[pve-devel] [PATCH docs] add section about bios and uefi

Fabian Gr├╝nbichler f.gruenbichler at proxmox.com
Tue Sep 13 15:23:46 CEST 2016

comments inline

On Tue, Sep 13, 2016 at 02:55:46PM +0200, Dominik Csapak wrote:
> this section explains what is the default and why,
> and explains when you need ovmf and why you need an efidisk
> also we explain how you can create an efidisk and that you
> have to set the resolution in the ovmf menu
> Signed-off-by: Dominik Csapak <d.csapak at proxmox.com>
> ---
>  qm.adoc | 32 ++++++++++++++++++++++++++++++++
>  1 file changed, 32 insertions(+)
> diff --git a/qm.adoc b/qm.adoc
> index 375cc39..24900b6 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. Normally this is good and fine for most standard setups.
> +

The last sentence is a bit redundant, maybe something like:
'SeaBIOS is sufficient for most standard setups.'

> +There are, however, some scenarios in which a BIOS is not a good firmware
> +too 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 <vmid> -efidisk0 <storage>:1,format=<format>
> +
> +Where *<storage>* is the storage where you want to have the disk, and
> +*<format>* 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'
>  ------------------------------------
> -- 
> 2.1.4
> _______________________________________________
> pve-devel mailing list
> pve-devel at pve.proxmox.com
> http://pve.proxmox.com/cgi-bin/mailman/listinfo/pve-devel

More information about the pve-devel mailing list