[PATCH] docs: Discourage users from using fwcfg

Michal Privoznik mprivozn at redhat.com
Mon Sep 7 14:20:02 UTC 2020

On 9/7/20 3:57 PM, Martin Kletzander wrote:
> On Mon, Sep 07, 2020 at 03:48:16PM +0200, Michal Privoznik wrote:
>> Even though this was brought up in upstream discussion [1] it
>> missed my patches: users should prefer <oemStrings/> over fwcfg.
>> The reason is that fwcfg is considered somewhat internal to QEMU
>> and it has limited number of slots and neither of these applies
>> to <oemStrings/>.
>> While I'm at it, I'm fixing the example too (because it contains
>> incorrect element name) and clarifying sysfs/ exposure.
>> 1: https://www.redhat.com/archives/libvir-list/2020-May/msg00957.html
>> Reported-by: Laszlo Ersek <lersek at redhat.com>
>> Signed-off-by: Michal Privoznik <mprivozn at redhat.com>
>> ---
>> docs/formatdomain.rst | 14 +++++++++-----
>> 1 file changed, 9 insertions(+), 5 deletions(-)

> It's nice that you say that, but people who would like to use fw_cfg for 
> passing
> in a huge blob, which is saved in a file, will read this, go to 
> <oemStrings/>
> and see that there is no way to pass a file as an input.  Should that be 
> dealt
> with somehow?  Or would that be discouraged as well?

Unfortunately, QEMU doesn't allow reading OEM strings from a file (at 
least quick glance over hw/smbios/smbios.c doesn't show any signs it's 


More information about the libvir-list mailing list