Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932559AbaGOMcE (ORCPT ); Tue, 15 Jul 2014 08:32:04 -0400 Received: from cn.fujitsu.com ([59.151.112.132]:12490 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1758321AbaGOMcA (ORCPT ); Tue, 15 Jul 2014 08:32:00 -0400 X-IronPort-AV: E=Sophos;i="5.00,896,1396972800"; d="scan'208";a="33293187" Message-ID: <53C51E66.7030208@cn.fujitsu.com> Date: Tue, 15 Jul 2014 20:28:22 +0800 From: Tang Chen User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:12.0) Gecko/20120430 Thunderbird/12.0.1 MIME-Version: 1.0 To: Gleb Natapov CC: Jan Kiszka , , , , , , , Subject: Re: [PATCH v2 5/5] kvm, mem-hotplug: Do not pin apic access page in memory. References: <1404824492-30095-1-git-send-email-tangchen@cn.fujitsu.com> <1404824492-30095-6-git-send-email-tangchen@cn.fujitsu.com> <20140712080442.GH4399@minantech.com> <53C38D55.2040307@cn.fujitsu.com> <20140714145822.GK4399@minantech.com> <53C51608.4080109@web.de> <20140715120921.GT18167@minantech.com> In-Reply-To: <20140715120921.GT18167@minantech.com> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.167.226.99] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/15/2014 08:09 PM, Gleb Natapov wrote: > On Tue, Jul 15, 2014 at 01:52:40PM +0200, Jan Kiszka wrote: ...... >> >> I cannot follow your concerns yet. Specifically, how should >> APIC_ACCESS_ADDR (the VMCS field, right?) change while L2 is running? We >> currently pin/unpin on L1->L2/L2->L1, respectively. Or what do you mean? >> > I am talking about this case: > if (cpu_has_secondary_exec_ctrls()) {a > } else { > exec_control |= > SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES; > vmcs_write64(APIC_ACCESS_ADDR, > page_to_phys(vcpu->kvm->arch.apic_access_page)); > } > We do not pin here. > Hi Gleb, 7905 if (exec_control & SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES) { ...... 7912 if (vmx->nested.apic_access_page) /* shouldn't happen */ 7913 nested_release_page(vmx->nested.apic_access_page); 7914 vmx->nested.apic_access_page = 7915 nested_get_page(vcpu, vmcs12->apic_access_addr); I thought you were talking about the problem here. We pin vmcs12->apic_access_addr in memory. And I think we should do the same thing to this page as to L1 vm. Right ? ...... 7922 if (!vmx->nested.apic_access_page) 7923 exec_control &= 7924 ~SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES; 7925 else 7926 vmcs_write64(APIC_ACCESS_ADDR, 7927 page_to_phys(vmx->nested.apic_access_page)); 7928 } else if (vm_need_virtualize_apic_accesses(vmx->vcpu.kvm)) { 7929 exec_control |= 7930 SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES; 7931 vmcs_write64(APIC_ACCESS_ADDR, 7932 page_to_phys(vcpu->kvm->arch.apic_access_page)); 7933 } And yes, we have the problem you said here. We can migrate the page while L2 vm is running. So I think we should enforce L2 vm to exit to L1. Right ? Thanks. -- 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/