From patchwork Mon Aug 29 16:25:00 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Brown X-Patchwork-Id: 12958175 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 BCCCFECAAD5 for ; Mon, 29 Aug 2022 16:35:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229753AbiH2QfZ (ORCPT ); Mon, 29 Aug 2022 12:35:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47706 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229738AbiH2QfY (ORCPT ); Mon, 29 Aug 2022 12:35:24 -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 1728119C34 for ; Mon, 29 Aug 2022 09:35:23 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id A7FAD611BD for ; Mon, 29 Aug 2022 16:35:22 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AF42EC4347C; Mon, 29 Aug 2022 16:35:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1661790922; bh=DNdz0MfFndJNgNHVZx0vWnDoBM1u55kaIwwlDgaROqg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=H4tyKCRzIH3WGa5oMyNIZhMtpmXFcFWPDTm8gd1mtiFrIXfQvPo8eihhkbBKxooC5 eYVnfgPIqDLSwcYf/XrchhQLzesyGWPFasbRS6o3coWVrUzo17qxRJTBsyFtNaHt38 0mmF8EFLUaEEAv0rC/OeCEaA9KeZrUtIsgC/88HwXeqOgZ8s4OrObMgEDNN18/UxRz 2Fd17/Qt2iM+Z244d4dJPsH7i02gp7xhxhNsG0bMshn5CCOm74TWP09EgsubNR1dZE MRh7V94BwEU8paiXWuwxXyPlUEzqnMpi1iNs/nO/hZRJ1erIMYFXXOQQcH4rkeuTIE JjI4qVrSlBAUw== From: Mark Brown To: Catalin Marinas , Will Deacon , Shuah Khan Cc: Marc Zyngier , Mark Rutland , Zhang Lei , linux-kselftest@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Mark Brown Subject: [PATCH v3 1/3] kselftest/arm64: Correct buffer allocation for SVE Z registers Date: Mon, 29 Aug 2022 17:25:00 +0100 Message-Id: <20220829162502.886816-2-broonie@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220829162502.886816-1-broonie@kernel.org> References: <20220829162502.886816-1-broonie@kernel.org> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=1460; i=broonie@kernel.org; h=from:subject; bh=DNdz0MfFndJNgNHVZx0vWnDoBM1u55kaIwwlDgaROqg=; b=owEBbQGS/pANAwAKASTWi3JdVIfQAcsmYgBjDOhb7hmLtHE4+oP5TALfAhsi/OSeQlXehOcaVmuA 77uU7OuJATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCYwzoWwAKCRAk1otyXVSH0BGeB/ 4qaCmgsaUpcOB/fYTFhRObGqDtriLa5HBZ6BBaO6NJM19w9qyWAHnQeDzIP654HehfEaJucNGu/BzA yDHsMRBpZs7d8V+is61MYJXnhBGud0sQ/yl7wDlaz1fiXaM61CDNb/BlZ3pB4YlBk0G+/04jto64oU H+MSnB8rx5d6ZJZpBuRA9D1fQnq18BXzdi1yWofLPs6EEoIPHYzNQSZtTAlPteY9/ylG9soGgaw7R9 eMF7u7O5aAUxJVhCdViBvHEQzdfQBeRcrRY5eOn9uHB3xuBHozYnqQ1mA9PkFlgPcmrLkW740NdBnS cawSc92OXz9KU/Jgn+f3IP02QJ6kCY X-Developer-Key: i=broonie@kernel.org; a=openpgp; fpr=3F2568AAC26998F9E813A1C5C3F436CA30F5D8EB Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org The buffer used for verifying SVE Z registers allocated enough space for 16 maximally sized registers rather than 32 due to using the macro for the number of P registers. In practice this didn't matter since for historical reasons the maximum VQ defined in the ABI is greater the architectural maximum so we will always allocate more space than is needed even with emulated platforms implementing the architectural maximum. Still, we should use the right define. Signed-off-by: Mark Brown Acked-by: Catalin Marinas --- tools/testing/selftests/arm64/abi/syscall-abi.