[PATCH 3.12 052/100] MIPS: KVM: Fix gfn range check in kseg0 tlb faults

[Jiri Slaby]

From: James Hogan <james.hogan@xxxxxxxxxx>

3.12-stable review patch.  If anyone has any objections, please let me know.

===============

commit 0741f52d1b980dbeb290afe67d88fc2928edd8ab upstream.

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: 858dd5d45733 ("KVM/MIPS32: MMU/TLB operations for the Guest.")
Signed-off-by: James Hogan <james.hogan@xxxxxxxxxx>
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: "Radim KrÄmÃÅ" <rkrcmar@xxxxxxxxxx>
Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Cc: linux-mips@xxxxxxxxxxxxxx
Cc: kvm@xxxxxxxxxxxxxxx
Signed-off-by: Radim KrÄmÃÅ <rkrcmar@xxxxxxxxxx>
[james.hogan@xxxxxxxxxx: Backport to v3.10.y - v3.15.y]
Signed-off-by: James Hogan <james.hogan@xxxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
 arch/mips/kvm/kvm_tlb.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/mips/kvm/kvm_tlb.c b/arch/mips/kvm/kvm_tlb.c
index 8aba2e54f90f..5a3c3731214f 100644
--- a/arch/mips/kvm/kvm_tlb.c
+++ b/arch/mips/kvm/kvm_tlb.c
@@ -312,7 +312,7 @@ 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();
-- 
2.9.3