From c366efc19e05c26288c3b260909f4c1593b4d4db Mon Sep 17 00:00:00 2001
From: Rob Bradford <robert.bradford@intel.com>
Date: Mon, 18 Jan 2021 13:55:37 +0000
Subject: [PATCH] virtio-devices: block, block_io_uring: Don't assume max queue
 count

Don't assume that the number of queues provided match the number of
queues offered. The virtio spec allows the driver to program fewer
queues.

Signed-off-by: Rob Bradford <robert.bradford@intel.com>
---
 virtio-devices/src/block.rs          | 5 +++--
 virtio-devices/src/block_io_uring.rs | 9 +++++----
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/virtio-devices/src/block.rs b/virtio-devices/src/block.rs
index 05e3bc3a2..84da8f0fa 100644
--- a/virtio-devices/src/block.rs
+++ b/virtio-devices/src/block.rs
@@ -444,8 +444,9 @@ impl<T: 'static + DiskFile + Send> VirtioDevice for Block<T> {
         self.update_writeback();
 
         let mut epoll_threads = Vec::new();
-        for i in 0..self.common.queue_sizes.len() {
+        for i in 0..queues.len() {
             let queue_evt = queue_evts.remove(0);
+            let queue = queues.remove(0);
             let kill_evt = self
                 .common
                 .kill_evt
@@ -467,7 +468,7 @@ impl<T: 'static + DiskFile + Send> VirtioDevice for Block<T> {
                     ActivateError::BadActivate
                 })?;
             let mut handler = BlockEpollHandler {
-                queue: queues.remove(0),
+                queue,
                 mem: mem.clone(),
                 disk_image: self.disk_image.clone(),
                 disk_nsectors: self.disk_nsectors,
diff --git a/virtio-devices/src/block_io_uring.rs b/virtio-devices/src/block_io_uring.rs
index 2d795cb2a..43653b7b2 100644
--- a/virtio-devices/src/block_io_uring.rs
+++ b/virtio-devices/src/block_io_uring.rs
@@ -493,9 +493,10 @@ impl VirtioDevice for BlockIoUring {
         self.update_writeback();
 
         let mut epoll_threads = Vec::new();
-        for i in 0..self.common.queue_sizes.len() {
-            let queue_size = self.common.queue_sizes[i] as usize;
+        for i in 0..queues.len() {
             let queue_evt = queue_evts.remove(0);
+            let queue = queues.remove(0);
+            let queue_size = queue.size;
             let io_uring = IoUring::new(queue_size as u32).map_err(|e| {
                 error!("failed to create io_uring instance: {}", e);
                 ActivateError::BadActivate
@@ -522,7 +523,7 @@ impl VirtioDevice for BlockIoUring {
                 })?;
 
             let mut handler = BlockIoUringEpollHandler {
-                queue: queues.remove(0),
+                queue,
                 mem: mem.clone(),
                 disk_image_fd: self.disk_image.as_raw_fd(),
                 disk_nsectors: self.disk_nsectors,
@@ -538,7 +539,7 @@ impl VirtioDevice for BlockIoUring {
                     error!("failed to create io_uring eventfd: {}", e);
                     ActivateError::BadActivate
                 })?,
-                request_list: HashMap::with_capacity(queue_size),
+                request_list: HashMap::with_capacity(queue_size.into()),
             };
 
             let paused = self.common.paused.clone();