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/arm64/abi/syscall-abi.c b/tools/testing/selftests/arm64/abi/syscall-abi.c index b632bfe9e022..95229fa73232 100644 --- a/tools/testing/selftests/arm64/abi/syscall-abi.c +++ b/tools/testing/selftests/arm64/abi/syscall-abi.c @@ -113,8 +113,8 @@ static int check_fpr(struct syscall_cfg *cfg, int sve_vl, int sme_vl, } static uint8_t z_zero[__SVE_ZREG_SIZE(SVE_VQ_MAX)]; -uint8_t z_in[SVE_NUM_PREGS * __SVE_ZREG_SIZE(SVE_VQ_MAX)]; -uint8_t z_out[SVE_NUM_PREGS * __SVE_ZREG_SIZE(SVE_VQ_MAX)]; +uint8_t z_in[SVE_NUM_ZREGS * __SVE_ZREG_SIZE(SVE_VQ_MAX)]; +uint8_t z_out[SVE_NUM_ZREGS * __SVE_ZREG_SIZE(SVE_VQ_MAX)]; static void setup_z(struct syscall_cfg *cfg, int sve_vl, int sme_vl, uint64_t svcr) From patchwork Mon Aug 29 16:25:01 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Brown X-Patchwork-Id: 12958176 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 5FAEDECAAD5 for ; Mon, 29 Aug 2022 16:35:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229738AbiH2Qfb (ORCPT ); Mon, 29 Aug 2022 12:35:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48016 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230119AbiH2Qf2 (ORCPT ); Mon, 29 Aug 2022 12:35:28 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CAA3122BCF for ; Mon, 29 Aug 2022 09:35:27 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 5126EB81115 for ; Mon, 29 Aug 2022 16:35:26 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A0505C43140; Mon, 29 Aug 2022 16:35:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1661790925; bh=I6wbY4rBExBRkBYLUHMGd3IIhweWX+ewlcK2hqnl2UM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bJN55/cT/Jv8gQBym99PQFhZVkPlgUyahwE7vFMqw+d7VCCdzvO1UsUKQxOKhrs7G 0h6tu5WJ4p4NEd0ExKS0E625aEk7Ry1vcI11rcf1YIlV6Y+SggtTa1Bstv7ymIk8Pv mEOmUIlZgwguHrx/4pt4xIHZgAPIcQVVtZ3hXKIvTHRgbzJl561nWUWbMa4I7/p8Qi Tx1s7JdpC8IFzPxwC2DZzFmnD3bG6h58IJfL04UsRfmuf2SMRZMkkYjArnawUEF8ns BT4XO674xlzGSnHjxkNTx/KfbcCZPm070alwOagYqe4K723lpmUgFNl2ztscqMGig5 YmugubJXWQbjw== From: Mark Brown To: Catalin Marinas , Will Deacon , Shuah Khan Cc: Marc Zyngier , Mark Rutland , Zhang Lei , linux-kselftest@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Mark Brown Subject: [PATCH v3 2/3] arm64/sve: Document our actual ABI for clearing registers on syscall Date: Mon, 29 Aug 2022 17:25:01 +0100 Message-Id: <20220829162502.886816-3-broonie@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220829162502.886816-1-broonie@kernel.org> References: <20220829162502.886816-1-broonie@kernel.org> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=1446; i=broonie@kernel.org; h=from:subject; bh=I6wbY4rBExBRkBYLUHMGd3IIhweWX+ewlcK2hqnl2UM=; b=owEBbQGS/pANAwAKASTWi3JdVIfQAcsmYgBjDOhc9QwzDpe3nJ1hAN12I5LNc/Gpmp6X+5qwHlQC GtmYMn+JATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCYwzoXAAKCRAk1otyXVSH0Gj/B/ 9PM726kcYnVozQ0nOQeDbXTdsXF/9ttCi4akkyNY7hvAmqN59eWkE30bKBwM/LiP2zkFtMIFfIKx1M My+FE9LoGI0qb2mw5MKVqLqz+yaIksmr07uqxdmYcOcy9vPSiK0tNb/NsoS517QAg89W73H627jguK 0f33pDEFbLihaKls2CabPwGS09mgXAwjJGmlyoXthXHmebxgeKBUBHgopki410tYT/tjwxckeyNtGR bvfDggkYjUPInzrKcuX4y3Gb4rvzEbSjGRmh61YcP+HOD2unpADiFOepnLL8Jdr/P/zqLT6IrdjF5q rm17qS1F6UNmzjZxP7WFpyTxmNUFRM X-Developer-Key: i=broonie@kernel.org; a=openpgp; fpr=3F2568AAC26998F9E813A1C5C3F436CA30F5D8EB Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org Currently our ABI documentation says that the state of the bits in the Z registers not shared with the V registers becomes undefined on syscall but our actual implementation unconditionally clears these bits. Taking advantage of the flexibility of our documented ABI would be a change in the observable ABI so there is concern around doing so, instead document the actual behaviour so that it is more discoverable for userspace programmers