KVM: PPC: Book3S HV: Make radix clear pte when unmapping

The current partition table unmap code clears the _PAGE_PRESENT bit
out of the pte, which leaves pud_huge/pmd_huge true and does not
clear pud_present/pmd_present.  This can confuse subsequent page
faults and possibly lead to the guest looping doing continual
hypervisor page faults.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>

diff --git a/arch/powerpc/kvm/book3s_64_mmu_radix.c b/arch/powerpc/kvm/book3s_64_mmu_radix.c
index a687028..361f42c 100644 (file)
--- a/arch/powerpc/kvm/book3s_64_mmu_radix.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_radix.c
@@ -584,7 +584,7 @@ int kvm_unmap_radix(struct kvm *kvm, struct kvm_memory_slot *memslot,
 
        ptep = __find_linux_pte(kvm->arch.pgtable, gpa, NULL, &shift);
        if (ptep && pte_present(*ptep)) {
-               old = kvmppc_radix_update_pte(kvm, ptep, _PAGE_PRESENT, 0,
+               old = kvmppc_radix_update_pte(kvm, ptep, ~0UL, 0,
                                              gpa, shift);
                kvmppc_radix_tlbie_page(kvm, gpa, shift);
                if ((old & _PAGE_DIRTY) && memslot->dirty_bitmap) {