From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754132AbaIKKTJ (ORCPT ); Thu, 11 Sep 2014 06:19:09 -0400 Received: from cn.fujitsu.com ([59.151.112.132]:49421 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1753776AbaIKKTG (ORCPT ); Thu, 11 Sep 2014 06:19:06 -0400 X-IronPort-AV: E=Sophos;i="5.04,504,1406563200"; d="scan'208";a="35809176" Message-ID: <5411776B.3070302@cn.fujitsu.com> Date: Thu, 11 Sep 2014 18:20:27 +0800 From: tangchen User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.1.0 MIME-Version: 1.0 To: Paolo Bonzini , , , , CC: , , , , Subject: Re: [PATCH v5 4/7] kvm, mem-hotplug: Reload L1' apic access page on migration in vcpu_enter_guest(). References: <1410413886-32213-1-git-send-email-tangchen@cn.fujitsu.com> <1410413886-32213-5-git-send-email-tangchen@cn.fujitsu.com> <541169AD.6060908@redhat.com> In-Reply-To: <541169AD.6060908@redhat.com> Content-Type: text/plain; charset="ISO-8859-15"; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/11/2014 05:21 PM, Paolo Bonzini wrote: > Il 11/09/2014 07:38, Tang Chen ha scritto: >> apic access page is pinned in memory. As a result, it cannot be migrated/hot-removed. >> Actually, it is not necessary to be pinned. >> >> The hpa of apic access page is stored in VMCS APIC_ACCESS_ADDR pointer. When >> the page is migrated, kvm_mmu_notifier_invalidate_page() will invalidate the >> corresponding ept entry. This patch introduces a new vcpu request named >> KVM_REQ_APIC_PAGE_RELOAD, and makes this request to all the vcpus at this time, >> and force all the vcpus exit guest, and re-enter guest till they updates the VMCS >> APIC_ACCESS_ADDR pointer to the new apic access page address, and updates >> kvm->arch.apic_access_page to the new page. >> >> Signed-off-by: Tang Chen >> --- >> arch/x86/include/asm/kvm_host.h | 1 + >> arch/x86/kvm/svm.c | 6 ++++++ >> arch/x86/kvm/vmx.c | 6 ++++++ >> arch/x86/kvm/x86.c | 15 +++++++++++++++ >> include/linux/kvm_host.h | 2 ++ >> virt/kvm/kvm_main.c | 12 ++++++++++++ >> 6 files changed, 42 insertions(+) >> >> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h >> index 35171c7..514183e 100644 >> --- a/arch/x86/include/asm/kvm_host.h >> +++ b/arch/x86/include/asm/kvm_host.h >> @@ -739,6 +739,7 @@ struct kvm_x86_ops { >> void (*hwapic_isr_update)(struct kvm *kvm, int isr); >> void (*load_eoi_exitmap)(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap); >> void (*set_virtual_x2apic_mode)(struct kvm_vcpu *vcpu, bool set); >> + void (*set_apic_access_page_addr)(struct kvm *kvm, hpa_t hpa); >> void (*deliver_posted_interrupt)(struct kvm_vcpu *vcpu, int vector); >> void (*sync_pir_to_irr)(struct kvm_vcpu *vcpu); >> int (*set_tss_addr)(struct kvm *kvm, unsigned int addr); >> diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c >> index 1d941ad..f2eacc4 100644 >> --- a/arch/x86/kvm/svm.c >> +++ b/arch/x86/kvm/svm.c >> @@ -3619,6 +3619,11 @@ static void svm_set_virtual_x2apic_mode(struct kvm_vcpu *vcpu, bool set) >> return; >> } >> >> +static void svm_set_apic_access_page_addr(struct kvm *kvm, hpa_t hpa) >> +{ >> + return; >> +} >> + >> static int svm_vm_has_apicv(struct kvm *kvm) >> { >> return 0; >> @@ -4373,6 +4378,7 @@ static struct kvm_x86_ops svm_x86_ops = { >> .enable_irq_window = enable_irq_window, >> .update_cr8_intercept = update_cr8_intercept, >> .set_virtual_x2apic_mode = svm_set_virtual_x2apic_mode, >> + .set_apic_access_page_addr = svm_set_apic_access_page_addr, >> .vm_has_apicv = svm_vm_has_apicv, >> .load_eoi_exitmap = svm_load_eoi_exitmap, >> .hwapic_isr_update = svm_hwapic_isr_update, >> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c >> index 63c4c3e..da6d55d 100644 >> --- a/arch/x86/kvm/vmx.c >> +++ b/arch/x86/kvm/vmx.c >> @@ -7093,6 +7093,11 @@ static void vmx_set_virtual_x2apic_mode(struct kvm_vcpu *vcpu, bool set) >> vmx_set_msr_bitmap(vcpu); >> } >> >> +static void vmx_set_apic_access_page_addr(struct kvm *kvm, hpa_t hpa) >> +{ >> + vmcs_write64(APIC_ACCESS_ADDR, hpa); > This