MIPS: KVM: Propagate kseg0/mapped tlb fault errors

commit 9b731bcfdec4c159ad2e4312e25d69221709b96a upstream.

Propagate errors from kvm_mips_handle_kseg0_tlb_fault() and
kvm_mips_handle_mapped_seg_tlb_fault(), usually triggering an internal
error since they normally indicate the guest accessed bad physical
memory or the commpage in an unexpected way.

Fixes: 858dd5d45733 ("KVM/MIPS32: MMU/TLB operations for the Guest.")
Fixes: e685c689f3a8 ("KVM/MIPS32: Privileged instruction/target branch emulation.")
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
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
[james.hogan@imgtec.com: Backport to v3.17.y - v4.4.y]
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/mips/kvm/emulate.c b/arch/mips/kvm/emulate.c
index dc10c77b7500767a05ff835078b8825ceab21f28..d6476d11212e5b20a7f8332330c99445ff932ac8 100644 (file)
--- a/arch/mips/kvm/emulate.c
+++ b/arch/mips/kvm/emulate.c
@@ -1629,8 +1629,14 @@ enum emulation_result kvm_mips_emulate_cache(uint32_t inst, uint32_t *opc,
 
        preempt_disable();
        if (KVM_GUEST_KSEGX(va) == KVM_GUEST_KSEG0) {
-               if (kvm_mips_host_tlb_lookup(vcpu, va) < 0)
-                       kvm_mips_handle_kseg0_tlb_fault(va, vcpu);
+               if (kvm_mips_host_tlb_lookup(vcpu, va) < 0 &&
+                   kvm_mips_handle_kseg0_tlb_fault(va, vcpu)) {
+                       kvm_err("%s: handling mapped kseg0 tlb fault for %lx, vcpu: %p, ASID: %#lx\n",
+                               __func__, va, vcpu, read_c0_entryhi());
+                       er = EMULATE_FAIL;
+                       preempt_enable();
+                       goto done;
+               }
        } else if ((KVM_GUEST_KSEGX(va) < KVM_GUEST_KSEG0) ||
                   KVM_GUEST_KSEGX(va) == KVM_GUEST_KSEG23) {
                int index;
@@ -1665,14 +1671,19 @@ enum emulation_result kvm_mips_emulate_cache(uint32_t inst, uint32_t *opc,
                                                                run, vcpu);
                                preempt_enable();
                                goto dont_update_pc;
-                       } else {
-                               /*
-                                * We fault an entry from the guest tlb to the
-                                * shadow host TLB
-                                */
-                               kvm_mips_handle_mapped_seg_tlb_fault(vcpu, tlb,
-                                                                    NULL,
-                                                                    NULL);
+                       }
+                       /*
+                        * We fault an entry from the guest tlb to the
+                        * shadow host TLB
+                        */
+                       if (kvm_mips_handle_mapped_seg_tlb_fault(vcpu, tlb,
+                                                                NULL, NULL)) {
+                               kvm_err("%s: handling mapped seg tlb fault for %lx, index: %u, vcpu: %p, ASID: %#lx\n",
+                                       __func__, va, index, vcpu,
+                                       read_c0_entryhi());
+                               er = EMULATE_FAIL;
+                               preempt_enable();
+                               goto done;
                        }
                }
        } else {
@@ -2633,8 +2644,13 @@ enum emulation_result kvm_mips_handle_tlbmiss(unsigned long cause,
                         * OK we have a Guest TLB entry, now inject it into the
                         * shadow host TLB
                         */
-                       kvm_mips_handle_mapped_seg_tlb_fault(vcpu, tlb, NULL,
-                                                            NULL);
+                       if (kvm_mips_handle_mapped_seg_tlb_fault(vcpu, tlb,
+                                                                NULL, NULL)) {
+                               kvm_err("%s: handling mapped seg tlb fault for %lx, index: %u, vcpu: %p, ASID: %#lx\n",
+                                       __func__, va, index, vcpu,
+                                       read_c0_entryhi());
+                               er = EMULATE_FAIL;
+                       }
                }
        }
 

diff --git a/arch/mips/kvm/tlb.c b/arch/mips/kvm/tlb.c
index 836b61aabf8612d8e27d0cbf43ceced6702a5eb2..7a7ed9ca01bbcb86fe2b0cb7265bcfe888e3b011 100644 (file)
--- a/arch/mips/kvm/tlb.c
+++ b/arch/mips/kvm/tlb.c
@@ -808,10 +808,16 @@ uint32_t kvm_get_inst(uint32_t *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],
-                                                            NULL, NULL);
+                       if (kvm_mips_handle_mapped_seg_tlb_fault(vcpu,
+                                               &vcpu->arch.guest_tlb[index],
+                                               NULL, NULL)) {
+                               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);