From nobody Sat Dec 27 10:55:48 2025 Received: from mgamail.intel.com (mgamail.intel.com [134.134.136.24]) (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 29DDC57892; Thu, 21 Dec 2023 09:03:56 +0000 (UTC) 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="DTPXkwad" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1703149436; x=1734685436; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=T3X3fq7AuhPHM7WBbIb8WSrvU0kDaKc1Pze+7ySZgmo=; b=DTPXkwadQomHmYUAJApWB3QTmecm6hxN6LGwSdA20O33cfl/db3+FdBI nnEzAeBEECjCFkl/Rp3gfukdboPuQru3gq3ZKIXrE7R2A/LjrOtPlpLlG Qk63IpbRujHhi7jYPjy8KDNX9/dcwsqArK7zgIw1ibmfnYqIyOnAAyEQR a4tbHKF8dhuLCF2CdkEnLfGUIYNEKTci8/p2X48SPZST92IQgEXqbjwyk tVoyoGEUm0MJOo28L6fZAcDW9wpici/JLachYJH3cz01K5T+6mTtHXPPI TaJei2Pd4bQGfNmLUVOydcxPPcp8h3vUmLHJaRL1fr9ETvHJ6T7BYW/On A==; X-IronPort-AV: E=McAfee;i="6600,9927,10930"; a="398729721" X-IronPort-AV: E=Sophos;i="6.04,293,1695711600"; d="scan'208";a="398729721" Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Dec 2023 01:03:46 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10930"; a="900028597" X-IronPort-AV: E=Sophos;i="6.04,293,1695711600"; d="scan'208";a="900028597" Received: from 984fee00a5ca.jf.intel.com (HELO embargo.jf.intel.com) ([10.165.9.183]) by orsmga004-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Dec 2023 01:03:11 -0800 From: Yang Weijiang To: seanjc@google.com, pbonzini@redhat.com, dave.hansen@intel.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org Cc: peterz@infradead.org, chao.gao@intel.com, rick.p.edgecombe@intel.com, mlevitsk@redhat.com, john.allen@amd.com, weijiang.yang@intel.com Subject: [PATCH v8 12/26] KVM: x86: Report XSS as to-be-saved if there are supported features Date: Thu, 21 Dec 2023 09:02:25 -0500 Message-Id: <20231221140239.4349-13-weijiang.yang@intel.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20231221140239.4349-1-weijiang.yang@intel.com> References: <20231221140239.4349-1-weijiang.yang@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" From: Sean Christopherson Add MSR_IA32_XSS to list of MSRs reported to userspace if supported_xss is non-zero, i.e. KVM supports at least one XSS based feature. Before enabling CET virtualization series, guest IA32_MSR_XSS is guaranteed to be 0, i.e., XSAVES/XRSTORS is executed in non-root mode with XSS =3D=3D 0, which equals to the effect of XSAVE/XRSTOR. Signed-off-by: Sean Christopherson Signed-off-by: Yang Weijiang Reviewed-by: Maxim Levitsky --- arch/x86/kvm/x86.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 594c9e025f95..b3a39886e418 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1464,6 +1464,7 @@ static const u32 msrs_to_save_base[] =3D { MSR_IA32_UMWAIT_CONTROL, =20 MSR_IA32_XFD, MSR_IA32_XFD_ERR, + MSR_IA32_XSS, }; =20 static const u32 msrs_to_save_pmu[] =3D { @@ -7374,6 +7375,10 @@ static void kvm_probe_msr_to_save(u32 msr_index) if (!(kvm_get_arch_capabilities() & ARCH_CAP_TSX_CTRL_MSR)) return; break; + case MSR_IA32_XSS: + if (!kvm_caps.supported_xss) + return; + break; default: break; } --=20 2.39.3