unable to find any master var store for loader error

[Michal Privoznik]

On 10/13/20 2:25 PM, daggs wrote:
> Greetings Michal,
> 
>> Sent: Tuesday, October 13, 2020 at 2:51 PM
>> From: "Michal Privoznik" <mprivozn at redhat.com>
>> To: "daggs" <daggs at gmx.com>, libvirt-users at redhat.com
>> Subject: Re: unable to find any master var store for loader error
>>
>> Hey,
>>
>> I'll paste the interesting part of domain XML here so that it doesn't
>> get lost:
>>
>>     <os>
>>       <type arch='x86_64' machine='pc-q35-5.0'>hvm</type>
>>       <loader readonly='yes'
>> type='pflash'>/usr/share/edk2-ovmf/OVMF_CODE.fd</loader>
>>       <nvram>/var/lib/libvirt/qemu/nvram/vm1_VARS.fd</nvram>
>>       <boot dev='hd'/>
>>     </os>
>>
>> And then in qemu.conf you define the pair:
>>
>> nvram = [
>> 	"/usr/share/edk2-ovmf/OVMF_CODE.fd:/usr/share/edk2-ovmf/OVMF_VARS.fd",
>> 	"/usr/share/edk2-ovmf/OVMF_CODE.secboot.fd:/usr/share/edk2-ovmf/OVMF_VARS.secboot.fd"
>> ]
>>
>> But as the comment in qemu.conf (just above your line) says, this is
>> ignored if FW metadata files exist which is exactly your case and this bug:
>>
>> https://bugzilla.redhat.com/show_bug.cgi?id=1763477
>>
>> For your convenience you can switch to <os firmware='efi'/> (the
>> <loader/> element will be removed automatically) or if you insist on
>> using the old style then provide @template attribute to <nvram/>:
>>
>> <nvram
>> template="/usr/share/edk2-ovmf/OVMF_CODE.fd">/var/lib/libvirt/qemu/nvram/vm1_VARS.fd</nvram>
>>
>>
>> There is an internal list that is still consulted when finding matching
>> _VARS fails, but your path is not on it:
>>
>> https://gitlab.com/libvirt/libvirt/-/blob/master/src/qemu/qemu_conf.c#L98
>>
>> But it exists mostly to give distros enough time to switch to FW
>> descriptors.
>>
>> Michal
>>
>>
> 
> thanks for the detailed explanation, I wanted to be sure I understand. the following is needed to be done:
> 1. replace this:
> <os>
>    <type arch='x86_64' machine='pc-q35-5.0'>hvm</type>
>    <loader readonly='yes' type='pflash'>/usr/share/edk2-ovmf/OVMF_CODE.fd</loader>
>    <nvram>/var/lib/libvirt/qemu/nvram/vm1_VARS.fd</nvram>
>    <boot dev='hd'/>
> </os>
> to this:
> <os firmware='efi'/>
>    <type arch='x86_64' machine='pc-q35-5.0'>hvm</type>
>    <boot dev='hd'/>
> </os>

Here, nvram will be generated, but if you want some other path than 
libvirt would generate you can provide it under <nvram/>. Yes. But 
you're using the default path anyway.

> 2. patch qemu_conf.c to include the custom paths of my fd files?
> 

There is a third option. Save the following under 
/etc/qemu/firmware/50-my-ovmf.json:

{
     "description": "UEFI firmware for x86_64",
     "interface-types": [
         "uefi"
     ],
     "mapping": {
         "device": "flash",
         "executable": {
             "filename": "/usr/share/edk2-ovmf/OVMF_CODE.fd",
             "format": "raw"
         },
         "nvram-template": {
             "filename": "/usr/share/edk2-ovmf/OVMF_VARS.fd",
             "format": "raw"
         }
     },
     "targets": [
         {
             "architecture": "x86_64",
             "machines": [
                 "pc-i440fx-*",
                 "pc-q35-*"
             ]
         }
     ],
     "features": [
         "acpi-s3",
         "amd-sev",
         "verbose-dynamic"
     ],
     "tags": [

     ]
}



Michal