target-i386: wake up processors that receive an SMI

An SMI should definitely wake up a processor in halted state!
This lets OVMF boot with SMM on multiprocessor systems, although
it halts very soon after that with a "CpuIndex != BspIndex"
assertion failure.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

target-i386/cpu.c

@@ -3063,7 +3063,9 @@ static bool x86_cpu_has_work(CPUState *cs)
            (cs->interrupt_request & (CPU_INTERRUPT_NMI |
                                      CPU_INTERRUPT_INIT |
                                      CPU_INTERRUPT_SIPI |
-                                     CPU_INTERRUPT_MCE));
+                                     CPU_INTERRUPT_MCE)) ||
+           ((cs->interrupt_request & CPU_INTERRUPT_SMI) &&
+            !(env->hflags & HF_SMM_MASK));
 }
 
 static Property x86_cpu_properties[] = {