From patchwork Sun May 2 14:53:57 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Avi Kivity X-Patchwork-Id: 96355 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter.kernel.org (8.14.3/8.14.3) with ESMTP id o42EtkVq023851 for ; Sun, 2 May 2010 14:55:47 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757508Ab0EBOyj (ORCPT ); Sun, 2 May 2010 10:54:39 -0400 Received: from mx1.redhat.com ([209.132.183.28]:16863 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757086Ab0EBOyh (ORCPT ); Sun, 2 May 2010 10:54:37 -0400 Received: from int-mx04.intmail.prod.int.phx2.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.17]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id o42Es0jk009822 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Sun, 2 May 2010 10:54:00 -0400 Received: from cleopatra.tlv.redhat.com (cleopatra.tlv.redhat.com [10.35.255.11]) by int-mx04.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id o42ErwM7027072; Sun, 2 May 2010 10:53:59 -0400 Received: from localhost.localdomain (file.tlv.redhat.com [10.35.255.8]) by cleopatra.tlv.redhat.com (Postfix) with ESMTP id 4E23D250AD7; Sun, 2 May 2010 17:53:58 +0300 (IDT) From: Avi Kivity To: Dexuan Cui , Sheng Yang , Ingo Molnar , "H. Peter Anvin" Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Subject: [PATCH 1/2] x86: eliminate TS_XSAVE Date: Sun, 2 May 2010 17:53:57 +0300 Message-Id: <1272812038-32484-2-git-send-email-avi@redhat.com> In-Reply-To: <1272812038-32484-1-git-send-email-avi@redhat.com> References: <1272812038-32484-1-git-send-email-avi@redhat.com> X-Scanned-By: MIMEDefang 2.67 on 10.5.11.17 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.3 (demeter.kernel.org [140.211.167.41]); Sun, 02 May 2010 14:55:47 +0000 (UTC) diff --git a/arch/x86/include/asm/i387.h b/arch/x86/include/asm/i387.h index da29309..52f95c0 100644 --- a/arch/x86/include/asm/i387.h +++ b/arch/x86/include/asm/i387.h @@ -56,6 +56,18 @@ extern int restore_i387_xstate_ia32(void __user *buf); #define X87_FSW_ES (1 << 7) /* Exception Summary */ +static inline bool use_xsave(void) +{ + bool has_xsave; + + alternative_io("xor %0, %0", + "mov $1, %0", + X86_FEATURE_XSAVE, + "=g"(has_xsave)); + + return has_xsave; +} + #ifdef CONFIG_X86_64 /* Ignore delayed exceptions from user space */ @@ -99,7 +111,7 @@ static inline void clear_fpu_state(struct task_struct *tsk) /* * xsave header may indicate the init state of the FP. */ - if ((task_thread_info(tsk)->status & TS_XSAVE) && + if (use_xsave() && !(xstate->xsave_hdr.xstate_bv & XSTATE_FP)) return; @@ -164,7 +176,7 @@ static inline void fxsave(struct task_struct *tsk) static inline void __save_init_fpu(struct task_struct *tsk) { - if (task_thread_info(tsk)->status & TS_XSAVE) + if (use_xsave()) xsave(tsk); else fxsave(tsk); @@ -218,7 +230,7 @@ static inline int fxrstor_checking(struct i387_fxsave_struct *fx) */ static inline void __save_init_fpu(struct task_struct *tsk) { - if (task_thread_info(tsk)->status & TS_XSAVE) { + if (use_xsave()) { struct xsave_struct *xstate = &tsk->thread.xstate->xsave; struct i387_fxsave_struct *fx = &tsk->thread.xstate->fxsave; @@ -266,7 +278,7 @@ end: static inline int restore_fpu_checking(struct task_struct *tsk) { - if (task_thread_info(tsk)->status & TS_XSAVE) + if (use_xsave()) return xrstor_checking(&tsk->thread.xstate->xsave); else return fxrstor_checking(&tsk->thread.xstate->fxsave); diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h index d017ed5..d4092fa 100644 --- a/arch/x86/include/asm/thread_info.h +++ b/arch/x86/include/asm/thread_info.h @@ -242,7 +242,6 @@ static inline struct thread_info *current_thread_info(void) #define TS_POLLING 0x0004 /* true if in idle loop and not sleeping */ #define TS_RESTORE_SIGMASK 0x0008 /* restore signal mask in do_signal() */ -#define TS_XSAVE 0x0010 /* Use xsave/xrstor */ #define tsk_is_polling(t) (task_thread_info(t)->status & TS_POLLING) diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 4868e4a..c1c00d0 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1243,10 +1243,7 @@ void __cpuinit cpu_init(void) /* * Force FPU initialization: */ - if (cpu_has_xsave) - current_thread_info()->status = TS_XSAVE; - else - current_thread_info()->status = 0; + current_thread_info()->status = 0; clear_used_math(); mxcsr_feature_mask_init(); diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c index 54c31c2..14ca1dc 100644 --- a/arch/x86/kernel/i387.c +++ b/arch/x86/kernel/i387.c @@ -102,10 +102,7 @@ void __cpuinit fpu_init(void) mxcsr_feature_mask_init(); /* clean state in init */ - if (cpu_has_xsave) - current_thread_info()->status = TS_XSAVE; - else - current_thread_info()->status = 0; + current_thread_info()->status = 0; clear_used_math(); } #endif /* CONFIG_X86_64 */ diff --git a/arch/x86/kernel/xsave.c b/arch/x86/kernel/xsave.c index 782c3a3..c1b0a11 100644 --- a/arch/x86/kernel/xsave.c +++ b/arch/x86/kernel/xsave.c @@ -99,7 +99,7 @@ int save_i387_xstate(void __user *buf) if (err) return err; - if (task_thread_info(tsk)->status & TS_XSAVE) + if (use_xsave()) err = xsave_user(buf); else err = fxsave_user(buf); @@ -116,7 +116,7 @@ int save_i387_xstate(void __user *buf) clear_used_math(); /* trigger finit */ - if (task_thread_info(tsk)->status & TS_XSAVE) { + if (use_xsave()) { struct _fpstate __user *fx = buf; struct _xstate __user *x = buf; u64 xstate_bv; @@ -225,7 +225,7 @@ int restore_i387_xstate(void __user *buf) clts(); task_thread_info(current)->status |= TS_USEDFPU; } - if (task_thread_info(tsk)->status & TS_XSAVE) + if (use_xsave()) err = restore_user_xstate(buf); else err = fxrstor_checking((__force struct i387_fxsave_struct *)