vhost-device-vsock: change default vring queue size to 1024

Although increasing queue size from 256 to 1024 increases the memory
usage of vhost-device-vsock, 1024 is a reasonable default which should
make vhost-device-vsock work by default (i.e., without using the
queue-size option) with devices that use vring queue size up to 1024
such as QEMU's vhost-user-vsock-device.

If Users require greater or smaller queue size, they can use the
'queue-size' option to configure the queue size.

Signed-off-by: Dorjoy Chowdhury <dorjoychy111@gmail.com>

vhost-device-vsock/src/main.rs

@@ -27,7 +27,7 @@ use vm_memory::{GuestMemoryAtomic, GuestMemoryMmap};
 
 const DEFAULT_GUEST_CID: u64 = 3;
 const DEFAULT_TX_BUFFER_SIZE: u32 = 64 * 1024;
-const DEFAULT_QUEUE_SIZE: usize = 256;
+const DEFAULT_QUEUE_SIZE: usize = 1024;
 const DEFAULT_GROUP_NAME: &str = "default";
 
 #[derive(Debug, ThisError)]