who might be able to take advantage of it and to record our decision about not changing the kernel ABI. This makes qemu's user mode implementation buggy since it does not clear these bits. Signed-off-by: Mark Brown Acked-by: Catalin Marinas --- Documentation/arm64/sve.rst | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/Documentation/arm64/sve.rst b/Documentation/arm64/sve.rst index 93c2c2990584..e39acf95d157 100644 --- a/Documentation/arm64/sve.rst +++ b/Documentation/arm64/sve.rst @@ -111,7 +111,7 @@ the SVE instruction set architecture. * On syscall, V0..V31 are preserved (as without SVE). Thus, bits [127:0] of Z0..Z31 are preserved. All other bits of Z0..Z31, and all of P0..P15 and FFR - become unspecified on return from a syscall. + become zero on return from a syscall. * The SVE registers are not used to pass arguments to or receive results from any syscall. From patchwork Mon Aug 29 16:25:02 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Brown X-Patchwork-Id: 12958177 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 30A9CECAAD2 for ; Mon, 29 Aug 2022 16:35:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230070AbiH2Qff (ORCPT ); Mon, 29 Aug 2022 12:35:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48298 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229841AbiH2Qfe (ORCPT ); Mon, 29 Aug 2022 12:35:34 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 16E421835A for ; Mon, 29 Aug 2022 09:35:32 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id BD0A8B81115 for ; Mon, 29 Aug 2022 16:35:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 98F26C433D7; Mon, 29 Aug 2022 16:35:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1661790928; bh=CIPBmVfQzkh057P6zvdPDrIMmBHR91ofrbBRCTsg6JQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=K21x9x1Xpk2h7QV3UuBjRbmSAzTyid4A11nSpWe7VUPAyBS1sI75gehm0nq0NaGhX XHau+hUfcRwCby32PJGAiK779BthPT4biTYJ8Ydfb10vJsnYVJ4IIo1729zIuyhaLH nS/Z7XIGf4CbjhwskfDLIece3ersPtMINV2+6dJaYoSo9A2TTIuKLuM8ZXs7W6cTjy kJMyttlQdtr87oCjviaVs18ntXypWef4lTeOiE94agu55wxW14Www81nRUJ1ayp7IV zhPFX1vqs+o8lYIbx4cSXQdBSJSxLoo2+OorJYovNFYQTb1kooMht+Myt81hv2KuEU 2UK5GWQMFUdPg== From: Mark Brown To: Catalin Marinas , Will Deacon , Shuah Khan Cc: Marc Zyngier , Mark Rutland , Zhang Lei , linux-kselftest@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Mark Brown Subject: [PATCH v3 3/3] kselftest/arm64: Enforce actual ABI for SVE syscalls Date: Mon, 29 Aug 2022 17:25:02 +0100 Message-Id: <20220829162502.886816-4-broonie@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220829162502.886816-1-broonie@kernel.org> References: <20220829162502.886816-1-broonie@kernel.org> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=3860; i=broonie@kernel.org; h=from:subject; bh=CIPBmVfQzkh057P6zvdPDrIMmBHR91ofrbBRCTsg6JQ=; b=owEBbQGS/pANAwAKASTWi3JdVIfQAcsmYgBjDOhdnpEhoEDG2B+XRiPlA45vp9CEmQ5KfPZbT89A 7vNdv/KJATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCYwzoXQAKCRAk1otyXVSH0OUcB/ 92h0A6InK6c2NEtI1HC27AWXr3nj9Zl22xRI57h4ksygZu4rqq+QrKab32Gl0ijHNYrlixfPkzAvai q/Cd0QAmxXuTc4JAG/1I8b5bqtRReDL0bEPeK9IHA2oZ38zT4QrvyFtmbe3Q+pBSP3BK4PDMVj4YO/ lApm3njoUCu3L5tr0w7z+o9+W4lN4lVRrASmUb7eJWp2e7UDJw/lPFeQBUDMCoxhNv3bw9JvI9zWpb L3kUHCNsZrteX/eQ4UwEs+r+Up3F3V8mg1crCueJ/NBDEr9ltIBYlS+glpalpyU7fJLL7PSVnPGXJu JrKXdfg5F0s9Rp1lhvYgNxg5ycXC5X X-Developer-Key: i=broonie@kernel.org; a=openpgp; fpr=3F2568AAC26998F9E813A1C5C3F436CA30F5D8EB Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org