From patchwork Thu Aug 21 11:46:50 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wanpeng Li X-Patchwork-Id: 4757011 Return-Path: X-Original-To: patchwork-kvm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 82B9B9F344 for ; Thu, 21 Aug 2014 11:45:04 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 97F582011D for ; Thu, 21 Aug 2014 11:45:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8FAB820109 for ; Thu, 21 Aug 2014 11:45:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754655AbaHULom (ORCPT ); Thu, 21 Aug 2014 07:44:42 -0400 Received: from mga09.intel.com ([134.134.136.24]:61221 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754609AbaHULoj (ORCPT ); Thu, 21 Aug 2014 07:44:39 -0400 Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga102.jf.intel.com with ESMTP; 21 Aug 2014 04:38:43 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.01,908,1400050800"; d="scan'208";a="591294480" Received: from unknown (HELO vt-ivt2.tsp.org) ([10.239.48.107]) by orsmga002.jf.intel.com with ESMTP; 21 Aug 2014 04:44:36 -0700 From: Wanpeng Li To: Paolo Bonzini Cc: Marcelo Tosatti , Gleb Natapov , Zhang Yang , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Wanpeng Li Subject: [PATCH v6 2/2] KVM: nVMX: nested TPR shadow/threshold emulation Date: Thu, 21 Aug 2014 19:46:50 +0800 Message-Id: <1408621610-9665-2-git-send-email-wanpeng.li@linux.intel.com> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1408621610-9665-1-git-send-email-wanpeng.li@linux.intel.com> References: <1408621610-9665-1-git-send-email-wanpeng.li@linux.intel.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Spam-Status: No, score=-7.6 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This patch fix bug https://bugzilla.kernel.org/show_bug.cgi?id=61411 TPR shadow/threshold feature is important to speed up the Windows guest. Besides, it is a must feature for certain VMM. We map virtual APIC page address and TPR threshold from L1 VMCS. If TPR_BELOW_THRESHOLD VM exit is triggered by L2 guest and L1 interested in, we inject it into L1 VMM for handling. Reviewed-by: Paolo Bonzini Signed-off-by: Wanpeng Li --- v5 -> v6: * fix bisect issue v4 -> v5: * moving the nested_vmx_failValid call inside the "if (!vmx->nested.virtual_apic_page)" v3 -> v4: * add Paolo's Reviewed-by * unconditionally fail the vmentry, with a comment * setup the TPR_SHADOW/virtual_apic_page of vmcs02 based on vmcs01 if L2 owns the APIC v2 -> v3: * nested vm entry failure if both tpr shadow and cr8 exiting bits are not set v1 -> v2: * don't take L0's "virtualize APIC accesses" setting into account * virtual_apic_page do exactly the same thing that is done for apic_access_page * add the tpr threshold field to the read-write fields for shadow VMCS arch/x86/kvm/vmx.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 48 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 24380a9..0eea49c 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -379,6 +379,7 @@ struct nested_vmx { * we must keep them pinned while L2 runs. */ struct page *apic_access_page; + struct page *virtual_apic_page; u64 msr_ia32_feature_control; struct hrtimer preemption_timer; @@ -533,6 +534,7 @@ static int max_shadow_read_only_fields = ARRAY_SIZE(shadow_read_only_fields); static unsigned long shadow_read_write_fields[] = { + TPR_THRESHOLD, GUEST_RIP, GUEST_RSP, GUEST_CR0, @@ -2330,7 +2332,7 @@ static __init void