KVM: do not use sigtimedwait to catch SIGBUS

[mirror_qemu.git] / kvm-all.c

diff --git a/kvm-all.c b/kvm-all.c
index a27c880c05df616c3e02c93a24118a51d281d2f0..0baa193763bee773425d5e178ba0ed52341eec54 100644 (file)
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -1893,6 +1893,12 @@ void kvm_cpu_synchronize_post_init(CPUState *cpu)
     run_on_cpu(cpu, do_kvm_cpu_synchronize_post_init, RUN_ON_CPU_NULL);
 }
 
+#ifdef KVM_HAVE_MCE_INJECTION
+static __thread void *pending_sigbus_addr;
+static __thread int pending_sigbus_code;
+static __thread bool have_sigbus_pending;
+#endif
+
 int kvm_cpu_exec(CPUState *cpu)
 {
     struct kvm_run *run = cpu->kvm_run;
@@ -1930,6 +1936,16 @@ int kvm_cpu_exec(CPUState *cpu)
 
         attrs = kvm_arch_post_run(cpu, run);
 
+#ifdef KVM_HAVE_MCE_INJECTION
+        if (unlikely(have_sigbus_pending)) {
+            qemu_mutex_lock_iothread();
+            kvm_arch_on_sigbus_vcpu(cpu, pending_sigbus_code,
+                                    pending_sigbus_addr);
+            have_sigbus_pending = false;
+            qemu_mutex_unlock_iothread();
+        }
+#endif
+
         if (run_ret < 0) {
             if (run_ret == -EINTR || run_ret == -EAGAIN) {
                 DPRINTF("io window exit\n");
@@ -2000,8 +2016,9 @@ int kvm_cpu_exec(CPUState *cpu)
                 ret = EXCP_INTERRUPT;
                 break;
             case KVM_SYSTEM_EVENT_CRASH:
+                kvm_cpu_synchronize_state(cpu);
                 qemu_mutex_lock_iothread();
-                qemu_system_guest_panicked();
+                qemu_system_guest_panicked(cpu_get_crash_info(cpu));
                 qemu_mutex_unlock_iothread();
                 ret = 0;
                 break;
@@ -2390,14 +2407,38 @@ int kvm_set_signal_mask(CPUState *cpu, const sigset_t *sigset)
 
     return r;
 }
+
+/* Called asynchronously in VCPU thread.  */
 int kvm_on_sigbus_vcpu(CPUState *cpu, int code, void *addr)
 {
-    return kvm_arch_on_sigbus_vcpu(cpu, code, addr);
+#ifdef KVM_HAVE_MCE_INJECTION
+    if (have_sigbus_pending) {
+        return 1;
+    }
+    have_sigbus_pending = true;
+    pending_sigbus_addr = addr;
+    pending_sigbus_code = code;
+    atomic_set(&cpu->exit_request, 1);
+    return 0;
+#else
+    return 1;
+#endif
 }
 
+/* Called synchronously (via signalfd) in main thread.  */
 int kvm_on_sigbus(int code, void *addr)
 {
-    return kvm_arch_on_sigbus(code, addr);
+#ifdef KVM_HAVE_MCE_INJECTION
+    /* Action required MCE kills the process if SIGBUS is blocked.  Because
+     * that's what happens in the I/O thread, where we handle MCE via signalfd,
+     * we can only get action optional here.
+     */
+    assert(code != BUS_MCEERR_AR);
+    kvm_arch_on_sigbus_vcpu(first_cpu, code, addr);
+    return 0;
+#else
+    return 1;
+#endif
 }
 
 int kvm_create_device(KVMState *s, uint64_t type, bool test)