Move Cloud Hypervisor to virtio-queue crate

Relying on the vm-virtio/virtio-queue crate from rust-vmm which has been
copied inside the Cloud Hypervisor tree, the entire codebase is moved to
the new definition of a Queue and other related structures.

The reason for this move is to follow the upstream until we get some
agreement for the patches that we need on top of that to make it
properly work with Cloud Hypervisor.

Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>

virtio-devices/src/vhost_user/vu_common_ctrl.rs

@@ -1,7 +1,6 @@
 // Copyright 2019 Intel Corporation. All Rights Reserved.
 // SPDX-License-Identifier: Apache-2.0
 
-use super::super::{Descriptor, Queue};
 use super::{Error, Result};
 use crate::vhost_user::Inflight;
 use crate::{
@@ -13,6 +12,7 @@ use std::ffi;
 use std::fs::File;
 use std::os::unix::io::{AsRawFd, FromRawFd, RawFd};
 use std::os::unix::net::UnixListener;
+use std::sync::atomic::Ordering;
 use std::sync::Arc;
 use std::thread::sleep;
 use std::time::{Duration, Instant};
@@ -23,7 +23,10 @@ use vhost::vhost_user::message::{
 };
 use vhost::vhost_user::{Master, MasterReqHandler, VhostUserMaster, VhostUserMasterReqHandler};
 use vhost::{VhostBackend, VhostUserDirtyLogRegion, VhostUserMemoryRegionInfo, VringConfigData};
-use vm_memory::{Address, Error as MmapError, FileOffset, GuestMemory, GuestMemoryRegion};
+use virtio_queue::{Descriptor, Queue};
+use vm_memory::{
+    Address, Error as MmapError, FileOffset, GuestMemory, GuestMemoryAtomic, GuestMemoryRegion,
+};
 use vm_migration::protocol::MemoryRangeTable;
 use vmm_sys_util::eventfd::EventFd;
 
@@ -148,7 +151,7 @@ impl VhostUserHandle {
     pub fn setup_vhost_user<S: VhostUserMasterReqHandler>(
         &mut self,
         mem: &GuestMemoryMmap,
-        queues: Vec<Queue>,
+        queues: Vec<Queue<GuestMemoryAtomic<GuestMemoryMmap>>>,
         queue_evts: Vec<EventFd>,
         virtio_interrupt: &Arc<dyn VirtioInterrupt>,
         acked_features: u64,
@@ -203,29 +206,37 @@ impl VhostUserHandle {
             let actual_size: usize = queue.actual_size().try_into().unwrap();
 
             let config_data = VringConfigData {
-                queue_max_size: queue.get_max_size(),
+                queue_max_size: queue.max_size(),
                 queue_size: queue.actual_size(),
                 flags: 0u32,
                 desc_table_addr: get_host_address_range(
                     mem,
-                    queue.desc_table,
+                    queue.state.desc_table,
                     actual_size * std::mem::size_of::<Descriptor>(),
                 )
                 .ok_or(Error::DescriptorTableAddress)? as u64,
                 // The used ring is {flags: u16; idx: u16; virtq_used_elem [{id: u16, len: u16}; actual_size]},
                 // i.e. 4 + (4 + 4) * actual_size.
-                used_ring_addr: get_host_address_range(mem, queue.used_ring, 4 + actual_size * 8)
-                    .ok_or(Error::UsedAddress)? as u64,
+                used_ring_addr: get_host_address_range(
+                    mem,
+                    queue.state.used_ring,
+                    4 + actual_size * 8,
+                )
+                .ok_or(Error::UsedAddress)? as u64,
                 // The used ring is {flags: u16; idx: u16; elem [u16; actual_size]},
                 // i.e. 4 + (2) * actual_size.
-                avail_ring_addr: get_host_address_range(mem, queue.avail_ring, 4 + actual_size * 2)
-                    .ok_or(Error::AvailAddress)? as u64,
+                avail_ring_addr: get_host_address_range(
+                    mem,
+                    queue.state.avail_ring,
+                    4 + actual_size * 2,
+                )
+                .ok_or(Error::AvailAddress)? as u64,
                 log_addr: None,
             };
 
             vrings_info.push(VringInfo {
                 config_data,
-                used_guest_addr: queue.used_ring.raw_value(),
+                used_guest_addr: queue.state.used_ring.raw_value(),
             });
 
             self.vu
@@ -235,8 +246,9 @@ impl VhostUserHandle {
                 .set_vring_base(
                     queue_index,
                     queue
-                        .used_index_from_memory(mem)
-                        .map_err(Error::GetAvailableIndex)?,
+                        .avail_idx(Ordering::Acquire)
+                        .map_err(Error::GetAvailableIndex)?
+                        .0,
                 )
                 .map_err(Error::VhostUserSetVringBase)?;
 
@@ -317,7 +329,7 @@ impl VhostUserHandle {
     pub fn reinitialize_vhost_user<S: VhostUserMasterReqHandler>(
         &mut self,
         mem: &GuestMemoryMmap,
-        queues: Vec<Queue>,
+        queues: Vec<Queue<GuestMemoryAtomic<GuestMemoryMmap>>>,
         queue_evts: Vec<EventFd>,
         virtio_interrupt: &Arc<dyn VirtioInterrupt>,
         acked_features: u64,