Getting Started Guide for ACRN Partitioned Mode¶

The ACRN hypervisor supports a partitioned scenario in which the OS running in a pre-launched VM can bypass the ACRN hypervisor and directly access isolated PCI devices. The following guidelines provide step-by-step instructions on how to set up the ACRN hypervisor partitioned scenario running two pre-launched VMs on an Intel NUC.

Validated Versions
Prerequisites
Update Kernel Image and Modules of Pre-Launched VM
Update ACRN Hypervisor Image
Update Ubuntu GRUB to Boot Hypervisor and Load Kernel Image
Partitioned Scenario Startup Check

Validated Versions ¶

Ubuntu version: 18.04
ACRN hypervisor tag: v2.7

Prerequisites ¶

Intel NUC Kit NUC11TNBi5.
NVMe disk
SATA disk
Storage device with USB interface (such as USB Flash or SATA disk connected with a USB 3.0 SATA converter).
Disable Intel Hyper Threading Technology in the BIOS to avoid interference from logical cores for the partitioned scenario.
In the partitioned scenario, two VMs (running Ubuntu OS) are started by the ACRN hypervisor. Each VM has its own root filesystem. Set up each VM by following the Ubuntu desktop installation instructions first on a SATA disk and then again on a storage device with a USB interface. The two pre-launched VMs will mount the root file systems via the SATA controller and the USB controller respectively.

Update Kernel Image and Modules of Pre-Launched VM ¶

On the local Ubuntu target machine, find the kernel file, copy to your (/boot directory) and name the file bzImage. The uname -r command returns the kernel release, for example, 5.4.0-89-generic):
```
sudo cp /boot/vmlinuz-$(uname -r)  /boot/bzImage
sudo cp /boot/initrd.img-$(uname -r) /boot/initrd_Image
```
The current ACRN partitioned scenario implementation requires a multi-boot capable bootloader to boot both the ACRN hypervisor and the bootable kernel image built from the previous step. Install the Ubuntu OS on the onboard NVMe SSD by following the Ubuntu desktop installation instructions. The Ubuntu installer creates 3 disk partitions on the onboard NVMe SSD. By default, the GRUB bootloader is installed on the EFI System Partition (ESP) that’s used to bootstrap the ACRN hypervisor.
After installing the Ubuntu OS, power off the Intel NUC. Attach the SATA disk and storage device with the USB interface to the Intel NUC. Power on the Intel NUC and make sure it boots the Ubuntu OS from the NVMe SSD. Plug in the removable disk with the kernel image into the Intel NUC and then copy the loadable kernel modules built in Step 1 to the /lib/modules/ folder on both the mounted SATA disk and storage device with USB interface. For example, assuming the SATA disk and storage device with USB interface are assigned to /dev/sda and /dev/sdb respectively, the following commands set up the partition mode loadable kernel modules onto the root file systems to be loaded by the pre-launched VMs:

To mount the Ubuntu OS root filesystem on the SATA disk:
```
sudo mount /dev/sda3 /mnt
sudo cp -r /lib/modules/* /mnt/lib/modules
sudo umount /mnt
```
To mount the Ubuntu OS root filesystem on the USB flash disk:
```
sudo mount /dev/sdb3 /mnt
sudo cp -r /lib/modules/* /mnt/lib/modules
sudo umount /mnt
```

Update ACRN Hypervisor Image ¶

Before building the ACRN hypervisor, find the I/O address of the serial port and the PCI BDF addresses of the SATA controller and the USB controllers on the Intel NUC. Enter the following command to get the I/O addresses of the serial port. The Intel NUC supports one serial port, ttyS0. Connect the serial port to the development workstation in order to access the ACRN serial console to switch between pre-launched VMs:

dmesg | grep ttyS0

Output example:

[    0.000000] console [ttyS0] enabled
[    1.562546] 00:01: ttyS0 at I/O 0x3f8 (irq = 4, base_baud = 115200) is
a 16550A

The following command prints detailed information about all PCI buses and devices in the system:

sudo lspci -vv

Output example:

00:14.0 USB controller: Intel Corporation Device 9ded (rev 30) (prog-if 30 [XHCI])
        Subsystem: Intel Corporation Device 7270
00:17.0 SATA controller: Intel Corporation Device 9dd3 (rev 30) (prog-if 01 [AHCI 1.0])
        Subsystem: Intel Corporation Device 7270
02:00.0 Non-Volatile memory controller: Intel Corporation Device f1a8 (rev 03) (prog-if 02 [NVM Express])
        Subsystem: Intel Corporation Device 390d
03:00.0 Ethernet controller: Intel Corporation I210 Gigabit Network Connection (rev 03)
        Subsystem: Intel Corporation I210 Gigabit Network Connection
04:00.0 Ethernet controller: Intel Corporation I210 Gigabit Network Connection (rev 03)
        Subsystem: Intel Corporation I210 Gigabit Network Connection

Clone the ACRN source code and configure the build options.

Refer to Getting Started Guide to set up the ACRN build environment on your development workstation.

Clone the ACRN source code and check out to the tag v2.7:
```
git clone https://github.com/projectacrn/acrn-hypervisor.git
cd acrn-hypervisor
git checkout v2.7
```
Check the pci_devs sections in misc/config_tools/data/nuc11tnbi5/partitioned.xml for each pre-launched VM to ensure you are using the right PCI device BDF information (as reported by lspci -vv). If you need to make changes to this file, create a copy of it and use it subsequently when building ACRN (SCENARIO=/path/to/newfile.xml).
Build the ACRN hypervisor and ACPI binaries for pre-launched VMs with default xmls:
```
make hypervisor BOARD=nuc11tnbi5 SCENARIO=partitioned
```
Note

The acrn.bin will be generated to ./build/hypervisor/acrn.bin. The ACPI_VM0.bin and ACPI_VM1.bin will be generated to ./build/hypervisor/acpi/.
Check the Ubuntu bootloader name.

