From 86bbee3264360de8ab5f8d2b277ac7d1045d0b80 Mon Sep 17 00:00:00 2001 From: johannst Date: Thu, 29 Jul 2021 21:33:05 +0000 Subject: deploy: d086ca4c6179628546796e60bfade25be061f045 --- tools/qemu.html | 157 +++++++++++++++++++++++++++++++++++++++----------------- 1 file changed, 111 insertions(+), 46 deletions(-) (limited to 'tools/qemu.html') diff --git a/tools/qemu.html b/tools/qemu.html index 03fd8bc..fc88733 100644 --- a/tools/qemu.html +++ b/tools/qemu.html @@ -169,44 +169,55 @@ Ctrl+a c switch between monitor and console

VM config snippet

Following command-line gives a good starting point to assemble a VM:

-
qemu-system-x86_64                              \
-        -cpu host -enable-kvm -smp 4            \
-        -m 8G                                   \
-        -vga virtio -display sdl,gl=on          \
-        -boot menu=on                           \
-        -cdrom <iso>                            \
-        -hda <disk>                             \
-        -device qemu-xhci,id=xhci               \
-        -device usb-host,bus=xhci.0,vendorid=0x05e1,productid=0x0408,id=capture-card
+
qemu-system-x86_64                 \
+    -cpu host -enable-kvm -smp 4   \
+    -m 8G                          \
+    -vga virtio -display sdl,gl=on \
+    -boot menu=on                  \
+    -cdrom <iso>                   \
+    -hda <disk>                    \
+    -device qemu-xhci,id=xhci      \
+    -device usb-host,bus=xhci.0,vendorid=0x05e1,productid=0x0408,id=capture-card
 

 
CPU & RAM

-
    
-
  • -cpu host emulate host CPU in guest VM
    • 
-
  • -enable-kvm use KVM instead software models (requires KVM on host machine)
    • 
-
  • -smp <N> number of guest CPUs
    • 
-

-

-
List available CPUs qemu-system-x86_64 -cpu help.

-

-
    
-
  • -m 8G size of guest RAM
    • 
-

+
# Emulate host CPU in guest VM, enabling all supported host featured (requires KVM).
+# List available CPUs `qemu-system-x86_64 -cpu help`.
+-cpu host
+
+# Enable KVM instead software emulation.
+-enable-kvm
+
+# Configure number of guest CPUs.
+-smp <N>
+
+# Configure size of guest RAM.
+-m 8G
+

 
Graphic & Display

-
    
-
  • -vga virtio use virtio as 3D video graphic accelerator (requires virgl in guest)
    • 
-
  • -display sdl,gl=on use sdl window and enable openGL context
    • 
-

+
# Use sdl window as display and enable openGL context.
+-display sdl,gl=on
+
+# Use vnc server as display (eg on display `:42` here).
+-display vnc=localhost:42
+
+# Confifure virtio as 3D video graphic accelerator (requires virgl in guest).
+-vga virtio
+

 
Boot Menu

-
    
-
  • -boot menu=on enables boot menu to select boot device (enter with ESC)
    • 
-

+
# Enables boot menu to select boot device (enter with `ESC`).
+-boot menu=on
+

 
Block devices

-
    
-
  • -cdrom <iso> attach cdrom drive with iso to a VM
    • 
-
  • -hda <disk> attach disk drive to a VM
    • 
-
  • -drive file=<file>,format=qcow2 generic way to configure & attach a drive to a VM
    • 
-

-
Create a disk with qemu-img

+
# Attach cdrom drive with iso to a VM.
+-cdrom <iso>
+
+# Attach disk drive to a VM.
+-hda <disk>
+
+# Generic way to configure & attach a drive to a VM.
+-drive file=<file>,format=qcow2
+

+
Create a disk with qemu-img

 
To create a qcow2 disk (qemu copy-on-write) of size 10G:

 
qemu-img create -f qcow2 disk.qcow2 10G
 

@@ -231,24 +242,78 @@ lsblk -f /dev/sda

USB

Host Controller

- +
# Add XHCI USB controller to the VM (supports USB 3.0, 2.0, 1.1).
+# `id=xhci` creates a usb bus named `xhci`.
+-device qemu-xhci,id=xhci
+

USB Device

- +
# Pass-through USB device from host identified by vendorid & productid and
+# attach to usb bus `xhci.0` (defined with controller `id`).
+-device usb-host,bus=xhci.0,vendorid=0x05e1,productid=0x0408
+

Debugging

- +
# Open gdbstub on tcp `<port>` (`-s` shorthand for `-gdb tcp::1234`).
+-gdb tcp::<port>
+
+# Freeze guest CPU at startup and wait for debugger connection.
+-S
+
+

IO redirection

+
# Create raw tcp server for `serial IO` and wait until a client connects
+# before executing the guest.
+-serial tcp:localhost:12345,server,wait
+
+# Create telnet server for `serial IO` and wait until a client connects
+# before executing the guest.
+-serial telnet:localhost:12345,server,wait
+
+# Configure redirection for the QEMU `mointor`, arguments similar to `-serial`
+# above.
+-monitor ...
+
+
+

In server mode use nowait to execute guest without waiting for a client +connection.

+
+

Network

+
# Redirect host tcp port `1234` to guest port `4321`.
+-nic user,hostfwd=tcp:localhost:1234-:4321
+
+

Shared drives

+
# Attach a `virtio-9p-pci` device to the VM.
+# The guest requires 9p support and can mount the shared drive as:
+#   mount -t 9p -o trans=virtio someName /mnt
+-virtfs local,id=someName,path=<someHostPath>,mount_tag=someName,security_model=none
+
+

Tracing

+
# List name of all trace points.
+-trace help
+
+# Enable trace points matching pattern and optionally write trace to file.
+-trace <pattern>[,file=<file>]
+
+# Enable trace points for all events listed in the <events> file.
+# File must contain one event/pattern per line.
+-trace events=<events>
+
+

Appendix: Direct Kernel boot

+

Example command line to directly boot a Kernel with an initrd ramdisk.

+
qemu-system-x86_64                                                     \
+    -cpu host                                                          \
+    -enable-kvm                                                        \
+    -kernel <dir>/arch/x86/boot/bzImage                                \
+    -append "earlyprintk=ttyS0 console=ttyS0 nokaslr init=/init debug" \
+    -initrd <dir>/initramfs.cpio.gz                                    \
+    ...
+
+

Instructions to build a minimal Kernel and initrd.

References

-- cgit v1.2.3