Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754836AbaG3PVM (ORCPT ); Wed, 30 Jul 2014 11:21:12 -0400 Received: from mx1.redhat.com ([209.132.183.28]:26862 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753866AbaG3PVK (ORCPT ); Wed, 30 Jul 2014 11:21:10 -0400 Message-ID: <53D90D5A.3060404@redhat.com> Date: Wed, 30 Jul 2014 17:20:58 +0200 From: Paolo Bonzini User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 MIME-Version: 1.0 To: Wanpeng Li , Jan Kiszka CC: Marcelo Tosatti , Gleb Natapov , Bandan Das , Zhang Yang , kvm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] KVM: nVMX: nested TPR shadow/threshold emulation References: <1406721880-5490-1-git-send-email-wanpeng.li@linux.intel.com> In-Reply-To: <1406721880-5490-1-git-send-email-wanpeng.li@linux.intel.com> X-Enigmail-Version: 1.6 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Il 30/07/2014 14:04, Wanpeng Li ha scritto: > @@ -7962,14 +7965,14 @@ static void prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12) > if (!vmx->rdtscp_enabled) > exec_control &= ~SECONDARY_EXEC_RDTSCP; > /* Take the following fields only from vmcs12 */ > - exec_control &= ~(SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES | > - SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY | > + exec_control &= ~(SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY | > SECONDARY_EXEC_APIC_REGISTER_VIRT); This change is wrong. You don't have to take L0's "virtualize APIC accesses" setting into account, because while running L2 you cannot modify L1's CR8 (only the virtual nested one). > + > + virtual_apic_page = nested_get_page(vcpu, > + vmcs12->virtual_apic_page_addr); > + if (vmcs_read64(VIRTUAL_APIC_PAGE_ADDR) != > + page_to_phys(virtual_apic_page)) > + vmcs_write64(VIRTUAL_APIC_PAGE_ADDR, > + page_to_phys(virtual_apic_page)); > + nested_release_page(virtual_apic_page); > + You cannot release this page here. You need to the exactly the same thing that is done for apic_access_page. One thing: > + if (nested_cpu_has(vmcs12, CPU_BASED_TPR_SHADOW)) > + vmcs_write32(TPR_THRESHOLD, vmcs12->tpr_threshold); I think you can just do this write unconditionally, since most hypervisors will enable this. Also, you probably can add the tpr threshold field to the read-write fields for shadow VMCS. Paolo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/