ci: Add integration test for virtio-blk with 'readonly=on'

Previous commit added 'readonly' support for virtio-blk to be able to
configure read-only devices, so add an integration test for this new
feature.

Signed-off-by: Sergio Lopez <slp@redhat.com>

src/main.rs

@@ -119,7 +119,7 @@ fn create_app<'a, 'b>(
                 .long("disk")
                 .help(
                     "Disk parameters \"path=<disk_image_path>,\
-                     iommu=on|off\"",
+                     readonly=on|off,iommu=on|off\"",
                 )
                 .takes_value(true)
                 .min_values(1)
@@ -2509,6 +2509,72 @@ mod tests {
         });
     }
 
+    #[cfg_attr(not(feature = "mmio"), test)]
+    fn test_virtio_blk_readonly() {
+        test_block!(tb, "", {
+            let mut clear = ClearDiskConfig::new();
+            let guest = Guest::new(&mut clear);
+            let mut blk_file_path = dirs::home_dir().unwrap();
+            blk_file_path.push("workloads");
+            blk_file_path.push("blk.img");
+
+            let mut cloud_child = Command::new("target/release/cloud-hypervisor")
+                .args(&["--cpus", "boot=1"])
+                .args(&["--memory", "size=512M,file=/dev/shm"])
+                .args(&["--kernel", guest.fw_path.as_str()])
+                .args(&[
+                    "--disk",
+                    format!(
+                        "path={}",
+                        guest.disk_config.disk(DiskType::OperatingSystem).unwrap()
+                    )
+                    .as_str(),
+                    format!(
+                        "path={}",
+                        guest.disk_config.disk(DiskType::CloudInit).unwrap()
+                    )
+                    .as_str(),
+                    format!("path={},readonly=on", blk_file_path.to_str().unwrap()).as_str(),
+                ])
+                .args(&["--net", guest.default_net_string().as_str()])
+                .spawn()
+                .unwrap();
+
+            thread::sleep(std::time::Duration::new(20, 0));
+
+            // Check both if /dev/vdc exists and if the block size is 16M.
+            aver_eq!(
+                tb,
+                guest
+                    .ssh_command("lsblk | grep vdc | grep -c 16M")
+                    .unwrap_or_default()
+                    .trim()
+                    .parse::<u32>()
+                    .unwrap_or_default(),
+                1
+            );
+
+            // Check both if /dev/vdc exists and if this block is RO.
+            aver_eq!(
+                tb,
+                guest
+                    .ssh_command("lsblk | grep vdc | awk '{print $5}'")
+                    .unwrap_or_default()
+                    .trim()
+                    .parse::<u32>()
+                    .unwrap_or_default(),
+                1
+            );
+
+            guest.ssh_command("sudo shutdown -h now")?;
+            thread::sleep(std::time::Duration::new(5, 0));
+            let _ = cloud_child.kill();
+            let _ = cloud_child.wait();
+
+            Ok(())
+        });
+    }
+
     #[cfg_attr(not(feature = "mmio"), test)]
     fn test_vhost_user_net() {
         test_block!(tb, "", {