| Message ID | 1404291637-15048-4-git-send-email-tangchen@cn.fujitsu.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, Jul 02, 2014 at 05:00:36PM +0800, Tang Chen wrote: > ept identity pagetable is pinned in memory, and as a result it cannot be > migrated/hot-removed. > > But actually it doesn't need to be pinned in memory. > > This patch introduces a new vcpu request: KVM_REQ_MIGRATE_EPT to reset ept > indetity pagetable related variable. This request will be made when > kvm_mmu_notifier_invalidate_page() is called when the page is unmapped > from the qemu user space to reset kvm->arch.ept_identity_pagetable to NULL. > And will also be made when ept violation happens to reset > kvm->arch.ept_identity_pagetable to the new page. kvm->arch.ept_identity_pagetable is never used as a page address, just boolean null/!null to see if identity pagetable is initialized. I do not see why would we want to track its address at all. Changing it to bool and assigning true during initialization should be enough. -- 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 07/03/2014 12:34 AM, Gleb Natapov wrote: > On Wed, Jul 02, 2014 at 05:00:36PM +0800, Tang Chen wrote: >> ept identity pagetable is pinned in memory, and as a result it cannot be >> migrated/hot-removed. >> >> But actually it doesn't need to be pinned in memory. >> >> This patch introduces a new vcpu request: KVM_REQ_MIGRATE_EPT to reset ept >> indetity pagetable related variable. This request will be made when >> kvm_mmu_notifier_invalidate_page() is called when the page is unmapped >> from the qemu user space to reset kvm->arch.ept_identity_pagetable to NULL. >> And will also be made when ept violation happens to reset >> kvm->arch.ept_identity_pagetable to the new page. > > kvm->arch.ept_identity_pagetable is never used as a page address, just > boolean null/!null to see if identity pagetable is initialized. I do > not see why would we want to track its address at all. Changing it to bool > and assigning true during initialization should be enough. OK, followed. -- 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 07/03/2014 12:34 AM, Gleb Natapov wrote: > On Wed, Jul 02, 2014 at 05:00:36PM +0800, Tang Chen wrote: >> ept identity pagetable is pinned in memory, and as a result it cannot be >> migrated/hot-removed. >> >> But actually it doesn't need to be pinned in memory. >> >> This patch introduces a new vcpu request: KVM_REQ_MIGRATE_EPT to reset ept >> indetity pagetable related variable. This request will be made when >> kvm_mmu_notifier_invalidate_page() is called when the page is unmapped >> from the qemu user space to reset kvm->arch.ept_identity_pagetable to NULL. >> And will also be made when ept violation happens to reset >> kvm->arch.ept_identity_pagetable to the new page. > > kvm->arch.ept_identity_pagetable is never used as a page address, just > boolean null/!null to see if identity pagetable is initialized. I do > not see why would we want to track its address at all. Changing it to bool > and assigning true during initialization should be enough. We already have kvm->arch.ept_identity_pagetable_done to indicate if the ept identity table is initialized. If we make kvm->arch.ept_identity_pagetable to bool, do you mean we have: kvm->arch.ept_identity_pagetable: indicate if ept page is allocated, kvm->arch.ept_identity_pagetable_done: indicate if ept page is initialized ? I don't think we need this. Shall we remove kvm->arch.ept_identity_pagetable ? Thanks. -- 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 Fri, Jul 04, 2014 at 10:36:06AM +0800, Tang Chen wrote: > Hi Gleb, > > On 07/03/2014 12:34 AM, Gleb Natapov wrote: > >On Wed, Jul 02, 2014 at 05:00:36PM +0800, Tang Chen wrote: > >>ept identity pagetable is pinned in memory, and as a result it cannot be > >>migrated/hot-removed. > >> > >>But actually it doesn't need to be pinned in memory. > >> > >>This patch introduces a new vcpu request: KVM_REQ_MIGRATE_EPT to reset ept > >>indetity pagetable related variable. This request will be made when > >>kvm_mmu_notifier_invalidate_page() is called when the page is unmapped > >>from