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=-16.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,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 816FCC433E0 for ; Wed, 20 Jan 2021 13:56:16 +0000 (UTC) Received: from whitealder.osuosl.org (smtp1.osuosl.org [140.211.166.138]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 1C3B52339E for ; Wed, 20 Jan 2021 13:56:15 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1C3B52339E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lists.linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=virtualization-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by whitealder.osuosl.org (Postfix) with ESMTP id B1B3786A1D; Wed, 20 Jan 2021 13:56:15 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from whitealder.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id T7yFo2unRaOb; Wed, 20 Jan 2021 13:56:11 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by whitealder.osuosl.org (Postfix) with ESMTP id 4125A86A28; Wed, 20 Jan 2021 13:56:06 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 2C058C1DA7; Wed, 20 Jan 2021 13:56:06 +0000 (UTC) Received: from hemlock.osuosl.org (smtp2.osuosl.org [140.211.166.133]) by lists.linuxfoundation.org (Postfix) with ESMTP id 8B3BCC013A for ; Wed, 20 Jan 2021 13:56:04 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by hemlock.osuosl.org (Postfix) with ESMTP id 7A25687113 for ; Wed, 20 Jan 2021 13:56:04 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from hemlock.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id y8wvAK5uIoF8 for ; Wed, 20 Jan 2021 13:56:03 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by hemlock.osuosl.org (Postfix) with ESMTPS id 8A87C8711B for ; Wed, 20 Jan 2021 13:56:03 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1611150962; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=/muUWGGP2zH35/xgppym3fqM4u0SphD3mtIprEyxGx4=; b=VMhJpHDcvSEXbFEWKA9GubVoQYp4VKaRYV9omEvfifdGNmsi2qdDYOkGgJ6+7WDTBR6gyk B71NjwQJcqEJvu/X24KcXkeH3pZwEr6mZKAvCfDxSMFiBAHsT80SVSZpgogWrNASZUrrCy YPoqNduc3X0yy06rcU/rkGtZqZpDqK8= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 2AF44AE65; Wed, 20 Jan 2021 13:56:02 +0000 (UTC) To: xen-devel@lists.xenproject.org, x86@kernel.org, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org Subject: [PATCH v4 09/15] x86: add new features for paravirt patching Date: Wed, 20 Jan 2021 14:55:49 +0100 Message-Id: <20210120135555.32594-10-jgross@suse.com> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20210120135555.32594-1-jgross@suse.com> References: <20210120135555.32594-1-jgross@suse.com> MIME-Version: 1.0 Cc: Juergen Gross , "VMware, Inc." , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , Thomas Gleixner X-BeenThere: virtualization@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Linux virtualization List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Juergen Gross via Virtualization Reply-To: Juergen Gross Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: virtualization-bounces@lists.linux-foundation.org Sender: "Virtualization" For being able to switch paravirt patching from special cased custom code sequences to ALTERNATIVE handling some X86_FEATURE_* are needed as new features. This enables to have the standard indirect pv call as the default code and to patch that with the non-Xen custom code sequence via ALTERNATIVE patching later. Make sure paravirt patching is performed before alternative patching. Signed-off-by: Juergen Gross --- V3: - add comment (Boris Petkov) - no negative features (Boris Petkov) V4: - move paravirt_set_cap() to paravirt-spinlocks.c --- arch/x86/include/asm/cpufeatures.h | 2 ++ arch/x86/include/asm/paravirt.h | 10 ++++++++++ arch/x86/kernel/alternative.c | 30 ++++++++++++++++++++++++++-- arch/x86/kernel/paravirt-spinlocks.c | 9 +++++++++ 4 files