In the current design, the partitioned scenario depends on the GRUB boot loader; otherwise, the hypervisor will fail to boot. Verify that the default bootloader is GRUB:
```
sudo update-grub -V
```
The above command output should contain the GRUB keyword.
Copy the artifact acrn.bin, ACPI_VM0.bin, and ACPI_VM1.bin to the /boot directory on NVME:
1. Copy acrn.bin, ACPI_VM1.bin and ACPI_VM0.bin to a removable disk.
2. Plug the removable disk into the Intel NUC’s USB port.
3. Copy the acrn.bin, ACPI_VM0.bin, and ACPI_VM1.bin from the removable disk to /boot directory.

Update Ubuntu GRUB to Boot Hypervisor and Load Kernel Image ¶

Append the following configuration to the /etc/grub.d/40_custom file:
```
menuentry 'ACRN hypervisor Partitioned Scenario' --id ACRN_Partitioned --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-simple-e23c76ae-b06d-4a6e-ad42-46b8eedfd7d3' {
        recordfail
        load_video
        gfxmode $linux_gfx_mode
        insmod gzio
        insmod part_gpt
        insmod ext2

        search --no-floppy --fs-uuid --set 9bd58889-add7-410c-bdb7-1fbc2af9b0e1
        echo 'Loading hypervisor partitioned scenario ...'
        multiboot2  /boot/acrn.bin root=PARTUUID="e515916d-aac4-4439-aaa0-33231a9f4d83"
        module2 /boot/bzImage XXXXXX
        module2 /boot/initrd_Image XXXXXX
        module2 /boot/ACPI_VM0.bin ACPI_VM0
        module2 /boot/ACPI_VM1.bin ACPI_VM1
}
```
Note

Update the UUID (--set) and PARTUUID (root= parameter) (or use the device node directly) of the root partition (e.g., /dev/nvme0n1p2). Hint: use sudo blkid. The kernel command-line arguments used to boot the pre-launched VMs is bootargs in the misc/config_tools/data/nuc11tnbi5/partitioned.xml file. The module2 /boot/bzImage param XXXXXX is the bzImage tag and must exactly match the kern_mod in the misc/config_tools/data/nuc11tnbi5/partitioned.xml file. The module2 /boot/initrd_Image param XXXXXX is the initrd_Image tag and must exactly match the ramdisk_mod in the misc/config_tools/data/nuc11tnbi5/partitioned.xml file. The module /boot/ACPI_VM0.bin is the binary of ACPI tables for pre-launched VM0. The parameter ACPI_VM0 is VM0’s ACPI tag and should not be modified. The module /boot/ACPI_VM1.bin is the binary of ACPI tables for pre-launched VM1. The parameter ACPI_VM1 is VM1’s ACPI tag and should not be modified.

Correct example Grub configuration (with module2 image paths set):

menuentry 'ACRN hypervisor Partitioned Scenario' --id ACRN_Partitioned --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-simple-e23c76ae-b06d-4a6e-ad42-46b8eedfd7d3' {
     recordfail
     load_video
     gfxmode $linux_gfx_mode
     insmod gzio
     insmod part_gpt
     insmod ext2
     search --no-floppy --fs-uuid --set 9bd58889-add7-410c-bdb7-1fbc2af9b0e1
     echo 'Loading hypervisor partitioned scenario ...'
     multiboot2  /boot/acrn.bin root=PARTUUID="e515916d-aac4-4439-aaa0-33231a9f4d83"
     module2 /boot/bzImage Linux_bzImage
     module2 /boot/initrd_Image Ubuntu
     module2 /boot/ACPI_VM0.bin ACPI_VM0
     module2 /boot/ACPI_VM1.bin ACPI_VM1
}

Modify the /etc/default/grub file as follows to make the GRUB menu visible when booting:

GRUB_DEFAULT=ACRN_Partitioned
#GRUB_HIDDEN_TIMEOUT=0
#GRUB_HIDDEN_TIMEOUT_QUIET=true
GRUB_TIMEOUT=10
GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
GRUB_CMDLINE_LINUX=""

Update GRUB:
```
sudo update-grub
```
Reboot the Intel NUC. Select the ACRN hypervisor Partitioned Scenario entry to boot the partitioned scenario of the ACRN hypervisor on the Intel NUC’s display. The GRUB loader will boot the hypervisor, and the hypervisor will automatically start the two pre-launched VMs.

Partitioned Scenario Startup Check ¶

Connect to the serial port as described in this Connecting to the serial port tutorial.
Use these steps to verify that the hypervisor is properly running:
1. Log in to the ACRN hypervisor shell from the serial console.
2. Use the vm_list to check the pre-launched VMs.
Use these steps to verify that the two pre-launched VMs are running properly:
1. Use the vm_console 0 to switch to VM0’s console.
2. The VM0’s OS should boot and log in.
3. Use a Ctrl + Space to return to the ACRN hypervisor shell.
4. Use the vm_console 1 to switch to VM1’s console.
5. The VM1’s OS should boot and log in.

Refer to the ACRN hypervisor shell user guide for more information about available commands.

Getting Started Guide for ACRN Partitioned Mode¶

Validated Versions¶

Prerequisites¶

Update Kernel Image and Modules of Pre-Launched VM¶

Update ACRN Hypervisor Image¶

Update Ubuntu GRUB to Boot Hypervisor and Load Kernel Image¶

Partitioned Scenario Startup Check¶