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 <tangchen@xxxxxxxxxxxxxx> --- 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 tovcpu_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); }.
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