[07/10] kvm: x86: mmu: Per-VM dirty logging mode

Message ID	20181020031543.124399-8-junaids@google.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <kvm-owner@kernel.org> Date: Fri, 19 Oct 2018 20:15:40 -0700 In-Reply-To: <20181020031543.124399-1-junaids@google.com> Message-Id: <20181020031543.124399-8-junaids@google.com> Mime-Version: 1.0 References: <20181020031543.124399-1-junaids@google.com> Subject: [PATCH 07/10] kvm: x86: mmu: Per-VM dirty logging mode From: Junaid Shahid <junaids@google.com> To: pbonzini@redhat.com Cc: kvm@vger.kernel.org, pfeiner@google.com Content-Type: text/plain; charset="UTF-8" Sender: kvm-owner@vger.kernel.org Precedence: bulk
Series	[01/10] kvm: mmu: spte_write_protect optimization \| expand [01/10] kvm: mmu: spte_write_protect optimization [02/10] kvm: mmu: Allow reading hardware dirty state from kvm_get_dirty_log_protect [03/10] kvm: x86: mmu: Change __rmap_clear_dirty to __rmap_test_and_clear_dirty [04/10] kvm: mmu: x86: Add dirty bit clearing notification hook [05/10] kvm: x86: mmu: Remove extra TLB flush from vmx_slot_enable_log_dirty() [06/10] kvm: x86: mmu: Use D bit for dirty logging [07/10] kvm: x86: mmu: Per-VM dirty logging mode [08/10] kvm: x86: mmu: Refactor kvm_mmu_slot_*_remove_write_access [09/10] kvm: x86: mmu: Ability to switch dirty logging mode dynamically [10/10] kvm: x86: mmu: Add IOCTLs to allow userspace to switch dirty logging mode

