crosvm: mmio register and queue check fixes

According to the Virtio specification, all MMIO register access must be
32-bit wide and aligned. However, this restriction is not true in
general for the config space. This change relaxes the restriction for
accesses to config space.

This change also checks that each queue is valid before activating a
device.

TEST=crosvm run
BUG=None

Change-Id: I10228d99992576837ff505aad56fefbc4d8eff78
Reviewed-on: https://chromium-review.googlesource.com/578314
Commit-Ready: Zach Reizner <zachr@chromium.org>
Tested-by: Zach Reizner <zachr@chromium.org>
Reviewed-by: Dylan Reid <dgreid@chromium.org>

1 files changed, 1 insertions, 2 deletions

diff --git a/src/hw/virtio/queue.rs b/src/hw/virtio/queue.rs
index b993715..1cdb9c0 100644
--- a/src/hw/virtio/queue.rs
+++ b/src/hw/virtio/queue.rs
@@ -3,7 +3,6 @@
 // found in the LICENSE file.
 
 use std::cmp::min;
-use std::result;
 
 use sys_util::{GuestAddress, GuestMemory};
 
@@ -203,7 +202,7 @@ impl Queue {
         min(self.size, self.max_size)
     }
 
-    fn is_valid(&self, mem: &GuestMemory) -> bool {
+    pub fn is_valid(&self, mem: &GuestMemory) -> bool {
         let queue_size = self.actual_size() as usize;
         let desc_table = self.desc_table;
         let desc_table_size = 16 * queue_size;