From mboxrd@z Thu Jan 1 00:00:00 1970 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=-9.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 9F8DAC433DF for ; Fri, 19 Jun 2020 14:08:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 862042166E for ; Fri, 19 Jun 2020 14:08:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733181AbgFSOIy (ORCPT ); Fri, 19 Jun 2020 10:08:54 -0400 Received: from mga06.intel.com ([134.134.136.31]:54754 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732664AbgFSOIV (ORCPT ); Fri, 19 Jun 2020 10:08:21 -0400 IronPort-SDR: RSVhp0ciGULioimL4pR9XJ2mscWeRDPjBUSg9IKD8R7N7lhFsppwrFcFXxsl8ckRynxfxx7oSv 1KdRPcH1Y4hA== X-IronPort-AV: E=McAfee;i="6000,8403,9656"; a="204452880" X-IronPort-AV: E=Sophos;i="5.75,255,1589266800"; d="scan'208";a="204452880" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Jun 2020 07:08:06 -0700 IronPort-SDR: mI46dL1kxtgpYfA1hwaKtplMWkBvdZzsK/ybGUYpD4TA7DJ/S742ckaAh5NWlOITdjG7KYY0ym s3BGHTtx8bpw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.75,255,1589266800"; d="scan'208";a="383837527" Received: from otc-lr-04.jf.intel.com ([10.54.39.143]) by fmsmga001.fm.intel.com with ESMTP; 19 Jun 2020 07:08:05 -0700 From: kan.liang@linux.intel.com To: peterz@infradead.org, mingo@redhat.com, acme@kernel.org, tglx@linutronix.de, bp@alien8.de, x86@kernel.org, linux-kernel@vger.kernel.org Cc: mark.rutland@arm.com, alexander.shishkin@linux.intel.com, jolsa@redhat.com, namhyung@kernel.org, dave.hansen@intel.com, yu-cheng.yu@intel.com, bigeasy@linutronix.de, gorcunov@gmail.com, hpa@zytor.com, alexey.budankov@linux.intel.com, eranian@google.com, ak@linux.intel.com, like.xu@linux.intel.com, yao.jin@linux.intel.com, Kan Liang Subject: [PATCH 19/21] x86/fpu/xstate: Add helpers for LBR dynamic supervisor feature Date: Fri, 19 Jun 2020 07:04:07 -0700 Message-Id: <1592575449-64278-20-git-send-email-kan.liang@linux.intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1592575449-64278-1-git-send-email-kan.liang@linux.intel.com> References: <1592575449-64278-1-git-send-email-kan.liang@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Kan Liang The LBR dynamic supervisor feature will be enabled in the perf subsystem later. A new structure, several helpers, and a macro are added as below to facilitate enabling the feature. - Currently, the structure for each state component is maintained in fpu/types.h. The structure for the new LBR state component should be maintained in the same place, which will be used in the following patch. - The perf subsystem will only need to save/restore the LBR state. However, the existing helpers save all supported supervisor states to a kernel buffer, which will be unnecessary. Two helpers are introduced to only save/restore requested dynamic supervisor states. The supervisor features in XFEATURE_MASK_SUPERVISOR_SUPPORTED and XFEATURE_MASK_SUPERVISOR_UNSUPPORTED mask cannot be saved/restored using these helpers. - The XSAVE buffer must be 64-byte aligned. A new macro is added to reflect the alignment requirement. The structure, the helpers, and the macro will be used in the following patch. Reviewed-by: Dave Hansen Signed-off-by: Kan Liang --- arch/x86/include/asm/fpu/types.h | 19 +++++++++++ arch/x86/include/asm/fpu/xstate.h | 5 +++ arch/x86/kernel/fpu/xstate.c | 72 +++++++++++++++++++++++++++++++++++++++ 3 files changed, 96 insertions(+) diff --git a/arch/x86/include/asm/fpu/types.h b/arch/x86/include/asm/fpu/types.h index 132e9cc..975f078 100644 --- a/arch/x86/include/asm/fpu/types.h +++ b/arch/x86/include/asm/fpu/types.h @@ -236,6 +236,25 @@ struct pkru_state { u32 pad; } __packed; +/* + * State component 15: Architectural LBR configuration state. + * The size of Arch LBR state depends on the number of LBRs (lbr_depth). + */ +struct arch_lbr_entry { + u64 lbr_from; + u64 lbr_to; + u64 lbr_info; +}; + +struct arch_lbr_state { + u64 lbr_ctl; + u64 lbr_depth; + u64 