[PATCH v2 11/11] KVM: MMU: apply page track notifier

From: Xiao Guangrong
Date: Wed Dec 23 2015 - 06:33:38 EST


Register the notifier to receive write track event so that we can update
our shadow page table

It makes kvm_mmu_pte_write() be the callback of the notifier, no function
is changed

Signed-off-by: Xiao Guangrong <guangrong.xiao@xxxxxxxxxxxxxxx>
---
arch/x86/include/asm/kvm_host.h | 5 +++--
arch/x86/kvm/mmu.c | 19 +++++++++++++++++--
arch/x86/kvm/x86.c | 4 ++--
3 files changed, 22 insertions(+), 6 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 1d2968e..28f5c7d 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -671,6 +671,7 @@ struct kvm_arch {
*/
struct list_head active_mmu_pages;
struct list_head zapped_obsolete_pages;
+ struct kvm_page_track_notifier_node mmu_sp_tracker;
struct kvm_page_track_notifier_head track_notifier_head;

struct list_head assigned_dev_head;
@@ -966,6 +967,8 @@ void kvm_mmu_module_exit(void);
void kvm_mmu_destroy(struct kvm_vcpu *vcpu);
int kvm_mmu_create(struct kvm_vcpu *vcpu);
void kvm_mmu_setup(struct kvm_vcpu *vcpu);
+void kvm_mmu_init_vm(struct kvm *kvm);
+void kvm_mmu_uninit_vm(struct kvm *kvm);
void kvm_mmu_set_mask_ptes(u64 user_mask, u64 accessed_mask,
u64 dirty_mask, u64 nx_mask, u64 x_mask);

@@ -1105,8 +1108,6 @@ void kvm_pic_clear_all(struct kvm_pic *pic, int irq_source_id);

void kvm_inject_nmi(struct kvm_vcpu *vcpu);

-void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
- const u8 *new, int bytes);
int kvm_mmu_unprotect_page(struct kvm *kvm, gfn_t gfn);
int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva);
void __kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu);
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 9f6a4ef..a420c43 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -4325,8 +4325,8 @@ static u64 *get_written_sptes(struct kvm_mmu_page *sp, gpa_t gpa, int *nspte)
return spte;
}

-void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
- const u8 *new, int bytes)
+static void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
+ const u8 *new, int bytes)
{
gfn_t gfn = gpa >> PAGE_SHIFT;
struct kvm_mmu_page *sp;
@@ -4540,6 +4540,21 @@ void kvm_mmu_setup(struct kvm_vcpu *vcpu)
init_kvm_mmu(vcpu);
}

+void kvm_mmu_init_vm(struct kvm *kvm)
+{
+ struct kvm_page_track_notifier_node *node = &kvm->arch.mmu_sp_tracker;
+
+ node->track_write = kvm_mmu_pte_write;
+ kvm_page_track_register_notifier(kvm, node);
+}
+
+void kvm_mmu_uninit_vm(struct kvm *kvm)
+{
+ struct kvm_page_track_notifier_node *node = &kvm->arch.mmu_sp_tracker;
+
+ kvm_page_track_unregister_notifier(kvm, node);
+}
+
/* The return value indicates if tlb flush on all vcpus is needed. */
typedef bool (*slot_level_handler) (struct kvm *kvm, struct kvm_rmap_head *rmap_head);

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index dc43d99..f06a4fc 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4330,7 +4330,6 @@ int emulator_write_phys(struct kvm_vcpu *vcpu, gpa_t gpa,
ret = kvm_vcpu_write_guest(vcpu, gpa, val, bytes);
if (ret < 0)
return 0;
- kvm_mmu_pte_write(vcpu, gpa, val, bytes);
kvm_page_track_write(vcpu, gpa, val, bytes);
return 1;
}
@@ -4589,7 +4588,6 @@ static int emulator_cmpxchg_emulated(struct x86_emulate_ctxt *ctxt,
return X86EMUL_CMPXCHG_FAILED;

kvm_vcpu_mark_page_dirty(vcpu, gpa >> PAGE_SHIFT);
- kvm_mmu_pte_write(vcpu, gpa, new, bytes);
kvm_page_track_write(vcpu, gpa, new, bytes);

return X86EMUL_CONTINUE;
@@ -7700,6 +7698,7 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
INIT_DELAYED_WORK(&kvm->arch.kvmclock_sync_work, kvmclock_sync_fn);

kvm_page_track_init(kvm);
+ kvm_mmu_init_vm(kvm);

return 0;
}
@@ -7827,6 +7826,7 @@ void kvm_arch_destroy_vm(struct kvm *kvm)
kfree(kvm->arch.vioapic);
kvm_free_vcpus(kvm);
kfree(rcu_dereference_check(kvm->arch.apic_map, 1));
+ kvm_mmu_uninit_vm(kvm);
}

void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *free,
--
1.8.3.1

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