hw/pci/msi: Restrict xen_is_pirq_msi() call to Xen

Similarly to the restriction in hw/pci/msix.c (see commit
e1e4bf2252 "msix: fix msix_vector_masked"), restrict the
xen_is_pirq_msi() call in msi_is_masked() to Xen.

No functional change intended.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>
Message-Id: <20231114143816.71079-7-philmd@linaro.org>

hw/pci/msi.c

@@ -23,6 +23,7 @@
 #include "hw/xen/xen.h"
 #include "qemu/range.h"
 #include "qapi/error.h"
+#include "sysemu/xen.h"
 
 #include "hw/i386/kvm/xen_evtchn.h"
 
@@ -308,7 +309,7 @@ bool msi_is_masked(const PCIDevice *dev, unsigned int vector)
     }
 
     data = pci_get_word(dev->config + msi_data_off(dev, msi64bit));
-    if (xen_is_pirq_msi(data)) {
+    if (xen_enabled() && xen_is_pirq_msi(data)) {
         return false;
     }