ler_from; + u64 ler_to; + u64 ler_info; + struct arch_lbr_entry entries[0]; +} __packed; + struct xstate_header { u64 xfeatures; u64 xcomp_bv; diff --git a/arch/x86/include/asm/fpu/xstate.h b/arch/x86/include/asm/fpu/xstate.h index 040c4d4..636c3ef 100644 --- a/arch/x86/include/asm/fpu/xstate.h +++ b/arch/x86/include/asm/fpu/xstate.h @@ -21,6 +21,8 @@ #define XSAVE_YMM_SIZE 256 #define XSAVE_YMM_OFFSET (XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET) +#define XSAVE_ALIGNMENT 64 + /* All currently supported user features */ #define XFEATURE_MASK_USER_SUPPORTED (XFEATURE_MASK_FP | \ XFEATURE_MASK_SSE | \ @@ -106,6 +108,9 @@ int copy_xstate_to_user(void __user *ubuf, struct xregs_state *xsave, unsigned i int copy_kernel_to_xstate(struct xregs_state *xsave, const void *kbuf); int copy_user_to_xstate(struct xregs_state *xsave, const void __user *ubuf); void copy_supervisor_to_kernel(struct xregs_state *xsave); +void copy_dynamic_supervisor_to_kernel(struct xregs_state *xstate, u64 mask); +void copy_kernel_to_dynamic_supervisor(struct xregs_state *xstate, u64 mask); + /* Validate an xstate header supplied by userspace (ptrace or sigreturn) */ int validate_user_xstate_header(const struct xstate_header *hdr); diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index 58d79f1..49e0347 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -1352,6 +1352,78 @@ void copy_supervisor_to_kernel(struct xregs_state *xstate) } } +/** + * copy_dynamic_supervisor_to_kernel() - Save dynamic supervisor states to + * an xsave area + * @xstate: A pointer to an xsave area + * @mask: Represent the dynamic supervisor features saved into the xsave area + * + * Only the dynamic supervisor states sets in the mask are saved into the xsave + * area (See the comment in XFEATURE_MASK_DYNAMIC for the details of dynamic + * supervisor feature). Besides the dynamic supervisor states, the legacy + * region and XSAVE header are also saved into the xsave area. The supervisor + * features in the XFEATURE_MASK_SUPERVISOR_SUPPORTED and + * XFEATURE_MASK_SUPERVISOR_UNSUPPORTED are not saved. + * + * The xsave area must be 64-bytes aligned. + */ +void copy_dynamic_supervisor_to_kernel(struct xregs_state *xstate, u64 mask) +{ + u64 dynamic_mask = xfeatures_mask_dynamic() & mask; + u32 lmask, hmask; + int err; + + if (WARN_ON_FPU(!boot_cpu_has(X86_FEATURE_XSAVES))) + return; + + if (WARN_ON_FPU(!dynamic_mask)) + return; + + lmask = dynamic_mask; + hmask = dynamic_mask >> 32; + + XSTATE_OP(XSAVES, xstate, lmask, hmask, err); + + /* Should never fault when copying to a kernel buffer */ + WARN_ON_FPU(err); +} + +/** + * copy_kernel_to_dynamic_supervisor() - Restore dynamic supervisor states from + * an xsave area + * @xstate: A pointer to an xsave area + * @mask: Represent the dynamic supervisor features restored from the xsave area + * + * Only the dynamic supervisor states sets in the mask are restored from the + * xsave area (See the comment in XFEATURE_MASK_DYNAMIC for the details of + * dynamic supervisor feature). Besides the dynamic supervisor states, the + * legacy region and XSAVE header are also restored from the xsave area. The + * supervisor features in the XFEATURE_MASK_SUPERVISOR_SUPPORTED and + * XFEATURE_MASK_SUPERVISOR_UNSUPPORTED are not restored. + * + * The xsave area must be 64-bytes aligned. + */ +void copy_kernel_to_dynamic_supervisor(struct xregs_state *xstate, u64 mask) +{ + u64 dynamic_mask = xfeatures_mask_dynamic() & mask; + u32 lmask, hmask; + int err; + + if (WARN_ON_FPU(!boot_cpu_has(X86_FEATURE_XSAVES))) + return; + + if (WARN_ON_FPU(!dynamic_mask)) + return; + + lmask = dynamic_mask; + hmask = dynamic_mask >> 32; + + XSTATE_OP(XRSTORS, xstate, lmask, hmask, err); + + /* Should never fault when copying from a kernel buffer */ + WARN_ON_FPU(err); +} + #ifdef CONFIG_PROC_PID_ARCH_STATUS /* * Report the amount of time elapsed in millisecond since last AVX512 -- 2.7.4