From patchwork Fri Jul 2 22:04:38 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Isaku Yamahata X-Patchwork-Id: 12356687 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EDBE9C07E99 for ; Fri, 2 Jul 2021 22:06:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D492B613CD for ; Fri, 2 Jul 2021 22:06:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234127AbhGBWJO (ORCPT ); Fri, 2 Jul 2021 18:09:14 -0400 Received: from mga12.intel.com ([192.55.52.136]:50197 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233134AbhGBWH6 (ORCPT ); Fri, 2 Jul 2021 18:07:58 -0400 X-IronPort-AV: E=McAfee;i="6200,9189,10033"; a="188472739" X-IronPort-AV: E=Sophos;i="5.83,320,1616482800"; d="scan'208";a="188472739" Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Jul 2021 15:05:25 -0700 X-IronPort-AV: E=Sophos;i="5.83,320,1616482800"; d="scan'208";a="642814777" Received: from ls.sc.intel.com (HELO localhost) ([143.183.96.54]) by fmsmga006-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Jul 2021 15:05:24 -0700 From: isaku.yamahata@intel.com To: Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H . Peter Anvin" , Paolo Bonzini , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , erdemaktas@google.com, Connor Kuehl , Sean Christopherson , x86@kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: isaku.yamahata@intel.com, isaku.yamahata@gmail.com, Sean Christopherson Subject: [RFC PATCH v2 32/69] KVM: x86: Allow host-initiated WRMSR to set X2APIC regardless of CPUID Date: Fri, 2 Jul 2021 15:04:38 -0700 Message-Id: <9b00cb86878e9986f47a0febce3c0d2872d91443.1625186503.git.isaku.yamahata@intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Sean Christopherson Let userspace, or in the case of TDX, KVM itself, enable X2APIC even if X2APIC is not reported as supported in the guest's CPU model. KVM generally does not force specific ordering between ioctls(), e.g. this forces userspace to configure CPUID before MSRs. And for TDX, vCPUs will always run with X2APIC enabled, e.g. KVM will want/need to enable X2APIC from time zero. Signed-off-by: Sean Christopherson Signed-off-by: Isaku Yamahata --- arch/x86/kvm/x86.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 3407870b6f44..c231a88d5946 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -437,8 +437,11 @@ int kvm_set_apic_base(struct kvm_vcpu *vcpu, struct msr_data *msr_info) { enum lapic_mode old_mode = kvm_get_apic_mode(vcpu); enum lapic_mode new_mode = kvm_apic_mode(msr_info->data); - u64 reserved_bits = kvm_vcpu_reserved_gpa_bits_raw(vcpu) | 0x2ff | - (guest_cpuid_has(vcpu, X86_FEATURE_X2APIC) ? 0 : X2APIC_ENABLE); + u64 reserved_bits = kvm_vcpu_reserved_gpa_bits_raw(vcpu) | 0x2ff; + + if (!msr_info->host_initiated && + !guest_cpuid_has(vcpu, X86_FEATURE_X2APIC)) + reserved_bits |= X2APIC_ENABLE; if ((msr_info->data & reserved_bits) != 0 || new_mode == LAPIC_MODE_INVALID) return 1;