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>
[bwh: Backported to 3.16: adjust filename, context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/arch/mips/kvm/kvm_mips_emul.c b/arch/mips/kvm/kvm_mips_emul.c
index 1983678883c98ddb70d93364744bd99db8631951..000a4de01985131a45493723c3426491558766e9 100644 (file)
--- a/arch/mips/kvm/kvm_mips_emul.c
+++ b/arch/mips/kvm/kvm_mips_emul.c
@@ -1481,9 +1481,13 @@ kvm_mips_emulate_cache(uint32_t inst, uint32_t *opc, uint32_t cause,
 
        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) {
@@ -1516,11 +1520,19 @@ kvm_mips_emulate_cache(uint32_t inst, uint32_t *opc, uint32_t cause,
                                                                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 {
@@ -2335,8 +2347,13 @@ kvm_mips_handle_tlbmiss(unsigned long cause, uint32_t *opc,
                            ("Injecting hi: %#lx, lo0: %#lx, lo1: %#lx into shadow host TLB\n",
                             tlb->tlb_hi, tlb->tlb_lo0, tlb->tlb_lo1);
                        /* 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/kvm_tlb.c b/arch/mips/kvm/kvm_tlb.c
index 888eee059840fac15865847dba56b161a014ced9..cb381bdc581270bc8cfcd358955764e0c9ee0223 100644 (file)
--- a/arch/mips/kvm/kvm_tlb.c
+++ b/arch/mips/kvm/kvm_tlb.c
@@ -801,10 +801,16 @@ 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);