changed, 49 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h index 84b887825f12..3ae8944b253a 100644 --- a/arch/x86/include/asm/cpufeatures.h +++ b/arch/x86/include/asm/cpufeatures.h @@ -238,6 +238,8 @@ #define X86_FEATURE_VMW_VMMCALL ( 8*32+19) /* "" VMware prefers VMMCALL hypercall instruction */ #define X86_FEATURE_SEV_ES ( 8*32+20) /* AMD Secure Encrypted Virtualization - Encrypted State */ #define X86_FEATURE_VM_PAGE_FLUSH ( 8*32+21) /* "" VM Page Flush MSR is supported */ +#define X86_FEATURE_PVUNLOCK ( 8*32+22) /* "" PV unlock function */ +#define X86_FEATURE_VCPUPREEMPT ( 8*32+23) /* "" PV vcpu_is_preempted function */ /* Intel-defined CPU features, CPUID level 0x00000007:0 (EBX), word 9 */ #define X86_FEATURE_FSGSBASE ( 9*32+ 0) /* RDFSBASE, WRFSBASE, RDGSBASE, WRGSBASE instructions*/ diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h index 1e45b46fae84..8c354099d9c3 100644 --- a/arch/x86/include/asm/paravirt.h +++ b/arch/x86/include/asm/paravirt.h @@ -47,6 +47,10 @@ static inline u64 paravirt_steal_clock(int cpu) return static_call(pv_steal_clock)(cpu); } +#ifdef CONFIG_PARAVIRT_SPINLOCKS +void __init paravirt_set_cap(void); +#endif + /* The paravirtualized I/O functions */ static inline void slow_down_io(void) { @@ -811,5 +815,11 @@ static inline void paravirt_arch_exit_mmap(struct mm_struct *mm) { } #endif + +#ifndef CONFIG_PARAVIRT_SPINLOCKS +static inline void paravirt_set_cap(void) +{ +} +#endif #endif /* __ASSEMBLY__ */ #endif /* _ASM_X86_PARAVIRT_H */ diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index 0a904fb2678b..221acb2b868a 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -28,6 +28,7 @@ #include #include #include +#include int __read_mostly alternatives_patched; @@ -730,6 +731,33 @@ void __init alternative_instructions(void) * patching. */ + /* + * Paravirt patching and alternative patching can be combined to + * replace a function call with a short direct code sequence (e.g. + * by setting a constant return value instead of doing that in an + * external function). + * In order to make this work the following sequence is required: + * 1. set (artificial) features depending on used paravirt + * functions which can later influence alternative patching + * 2. apply paravirt patching (generally replacing an indirect + * function call with a direct one) + * 3. apply alternative patching (e.g. replacing a direct function + * call with a custom code sequence) + * Doing paravirt patching after alternative patching would clobber + * the optimization of the custom code with a function call again. + */ + paravirt_set_cap(); + + /* + * First patch paravirt functions, such that we overwrite the indirect + * call with the direct call. + */ + apply_paravirt(__parainstructions, __parainstructions_end); + + /* + * Then patch alternatives, such that those paravirt calls that are in + * alternatives can be overwritten by their immediate fragments. + */ apply_alternatives(__alt_instructions, __alt_instructions_end); #ifdef CONFIG_SMP @@ -748,8 +776,6 @@ void __init alternative_instructions(void) } #endif - apply_paravirt(__parainstructions, __parainstructions_end); - restart_nmi(); alternatives_patched = 1; } diff --git a/arch/x86/kernel/paravirt-spinlocks.c b/arch/x86/kernel/paravirt-spinlocks.c index 4f75d0cf6305..9e1ea99ad9df 100644 --- a/arch/x86/kernel/paravirt-spinlocks.c +++ b/arch/x86/kernel/paravirt-spinlocks.c @@ -32,3 +32,12 @@ bool pv_is_native_vcpu_is_preempted(void) return pv_ops.lock.vcpu_is_preempted.func == __raw_callee_save___native_vcpu_is_preempted; } + +void __init paravirt_set_cap(void) +{ + if (!pv_is_native_spin_unlock()) + setup_force_cpu_cap(X86_FEATURE_PVUNLOCK); + + if (!pv_is_native_vcpu_is_preempted()) + setup_force_cpu_cap(X86_FEATURE_VCPUPREEMPT); +} -- 2.26.2 _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization