From patchwork Sat Jul 10 13:02:48 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Chang S. Bae" X-Patchwork-Id: 12368591 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=-17.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,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 48548C07E95 for ; Sat, 10 Jul 2021 13:09:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1E6FE613ED for ; Sat, 10 Jul 2021 13:09:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231232AbhGJNLy (ORCPT ); Sat, 10 Jul 2021 09:11:54 -0400 Received: from mga11.intel.com ([192.55.52.93]:46545 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229656AbhGJNLx (ORCPT ); Sat, 10 Jul 2021 09:11:53 -0400 X-IronPort-AV: E=McAfee;i="6200,9189,10040"; a="206812197" X-IronPort-AV: E=Sophos;i="5.84,229,1620716400"; d="scan'208";a="206812197" Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Jul 2021 06:09:07 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.84,229,1620716400"; d="scan'208";a="488742364" Received: from chang-linux-3.sc.intel.com ([172.25.66.175]) by FMSMGA003.fm.intel.com with ESMTP; 10 Jul 2021 06:09:06 -0700 From: "Chang S. Bae" To: bp@suse.de, luto@kernel.org, tglx@linutronix.de, mingo@kernel.org, x86@kernel.org Cc: len.brown@intel.com, dave.hansen@intel.com, thiago.macieira@intel.com, jing2.liu@intel.com, ravi.v.shankar@intel.com, linux-kernel@vger.kernel.org, chang.seok.bae@intel.com, kvm@vger.kernel.org Subject: [PATCH v7 01/26] x86/fpu/xstate: Modify the initialization helper to handle both static and dynamic buffers Date: Sat, 10 Jul 2021 06:02:48 -0700 Message-Id: <20210710130313.5072-2-chang.seok.bae@intel.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20210710130313.5072-1-chang.seok.bae@intel.com> References: <20210710130313.5072-1-chang.seok.bae@intel.com> Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Have the function initializing the XSTATE buffer take a struct fpu * pointer in preparation for dynamic state buffer support. init_fpstate is a special case, which is indicated by a null pointer parameter to fpstate_init(). Also, fpstate_init_xstate() now accepts the state component bitmap to customize the compacted format. No functional change. Signed-off-by: Chang S. Bae Reviewed-by: Len Brown Cc: x86@kernel.org Cc: linux-kernel@vger.kernel.org Cc: kvm@vger.kernel.org --- Changes from v5: * Moved fpstate_init_xstate() back to the header (again). * Massaged the changelog. Changes from v4: * Added a proper function description. (Borislav Petkov) * Added the likely() statement as a null pointer is a special case. Changes from v3: * Updated the changelog. (Borislav Petkov) * Updated the function comment to use kernel-doc style. (Borislav Petkov) Changes from v2: * Updated the changelog with task->fpu removed. (Borislav Petkov) --- arch/x86/include/asm/fpu/internal.h | 11 ++++++++++- arch/x86/kernel/fpu/core.c | 28 +++++++++++++++++----------- arch/x86/kernel/fpu/init.c | 2 +- arch/x86/kernel/fpu/xstate.c | 3 +-- arch/x86/kvm/x86.c | 2 +- 5 files changed, 30 insertions(+), 16 deletions(-) diff --git a/arch/x86/include/asm/fpu/internal.h b/arch/x86/include/asm/fpu/internal.h index 5a18694a89b2..c7a64e2806a9 100644 --- a/arch/x86/include/asm/fpu/internal.h +++ b/arch/x86/include/asm/fpu/internal.h @@ -80,7 +80,7 @@ static __always_inline __pure bool use_fxsr(void) extern union fpregs_state init_fpstate; -extern void fpstate_init(union fpregs_state *state); +extern void fpstate_init(struct fpu *fpu); #ifdef CONFIG_MATH_EMULATION extern void fpstate_init_soft(struct swregs_state *soft); #else @@ -88,6 +88,15 @@ static inline void fpstate_init_soft(struct swregs_state *soft) {} #endif extern void save_fpregs_to_fpstate(struct fpu *fpu); +static inline void fpstate_init_xstate(struct xregs_state *xsave, u64 mask) +{ + /* + * XRSTORS requires these bits set in xcomp_bv, or it will + * trigger #GP: + */ + xsave->header.xcomp_bv = XCOMP_BV_COMPACTED_FORMAT | mask; +} + /* Returns 0 or the negated trap number, which results in -EFAULT for #PF */ #define user_insn(insn, output, input...) \ ({ \ diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index 7ada7bd03a32..6bc8ad4a3bd7 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -203,15 +203,6 @@ void fpu_sync_fpstate(struct fpu *fpu) fpregs_unlock(); } -static inline void fpstate_init_xstate(struct xregs_state *xsave) -{ - /* - * XRSTORS requires these bits set in xcomp_bv, or it will - * trigger #GP: - */ - xsave->header.xcomp_bv = XCOMP_BV_COMPACTED_FORMAT | xfeatures_mask_all; -} - static inline void fpstate_init_fxstate(struct fxregs_state *fx) { fx->cwd = 0x37f; @@ -229,8 +220,23 @@ static inline void fpstate_init_fstate(struct fregs_state *fp) fp->fos = 0xffff0000u; } -void fpstate_init(union fpregs_state *state) +/** + * + * fpstate_init() - initialize the xstate buffer + * + * If @fpu is NULL, initialize init_fpstate. + * + * @fpu: A struct fpu * pointer + */ +void fpstate_init(struct fpu *fpu) { + union fpregs_state *state; + + if (likely(fpu)) + state = &fpu->state; + else + state = &init_fpstate; + if (!static_cpu_has(X86_FEATURE_FPU)) { fpstate_init_soft(&state->soft); return; @@ -239,7 +245,7 @@ void fpstate_init(union fpregs_state *state) memset(state, 0, fpu_kernel_xstate_size); if (static_cpu_has(X86_FEATURE_XSAVES)) - fpstate_init_xstate(&state->xsave); + fpstate_init_xstate(&state->xsave, xfeatures_mask_all); if (static_cpu_has(X86_FEATURE_FXSR)) fpstate_init_fxstate(&state->fxsave); else diff --git a/arch/x86/kernel/fpu/init.c b/arch/x86/kernel/fpu/init.c index 64e29927cc32..e14c72bc8706 100644 --- a/arch/x86/kernel/fpu/init.c +++ b/arch/x86/kernel/fpu/init.c @@ -124,7 +124,7 @@ static void __init fpu__init_system_generic(void) * Set up the legacy init FPU context. (xstate init might overwrite this * with a more modern format, if the CPU supports it.) */ - fpstate_init(&init_fpstate); + fpstate_init(NULL); fpu__init_system_mxcsr(); } diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index c8def1b7f8fb..d4fdceb9a309 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -395,8 +395,7 @@ static void __init setup_init_fpu_buf(void) print_xstate_features(); if (boot_cpu_has(X86_FEATURE_XSAVES)) - init_fpstate.xsave.header.xcomp_bv = XCOMP_BV_COMPACTED_FORMAT | - xfeatures_mask_all; + fpstate_init_xstate(&init_fpstate.xsave, xfeatures_mask_all); /* * Init all the features state with header.xfeatures being 0x0 diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index c6dc1b445231..606b66c9b44a 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -10597,7 +10597,7 @@ static void fx_init(struct kvm_vcpu *vcpu) if (!vcpu->arch.guest_fpu) return; - fpstate_init(&vcpu->arch.guest_fpu->state); + fpstate_init(vcpu->arch.guest_fpu); if (boot_cpu_has(X86_FEATURE_XSAVES)) vcpu->arch.guest_fpu->state.xsave.header.xcomp_bv = host_xcr0 | XSTATE_COMPACTION_ENABLED;