From patchwork Thu Jun 16 08:46:31 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Yang, Weijiang" X-Patchwork-Id: 12883573 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 DD581C433EF for ; Thu, 16 Jun 2022 08:49:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1376489AbiFPItF (ORCPT ); Thu, 16 Jun 2022 04:49:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35260 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1376318AbiFPIsv (ORCPT ); Thu, 16 Jun 2022 04:48:51 -0400 Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DC8231A3AC; Thu, 16 Jun 2022 01:47:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1655369263; x=1686905263; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=IQkHWXIhJkLWuzUiRVSy3/hnrnF2/6up2mxzDX06RXk=; b=g1tyla9ZBRLbEmnA5s4+Lt5aVyRyeTG2xbu2N1/uN7rvlxqtRBuD3Fad HtRmcFFEvSaEW7Lk+HZKpIeu2jyjvok/z+an8TZCY3WsvpyUkkOBMpC7V k4A/kaw17JMZMOjunDLnpuFzW259URG8YnOg21ABP1mpidQ0iww9zYYBt dn7eXt75SEp+kZiv1JbgxHSjJIM9HumIvtVV80tI3Y7tYfyVlhwOAepoU yxvVYrXeCGZQnphVhnH92Nl5mp4LFzHQtnRhK809sEe9Mi8LxDTVHk2km CMOm43atldtYNUa3skmA6sn1oabuW0E4tkkhnp9QcsgRKcFPAcVfOLVwU w==; X-IronPort-AV: E=McAfee;i="6400,9594,10379"; a="259664553" X-IronPort-AV: E=Sophos;i="5.91,304,1647327600"; d="scan'208";a="259664553" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Jun 2022 01:47:41 -0700 X-IronPort-AV: E=Sophos;i="5.91,304,1647327600"; d="scan'208";a="613083146" Received: from embargo.jf.intel.com ([10.165.9.183]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Jun 2022 01:47:40 -0700 From: Yang Weijiang To: pbonzini@redhat.com, seanjc@google.com, x86@kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, rick.p.edgecombe@intel.com Cc: weijiang.yang@intel.com, Zhang Yi Z Subject: [PATCH 07/19] KVM: x86: Refresh CPUID on writes to MSR_IA32_XSS Date: Thu, 16 Jun 2022 04:46:31 -0400 Message-Id: <20220616084643.19564-8-weijiang.yang@intel.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20220616084643.19564-1-weijiang.yang@intel.com> References: <20220616084643.19564-1-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 d47222ab8e6e..46ca0f1abbcb 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -240,9 +240,19 @@ 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 f525228168b8..06fbd3daf393 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3605,8 +3605,10 @@ 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)