MIPS: KVM: Fix gfn range check in kseg0 tlb faults

James Hogan · rkrcmar · commit 0741f52d1b98 · 2016-08-12T12:01:29.000+02:00
Two consecutive gfns are loaded into host TLB, so ensure the range check isn't off by one if guest_pmap_npages is odd. Fixes: 858dd5d ("KVM/MIPS32: MMU/TLB operations for the Guest.") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: "Radim Krčmář" <rkrcmar@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Cc: <stable@vger.kernel.org> # 3.10.x- Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
diff --git a/arch/mips/kvm/mmu.c b/arch/mips/kvm/mmu.c
@@ -99,7 +99,7 @@ int kvm_mips_handle_kseg0_tlb_fault(unsigned long badvaddr,
 	}
 
 	gfn = (KVM_GUEST_CPHYSADDR(badvaddr) >> PAGE_SHIFT);
-	if (gfn >= kvm->arch.guest_pmap_npages) {
+	if ((gfn | 1) >= kvm->arch.guest_pmap_npages) {
 		kvm_err("%s: Invalid gfn: %#llx, BadVaddr: %#lx\n", __func__,
 			gfn, badvaddr);
 		kvm_mips_dump_host_tlbs();

Original file line number	Diff line number	Diff line change
`@@ -99,7 +99,7 @@ int kvm_mips_handle_kseg0_tlb_fault(unsigned long badvaddr,`
`99`	`99`	`}`
`100`	`100`
`101`	`101`	`gfn = (KVM_GUEST_CPHYSADDR(badvaddr) >> PAGE_SHIFT);`
`102`		`- if (gfn >= kvm->arch.guest_pmap_npages) {`
	`102`	`+ if ((gfn \| 1) >= kvm->arch.guest_pmap_npages) {`
`103`	`103`	`kvm_err("%s: Invalid gfn: %#llx, BadVaddr: %#lx\n", __func__,`
`104`	`104`	`gfn, badvaddr);`
`105`	`105`	`kvm_mips_dump_host_tlbs();`