From nobody Thu Sep 18 05:26:22 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 7790EC4332F for ; Sat, 10 Dec 2022 16:19:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229902AbiLJQTN (ORCPT ); Sat, 10 Dec 2022 11:19:13 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45590 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229877AbiLJQTD (ORCPT ); Sat, 10 Dec 2022 11:19:03 -0500 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C3661193F0; Sat, 10 Dec 2022 08:18:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1670689138; x=1702225138; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=sSdYThVrddLtjTse/5AQd2MpfOega7QZ/yPiX4mvGVs=; b=ibIpHy57kBOjhYGb/FTX1tuNxG/GYy8/JmXOpBqvWpL8iSNftS8YEHMP FnQ/NKuodRm1FF0sCrlBnl/teFyPVwk8swnbNSAVuj618WQXwASYIoyP5 JK/06cWXem+Nud4yirh3YpqvHpI6UKBW/ATmZ+mPp+Rb9A0EnDdQDAwup z7VWFC0/m6NNnAkkpSyGr754wRLWssVuSTua4Hs6VRO+Mn/VpUGSSwOuu U+2b/cGfFmd5ac7d6wEbtPkvd0JlS4LRmuGCJ8sfFi5f+W+ntV7wxIMcF VdR7Bm4k1+bGikIdokQn91vHrcRK+3DROu0QbOMHhKHVGeo5e9VipZdMi g==; X-IronPort-AV: E=McAfee;i="6500,9779,10557"; a="318780447" X-IronPort-AV: E=Sophos;i="5.96,234,1665471600"; d="scan'208";a="318780447" 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 08:18:58 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10557"; a="711208638" X-IronPort-AV: E=Sophos;i="5.96,234,1665471600"; d="scan'208";a="711208638" 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 08:18:55 -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 3/9] KVM: x86: Add a kvm-only leaf for BHI_CTRL Date: Sun, 11 Dec 2022 00:00:40 +0800 Message-Id: <20221210160046.2608762-4-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 BHI_CTRL. If a guest is using BHB-clearing sequence and cannot see BHI_CTRL and the host enumerates BHI, KVM is responsible for setting BHI_DIS_S for the guest. This allows VM migration from parts doesn't enumerate BHI to those that enumerate BHI. Signed-off-by: Zhang Chen --- arch/x86/kvm/cpuid.c | 2 +- arch/x86/kvm/reverse_cpuid.h | 2 ++ 2 files changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 8d45bc0b4b7c..91af27cc57e5 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -669,7 +669,7 @@ void kvm_set_cpu_caps(void) ); =20 kvm_cpu_cap_init_scattered(CPUID_7_2_EDX, - SF(RRSBA_CTRL) + SF(RRSBA_CTRL) | F(BHI_CTRL) ); =20 kvm_cpu_cap_mask(CPUID_8000_0001_ECX, diff --git a/arch/x86/kvm/reverse_cpuid.h b/arch/x86/kvm/reverse_cpuid.h index 4c38ed61c505..cf4e209ce2f6 100644 --- a/arch/x86/kvm/reverse_cpuid.h +++ b/arch/x86/kvm/reverse_cpuid.h @@ -27,6 +27,8 @@ enum kvm_only_cpuid_leafs { =20 /* Intel-defined sub-features, CPUID level 0x00000007:2 (EDX)*/ #define KVM_X86_FEATURE_RRSBA_CTRL KVM_X86_FEATURE(CPUID_7_2_EDX, 2) +/* X86_FEATURE_BHI_CTRL only used by KVM */ +#define X86_FEATURE_BHI_CTRL KVM_X86_FEATURE(CPUID_7_2_EDX, 4) =20 struct cpuid_reg { u32 function; --=20 2.25.1