Merge tag 'kvm-ppc-fixes-5.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc into kvm-master

PPC KVM fix for 5.7

- Fix a regression introduced in the last merge window, which results
  in guests in HPT mode dying randomly.

Author: bonzini

arch/powerpc/kvm/book3s_64_mmu_hv.c

@@ -604,18 +604,19 @@ int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu,
 	 */
 	local_irq_disable();
 	ptep = __find_linux_pte(vcpu->arch.pgdir, hva, NULL, &shift);
+	pte = __pte(0);
+	if (ptep)
+		pte = *ptep;
+	local_irq_enable();
 	/*
 	 * If the PTE disappeared temporarily due to a THP
 	 * collapse, just return and let the guest try again.
 	 */
-	if (!ptep) {
-		local_irq_enable();
+	if (!pte_present(pte)) {
 		if (page)
 			put_page(page);
 		return RESUME_GUEST;
 	}
-	pte = *ptep;
-	local_irq_enable();
 	hpa = pte_pfn(pte) << PAGE_SHIFT;
 	pte_size = PAGE_SIZE;
 	if (shift)

arch/powerpc/kvm/book3s_64_mmu_radix.c

@@ -815,18 +815,19 @@ int kvmppc_book3s_instantiate_page(struct kvm_vcpu *vcpu,
 	 */
 	local_irq_disable();
 	ptep = __find_linux_pte(vcpu->arch.pgdir, hva, NULL, &shift);
+	pte = __pte(0);
+	if (ptep)
+		pte = *ptep;
+	local_irq_enable();
 	/*
 	 * If the PTE disappeared temporarily due to a THP
 	 * collapse, just return and let the guest try again.
 	 */
-	if (!ptep) {
-		local_irq_enable();
+	if (!pte_present(pte)) {
 		if (page)
 			put_page(page);
 		return RESUME_GUEST;
 	}
-	pte = *ptep;
-	local_irq_enable();
 
 	/* If we're logging dirty pages, always map single pages */
 	large_enable = !(memslot->flags & KVM_MEM_LOG_DIRTY_PAGES);