| Message ID | 1409134661-27916-5-git-send-email-tangchen@cn.fujitsu.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, Aug 27, 2014 at 06:17:39PM +0800, Tang Chen wrote: > 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@cn.fujitsu.com> > --- > 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); > +} > + > 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)); I am a little bit worried that here all vcpus write to vcpu->kvm->arch.apic_access_page without any locking. It is probably benign since pointer write is atomic on x86. Paolo? Do we even need apic_access_page? Why not call gfn_to_page(APIC_DEFAULT_PHYS_BASE >> PAGE_SHIFT) put_page() on rare occasions we need to know its address? > +} > + > /* > * 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. > + * So need to update it when it becomes invalid. > + */ > + 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); > } > -- > 1.8.3.1 > -- Gleb. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Gleb, On 09/03/2014 12:00 AM, Gleb Natapov wrote: > ...... > +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)); > I am a little bit worried that here all vcpus write to vcpu->kvm->arch.apic_access_page > without any locking. It is probably benign since pointer write is atomic on x86. Paolo? > > Do we even need apic_access_page? Why not call > gfn_to_page(APIC_DEFAULT_PHYS_BASE >> PAGE_SHIFT) > put_page() > on rare occasions we need to know its address? Isn't it a necessary item defined in hardware spec ? I didn't read intel spec deeply, but according to the code, the page's address is written into vmcs. And it made me think that we cannnot remove it. Thanks. > >> +} >> + >> /* >> * 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. >> + * So need to update it when it becomes invalid. >> + */ >> + 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); >> } >> -- >> 1.8.3.1 >> > -- > Gleb. > . > -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, Sep 03, 2014 at 09:42:30AM +0800, tangchen wrote: > Hi Gleb, > > On 09/03/2014 12:00 AM, Gleb Natapov wrote: > >...... > >+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)); > >I am a little bit worried that here all vcpus write to vcpu->kvm->arch.apic_access_page > >without any locking. It is probably benign since pointer write is atomic on x86. Paolo? > > > >Do we even need apic_access_page? Why not call > > gfn_to_page(APIC_DEFAULT_PHYS_BASE >> PAGE_SHIFT) > > put_page() > >on rare occasions we need to know its address? > > Isn't it a necessary item defined in hardware spec ? > vcpu->kvm->arch.apic_access_page? No. This is internal kvm data structure. > I didn't read intel spec deeply, but according to the code, the page's > address is > written into vmcs. And it made me think that we cannnot remove it. > We cannot remove writing of apic page address into vmcs, but this is not done by assigning to vcpu->kvm->arch.apic_access_page, but by vmwrite in set_apic_access_page_addr(). -- Gleb. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Gleb, On 09/03/2014 11:04 PM, Gleb Natapov wrote: > On Wed, Sep 03, 2014 at 09:42:30AM +0800, tangchen wrote: >> Hi Gleb, >> >> On 09/03/2014 12:00 AM, Gleb Natapov wrote: >>> ...... >>> +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)); >>> I am a little bit worried that here all vcpus write to vcpu->kvm->arch.apic_access_page >>> without any locking. It is probably benign since pointer write is atomic on x86. Paolo? >>> >>> Do we even need apic_access_page? Why not call >>> gfn_to_page(APIC_DEFAULT_PHYS_BASE >> PAGE_SHIFT) >>> put_page() >>> on rare occasions we need to know its address? >> Isn't it a necessary item defined in hardware spec ? >> > vcpu->kvm->arch.apic_access_page? No. This is internal kvm data structure. > >> I didn't read intel spec deeply, but according to the code, the page's >> address is >> written into vmcs. And it made me think that we cannnot remove it. >> > We cannot remove writing of apic page address into vmcs, but this is not done by > assigning to vcpu->kvm->arch.apic_access_page, but by vmwrite in set_apic_access_page_addr(). OK, I'll try to remove kvm->arch.apic_access_page and send a patch for it soon. BTW, if you don't have objection to the first two patches, would you please help to commit them first ? Thanks. > > -- > Gleb. > . > -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, Sep 09, 2014 at 03:13:07PM +0800, tangchen wrote: > Hi Gleb, > > On 09/03/2014 11:04 PM, Gleb Natapov wrote: > >On Wed, Sep 03, 2014 at 09:42:30AM +0800, tangchen wrote: > >>Hi Gleb, > >> > >>On 09/03/2014 12:00 AM, Gleb Natapov wrote: > >>>...... > >>>+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)); > >>>I am a little bit worried that here all vcpus write to vcpu->kvm->arch.apic_access_page > >>>without any locking. It is probably benign since pointer write is atomic on x86. Paolo? > >>> > >>>Do we even need apic_access_page? Why not call > >>> gfn_to_page(APIC_DEFAULT_PHYS_BASE >> PAGE_SHIFT) > >>> put_page() > >>>on rare occasions we need to know its address? > >>Isn't it a necessary item defined in hardware spec ? > >> > >vcpu->kvm->arch.apic_access_page? No. This is internal kvm data structure. > > > >>I didn't read intel spec deeply, but according to the code, the page's > >>address is > >>written into vmcs. And it made me think that we cannnot remove it. > >> > >We cannot remove writing of apic page address into vmcs, but this is not done by > >assigning to vcpu->kvm->arch.apic_access_page, but by vmwrite in set_apic_access_page_addr(). > > OK, I'll try to remove kvm->arch.apic_access_page and send a patch for it > soon. > > BTW, if you don't have objection to the first two patches, would you please > help to > commit them first ? > I acked them and CCed Paolo to this reply. I hope he will look at the series too. -- Gleb. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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); +} + 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. + * So need to update it when it becomes invalid. + */ + 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); }
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@cn.fujitsu.com> --- 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(+)