hw/mem/cxl-type3: Add MSIX support

This will be used by several upcoming patch sets so break it out
such that it doesn't matter which one lands first.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Message-Id: <20221014151045.24781-3-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

hw/mem/cxl_type3.c

@@ -13,6 +13,7 @@
 #include "qemu/rcu.h"
 #include "sysemu/hostmem.h"
 #include "hw/cxl/cxl.h"
+#include "hw/pci/msix.h"
 
 /*
  * Null value of all Fs suggested by IEEE RA guidelines for use of
@@ -146,6 +147,8 @@ static void ct3_realize(PCIDevice *pci_dev, Error **errp)
     ComponentRegisters *regs = &cxl_cstate->crb;
     MemoryRegion *mr = &regs->component_registers;
     uint8_t *pci_conf = pci_dev->config;
+    unsigned short msix_num = 1;
+    int i;
 
     if (!cxl_setup_memory(ct3d, errp)) {
         return;
@@ -180,6 +183,12 @@ static void ct3_realize(PCIDevice *pci_dev, Error **errp)
                      PCI_BASE_ADDRESS_SPACE_MEMORY |
                          PCI_BASE_ADDRESS_MEM_TYPE_64,
                      &ct3d->cxl_dstate.device_registers);
+
+    /* MSI(-X) Initailization */
+    msix_init_exclusive_bar(pci_dev, msix_num, 4, NULL);
+    for (i = 0; i < msix_num; i++) {
+        msix_vector_use(pci_dev, i);
+    }
 }
 
 static void ct3_exit(PCIDevice *pci_dev)