has to be guarded by "if (!is_guest_mode(vcpu))". Since we cannot get vcpu through kvm, I'd like to move this check to vcpu_reload_apic_access_page() when kvm_x86_ops->set_apic_access_page_addr() is called. Thanks. > >> +} >> + >> static void vmx_hwapic_isr_update(struct kvm *kvm, int isr) >> { >> u16 status; >> @@ -8910,6 +8915,7 @@ static struct kvm_x86_ops vmx_x86_ops = { >> .enable_irq_window = enable_irq_window, >> .update_cr8_intercept = update_cr8_intercept, >> .set_virtual_x2apic_mode = vmx_set_virtual_x2apic_mode, >> + .set_apic_access_page_addr = vmx_set_apic_access_page_addr, >> .vm_has_apicv = vmx_vm_has_apicv, >> .load_eoi_exitmap = vmx_load_eoi_exitmap, >> .hwapic_irr_update = vmx_hwapic_irr_update, >> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c >> index e05bd58..96f4188 100644 >> --- a/arch/x86/kvm/x86.c >> +++ b/arch/x86/kvm/x86.c >> @@ -5989,6 +5989,19 @@ static void vcpu_scan_ioapic(struct kvm_vcpu *vcpu) >> kvm_apic_update_tmr(vcpu, tmr); >> } >> >> +static void vcpu_reload_apic_access_page(struct kvm_vcpu *vcpu) >> +{ >> + /* >> + * apic access page could be migrated. When the page is being migrated, >> + * GUP will wait till the migrate entry is replaced with the new pte >> + * entry pointing to the new page. >> + */ >> + vcpu->kvm->arch.apic_access_page = gfn_to_page(vcpu->kvm, >> + APIC_DEFAULT_PHYS_BASE >> PAGE_SHIFT); >> + kvm_x86_ops->set_apic_access_page_addr(vcpu->kvm, >> + page_to_phys(vcpu->kvm->arch.apic_access_page)); >> +} >> + >> /* >> * Returns 1 to let __vcpu_run() continue the guest execution loop without >> * exiting to the userspace. Otherwise, the value will be returned to the >> @@ -6049,6 +6062,8 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) >> kvm_deliver_pmi(vcpu); >> if (kvm_check_request(KVM_REQ_SCAN_IOAPIC, vcpu)) >> vcpu_scan_ioapic(vcpu); >> + if (kvm_check_request(KVM_REQ_APIC_PAGE_RELOAD, vcpu)) >> + vcpu_reload_apic_access_page(vcpu); >> } >> >> if (kvm_check_request(KVM_REQ_EVENT, vcpu) || req_int_win) { >> diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h >> index a4c33b3..8be076a 100644 >> --- a/include/linux/kvm_host.h >> +++ b/include/linux/kvm_host.h >> @@ -136,6 +136,7 @@ static inline bool is_error_page(struct page *page) >> #define KVM_REQ_GLOBAL_CLOCK_UPDATE 22 >> #define KVM_REQ_ENABLE_IBS 23 >> #define KVM_REQ_DISABLE_IBS 24 >> +#define KVM_REQ_APIC_PAGE_RELOAD 25 >> >> #define KVM_USERSPACE_IRQ_SOURCE_ID 0 >> #define KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID 1 >> @@ -579,6 +580,7 @@ void kvm_flush_remote_tlbs(struct kvm *kvm); >> void kvm_reload_remote_mmus(struct kvm *kvm); >> void kvm_make_mclock_inprogress_request(struct kvm *kvm); >> void kvm_make_scan_ioapic_request(struct kvm *kvm); >> +void kvm_reload_apic_access_page(struct kvm *kvm); >> >> long kvm_arch_dev_ioctl(struct file *filp, >> unsigned int ioctl, unsigned long arg); >> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c >> index 33712fb..d8280de 100644 >> --- a/virt/kvm/kvm_main.c >> +++ b/virt/kvm/kvm_main.c >> @@ -210,6 +210,11 @@ void kvm_make_scan_ioapic_request(struct kvm *kvm) >> make_all_cpus_request(kvm, KVM_REQ_SCAN_IOAPIC); >> } >> >> +void kvm_reload_apic_access_page(struct kvm *kvm) >> +{ >> + make_all_cpus_request(kvm, KVM_REQ_APIC_PAGE_RELOAD); >> +} >> + >> int kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id) >> { >> struct page *page; >> @@ -294,6 +299,13 @@ static void kvm_mmu_notifier_invalidate_page(struct mmu_notifier *mn, >> if (need_tlb_flush) >> kvm_flush_remote_tlbs(kvm); >> >> + /* >> + * The physical address of apic access page is stroed in VMCS. > Typo: stored, not stroed. > >> + * So need to update it when it becomes invalid. > Please remove "so need to". > > Paolo > >> + */ >> + if (address == gfn_to_hva(kvm, APIC_DEFAULT_PHYS_BASE >> PAGE_SHIFT)) >> + kvm_reload_apic_access_page(kvm); >> + >> spin_unlock(&kvm->mmu_lock); >> srcu_read_unlock(&kvm->srcu, idx); >> } >> > . >