Commit 03b755b2 authored by Paolo Bonzini's avatar Paolo Bonzini
Browse files

KVM: e500: map readonly host pages for read 



The new __kvm_faultin_pfn() function is upset by the fact that e500 KVM
ignores host page permissions - __kvm_faultin requires a "writable"
outgoing argument, but e500 KVM is nonchalantly passing NULL.

If the host page permissions do not include writability, the shadow
TLB entry is forcibly mapped read-only.

Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent f2104bf2

arch/powerpc/kvm/e500_mmu_host.c

+3 −2
Original line number Diff line number Diff line
@@ -374,6 +374,7 @@ static inline int kvmppc_e500_shadow_map(struct kvmppc_vcpu_e500 *vcpu_e500, 
			unsigned long slot_start, slot_end;



			pfnmap = 1;

			writable = vma->vm_flags & VM_WRITE;



			start = vma->vm_pgoff;

			end = start +
@@ -449,7 +450,7 @@ static inline int kvmppc_e500_shadow_map(struct kvmppc_vcpu_e500 *vcpu_e500, 


	if (likely(!pfnmap)) {

		tsize_pages = 1UL << (tsize + 10 - PAGE_SHIFT);

		pfn = __kvm_faultin_pfn(slot, gfn, FOLL_WRITE, NULL, &page);

		pfn = __kvm_faultin_pfn(slot, gfn, FOLL_WRITE, &writable, &page);

		if (is_error_noslot_pfn(pfn)) {

			if (printk_ratelimit())

				pr_err("%s: real page not found for gfn %lx\n",
@@ -494,7 +495,7 @@ static inline int kvmppc_e500_shadow_map(struct kvmppc_vcpu_e500 *vcpu_e500, 
	}

	local_irq_restore(flags);



	kvmppc_e500_ref_setup(ref, gtlbe, pfn, wimg, true);

	kvmppc_e500_ref_setup(ref, gtlbe, pfn, wimg, writable);

	kvmppc_e500_setup_stlbe(&vcpu_e500->vcpu, gtlbe, tsize,

				ref, gvaddr, stlbe);

	writable = tlbe_is_writable(stlbe);