cross_vm_connectors: Add a device name register The event PCI BAR allocates a 4K frame but only uses the first 8 bytes for sending and receiving events. The next 50 bytes are now used to store a device name that a guest OS can use to identify different devices. A default of "connector" is used because this was the name that the Linux kernel module would give to all devices before this change.

diff --git a/libsel4vmmplatsupport/include/sel4vmmplatsupport/drivers/cross_vm_connection.h b/libsel4vmmplatsupport/include/sel4vmmplatsupport/drivers/cross_vm_connection.h
index da8ff9b..df4cad4 100644
--- a/libsel4vmmplatsupport/include/sel4vmmplatsupport/drivers/cross_vm_connection.h
+++ b/libsel4vmmplatsupport/include/sel4vmmplatsupport/drivers/cross_vm_connection.h

@@ -55,6 +55,7 @@
     crossvm_dataport_handle_t *dataport;
     emit_fn emit_fn;
     seL4_Word consume_id;
+    const char *connection_name;
 } crossvm_handle_t;
 
 /***

diff --git a/libsel4vmmplatsupport/src/drivers/cross_vm_connection.c b/libsel4vmmplatsupport/src/drivers/cross_vm_connection.c
index d875175..dde6f3b 100644
--- a/libsel4vmmplatsupport/src/drivers/cross_vm_connection.c
+++ b/libsel4vmmplatsupport/src/drivers/cross_vm_connection.c

@@ -35,6 +35,8 @@
 #define EVENT_BAR_EMIT_REGISTER_INDEX 0
 #define EVENT_BAR_CONSUME_EVENT_REGISTER 0x4
 #define EVENT_BAR_CONSUME_EVENT_REGISTER_INDEX 1
+#define EVENT_BAR_DEVICE_NAME_REGISTER 0x8
+#define EVENT_BAR_DEVICE_NAME_MAX_LEN 50
 
 struct connection_info {
     uintptr_t event_address;
@@ -291,6 +293,12 @@
             return -1;
         }
         info[i].connection = connections[i];
+        if (connections[i].connection_name == NULL) {
+            connections[i].connection_name = "connector";
+        }
+        strncpy(info[i].event_registers + EVENT_BAR_DEVICE_NAME_REGISTER, connections[i].connection_name,
+                EVENT_BAR_DEVICE_NAME_MAX_LEN);
+
         connection_curr_addr += dataport_size;
     }
     return 0;