1 files changed, 52 insertions, 0 deletions

diff --git a/target/arm/kvm.c b/target/arm/kvm.c
index 7c672c78b8..3a46f54f1f 100644
--- a/target/arm/kvm.c
+++ b/target/arm/kvm.c
@@ -39,6 +39,7 @@ const KVMCapabilityInfo kvm_arch_required_capabilities[] = {
 
 static bool cap_has_mp_state;
 static bool cap_has_inject_serror_esr;
+static bool cap_has_inject_ext_dabt;
 
 static ARMHostCPUFeatures arm_host_cpu_features;
 
@@ -245,6 +246,16 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
         ret = -EINVAL;
     }
 
+    if (kvm_check_extension(s, KVM_CAP_ARM_NISV_TO_USER)) {
+        if (kvm_vm_enable_cap(s, KVM_CAP_ARM_NISV_TO_USER, 0)) {
+            error_report("Failed to enable KVM_CAP_ARM_NISV_TO_USER cap");
+        } else {
+            /* Set status for supporting the external dabt injection */
+            cap_has_inject_ext_dabt = kvm_check_extension(s,
+                                    KVM_CAP_ARM_INJECT_EXT_DABT);
+        }
+    }
+
     return ret;
 }
 
@@ -810,6 +821,42 @@ void kvm_arm_vm_state_change(void *opaque, int running, RunState state)
     }
 }
 
+/**
+ * kvm_arm_handle_dabt_nisv:
+ * @cs: CPUState
+ * @esr_iss: ISS encoding (limited) for the exception from Data Abort
+ *           ISV bit set to '0b0' -> no valid instruction syndrome
+ * @fault_ipa: faulting address for the synchronous data abort
+ *
+ * Returns: 0 if the exception has been handled, < 0 otherwise
+ */
+static int kvm_arm_handle_dabt_nisv(CPUState *cs, uint64_t esr_iss,
+                                    uint64_t fault_ipa)
+{
+    /*
+     * Request KVM to inject the external data abort into the guest
+     */
+    if (cap_has_inject_ext_dabt) {
+        struct kvm_vcpu_events events = { };
+        /*
+         * The external data abort event will be handled immediately by KVM
+         * using the address fault that triggered the exit on given VCPU.
+         * Requesting injection of the external data abort does not rely
+         * on any other VCPU state. Therefore, in this particular case, the VCPU
+         * synchronization can be exceptionally skipped.
+         */
+        events.exception.ext_dabt_pending = 1;
+        /* KVM_CAP_ARM_INJECT_EXT_DABT implies KVM_CAP_VCPU_EVENTS */
+        return kvm_vcpu_ioctl(cs, KVM_SET_VCPU_EVENTS, &events);
+    } else {
+        error_report("Data abort exception triggered by guest memory access "
+                     "at physical address: 0x"  TARGET_FMT_lx,
+                     (target_ulong)fault_ipa);
+        error_printf("KVM unable to emulate faulting instruction.\n");
+    }
+    return -1;
+}
+
 int kvm_arch_handle_exit(CPUState *cs, struct kvm_run *run)
 {
     int ret = 0;
@@ -820,6 +867,11 @@ int kvm_arch_handle_exit(CPUState *cs, struct kvm_run *run)
             ret = EXCP_DEBUG;
         } /* otherwise return to guest */
         break;
+    case KVM_EXIT_ARM_NISV:
+        /* External DABT with no valid iss to decode */
+        ret = kvm_arm_handle_dabt_nisv(cs, run->arm_nisv.esr_iss,
+                                       run->arm_nisv.fault_ipa);
+        break;
     default:
         qemu_log_mask(LOG_UNIMP, "%s: un-handled exit reason %d\n",
                       __func__, run->exit_reason);