Introduce MSIMessage structure

Will be used for generating and distributing MSI messages, both in
emulation mode and under KVM.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

hw/msi.h

@@ -24,6 +24,11 @@
 #include "qemu-common.h"
 #include "pci.h"
 
+struct MSIMessage {
+    uint64_t address;
+    uint32_t data;
+};
+
 extern bool msi_supported;
 
 bool msi_enabled(const PCIDevice *dev);

qemu-common.h

@@ -248,6 +248,7 @@ typedef struct PCIEAERLog PCIEAERLog;
 typedef struct PCIEAERErr PCIEAERErr;
 typedef struct PCIEPort PCIEPort;
 typedef struct PCIESlot PCIESlot;
+typedef struct MSIMessage MSIMessage;
 typedef struct SerialState SerialState;
 typedef struct IRQState *qemu_irq;
 typedef struct PCMCIACardState PCMCIACardState;