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 78187944494a..3da22c92a5d6 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -920,6 +920,8 @@ struct kvm_arch { bool guest_can_read_msr_platform_info; bool exception_payload_enabled; + + u8 dirty_logging_mode; }; struct kvm_vm_stat { @@ -1199,6 +1201,8 @@ struct kvm_arch_async_pf { extern struct kvm_x86_ops *kvm_x86_ops; +extern u8 kvm_default_dirty_log_mode; + #define __KVM_HAVE_ARCH_VM_ALLOC static inline struct kvm *kvm_arch_alloc_vm(void) { diff --git a/arch/x86/include/uapi/asm/kvm.h b/arch/x86/include/uapi/asm/kvm.h index dabfcf7c3941..2b1c442bffe6 100644 --- a/arch/x86/include/uapi/asm/kvm.h +++ b/arch/x86/include/uapi/asm/kvm.h @@ -420,4 +420,8 @@ struct kvm_nested_state { __u8 data[0]; }; +#define KVM_DIRTY_LOG_MODE_WRPROT 1 +#define KVM_DIRTY_LOG_MODE_DBIT 2 +#define KVM_DIRTY_LOG_MODE_PML 4 + #endif /* _ASM_X86_KVM_H */ diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 3f782d33e078..2714dbea2d88 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -262,6 +262,8 @@ static const u64 shadow_nonpresent_or_rsvd_mask_len = 5; */ static u64 __read_mostly shadow_nonpresent_or_rsvd_lower_gfn_mask; +u8 __read_mostly kvm_default_dirty_log_mode; +EXPORT_SYMBOL_GPL(kvm_default_dirty_log_mode); static void mmu_spte_set(u64 *sptep, u64 spte); static union kvm_mmu_page_role @@ -432,8 +434,12 @@ void kvm_mmu_set_mask_ptes(u64 user_mask, u64 accessed_mask, shadow_acc_track_mask = acc_track_mask; shadow_me_mask = me_mask; - if (shadow_dirty_mask == 0) + if (shadow_dirty_mask == 0) { enable_d_bit_logging = false; + + if (kvm_default_dirty_log_mode == KVM_DIRTY_LOG_MODE_DBIT) + kvm_default_dirty_log_mode = KVM_DIRTY_LOG_MODE_WRPROT; + } } EXPORT_SYMBOL_GPL(kvm_mmu_set_mask_ptes); @@ -719,7 +725,7 @@ static void spte_dirty_mask_cleared(struct kvm *kvm, u64 *sptep) * the D bit would result in those pages being unnecessarily reported as * dirty again in the next round. */ - if (enable_d_bit_logging) { + if (kvm->arch.dirty_logging_mode == KVM_DIRTY_LOG_MODE_DBIT) { gfn_t gfn; struct kvm_mmu_page *sp = page_header(__pa(sptep)); @@ -1722,14 +1728,19 @@ void kvm_arch_mmu_get_and_reset_log_dirty(struct kvm *kvm, struct kvm_memory_slot *slot, gfn_t gfn_offset, unsigned long *mask) { - if (kvm_x86_ops->get_and_reset_log_dirty) - kvm_x86_ops->get_and_reset_log_dirty(kvm, slot, gfn_offset, - mask); - else if (enable_d_bit_logging) + switch (kvm->arch.dirty_logging_mode) { + case KVM_DIRTY_LOG_MODE_WRPROT: + kvm_mmu_write_protect_pt_masked(kvm, slot, gfn_offset, *mask); + break; + case KVM_DIRTY_LOG_MODE_DBIT: *mask |= kvm_mmu_shadow_dirty_mask_test_and_clear(kvm, slot, gfn_offset); - else - kvm_mmu_write_protect_pt_masked(kvm, slot, gfn_offset, *mask); + break; + default: + if (kvm_x86_ops->get_and_reset_log_dirty) + kvm_x86_ops->get_and_reset_log_dirty(kvm, slot, + gfn_offset, mask); + } } /** @@ -6057,6 +6068,9 @@ int kvm_mmu_module_init(void) BUILD_BUG_ON(sizeof(union kvm_mmu_role) != sizeof(u64)); kvm_mmu_reset_all_pte_masks(); + kvm_default_dirty_log_mode = enable_d_bit_logging + ? KVM_DIRTY_LOG_MODE_DBIT + : KVM_DIRTY_LOG_MODE_WRPROT; pte_list_desc_cache = kmem_cache_create("pte_list_desc", sizeof(struct pte_list_desc), diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index d9be8e631f17..c6b0477c855e 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -7992,7 +7992,8 @@ static __init int hardware_setup(void) kvm_x86_ops->slot_disable_log_dirty = NULL; kvm_x86_ops->flush_log_dirty = NULL; kvm_x86_ops->get_and_reset_log_dirty = NULL; - } + } else + kvm_default_dirty_log_mode = KVM_DIRTY_LOG_MODE_PML; if (!cpu_has_vmx_preemption_timer()) kvm_x86_ops->request_immediate_exit = __kvm_request_immediate_exit; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index ab710956b8a2..9d22d4eeb5dc 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -4404,11 +4404,17 @@ int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log) mutex_lock(&kvm->slots_lock); - /* - * Flush potentially hardware-cached dirty pages to dirty_bitmap. - */ - if (kvm_x86_ops->flush_log_dirty) - kvm_x86_ops->flush_log_dirty(kvm); + switch (kvm->arch.dirty_logging_mode) { + case KVM_DIRTY_LOG_MODE_WRPROT: + case KVM_DIRTY_LOG_MODE_DBIT: + break; + default: + /* + * Flush potentially hardware-cached dirty pages to dirty_bitmap. + */ + if (kvm_x86_ops->flush_log_dirty) + kvm_x86_ops->flush_log_dirty(kvm); + } r = kvm_get_dirty_log_protect(kvm, log, &is_dirty); @@ -9020,6 +9026,8 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type) kvm->arch.guest_can_read_msr_platform_info = true; + kvm->arch.dirty_logging_mode = kvm_default_dirty_log_mode; + INIT_DELAYED_WORK(&kvm->arch.kvmclock_update_work, kvmclock_update_fn); INIT_DELAYED_WORK(&kvm->arch.kvmclock_sync_work, kvmclock_sync_fn); @@ -9302,15 +9310,26 @@ static void kvm_mmu_slot_apply_flags(struct kvm *kvm, * See the comments in fast_page_fault(). */ if (new->flags & KVM_MEM_LOG_DIRTY_PAGES) { - if (kvm_x86_ops->slot_enable_log_dirty) - kvm_x86_ops->slot_enable_log_dirty(kvm, new); - else if (enable_d_bit_logging) - kvm_mmu_slot_wrprot_lpage_and_clear_dirty(kvm, new); - else + switch (kvm->arch.dirty_logging_mode) { + case KVM_DIRTY_LOG_MODE_WRPROT: kvm_mmu_slot_remove_write_access(kvm, new); + break; + case KVM_DIRTY_LOG_MODE_DBIT: + kvm_mmu_slot_wrprot_lpage_and_clear_dirty(kvm, new); + break; + default: + if (kvm_x86_ops->slot_enable_log_dirty) + kvm_x86_ops->slot_enable_log_dirty(kvm, new); + } } else { - if (kvm_x86_ops->slot_disable_log_dirty) - kvm_x86_ops->slot_disable_log_dirty(kvm, new); + switch (kvm->arch.dirty_logging_mode) { + case KVM_DIRTY_LOG_MODE_WRPROT: + case KVM_DIRTY_LOG_MODE_DBIT: + break; + default: + if (kvm_x86_ops->slot_disable_log_dirty) + kvm_x86_ops->slot_disable_log_dirty(kvm, new); + } } }

[07/10] kvm: x86: mmu: Per-VM dirty logging mode

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