diff --git a/qm.adoc b/qm.adoc index 375cc39..5d0225d 100644 --- a/qm.adoc +++ b/qm.adoc @@ -368,6 +368,38 @@ if you use a SPICE client which supports it. If you add a SPICE USB port to your VM, you can passthrough a USB device from where your SPICE client is, directly to the VM (for example an input device or hardware dongle). +BIOS and UEFI +~~~~~~~~~~~~~ + +In order to properly emulate a computer, QEMU needs to use a firmware. +By default QEMU uses *SeaBIOS* for this, which is an open-source, x86 BIOS +implementation. SeaBIOS is a good choice for most standard setups. + +There are, however, some scenarios in which a BIOS is not a good firmware +to boot from, e.g. if you want to do VGA passthrough. footnote:[Alex Williamson has a very good blog entry about this. +http://vfio.blogspot.co.at/2014/08/primary-graphics-assignment-without-vga.html] +In such cases, you should rather use *OVMF*, which is an open-source UEFI implemenation. footnote:[See the OVMF Project http://www.tianocore.org/ovmf/] + +If you want to use OVMF, there are several things to consider: + +In order to save things like the *boot order*, there needs to be an EFI Disk. +This disk will be included in backups and snapshots, and there can only be one. + +You can create such a disk with the following command: + + qm set -efidisk0 :1,format= + +Where ** is the storage where you want to have the disk, and +** is a format which the storage supports. Alternatively, you can +create such a disk through the web interface with 'Add' -> 'EFI Disk' in the +hardware section of a VM. + +When using OVMF with a virtual display (without VGA passthrough), +you need to set the client resolution in the OVMF menu(which you can reach +with a press of the ESC button during boot), or you have to choose +SPICE as the display type. + + Managing Virtual Machines with 'qm' ------------------------------------