the qemu user space to reset kvm->arch.ept_identity_pagetable to NULL. > >>And will also be made when ept violation happens to reset > >>kvm->arch.ept_identity_pagetable to the new page. > > > >kvm->arch.ept_identity_pagetable is never used as a page address, just > >boolean null/!null to see if identity pagetable is initialized. I do > >not see why would we want to track its address at all. Changing it to bool > >and assigning true during initialization should be enough. > > We already have kvm->arch.ept_identity_pagetable_done to indicate if the ept > identity table is initialized. If we make kvm->arch.ept_identity_pagetable > to > bool, do you mean we have: > > kvm->arch.ept_identity_pagetable: indicate if ept page is allocated, > kvm->arch.ept_identity_pagetable_done: indicate if ept page is initialized ? > ept_identity_pagetable also means that a memory slot for identity page is initialized. > I don't think we need this. Shall we remove kvm->arch.ept_identity_pagetable > ? > May be those two can be consolidated somehow, but lets leave it to a separate patch to make this one simpler. -- 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 4931415..8771c0f 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -581,6 +581,7 @@ struct kvm_arch { struct page *ept_identity_pagetable; bool ept_identity_pagetable_done; gpa_t ept_identity_map_addr; + bool ept_identity_pagetable_migrated; unsigned long irq_sources_bitmap; s64 kvmclock_offset; diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 9314678..c0d72f6 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -3425,6 +3425,17 @@ static int tdp_page_fault(struct kvm_vcpu *vcpu, gva_t gpa, u32 error_code, transparent_hugepage_adjust(vcpu, &gfn, &pfn, &level); r = __direct_map(vcpu, gpa, write, map_writable, level, gfn, pfn, prefault); + + /* + * Update ept identity pagetable page and apic access page if + * they are migrated. + */ + if (gpa == vcpu->kvm->arch.ept_identity_map_addr && + vcpu->kvm->arch.ept_identity_pagetable_migrated) { + vcpu->kvm->arch.ept_identity_pagetable_migrated = false; + kvm_make_request(KVM_REQ_MIGRATE_EPT, vcpu); + } + spin_unlock(&vcpu->kvm->mmu_lock); return r; diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 366b5b3..c336cb3 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -4018,7 +4018,8 @@ static int alloc_identity_pagetable(struct kvm *kvm) if (r) goto out; - page = gfn_to_page(kvm, kvm->arch.ept_identity_map_addr >> PAGE_SHIFT); + page = gfn_to_page_no_pin(kvm, + kvm->arch.ept_identity_map_addr >> PAGE_SHIFT); if (is_error_page(page)) { r = -EFAULT; goto out; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index f32a025..a26524f 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -5929,6 +5929,20 @@ static void vcpu_scan_ioapic(struct kvm_vcpu *vcpu) kvm_apic_update_tmr(vcpu, tmr); } +static void vcpu_migrated_page_update_ept(struct kvm_vcpu *vcpu) +{ + struct kvm *kvm = vcpu->kvm; + + if (kvm->arch.ept_identity_pagetable_migrated) + kvm->arch.ept_identity_pagetable = NULL; + else { + struct page *page; + page = gfn_to_page_no_pin(kvm, + kvm->arch.ept_identity_map_addr >> PAGE_SHIFT); + kvm->arch.ept_identity_pagetable = 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 @@ -5989,6 +6003,8 @@ 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_MIGRATE_EPT, vcpu)) + vcpu_migrated_page_update_ept(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 7c58d9d..4b7e51a 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_MIGRATE_EPT 25 #define KVM_USERSPACE_IRQ_SOURCE_ID 0 #define KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID 1 diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 6091849..d271e89 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -294,6 +294,12 @@ static void kvm_mmu_notifier_invalidate_page(struct mmu_notifier *mn, if (need_tlb_flush) kvm_flush_remote_tlbs(kvm); + if (address == + gfn_to_hva(kvm, kvm->arch.ept_identity_map_addr >> PAGE_SHIFT)) { + kvm->arch.ept_identity_pagetable_migrated = true; + kvm_make_request(KVM_REQ_MIGRATE_EPT, kvm->vcpus[0]); + } + spin_unlock(&kvm->mmu_lock); srcu_read_unlock(&kvm->srcu, idx); }