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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 370A0C433EF for ; Wed, 5 Jan 2022 12:36:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240264AbiAEMgt (ORCPT ); Wed, 5 Jan 2022 07:36:49 -0500 Received: from mga04.intel.com ([192.55.52.120]:6468 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240119AbiAEMgL (ORCPT ); Wed, 5 Jan 2022 07:36:11 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1641386171; x=1672922171; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=9ikQIeAI7bgDZMp4PMT+Z9stDWFN29Q+i4g4969BawI=; b=RI/W0qgcuj7F3yYKGlZr+6k3VaTFHi6qeCuzdV3ynk/obIxLK9WjQJ8i 59HQTVF8JNK3ZQ/K6AqjNWbFkI70BKxJ2o11QFn90lSetpme+n8d+XsWA kmN4NMAutkz8k5PRPs9lWWnixTj5Vql5xwSwlYrx0mFqHnO2HowHuh/Lg YvwqSPkyii8I5+V7u+vTleOCiDJ2vR7oyjJS1FuZkyXlTe1hOx4XEKA5z tc54K1oa1UkXximyU4zWEmdkrZ8xcMVId8Sya5kIdyv5mXqqHll5H6GIm 3Qr8w7NOz+dpg979rkGTOhpzwoQekFyO4Qf1FhSCqxO0js5wmwhw2RkUj w==; X-IronPort-AV: E=McAfee;i="6200,9189,10217"; a="241249382" X-IronPort-AV: E=Sophos;i="5.88,263,1635231600"; d="scan'208";a="241249382" Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Jan 2022 04:35:40 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.88,263,1635231600"; d="scan'208";a="591004871" Received: from 984fee00bf64.jf.intel.com ([10.165.54.77]) by fmsmga004.fm.intel.com with ESMTP; 05 Jan 2022 04:35:39 -0800 From: Yang Zhong To: x86@kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, pbonzini@redhat.com, corbet@lwn.net, shuah@kernel.org, seanjc@google.com Cc: jun.nakajima@intel.com, kevin.tian@intel.com, jing2.liu@linux.intel.com, jing2.liu@intel.com, guang.zeng@intel.com, wei.w.wang@intel.com, yang.zhong@intel.com Subject: [PATCH v5 14/21] kvm: x86: Disable RDMSR interception of IA32_XFD_ERR Date: Wed, 5 Jan 2022 04:35:25 -0800 Message-Id: <20220105123532.12586-15-yang.zhong@intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220105123532.12586-1-yang.zhong@intel.com> References: <20220105123532.12586-1-yang.zhong@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jing Liu This saves one unnecessary VM-exit in guest #NM handler, given that the MSR is already restored with the guest value before the guest is resumed. Suggested-by: Paolo Bonzini Signed-off-by: Jing Liu Signed-off-by: Yang Zhong --- arch/x86/kvm/vmx/vmx.c | 6 ++++++ arch/x86/kvm/vmx/vmx.h | 2 +- 2 files changed, 7 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 939e6aad128c..b601dc8a7f13 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -162,6 +162,7 @@ static u32 vmx_possible_passthrough_msrs[MAX_POSSIBLE_PASSTHROUGH_MSRS] = { MSR_FS_BASE, MSR_GS_BASE, MSR_KERNEL_GS_BASE, + MSR_IA32_XFD_ERR, #endif MSR_IA32_SYSENTER_CS, MSR_IA32_SYSENTER_ESP, @@ -7290,6 +7291,11 @@ static void vmx_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu) } } + if (kvm_cpu_cap_has(X86_FEATURE_XFD)) + vmx_set_intercept_for_msr(vcpu, MSR_IA32_XFD_ERR, MSR_TYPE_R, + !guest_cpuid_has(vcpu, X86_FEATURE_XFD)); + + set_cr4_guest_host_mask(vmx); vmx_write_encls_bitmap(vcpu, NULL); diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h index acb874db02da..e0922c80c9d1 100644 --- a/arch/x86/kvm/vmx/vmx.h +++ b/arch/x86/kvm/vmx/vmx.h @@ -352,7 +352,7 @@ struct vcpu_vmx { struct lbr_desc lbr_desc; /* Save desired MSR intercept (read: pass-through) state */ -#define MAX_POSSIBLE_PASSTHROUGH_MSRS 13 +#define MAX_POSSIBLE_PASSTHROUGH_MSRS 14 struct { DECLARE_BITMAP(read, MAX_POSSIBLE_PASSTHROUGH_MSRS); DECLARE_BITMAP(write, MAX_POSSIBLE_PASSTHROUGH_MSRS);