From patchwork Thu May 11 04:08:43 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Yang, Weijiang" X-Patchwork-Id: 13237545 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 92350C77B7F for ; Thu, 11 May 2023 07:13:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237424AbjEKHNp (ORCPT ); Thu, 11 May 2023 03:13:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47414 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237174AbjEKHNk (ORCPT ); Thu, 11 May 2023 03:13:40 -0400 Received: from mga18.intel.com (mga18.intel.com [134.134.136.126]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3DC0D2D6A; Thu, 11 May 2023 00:13:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1683789212; x=1715325212; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=7J0BAjKpZeee0YTws2bhg1lRumDrGh+SHYT9zVcLiQI=; b=ZXxOZbgg6h0AcatxizMAgzefIy8sFAe70lc+skijsFs03JCXvTFYHpJk aNSk99IPDb6H5rC7DW/X+zjairDBnxqmi+l0a9M4GROUw/gSXxqx5HjhV uHSxBhnXZW5Wblo+pL5j8K8sGFBHmt2V1yz0mWSgJ9XGLfkT5fQoRlpHa VV4OohyJkxImzYEy89uTt6w+Dt34gZ6P1JsY8+C3U7uRBq9e9fWMJVbIB 1gBm04D+2uZkKNVm1v8Rp2wFiIWgDHn0kuOCqFF0l9Ee2Rgdvo0ZbKR1K Zr0cM9bldTFMgATKvvLRSNj+o5OojdWGiBVHLiwsy7ORArutN/jFMlpxr w==; X-IronPort-AV: E=McAfee;i="6600,9927,10706"; a="334896562" X-IronPort-AV: E=Sophos;i="5.99,266,1677571200"; d="scan'208";a="334896562" Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 May 2023 00:13:31 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10706"; a="1029512362" X-IronPort-AV: E=Sophos;i="5.99,266,1677571200"; d="scan'208";a="1029512362" Received: from embargo.jf.intel.com ([10.165.9.183]) by fmsmga005-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 May 2023 00:13:23 -0700 From: Yang Weijiang To: seanjc@google.com, pbonzini@redhat.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org Cc: peterz@infradead.org, rppt@kernel.org, binbin.wu@linux.intel.com, rick.p.edgecombe@intel.com, weijiang.yang@intel.com, john.allen@amd.com, Zhang Yi Z Subject: [PATCH v3 07/21] KVM:x86: Refresh CPUID on write to guest MSR_IA32_XSS Date: Thu, 11 May 2023 00:08:43 -0400 Message-Id: <20230511040857.6094-8-weijiang.yang@intel.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20230511040857.6094-1-weijiang.yang@intel.com> References: <20230511040857.6094-1-weijiang.yang@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Update CPUID(EAX=0DH,ECX=1) when the guest's XSS is modified. CPUID(EAX=0DH,ECX=1).EBX reports current required storage size for all features enabled via XCR0 | XSS so that guest can allocate correct xsave buffer. Note, KVM does not yet support any XSS based features, i.e. supported_xss is guaranteed to be zero at this time. Co-developed-by: Zhang Yi Z Signed-off-by: Zhang Yi Z Signed-off-by: Yang Weijiang --- arch/x86/kvm/cpuid.c | 7 +++++-- arch/x86/kvm/x86.c | 6 ++++-- 2 files changed, 9 insertions(+), 4 deletions(-) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 123bf8b97a4b..cbb1b8a65502 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -277,8 +277,11 @@ static void __kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu, struct kvm_cpuid_e best = cpuid_entry2_find(entries, nent, 0xD, 1); if (best && (cpuid_entry_has(best, X86_FEATURE_XSAVES) || - cpuid_entry_has(best, X86_FEATURE_XSAVEC))) - best->ebx = xstate_required_size(vcpu->arch.xcr0, true); + cpuid_entry_has(best, X86_FEATURE_XSAVEC))) { + u64 xstate = vcpu->arch.xcr0 | vcpu->arch.ia32_xss; + + best->ebx = xstate_required_size(xstate, true); + } best = __kvm_find_kvm_cpuid_features(vcpu, entries, nent); if (kvm_hlt_in_guest(vcpu->kvm) && best && diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 33a780fe820b..ab3360a10933 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3776,8 +3776,10 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) */ if (data & ~kvm_caps.supported_xss) return 1; - vcpu->arch.ia32_xss = data; - kvm_update_cpuid_runtime(vcpu); + if (vcpu->arch.ia32_xss != data) { + vcpu->arch.ia32_xss = data; + kvm_update_cpuid_runtime(vcpu); + } break; case MSR_SMI_COUNT: if (!msr_info->host_initiated)