snp.sh: Updated Ubuntu SNP guest launch to generalize across various OS

Generalize a way to get and install SNP guest kernel package(AMDSEV build), generalize initrd pattern to make it match across different OS linux distros, and set the default ubuntu guest kernel append parameter.

Signed-off-by: Harika Nittala <[email protected]>

tools/snp.sh

@@ -84,7 +84,7 @@ CPU_MODEL="${CPU_MODEL:-EPYC-v4}"
 GUEST_USER="${GUEST_USER:-amd}"
 GUEST_PASS="${GUEST_PASS:-amd}"
 GUEST_SSH_KEY_PATH="${GUEST_SSH_KEY_PATH:-${LAUNCH_WORKING_DIR}/${GUEST_NAME}-key}"
-GUEST_ROOT_LABEL="${GUEST_ROOT_LABEL:-cloudimg-rootfs}"
+GUEST_ROOT_LABEL="${GUEST_ROOT_LABEL:""}"
 GUEST_KERNEL_APPEND="root=LABEL=${GUEST_ROOT_LABEL} ro console=ttyS0"
 QEMU_CMDLINE_FILE="${QEMU_CMDLINE:-${LAUNCH_WORKING_DIR}/qemu.cmdline}"
 IMAGE="${IMAGE:-${LAUNCH_WORKING_DIR}/${GUEST_NAME}.img}"
@@ -102,6 +102,8 @@ CLOUD_INIT_IMAGE_URL="https://cloud-images.ubuntu.com/jammy/current/jammy-server
 CLOUD_INIT_IMAGE_URL_UBUNTU="https://cloud-images.ubuntu.com/jammy/current/jammy-server-cloudimg-amd64.img"
 IMAGE_BASENAME_UBUNTU=$(basename "${CLOUD_INIT_IMAGE_URL_UBUNTU}")
 IMAGE_BASENAME=""
+GUEST_ROOT_LABEL_UBUNTU="cloudimg-rootfs"
+GUEST_KERNEL_APPEND_UBUNTU="root=LABEL=${GUEST_ROOT_LABEL_UBUNTU} ro console=ttyS0"
 DRACUT_TARBALL_URL="https://github.com/dracutdevs/dracut/archive/refs/tags/059.tar.gz"
 SEV_SNP_MEASURE_VERSION="0.0.11"
 
@@ -926,6 +928,53 @@ build_and_install_amdsev() {
   save_binary_paths
 }
 
+get_package_install_command(){
+  local linux_distro=$(get_linux_distro)
+
+  case ${linux_distro} in
+    ubuntu)
+      echo "dpkg -i"
+      ;;
+    *)
+      >&2 echo -e "ERROR: ${linux_distro}"
+      return 1
+      ;;
+  esac
+}
+
+get_guest_kernel_package(){
+  local linux_distro=$(get_linux_distro)
+  local guest_kernel_version=$(get_guest_kernel_version)
+
+  pushd "${SETUP_WORKING_DIR}/AMDSEV/linux" >/dev/null
+    case ${linux_distro} in
+      ubuntu)
+          echo $(realpath linux-image*${guest_kernel_version}*.deb| grep -v dbg)
+          ;;
+      *)
+        >&2 echo -e "ERROR: ${linux_distro}"
+        return 1
+        ;;
+    esac
+  popd>/dev/null
+}
+
+set_default_guest_kernel_append() {
+  local linux_distro=$(get_linux_distro)
+
+  # Sets default kernel append based on the linux distro
+  case ${linux_distro} in
+    ubuntu)
+      GUEST_ROOT_LABEL="${GUEST_ROOT_LABEL_UBUNTU}"
+      GUEST_KERNEL_APPEND="${GUEST_KERNEL_APPEND_UBUNTU}"
+      ;;
+    *)
+      >&2 echo -e "ERROR: ${linux_distro}"
+      return 1
+      ;;
+  esac
+}
+
 setup_and_launch_guest() {
   # Return error if user specified file that doesn't exist
   if [ ! -f "${IMAGE}" ] && ${SKIP_IMAGE_CREATE}; then
@@ -965,17 +1014,22 @@ setup_and_launch_guest() {
 
     # Install the guest kernel, retrieve the initrd and then reboot
     local guest_kernel_version=$(get_guest_kernel_version)
-    local guest_kernel_deb=$(echo "$(realpath ${SETUP_WORKING_DIR}/AMDSEV/linux/linux-image*snp-guest*.deb)" | grep -v dbg)
-    local guest_initrd_basename="initrd.img-${guest_kernel_version}"
-    wait_and_retry_command "scp_guest_command ${guest_kernel_deb} ${GUEST_USER}@localhost:/home/${GUEST_USER}"
-    ssh_guest_command "sudo dpkg -i /home/${GUEST_USER}/$(basename ${guest_kernel_deb})"
+    local guest_kernel_package=$(get_guest_kernel_package)
+    local guest_initrd_basename="init*${guest_kernel_version}*"
+    local os_package_install_command=$(get_package_install_command)
+    wait_and_retry_command "scp_guest_command ${guest_kernel_package} ${GUEST_USER}@localhost:/home/${GUEST_USER}"
+    ssh_guest_command "sudo ${os_package_install_command} /home/${GUEST_USER}/$(basename ${guest_kernel_package})"
     scp_guest_command "${GUEST_USER}@localhost:/boot/${guest_initrd_basename}" "${LAUNCH_WORKING_DIR}"
+
     ssh_guest_command "sudo shutdown now" || true
     echo "true" > "${guest_kernel_installed_file}"
 
     # Update the initrd file path and name in the guest launch source-bins file
     sed -i -e "s|^\(INITRD_BIN=\).*$|\1\"${LAUNCH_WORKING_DIR}/${guest_initrd_basename}\"|g" "${LAUNCH_WORKING_DIR}/source-bins"
 
+    # Set the default guest kernel append parameter as per the linux distro
+    [ -z "${GUEST_ROOT_LABEL}" ] && set_default_guest_kernel_append
+
     # Wait for shutdown to complete
     wait_and_retry_command "! ps aux | grep \"${WORKING_DIR}.*qemu.*${IMAGE}\" | grep -v \"tail.*qemu.log\" | grep -v \"grep.*qemu\""