vm: implement the VM interface for VirtualBox

This change adds VirtualBox support to syzkaller. It implements the VM
interface for VirtualBox and provides:

- full VM lifecycle operations (create, boot, stop, snapshot restore)
- serial console hookup and integration with the output merger
- proper boot wait logic similar to qemu, using SSH readiness
- boot-time crash capture using collected console output

2 files changed, 107 insertions, 0 deletions

diff --git a/docs/linux/setup.md b/docs/linux/setup.md
index cf7f2c273..c1c61690e 100644
--- a/docs/linux/setup.md
+++ b/docs/linux/setup.md
@@ -13,6 +13,7 @@ Instructions for a particular VM type or kernel architecture can be found on the
 - [Setup: Linux host, Android virtual device, x86-64 kernel](setup_linux-host_android-virtual-device_x86-64-kernel.md)
 - [Setup: Linux isolated host](setup_linux-host_isolated.md)
 - [Setup: Ubuntu host, VMware vm, x86-64 kernel](setup_ubuntu-host_vmware-vm_x86-64-kernel.md)
+- [Setup: Ubuntu host, VirtualBox vm, x86-64 kernel](setup_ubuntu-host_virtualbox-vm_x86-64-kernel.md)
 
 ## Install
 
diff --git a/docs/linux/setup_ubuntu-host_virtualbox-vm_x86-64-kernel.md b/docs/linux/setup_ubuntu-host_virtualbox-vm_x86-64-kernel.md
new file mode 100644
index 000000000..f5cde0fd5
--- /dev/null
+++ b/docs/linux/setup_ubuntu-host_virtualbox-vm_x86-64-kernel.md
@@ -0,0 +1,106 @@
+# Setup: Ubuntu host, VirtualBox vm, x86-64 kernel
+
+These are the instructions on how to fuzz the x86-64 kernel in VirtualBox with Ubuntu on the host machine and Debian Bullseye in the virtual machines.
+
+In the instructions below, the `$VAR` notation (e.g. `$GCC`, `$KERNEL`, etc.) is used to denote paths to directories that are either created when executing the instructions (e.g. when unpacking GCC archive, a directory will be created), or that you have to create yourself before running the instructions. Substitute the values for those variables manually.
+
+## GCC and Kernel
+
+You can follow the same [instructions](/docs/linux/setup_ubuntu-host_qemu-vm_x86-64-kernel.md) for obtaining GCC and building the Linux kernel as when using QEMU.
+
+## Image
+
+Install debootstrap:
+
+``` bash
+sudo apt-get install debootstrap
+```
+
+To create a Debian Bullseye Linux user space in the $USERSPACE dir do:
+```
+sudo mkdir -p $USERSPACE
+sudo debootstrap --include=openssh-server,curl,tar,gcc,libc6-dev,time,strace,sudo,less,psmisc,selinux-utils,policycoreutils,checkpolicy,selinux-policy-default,firmware-atheros,open-vm-tools --components=main,contrib,non-free bullseye $USERSPACE
+```
+
+Note: it is important to include the `open-vm-tools` package in the user space as it provides better VM management.
+
+To create a Debian Bullseye Linux VMDK do:
+
+```
+wget https://raw.githubusercontent.com/google/syzkaller/master/tools/create-gce-image.sh -O create-gce-image.sh
+chmod +x create-gce-image.sh
+./create-gce-image.sh $USERSPACE $KERNEL/arch/x86/boot/bzImage
+qemu-img convert -f raw -O vdi disk.raw disk.vdi
+```
+
+The result should be `disk.vdi` for the disk image. You can delete `disk.raw` if you want.
+
+## VirtualBox
+
+Open VirtualBox and start the New Virtual Machine Wizard.
+Assuming you want to create the new VM in `$VMPATH`, complete the wizard as follows:
+
+* Create New Virtual Machine
+* Virtual Machine Name and Location: select `$VMPATH` as location and "debian" as name
+* Guest OS type: Debian 64-bit
+* Disk: select "Use an existing virtual disk"
+* Import the `disk.vdi` file, and select the imported `.vdi` file as an Hard Disk File.
+
+When you complete the wizard, you should have `$VMPATH/debian.vbox`. From this point onward, you no longer need the VirtualBox UI.
+
+To test the fuzzing environment before getting started, follow the instructions below:
+Forwarding port 2222 on your host machine to port 22:
+``` bash
+VBoxManage modifyvm debian --natpf1 "test,tcp,,2222,,22"
+```
+
+Starting the Debian VM (headless):
+``` bash
+VBoxManage startvm debian --type headless
+```
+
+SSH into the VM:
+``` bash
+ssh -p 2222 root@127.0.0.1
+```
+
+Stopping the VM:
+``` bash
+VBoxManage controlvm debian poweroff
+```
+
+If all of the above `VBoxManage` commands work, then you can proceed to running syzkaller.
+
+## syzkaller
+
+Create a manager config like the following, replacing the environment variables $GOPATH, $KERNEL and $VMPATH with their actual values.
+
+```
+{
+    "target": "linux/amd64",
+    "http": "127.0.0.1:56741",
+    "workdir": "$GOPATH/src/github.com/google/syzkaller/workdir",
+    "kernel_obj": "$KERNEL",
+    "sshkey": "$IMAGE/key",
+    "syzkaller": "$GOPATH/src/github.com/google/syzkaller",
+    "procs": 8,
+    "type": "virtualbox",
+    "vm": {
+        "count": 4,
+        "base_vm_name": "debian"
+    }
+}
+```
+
+Run syzkaller manager:
+
+``` bash
+mkdir workdir
+./bin/syz-manager -config=my.cfg
+```
+
+Syzkaller will create full clone VMs from the `debian` VM and then use ssh to copy and execute programs in them.
+The `debian` VM will not be started and its disk will remain unmodified.
+
+If you get issues after `syz-manager` starts, consider running it with the `-debug` flag.
+Also see [this page](/docs/troubleshooting.md) for troubleshooting tips.
\ No newline at end of file