARRAY_SIZE(all_types_tests); i++) { + if (all_supported) + all_types_tests[i].test(); + else + ksft_test_result_skip("%s\n", all_types_tests[i].name); + } + ksft_exit_pass(); }