Currently syscall-abi permits the bits in Z registers not shared with the V registers as well as all of the predicate registers to be preserved on syscall but the actual implementation has always cleared them and our documentation has now been updated to make that the documented ABI so update the syscall-abi test to match. Signed-off-by: Mark Brown Acked-by: Catalin Marinas --- .../testing/selftests/arm64/abi/syscall-abi.c | 57 ++++++++++++------- 1 file changed, 38 insertions(+), 19 deletions(-) diff --git a/tools/testing/selftests/arm64/abi/syscall-abi.c b/tools/testing/selftests/arm64/abi/syscall-abi.c index 95229fa73232..dd7ebe536d05 100644 --- a/tools/testing/selftests/arm64/abi/syscall-abi.c +++ b/tools/testing/selftests/arm64/abi/syscall-abi.c @@ -112,6 +112,8 @@ static int check_fpr(struct syscall_cfg *cfg, int sve_vl, int sme_vl, return errors; } +#define SVE_Z_SHARED_BYTES (128 / 8) + static uint8_t z_zero[__SVE_ZREG_SIZE(SVE_VQ_MAX)]; uint8_t z_in[SVE_NUM_ZREGS * __SVE_ZREG_SIZE(SVE_VQ_MAX)]; uint8_t z_out[SVE_NUM_ZREGS * __SVE_ZREG_SIZE(SVE_VQ_MAX)]; @@ -133,22 +135,39 @@ static int check_z(struct syscall_cfg *cfg, int sve_vl, int sme_vl, if (!sve_vl) return 0; - /* - * After a syscall the low 128 bits of the Z registers should - * be preserved and the rest be zeroed or preserved, except if - * we were in streaming mode in which case the low 128 bits may - * also be cleared by the transition out of streaming mode. - */ for (i = 0; i < SVE_NUM_ZREGS; i++) { - void *in = &z_in[reg_size * i]; - void *out = &z_out[reg_size * i]; - - if ((memcmp(in, out, SVE_VQ_BYTES) != 0) && - !((svcr & SVCR_SM_MASK) && - memcmp(z_zero, out, SVE_VQ_BYTES) == 0)) { - ksft_print_msg("%s SVE VL %d Z%d low 128 bits changed\n", - cfg->name, sve_vl, i); - errors++; + uint8_t *in = &z_in[reg_size * i]; + uint8_t *out = &z_out[reg_size * i]; + + if (svcr & SVCR_SM_MASK) { + /* + * In streaming mode the whole register should + * be cleared by the transition out of + * streaming mode. + */ + if (memcmp(z_zero, out, reg_size) != 0) { + ksft_print_msg("%s SVE VL %d Z%d non-zero\n", + cfg->name, sve_vl, i); + errors++; + } + } else { + /* + * For standard SVE the low 128 bits should be + * preserved and any additional bits cleared. + */ + if (memcmp(in, out, SVE_Z_SHARED_BYTES) != 0) { + ksft_print_msg("%s SVE VL %d Z%d low 128 bits changed\n", + cfg->name, sve_vl, i); + errors++; + } + + if (reg_size > SVE_Z_SHARED_BYTES && + (memcmp(z_zero, out + SVE_Z_SHARED_BYTES, + reg_size - SVE_Z_SHARED_BYTES) != 0)) { + ksft_print_msg("%s SVE VL %d Z%d high bits non-zero\n", + cfg->name, sve_vl, i); + errors++; + } } } @@ -176,9 +195,9 @@ static int check_p(struct syscall_cfg *cfg, int sve_vl, int sme_vl, if (!sve_vl) return 0; - /* After a syscall the P registers should be preserved or zeroed */ + /* After a syscall the P registers should be zeroed */ for (i = 0; i < SVE_NUM_PREGS * reg_size; i++) - if (p_out[i] && (p_in[i] != p_out[i])) + if (p_out[i]) errors++; if (errors) ksft_print_msg("%s SVE VL %d predicate registers non-zero\n", @@ -226,9 +245,9 @@ static int check_ffr(struct syscall_cfg *cfg, int sve_vl, int sme_vl, !(getauxval(AT_HWCAP2) & HWCAP2_SME_FA64)) return 0; - /* After a syscall the P registers should be preserved or zeroed */ + /* After a syscall FFR should be zeroed */ for (i = 0; i < reg_size; i++) - if (ffr_out[i] && (ffr_in[i] != ffr_out[i])) + if (ffr_out[i]) errors++; if (errors) ksft_print_msg("%s SVE VL %d FFR non-zero\n",