KVM: ppc: stop leaking host memory on VM exit

When the VM exits, we must call put_page() for every page referenced in the
shadow TLB.

Without this patch, we usually leak 30-50 host pages (120 - 200 KiB with 4 KiB
pages). The maximum number of pages leaked is the size of our shadow TLB, 64
pages.

Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index 8931ba729d2b519ec4d4efb1d0851301d96e1d3a..bb62ad876de32750c70cc7ecd91adcb9f0539d5a 100644 (file)
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -104,4 +104,6 @@ static inline void kvmppc_set_pid(struct kvm_vcpu *vcpu, u32 new_pid)
        }
 }
 
+extern void kvmppc_core_destroy_mmu(struct kvm_vcpu *vcpu);
+
 #endif /* __POWERPC_KVM_PPC_H__ */

diff --git a/arch/powerpc/kvm/44x_tlb.c b/arch/powerpc/kvm/44x_tlb.c
index 2e227a412bc240f2bc889b0c7c1fe2e17a7bdd8c..ad72c6f9811f62ed05695ca23221bd2d9b87f31a 100644 (file)
--- a/arch/powerpc/kvm/44x_tlb.c
+++ b/arch/powerpc/kvm/44x_tlb.c
@@ -124,6 +124,14 @@ static void kvmppc_44x_shadow_release(struct kvm_vcpu *vcpu,
        }
 }
 
+void kvmppc_core_destroy_mmu(struct kvm_vcpu *vcpu)
+{
+       int i;
+
+       for (i = 0; i <= tlb_44x_hwater; i++)
+               kvmppc_44x_shadow_release(vcpu, i);
+}
+
 void kvmppc_tlbe_set_modified(struct kvm_vcpu *vcpu, unsigned int i)
 {
     vcpu->arch.shadow_tlb_mod[i] = 1;

diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index 90a6fc422b238ccbd38becc6d36546c0a7ca0cd0..fda9baada132b1c5348dfec8b84ba99d8bc24dc1 100644 (file)
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -238,6 +238,7 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
 
 void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu)
 {
+       kvmppc_core_destroy_mmu(vcpu);
 }
 
 /* Note: clearing MSR[DE] just means that the debug interrupt will not be