virt: acrn: remove WQ_UNBOUND flag

Due to the two level schedule model in type 1 hypervisor, Service OS
kernel's scheduler does not aware the running status of the User VM,
which means, a thread may be schedule to a CPU which is idle in Service
OS but actually running in User VM.
For the ioreq dispatch workqueue, as it was in the critical path of I/O
request, and ACRN hypervisor only inject the ioreq interrupt to CPU0, so
migrate to other CPU is meaningless and will bring more latency.
So, remove the WQ_UNBOUND flag, and let CPU0 do the dispatch directly.

Signed-off-by: Conghui <conghui.chen@intel.com>
Reviewed-by: Fei Li <fei1.li@intel.com>

drivers/virt/acrn/ioreq.c

@@ -596,7 +596,7 @@ int acrn_ioreq_intr_setup(void)
 {
 	acrn_setup_intr_handler(ioreq_intr_handler);
 	ioreq_wq = alloc_workqueue("ioreq_wq",
-				   WQ_HIGHPRI | WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
+				   WQ_HIGHPRI | WQ_MEM_RECLAIM, 1);
 	if (!ioreq_wq) {
 		dev_err(acrn_dev.this_device, "Failed to alloc workqueue!\n");
 		acrn_remove_intr_handler();