q35: Suppress SMM BIOS initialization under KVM

Same as for i44fx: KVM does not support SMM yet. Signal it initialized
to Seabios to avoid failures.
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NJason Baron <jbaron@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

hw/acpi_ich9.c

@@ -28,6 +28,7 @@
 #include "qemu-timer.h"
 #include "sysemu.h"
 #include "acpi.h"
+#include "kvm.h"
 
 #include "ich9.h"
 
@@ -292,6 +293,12 @@ static void pm_reset(void *opaque)
     acpi_pm_tmr_reset(&pm->acpi_regs);
     acpi_gpe_reset(&pm->acpi_regs);
 
+    if (kvm_enabled()) {
+        /* Mark SMM as already inited to prevent SMM from running. KVM does not
+         * support SMM mode. */
+        pm->smi_en |= ICH9_PMIO_SMI_EN_APMC_EN;
+    }
+
     pm_update_sci(pm);
 }