Using partition mode on UP2¶

This tutorial describes the steps needed to use partition mode with the ACRN hypervisor on UP2.

Build kernel and modules for partition mode guest¶

Build kernel and modules

git clone https://github.com/projectacrn/acrn-kernel.git
cd ~/acrn-kernel
cp kernel_config_partition_os .config
make oldconfig
make

Install modules

First of all, please prepare one USB flash drive and one SATA disk. Plug them in one PC and follow Clear Linux’s online instruction <https://clearlinux.org/documentation/clear-linux/get-started/bare-metal-install#bare-metal-install> to install Clear Linux on them.

Plug the USB flash drive and SATA disk into your PC. Assuming Clear Linux rootfs is installed into /dev/sdx3.
```
mount /dev/sdx3 /mnt/sdx3
cd ~/acrn-kernel
make INSTALL_MOD_PATH=/mnt/sdx3/ modules_install
```
Install kernel

First, please following Ubuntu’s online instruction <https://tutorials.ubuntu.com/tutorial/tutorial-install-ubuntu-desktop?_ga=2.114179015.1954550575.1530817291-1278304647.1523530035> to install it on your UP2’s eMMC.

Copy kernel image to EFI System Partition
```
scp username@IP:~/acrn-kernel/arch/x86/boot/bzImage /boot/efi/
```

Enabling partition mode¶

Clone ACRN source code

git clone https://github.com/projectacrn/acrn-hypervisor.git

Configure the ACRN hypervisor to use partition mode
```
cd ~/acrn-hypervisor/hypervisor
make menuconfig
```
Select entry Hypervisor mode (Sharing mode) and press Enter. Then select Partition mode sub-entry.
Configure the ACRN hypervisor’s serial base address
```
cd ~/acrn-hypervisor/hypervisor
make menuconfig
```
Select entry Base address of serial MMIO region and press Enter. Then we will see a prompt msgbox with title Value for `Base address of serial MMIO region` (hex). Please type the serial base mmio address of your UP2 board and press Enter.

Configure the PCI info about devices assigned to vm.

For the current code, we can only configure it by modifying the vpci_vdev_arrary structure (one per vm) in source code file hypervisor/partition/vm_description.c.

Here is an reference patch for configuring vm1’s assgined PCI devices based on UP2 board. This patch can also apply to other vms you try to configure.

diff --git a/hypervisor/partition/vm_description.c b/hypervisor/partition/vm_description.c
index 12818185..88799b00 100644
--- a/hypervisor/partition/vm_description.c
+++ b/hypervisor/partition/vm_description.c
@@ -41,6 +41,7 @@ static struct vpci_vdev_array vpci_vdev_array1 = {
                }
         },

         {/*vdev 1: SATA controller*/
          .vbdf.bits = {.b = 0x00U, .d = 0x01U, .f = 0x0U},
          .ops = &pci_ops_vdev_pt,
@@ -65,23 +66,24 @@ static struct vpci_vdev_array vpci_vdev_array1 = {
                .bdf.bits = {.b = 0x00U, .d = 0x12U, .f = 0x0U},
                .bar = {
                        [0] = {
-                       .base = 0xb3f10000UL,
+                       .base = 0x91514000UL,
                        .size = 0x2000UL,
                        .type = PCIBAR_MEM32
                        },
                        [1] = {
-                       .base = 0xb3f53000UL,
+                       .base = 0x91537000UL,
                        .size = 0x100UL,
                        .type = PCIBAR_MEM32
                        },
                        [5] = {
-                       .base = 0xb3f52000UL,
+                       .base = 0x91536000UL,
                        .size = 0x800UL,
                        .type = PCIBAR_MEM32
                        },
                 }
               }
            },
         }
  };

Configure .bootargs

A default command line is pre-configured in the source code. Here we just configure root= option to help kernel locate the right rootfs and keep the other options as default.

@@ -171,7 +180,8 @@ struct vm_description_array vm_desc_partition = {
                                .start_hpa = 0x100000000UL,
                                .mem_size = 0x20000000UL, /* uses contiguous memory from host */
                                .vm_vuart = true,
-                               .bootargs = "root=/dev/sda rw rootwait noxsave maxcpus=2 nohpet console=hvc0 \
+                               .bootargs = "root=PARTUUID=<Your rootfs PARTUUID> rw rootwait noxsave maxcpus=2 nohpet console=hvc0 \
                                              console=ttyS0 no_timer_check ignore_loglevel log_buf_len=16M \
                                              consoleblank=0 tsc=reliable xapic_phys",
                                .vpci_vdev_array = &vpci_vdev_array1,

Build ACRN with the above changes.
```
$ make PLATFORM=sbl
```

Install ACRN

First we should add one menuentry in /boot/efi/grub/grub.cfg on UP2 board

menuentry 'ACRN Partition Mode' --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

        echo 'Loading partition mode hypervisor ...'
        multiboot /acrn.32.out
        module /bzImage
}

Copy acrn.32.out and bzImage to /boot/efi

scp username@IP:~/acrn-hypervisor/hypervisor/build/acrn.32.out /boot/efi

Boot ACRN

Plug the USB flash drive and SATA Disk into your UP2 board and then reboot the board to the built-in EFI shell. Then execute the following command to load the ACRN hypervisor.
```
shell> fs1:
fs1:\> EFI\ubuntu\grubx64.efi
```
Here we will see the following GRUB menu. Select entry ACRN Partition Mode and press Enter and then the ACRN hypervisor will be loaded automatically.
```
*Ubuntu
 ACRN Partition Mode
 Advanced options for Ubuntu
 System setup
 Restore Ubuntu 16.04 to factory state
```

Playing with ACRN hypervisor with partition mode¶

Connect the serial port of the UP2 board with another PC and use the following command to check if vms booted successfully. If vms are booted successfully, we will see the following message.

ACRN:\>sos_console 1

----- Entering Guest 1 Shell -----

root@clr-e8216ad453ad4f08914d83cbc50f838c ~ #

---Entering ACRN SHELL---
ACRN:\>sos_console 2

----- Entering Guest 2 Shell -----

root@clr-bdbe97b256864a92b44a9449bf229769 ~ #

---Entering ACRN SHELL---
ACRN:\>