block: Set an option to pin virtio block threads to host cpus

Currently the only way to set the affinity for virtio block threads is
to boot the VM, search for the tid of each of the virtio block threads,
then set the affinity manually. This commit adds an option to pin virtio
block queues to specific host cpus (similar to pinning vcpus to host
cpus). A queue_affinity option has been added to the disk flag in
the cli to specify a mapping of queue indices to host cpus.

Signed-off-by: acarp <acarp@crusoeenergy.com>

fuzz/fuzz_targets/block.rs

@@ -21,6 +21,7 @@ use virtio_devices::{Block, VirtioDevice, VirtioInterrupt, VirtioInterruptType};
 use virtio_queue::{Queue, QueueT};
 use vm_memory::{bitmap::AtomicBitmap, Bytes, GuestAddress, GuestMemoryAtomic};
 use vmm_sys_util::eventfd::{EventFd, EFD_NONBLOCK};
+use std::collections::BTreeMap;
 
 type GuestMemoryMmap = vm_memory::GuestMemoryMmap<AtomicBitmap>;
 
@@ -49,6 +50,7 @@ fuzz_target!(|bytes| {
     let shm = memfd_create(&ffi::CString::new("fuzz").unwrap(), 0).unwrap();
     let disk_file: File = unsafe { File::from_raw_fd(shm) };
     let qcow_disk = Box::new(RawFileDiskSync::new(disk_file)) as Box<dyn DiskFile>;
+    let queue_affinity = BTreeMap::new();
     let mut block = Block::new(
         "tmp".to_owned(),
         qcow_disk,
@@ -62,6 +64,7 @@ fuzz_target!(|bytes| {
         None,
         EventFd::new(EFD_NONBLOCK).unwrap(),
         None,
+        queue_affinity,
     )
     .unwrap();