nested_vmx_setup_ctls_msrs(void) CPU_BASED_MOV_DR_EXITING | CPU_BASED_UNCOND_IO_EXITING | CPU_BASED_USE_IO_BITMAPS | CPU_BASED_MONITOR_EXITING | CPU_BASED_RDPMC_EXITING | CPU_BASED_RDTSC_EXITING | - CPU_BASED_PAUSE_EXITING | + CPU_BASED_PAUSE_EXITING | CPU_BASED_TPR_SHADOW | CPU_BASED_ACTIVATE_SECONDARY_CONTROLS; /* * We can allow some features even when not supported by the @@ -6150,6 +6152,10 @@ static void free_nested(struct vcpu_vmx *vmx) nested_release_page(vmx->nested.apic_access_page); vmx->nested.apic_access_page = 0; } + if (vmx->nested.virtual_apic_page) { + nested_release_page(vmx->nested.virtual_apic_page); + vmx->nested.virtual_apic_page = 0; + } nested_free_all_saved_vmcss(vmx); } @@ -6938,7 +6944,7 @@ static bool nested_vmx_exit_handled(struct kvm_vcpu *vcpu) case EXIT_REASON_MCE_DURING_VMENTRY: return 0; case EXIT_REASON_TPR_BELOW_THRESHOLD: - return 1; + return nested_cpu_has(vmcs12, CPU_BASED_TPR_SHADOW); case EXIT_REASON_APIC_ACCESS: return nested_cpu_has2(vmcs12, SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES); @@ -7059,6 +7065,12 @@ static int vmx_handle_exit(struct kvm_vcpu *vcpu) static void update_cr8_intercept(struct kvm_vcpu *vcpu, int tpr, int irr) { + struct vmcs12 *vmcs12 = get_vmcs12(vcpu); + + if (is_guest_mode(vcpu) && + nested_cpu_has(vmcs12, CPU_BASED_TPR_SHADOW)) + return; + if (irr == -1 || tpr < irr) { vmcs_write32(TPR_THRESHOLD, 0); return; @@ -7847,6 +7859,27 @@ static bool nested_get_vmcs12_pages(struct kvm_vcpu *vcpu, vmx->nested.apic_access_page = nested_get_page(vcpu, vmcs12->apic_access_addr); } + + if (nested_cpu_has(vmcs12, CPU_BASED_TPR_SHADOW)) { + if (vmx->nested.virtual_apic_page) /* shouldn't happen */ + nested_release_page(vmx->nested.virtual_apic_page); + vmx->nested.virtual_apic_page = + nested_get_page(vcpu, vmcs12->virtual_apic_page_addr); + + /* + * Failing the vm entry is _not_ what the processor does + * but it's basically the only possibility we have. + * We could still enter the guest if CR8 load exits are + * enabled, CR8 store exits are enabled, and virtualize APIC + * access is disabled; in this case the processor would never + * use the TPR shadow and we could simply clear the bit from + * the execution control. But such a configuration is useless, + * so let's keep the code simple. + */ + if (!vmx->nested.virtual_apic_page) + return false; + } + return true; } @@ -8040,6 +8073,15 @@ static void prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12) exec_control &= ~CPU_BASED_VIRTUAL_NMI_PENDING; exec_control &= ~CPU_BASED_TPR_SHADOW; exec_control |= vmcs12->cpu_based_vm_exec_control; + + if (exec_control & CPU_BASED_TPR_SHADOW) { + vmcs_write64(VIRTUAL_APIC_PAGE_ADDR, + page_to_phys(vmx->nested.virtual_apic_page)); + vmcs_write32(TPR_THRESHOLD, vmcs12->tpr_threshold); + } else if (vm_need_tpr_shadow(vmx->vcpu.kvm)) + vmcs_write64(VIRTUAL_APIC_PAGE_ADDR, + __pa(vmx->vcpu.arch.apic->regs)); + /* * Merging of IO and MSR bitmaps not currently supported. * Rather, exit every time. @@ -8807,6 +8849,10 @@ static void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 exit_reason, nested_release_page(vmx->nested.apic_access_page); vmx->nested.apic_access_page = 0; } + if (vmx->nested.virtual_apic_page) { + nested_release_page(vmx->nested.virtual_apic_page); + vmx->nested.virtual_apic_page = 0; + } /* * Exiting from L2 to L1, we're now back to L1 which thinks it just