From nobody Mon Feb 9 13:36:54 2026 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.9]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6E6E4231829; Tue, 13 Jan 2026 00:18:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.9 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768263529; cv=none; b=ZAvP8E5uraPQtW8+RIMwDo2yMTWmUR+1I+pk2DSAc0NwVAVPjgWtHs20AJBNnFWIPq3gn8IwiuuZFH60XoTEG93XwwBmO3MxryPoDIR0ybDC9iEat7Z02+nXUkxfrHuPnn0BwQUGpPmkJH+7Rnvt9mkOZ2xzkJYCdSdGZH2IYic= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768263529; c=relaxed/simple; bh=aJDl/dLPu2CRPvLxhv0nvmTvQ6Z0nXekpGldPpU1kdI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=XP25Zz/An4QuCEUkDI37qJzvFz8s1fNkXq91Q2MhHpthoSZnwzAY5dB0IOBypcgVTVTH8s1jv7CBo8K5Nl/laGQUDycI3qXF/xrU+jFK5U5Vc9oo5xPN/2GNQIbOGCxUe81Tz80jZqLPwVPU2ltAeHXqbXMy6l3Wdr0aXW/9dJE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=CwKlG+C0; arc=none smtp.client-ip=192.198.163.9 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="CwKlG+C0" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1768263528; x=1799799528; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=aJDl/dLPu2CRPvLxhv0nvmTvQ6Z0nXekpGldPpU1kdI=; b=CwKlG+C0enDHa4Yv5VBLrWyPlsWQAo8k9k0dsoI9z6TuzJFrv58PPDiz kDE9g6aUsqcsB/FWtfaZBFDO8T56sXThDdvAFV6mdrrjWm7a1t5p5tbxf 9QGeXI3DKqraoSNW4HYbFIGD+bwhv5rTy4SWJGyy9GpldiU/Hdgiy9CSl NSeoJHOdYtA/7MR5BSMFFcRZ38gd0cKEkJ6KkkAZ6b8owfNra4aOGEFNe Ea+gl6vcnCuGve8ttUM1UtNadELPzK2rP+NLtyXAAnf9fWuZPBjDh5TYJ PFoce3GJJ8IqmRpUpCTbFTx5I+tm2/Ujnq6kpaigPySf5vuEpA3xDbe7t g==; X-CSE-ConnectionGUID: KBzdVkJ+RGO9OhtuDT5/Xw== X-CSE-MsgGUID: iOzoOMPrTo6Jr8Be/Dr5mQ== X-IronPort-AV: E=McAfee;i="6800,10657,11669"; a="80264291" X-IronPort-AV: E=Sophos;i="6.21,222,1763452800"; d="scan'208";a="80264291" Received: from orviesa009.jf.intel.com ([10.64.159.149]) by fmvoesa103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Jan 2026 16:18:48 -0800 X-CSE-ConnectionGUID: q7mfnKIWS2+qZkO2vBm4ow== X-CSE-MsgGUID: yPN8q+/kT+6eUprl2fmHyw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.21,222,1763452800"; d="scan'208";a="204042313" Received: from chang-linux-3.sc.intel.com (HELO chang-linux-3) ([172.25.66.172]) by orviesa009.jf.intel.com with ESMTP; 12 Jan 2026 16:18:48 -0800 From: "Chang S. Bae" To: pbonzini@redhat.com, seanjc@google.com Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, chao.gao@intel.com, chang.seok.bae@intel.com Subject: [PATCH v2 15/16] KVM: x86: Expose APX sub-features to guests Date: Mon, 12 Jan 2026 23:54:07 +0000 Message-ID: <20260112235408.168200-16-chang.seok.bae@intel.com> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20260112235408.168200-1-chang.seok.bae@intel.com> References: <20260112235408.168200-1-chang.seok.bae@intel.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Add CPUID leaf 0x29 sub-leaf 0 to enumerate APX sub-features to guests. This leaf currently defines the following sub-features: * New Conditional Instructions (NCI) * New Data Destination (NDD) * Flags Suppression (NF) The CPUID leaf is only exposed if the APX feature is enabled. Signed-off-by: Chang S. Bae --- arch/x86/include/asm/kvm_host.h | 1 + arch/x86/kvm/cpuid.c | 10 ++++++++-- arch/x86/kvm/reverse_cpuid.h | 4 ++++ 3 files changed, 13 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_hos= t.h index 9dedb8d77222..d75a76152340 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -794,6 +794,7 @@ enum kvm_only_cpuid_leafs { CPUID_24_0_EBX, CPUID_8000_0021_ECX, CPUID_7_1_ECX, + CPUID_29_0_EBX, NR_KVM_CPU_CAPS, =20 NKVMCAPINTS =3D NR_KVM_CPU_CAPS - NCAPINTS, diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 5431e31a4851..347b8f2402c7 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -1070,6 +1070,10 @@ void kvm_set_cpu_caps(void) F(AVX10_512), ); =20 + kvm_cpu_cap_init(CPUID_29_0_EBX, + F(APX_NCI_NDD_NF), + ); + kvm_cpu_cap_init(CPUID_8000_0001_ECX, F(LAHF_LM), F(CMP_LEGACY), @@ -1648,8 +1652,10 @@ static inline int __do_cpuid_func(struct kvm_cpuid_a= rray *array, u32 function) break; } case 0x29: { - /* No APX sub-features are supported yet */ - entry->eax =3D entry->ebx =3D entry->ecx =3D entry->edx =3D 0; + if (!(kvm_caps.supported_xcr0 & XFEATURE_MASK_APX)) { + entry->eax =3D entry->ebx =3D entry->ecx =3D entry->edx =3D 0; + break; + } break; } case KVM_CPUID_SIGNATURE: { diff --git a/arch/x86/kvm/reverse_cpuid.h b/arch/x86/kvm/reverse_cpuid.h index e538b5444919..f8587586d031 100644 --- a/arch/x86/kvm/reverse_cpuid.h +++ b/arch/x86/kvm/reverse_cpuid.h @@ -50,6 +50,9 @@ #define X86_FEATURE_AVX10_256 KVM_X86_FEATURE(CPUID_24_0_EBX, 17) #define X86_FEATURE_AVX10_512 KVM_X86_FEATURE(CPUID_24_0_EBX, 18) =20 +/* Intel-defined sub-features, CPUID level 0x00000029:0 (EBX) */ +#define X86_FEATURE_APX_NCI_NDD_NF KVM_X86_FEATURE(CPUID_29_0_EBX, 0) + /* CPUID level 0x80000007 (EDX). */ #define KVM_X86_FEATURE_CONSTANT_TSC KVM_X86_FEATURE(CPUID_8000_0007_EDX, = 8) =20 @@ -91,6 +94,7 @@ static const struct cpuid_reg reverse_cpuid[] =3D { [CPUID_24_0_EBX] =3D { 0x24, 0, CPUID_EBX}, [CPUID_8000_0021_ECX] =3D {0x80000021, 0, CPUID_ECX}, [CPUID_7_1_ECX] =3D { 7, 1, CPUID_ECX}, + [CPUID_29_0_EBX] =3D { 0x29, 0, CPUID_EBX}, }; =20 /* --=20 2.51.0