KVM: Add mmu cache clear function

Functions that play around with the physical memory map
need a way to clear mappings to possibly nonexistent or
invalid memory.  Both the mmu cache and the processor tlb
are cleared.

Signed-off-by: Dor Laor <dor.laor@qumranet.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>

2 files changed, 18 insertions, 0 deletions

diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h
index 6d0bd7aab9..59357bea5b 100644
--- a/drivers/kvm/kvm.h
+++ b/drivers/kvm/kvm.h
@@ -430,6 +430,7 @@ int kvm_mmu_setup(struct kvm_vcpu *vcpu);
 
 int kvm_mmu_reset_context(struct kvm_vcpu *vcpu);
 void kvm_mmu_slot_remove_write_access(struct kvm_vcpu *vcpu, int slot);
+void kvm_mmu_zap_all(struct kvm_vcpu *vcpu);
 
 hpa_t gpa_to_hpa(struct kvm_vcpu *vcpu, gpa_t gpa);
 #define HPA_MSB ((sizeof(hpa_t) * 8) - 1)
diff --git a/drivers/kvm/mmu.c b/drivers/kvm/mmu.c
index d81b9cd346..376800a339 100644
--- a/drivers/kvm/mmu.c
+++ b/drivers/kvm/mmu.c
@@ -1314,6 +1314,23 @@ void kvm_mmu_slot_remove_write_access(struct kvm_vcpu *vcpu, int slot)
         }
 }
 
+void kvm_mmu_zap_all(struct kvm_vcpu *vcpu)
+{
+        destroy_kvm_mmu(vcpu);
+
+        while (!list_empty(&vcpu->kvm->active_mmu_pages)) {
+                struct kvm_mmu_page *page;
+
+                page = container_of(vcpu->kvm->active_mmu_pages.next,
+                                    struct kvm_mmu_page, link);
+                kvm_mmu_zap_page(vcpu, page);
+        }
+
+        mmu_free_memory_caches(vcpu);
+        kvm_arch_ops->tlb_flush(vcpu);
+        init_kvm_mmu(vcpu);
+}
+
 #ifdef AUDIT
 
 static const char *audit_msg;