CI: Use snapshot instead of copying VM image

Because the Windows VM image is large, copying whole the image sometimes
fails due to free disk space shortage. This commit replaces it with
snapshot.

Signed-off-by: Akira Moroo <[email protected]>

Author: retrage

run_integration_tests.sh

@@ -21,10 +21,25 @@ if [ "$TARGET" == "linux" ]; then
   bash ./fetch_disk_images.sh
 fi
 
+WIN_IMAGE_FILE="./resources/images/windows-server-2019.raw"
+if [ -e $WIN_IMAGE_FILE ]; then
+  export img_blk_size=$(du -b -B 512 $WIN_IMAGE_FILE | awk '{print $1;}')
+  export loop_device=$(sudo losetup --find --show --read-only $WIN_IMAGE_FILE)
+  sudo dmsetup create windows-base --table "0 $img_blk_size linear $loop_device 0"
+  sudo dmsetup mknodes
+  sudo dmsetup create windows-snapshot-base --table "0 $img_blk_size snapshot-origin /dev/mapper/windows-base"
+  sudo dmsetup mknodes
+fi
+
 # Add the user to the kvm group (if not already in it), so they can run VMs
 id -nGz "$USER" | grep -qzxF kvm || sudo adduser "$USER" kvm
 
 newgrp kvm << EOF
 export RUST_BACKTRACE=1
 cargo test --features "integration_tests" "integration::tests::${TARGET}"
 EOF
+
+if [ -e $WIN_IMAGE_FILE ]; then
+  sudo dmsetup remove_all -f
+  sudo losetup -D
+fi

src/integration.rs

@@ -536,10 +536,20 @@ mod tests {
             }
         }
 
+        fn prepare_windows_os_disk(_: &TempDir, image_name: &str) -> String {
+            let src_osdisk = std::env::current_dir()
+                .unwrap()
+                .join("resources")
+                .join("images")
+                .join(image_name);
+            let dest_osdisk = src_osdisk;
+            dest_osdisk.to_str().unwrap().to_owned()
+        }
+
         fn test_boot_qemu_windows_common(fw: &Firmware) {
             let tmp_dir = TempDir::new().expect("Expect creating temporary directory to succeed");
             let net = GuestNetworkConfig::new(COUNTER.fetch_add(1, Ordering::SeqCst) as u8);
-            let os = prepare_os_disk(&tmp_dir, WINDOWS_IMAGE_NAME);
+            let os = prepare_windows_os_disk(&tmp_dir, WINDOWS_IMAGE_NAME);
 
             prepare_tap(&net);
 
@@ -622,7 +632,7 @@ mod tests {
         #[cfg(not(feature = "coreboot"))]
         fn test_boot_ch_windows() {
             let tmp_dir = TempDir::new().expect("Expect creating temporary directory to succeed");
-            let os = prepare_os_disk(&tmp_dir, WINDOWS_IMAGE_NAME);
+            let os = prepare_windows_os_disk(&tmp_dir, WINDOWS_IMAGE_NAME);
 
             let mut c = Command::new("./resources/cloud-hypervisor");
             c.args(&[