1 files changed, 45 insertions, 25 deletions

diff --git a/arch/mips/kvm/mmu.c b/arch/mips/kvm/mmu.c
index 57319ee57c4f..121008c0fcc9 100644
--- a/arch/mips/kvm/mmu.c
+++ b/arch/mips/kvm/mmu.c
@@ -40,7 +40,7 @@ static int kvm_mips_map_page(struct kvm *kvm, gfn_t gfn)
         srcu_idx = srcu_read_lock(&kvm->srcu);
         pfn = gfn_to_pfn(kvm, gfn);
 
-        if (is_error_pfn(pfn)) {
+        if (is_error_noslot_pfn(pfn)) {
                 kvm_err("Couldn't get pfn for gfn %#llx!\n", gfn);
                 err = -EFAULT;
                 goto out;
@@ -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();
@@ -138,35 +138,49 @@ int kvm_mips_handle_mapped_seg_tlb_fault(struct kvm_vcpu *vcpu,
         unsigned long entryhi = 0, entrylo0 = 0, entrylo1 = 0;
         struct kvm *kvm = vcpu->kvm;
         kvm_pfn_t pfn0, pfn1;
+        gfn_t gfn0, gfn1;
+        long tlb_lo[2];
         int ret;
 
-        if ((tlb->tlb_hi & VPN2_MASK) == 0) {
-                pfn0 = 0;
-                pfn1 = 0;
-        } else {
-                if (kvm_mips_map_page(kvm, mips3_tlbpfn_to_paddr(tlb->tlb_lo[0])
-                                           >> PAGE_SHIFT) < 0)
-                        return -1;
-
-                if (kvm_mips_map_page(kvm, mips3_tlbpfn_to_paddr(tlb->tlb_lo[1])
-                                           >> PAGE_SHIFT) < 0)
-                        return -1;
-
-                pfn0 = kvm->arch.guest_pmap[
-                        mips3_tlbpfn_to_paddr(tlb->tlb_lo[0]) >> PAGE_SHIFT];
-                pfn1 = kvm->arch.guest_pmap[
-                        mips3_tlbpfn_to_paddr(tlb->tlb_lo[1]) >> PAGE_SHIFT];
+        tlb_lo[0] = tlb->tlb_lo[0];
+        tlb_lo[1] = tlb->tlb_lo[1];
+
+        /*
+         * The commpage address must not be mapped to anything else if the guest
+         * TLB contains entries nearby, or commpage accesses will break.
+         */
+        if (!((tlb->tlb_hi ^ KVM_GUEST_COMMPAGE_ADDR) &
+                        VPN2_MASK & (PAGE_MASK << 1)))
+                tlb_lo[(KVM_GUEST_COMMPAGE_ADDR >> PAGE_SHIFT) & 1] = 0;
+
+        gfn0 = mips3_tlbpfn_to_paddr(tlb_lo[0]) >> PAGE_SHIFT;
+        gfn1 = mips3_tlbpfn_to_paddr(tlb_lo[1]) >> PAGE_SHIFT;
+        if (gfn0 >= kvm->arch.guest_pmap_npages ||
+            gfn1 >= kvm->arch.guest_pmap_npages) {
+                kvm_err("%s: Invalid gfn: [%#llx, %#llx], EHi: %#lx\n",
+                        __func__, gfn0, gfn1, tlb->tlb_hi);
+                kvm_mips_dump_guest_tlbs(vcpu);
+                return -1;
         }
 
+        if (kvm_mips_map_page(kvm, gfn0) < 0)
+                return -1;
+
+        if (kvm_mips_map_page(kvm, gfn1) < 0)
+                return -1;
+
+        pfn0 = kvm->arch.guest_pmap[gfn0];
+        pfn1 = kvm->arch.guest_pmap[gfn1];
+
         /* Get attributes from the Guest TLB */
         entrylo0 = mips3_paddr_to_tlbpfn(pfn0 << PAGE_SHIFT) |
                 ((_page_cachable_default >> _CACHE_SHIFT) << ENTRYLO_C_SHIFT) |
-                (tlb->tlb_lo[0] & ENTRYLO_D) |
-                (tlb->tlb_lo[0] & ENTRYLO_V);
+                (tlb_lo[0] & ENTRYLO_D) |
+                (tlb_lo[0] & ENTRYLO_V);
         entrylo1 = mips3_paddr_to_tlbpfn(pfn1 << PAGE_SHIFT) |
                 ((_page_cachable_default >> _CACHE_SHIFT) << ENTRYLO_C_SHIFT) |
-                (tlb->tlb_lo[1] & ENTRYLO_D) |
-                (tlb->tlb_lo[1] & ENTRYLO_V);
+                (tlb_lo[1] & ENTRYLO_D) |
+                (tlb_lo[1] & ENTRYLO_V);
 
         kvm_debug("@ %#lx tlb_lo0: 0x%08lx tlb_lo1: 0x%08lx\n", vcpu->arch.pc,
                   tlb->tlb_lo[0], tlb->tlb_lo[1]);
@@ -354,9 +368,15 @@ u32 kvm_get_inst(u32 *opc, struct kvm_vcpu *vcpu)
                                 local_irq_restore(flags);
                                 return KVM_INVALID_INST;
                         }
-                        kvm_mips_handle_mapped_seg_tlb_fault(vcpu,
-                                                             &vcpu->arch.
-                                                             guest_tlb[index]);
+                        if (kvm_mips_handle_mapped_seg_tlb_fault(vcpu,
+                                                &vcpu->arch.guest_tlb[index])) {
+                                kvm_err("%s: handling mapped seg tlb fault failed for %p, index: %u, vcpu: %p, ASID: %#lx\n",
+                                        __func__, opc, index, vcpu,
+                                        read_c0_entryhi());
+                                kvm_mips_dump_guest_tlbs(vcpu);
+                                local_irq_restore(flags);
+                                return KVM_INVALID_INST;
+                        }
                         inst = *(opc);
                 }
                 local_irq_restore(flags);