[PATCH 4/5] KVM: PPC: Book3S PR: Invalidate SLB entries properly

[Paul Mackerras <paulus@samba.org>]

At present, if the guest creates a valid SLB (segment lookaside buffer)
entry with the slbmte instruction, then invalidates it with the slbie
instruction, then reads the entry with the slbmfee/slbmfev instructions,
the result of the slbmfee will have the valid bit set, even though the
entry is not actually considered valid by the host.  This is confusing,
if not worse.  This fixes it by zeroing out the orige and origv fields
of the SLB entry structure when the entry is invalidated.

Signed-off-by: Paul Mackerras <paulus@samba.org>
---
 arch/powerpc/kvm/book3s_64_mmu.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/kvm/book3s_64_mmu.c b/arch/powerpc/kvm/book3s_64_mmu.c
index 2e93bb5..7519124 100644
--- a/arch/powerpc/kvm/book3s_64_mmu.c
+++ b/arch/powerpc/kvm/book3s_64_mmu.c
@@ -376,6 +376,8 @@ static void kvmppc_mmu_book3s_64_slbie(struct kvm_vcpu *vcpu, u64 ea)
 	dprintk("KVM MMU: slbie(0x%llx, 0x%llx)\n", ea, slbe->esid);
 
 	slbe->valid = false;
+	slbe->orige = 0;
+	slbe->origv = 0;
 
 	kvmppc_mmu_map_segment(vcpu, ea);
 }
@@ -386,8 +388,11 @@ static void kvmppc_mmu_book3s_64_slbia(struct kvm_vcpu *vcpu)
 
 	dprintk("KVM MMU: slbia()\n");
 
-	for (i = 1; i < vcpu->arch.slb_nr; i++)
+	for (i = 1; i < vcpu->arch.slb_nr; i++) {
 		vcpu->arch.slb[i].valid = false;
+		vcpu->arch.slb[i].orige = 0;
+		vcpu->arch.slb[i].origv = 0;
+	}
 
 	if (vcpu->arch.shared->msr & MSR_IR) {
 		kvmppc_mmu_flush_segments(vcpu);
-- 
1.8.3.1