From mboxrd@z Thu Jan 1 00:00:00 1970 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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 7F5D7C83000 for ; Tue, 28 Apr 2020 23:10:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5957B20656 for ; Tue, 28 Apr 2020 23:10:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726822AbgD1XKh (ORCPT ); Tue, 28 Apr 2020 19:10:37 -0400 Received: from mga04.intel.com ([192.55.52.120]:60554 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726474AbgD1XKa (ORCPT ); Tue, 28 Apr 2020 19:10:30 -0400 IronPort-SDR: yPQrueutqA7+ZzVCkeo6dpzVxsAKJ3M8rzadjLlra1EMRE3YKCphSfNuUsZhLTeLGU36F0vOOS jT65xECDLTow== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Apr 2020 16:10:28 -0700 IronPort-SDR: HBNXtjzUTGy9RAIvMbWj7UjVEywi0T3ruJwfW6/gbOr7TCtwpoBMi6TcjOmDKS/wBs8gbDZ23Q UybHlICfsxpw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.73,328,1583222400"; d="scan'208";a="257774906" Received: from sjchrist-coffee.jf.intel.com ([10.54.74.202]) by orsmga003.jf.intel.com with ESMTP; 28 Apr 2020 16:10:26 -0700 From: Sean Christopherson To: Paolo Bonzini Cc: Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , kvm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 1/2] KVM: nVMX: Truncate writes to vmcs.SYSENTER_EIP/ESP for 32-bit vCPU Date: Tue, 28 Apr 2020 16:10:24 -0700 Message-Id: <20200428231025.12766-2-sean.j.christopherson@intel.com> X-Mailer: git-send-email 2.26.0 In-Reply-To: <20200428231025.12766-1-sean.j.christopherson@intel.com> References: <20200428231025.12766-1-sean.j.christopherson@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Explicitly truncate the data written to vmcs.SYSENTER_EIP/ESP on WRMSR if the virtual CPU doesn't support 64-bit mode. The SYSENTER address fields in the VMCS are natural width, i.e. bits 63:32 are dropped if the CPU doesn't support Intel 64 architectures. This behavior is visible to the guest after a VM-Exit/VM-Exit roundtrip, e.g. if the guest sets bits 63:32 in the actual MSR. Signed-off-by: Sean Christopherson --- arch/x86/kvm/vmx/vmx.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 3ab6ca6062ce..bc91ce499a7a 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -1936,6 +1936,16 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) return 0; } +static u64 nested_vmx_truncate_sysenter_addr(struct kvm_vcpu *vcpu, + u64 data) +{ +#ifdef CONFIG_X86_64 + if (!guest_cpuid_has(vcpu, X86_FEATURE_LM)) + return (u32)data; +#endif + return (unsigned long)data; +} + /* * Writes msr value into the appropriate "register". * Returns 0 on success, non-0 otherwise. @@ -1973,13 +1983,17 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) vmcs_write32(GUEST_SYSENTER_CS, data); break; case MSR_IA32_SYSENTER_EIP: - if (is_guest_mode(vcpu)) + if (is_guest_mode(vcpu)) { + data = nested_vmx_truncate_sysenter_addr(vcpu, data); get_vmcs12(vcpu)->guest_sysenter_eip = data; + } vmcs_writel(GUEST_SYSENTER_EIP, data); break; case MSR_IA32_SYSENTER_ESP: - if (is_guest_mode(vcpu)) + if (is_guest_mode(vcpu)) { + data = nested_vmx_truncate_sysenter_addr(vcpu, data); get_vmcs12(vcpu)->guest_sysenter_esp = data; + } vmcs_writel(GUEST_SYSENTER_ESP, data); break; case MSR_IA32_DEBUGCTLMSR: -- 2.26.0