From patchwork Wed Aug 31 22:34:26 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Yang, Weijiang" X-Patchwork-Id: 12961644 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 128A3ECAAD5 for ; Thu, 1 Sep 2022 01:37:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232753AbiIABhN (ORCPT ); Wed, 31 Aug 2022 21:37:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34408 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232561AbiIABhG (ORCPT ); Wed, 31 Aug 2022 21:37:06 -0400 Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AC39515C379; Wed, 31 Aug 2022 18:37:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1661996222; x=1693532222; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=A8cSJfD6phET24cDsO35U4HPGEFSMDkBaLc3qK9pReM=; b=Yt6NiUjU8fAJnk4FJ7kSaJL8IbkzSmXiT/I5z7JCSATLIYKHDt3QD9aL Uzq6j8VT04uYlh9ZfFq5pBRfWmBJTTKuwtRop8waublSejAIxm3eWS65J 76CnSBQ/+QzPvYzHSwI7Moo2qm67gB0MsX6rhsXGR099YyaNY4VXyRcbx QErKcIbOxhVM4DFPxBUhfkD0Uqm90BwJT7oM1BOVeptPsfoBPsTZQ7Pwg 4GLlx/SVqVzRJ8B8NZC9Mneeb467dZIMpmm55fdz4JlVYUu2i1u+XMM4P PYY2+qKpdieP7oICj1KJncV5jXnHD4lG6c85WEz0Yy0ZJlIK6wLIGvkIG g==; X-IronPort-AV: E=McAfee;i="6500,9779,10456"; a="321735077" X-IronPort-AV: E=Sophos;i="5.93,279,1654585200"; d="scan'208";a="321735077" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 31 Aug 2022 18:37:00 -0700 X-IronPort-AV: E=Sophos;i="5.93,279,1654585200"; d="scan'208";a="754625976" Received: from embargo.jf.intel.com ([10.165.9.183]) by fmsmga001-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 31 Aug 2022 18:37:00 -0700 From: Yang Weijiang To: pbonzini@redhat.com, seanjc@google.com, kvm@vger.kernel.org Cc: like.xu.linux@gmail.com, kan.liang@linux.intel.com, wei.w.wang@intel.com, linux-kernel@vger.kernel.org Subject: [PATCH 03/15] KVM: x86: Refresh CPUID on writes to MSR_IA32_XSS Date: Wed, 31 Aug 2022 18:34:26 -0400 Message-Id: <20220831223438.413090-4-weijiang.yang@intel.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20220831223438.413090-1-weijiang.yang@intel.com> References: <20220831223438.413090-1-weijiang.yang@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Updated CPUID.0xD.0x1, which reports the current required storage size of all features enabled via XCR0 | XSS, when the guest's XSS is modified. 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 Message-Id: <20220517154100.29983-5-weijiang.yang@intel.com> Signed-off-by: Paolo Bonzini --- arch/x86/kvm/cpuid.c | 16 +++++++++++++--- arch/x86/kvm/x86.c | 6 ++++-- 2 files changed, 17 insertions(+), 5 deletions(-) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 75dcf7a72605..9ca592e969e3 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -272,9 +272,19 @@ static void __kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu, struct kvm_cpuid_e best->ebx = xstate_required_size(vcpu->arch.xcr0, false); 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); + if (best) { + if (cpuid_entry_has(best, X86_FEATURE_XSAVES) || + cpuid_entry_has(best, X86_FEATURE_XSAVEC)) { + u64 xstate = vcpu->arch.xcr0 | vcpu->arch.ia32_xss; + + best->ebx = xstate_required_size(xstate, true); + } + + if (!cpuid_entry_has(best, X86_FEATURE_XSAVES)) { + best->ecx = 0; + best->edx = 0; + } + } 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 17663cade3fa..92ff5f7d944b 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3647,8 +3647,10 @@ 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)