From nobody Thu Sep 18 05:26:21 2025 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 27D7EC4708D for ; Sat, 10 Dec 2022 16:19:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229934AbiLJQTJ (ORCPT ); Sat, 10 Dec 2022 11:19:09 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45460 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229863AbiLJQS6 (ORCPT ); Sat, 10 Dec 2022 11:18:58 -0500 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D54041903C; Sat, 10 Dec 2022 08:18:55 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1670689135; x=1702225135; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=jJywodcOgHQB5TBBvwp4cOqodYErhHuV9OjQHIcmq+8=; b=kD8bJerWlYZ84OWcjdj+cNsMLrho4toNcJf9C2/Tlw0qX6YpnLAllWSo +v+QDkLr+4J7PXi3xd1x9jnpgvCxS9Kb9a3aZWaVD70NMRnpzVo8uzBCX fT+wfVOVJZGqx9HTHZqAsSsWpVvgpczAbyRcakkp82K46fjoVlmXxNJ7S dnWnBt43w9n+aOs890fSzZYpmpgB/m4w6jffotBglmFDO8nzww8o2rby3 nNgbFK4sn1gY4ehUvKBMNLSfbPbxrYRx6A9QZMp7hYfP8Xfb5pu1xdCyd 8ygFunGZYZ9d39qc+Yrimq6eUMWeX11GpZB7lFX9o3Efv+SYQbeqKTFBh w==; X-IronPort-AV: E=McAfee;i="6500,9779,10557"; a="318780434" X-IronPort-AV: E=Sophos;i="5.96,234,1665471600"; d="scan'208";a="318780434" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Dec 2022 08:18:55 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10557"; a="711208627" X-IronPort-AV: E=Sophos;i="5.96,234,1665471600"; d="scan'208";a="711208627" Received: from unknown (HELO localhost.localdomain) ([10.239.161.133]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Dec 2022 08:18:52 -0800 From: Zhang Chen To: x86@kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: Zhang Chen , Chao Gao , Pawan Gupta , Paolo Bonzini , Sean Christopherson , "H. Peter Anvin" , Dave Hansen , Borislav Petkov , Ingo Molnar , Thomas Gleixner Subject: [RFC PATCH 2/9] KVM: x86: Add a kvm-only leaf for RRSBA_CTRL Date: Sun, 11 Dec 2022 00:00:39 +0800 Message-Id: <20221210160046.2608762-3-chen.zhang@intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20221210160046.2608762-1-chen.zhang@intel.com> References: <20221210160046.2608762-1-chen.zhang@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" KVM needs to check if guests can see RRSBA_CTRL. If a guest is using retpoline and cannot see RRSBA_CTRL and the host enumerates RRSBA, KVM is responsible for setting RRSBA_DIS_S for the guest. This allows VM migration from parts doesn't enumerates RRSBA to those that enumerate RRSBA. Signed-off-by: Zhang Chen --- arch/x86/kvm/cpuid.c | 4 ++++ arch/x86/kvm/reverse_cpuid.h | 7 +++++++ 2 files changed, 11 insertions(+) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 62bc7a01cecc..8d45bc0b4b7c 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -668,6 +668,10 @@ void kvm_set_cpu_caps(void) SF(SGX1) | SF(SGX2) ); =20 + kvm_cpu_cap_init_scattered(CPUID_7_2_EDX, + SF(RRSBA_CTRL) + ); + kvm_cpu_cap_mask(CPUID_8000_0001_ECX, F(LAHF_LM) | F(CMP_LEGACY) | 0 /*SVM*/ | 0 /* ExtApicSpace */ | F(CR8_LEGACY) | F(ABM) | F(SSE4A) | F(MISALIGNSSE) | diff --git a/arch/x86/kvm/reverse_cpuid.h b/arch/x86/kvm/reverse_cpuid.h index a19d473d0184..4c38ed61c505 100644 --- a/arch/x86/kvm/reverse_cpuid.h +++ b/arch/x86/kvm/reverse_cpuid.h @@ -13,6 +13,7 @@ */ enum kvm_only_cpuid_leafs { CPUID_12_EAX =3D NCAPINTS, + CPUID_7_2_EDX, NR_KVM_CPU_CAPS, =20 NKVMCAPINTS =3D NR_KVM_CPU_CAPS - NCAPINTS, @@ -24,6 +25,9 @@ enum kvm_only_cpuid_leafs { #define KVM_X86_FEATURE_SGX1 KVM_X86_FEATURE(CPUID_12_EAX, 0) #define KVM_X86_FEATURE_SGX2 KVM_X86_FEATURE(CPUID_12_EAX, 1) =20 +/* Intel-defined sub-features, CPUID level 0x00000007:2 (EDX)*/ +#define KVM_X86_FEATURE_RRSBA_CTRL KVM_X86_FEATURE(CPUID_7_2_EDX, 2) + struct cpuid_reg { u32 function; u32 index; @@ -46,6 +50,7 @@ static const struct cpuid_reg reverse_cpuid[] =3D { [CPUID_8000_0007_EBX] =3D {0x80000007, 0, CPUID_EBX}, [CPUID_7_EDX] =3D { 7, 0, CPUID_EDX}, [CPUID_7_1_EAX] =3D { 7, 1, CPUID_EAX}, + [CPUID_7_2_EDX] =3D { 7, 2, CPUID_EDX}, [CPUID_12_EAX] =3D {0x00000012, 0, CPUID_EAX}, [CPUID_8000_001F_EAX] =3D {0x8000001f, 0, CPUID_EAX}, }; @@ -78,6 +83,8 @@ static __always_inline u32 __feature_translate(int x86_fe= ature) return KVM_X86_FEATURE_SGX1; else if (x86_feature =3D=3D X86_FEATURE_SGX2) return KVM_X86_FEATURE_SGX2; + else if (x86_feature =3D=3D X86_FEATURE_RRSBA_CTRL) + return KVM_X86_FEATURE_RRSBA_CTRL; =20 return x86_feature; } --=20 2.25.1