libvirt users - Nov 2021 - virsh create fails with "Unable to find any firmware to satisfy 'efi'" for aarch64 guest on macOS

On 11/27/21 00:08, Nathan Vander Wilt wrote:
> I am having trouble when I `virsh create test.xml` with an aarch64
> guest on a macOS (Apple Silicon) host. I've wrestled with a variety of
> issues but the one I simply haven't been able to get past is this
> regarding the UEFI firmware:
> 
> error: Failed to create domain from test.xml
> error: operation failed: Unable to find any firmware to satisfy
'efi'
> <
> This is with `virsh --version` of 7.9.0 and `qemu-system-aarch64
> --version` of 6.1.0, both installed via the common `brew` tool from
> its main 'homebrew/core' tap. I have confirmed that the
loader/nvram
> files referenced do exist.
> 
> Running `qemu-system-aarch64 -L help` outputs two lines:
> 
> /opt/homebrew/Cellar/qemu/6.1.0_1/bin/../share/qemu-firmware
> /opt/homebrew/Cellar/qemu/6.1.0_1/bin/../share/qemu
> 
> The ?/share/qemu-firmware folder does NOT exist, but symlinking it to
> a ?/share/qemu/firmware folder which does exist does not improve the
> situation.
> 
> I have also tried renaming the ?/share/qemu/firmware folder (e.g. `mv
> firmware zzz-firmware`) as some notes I found led me to believe that
> libvirst might ignore my loader/nvram settings entirely if QEMU had
> the "new" firmware JSON configuration stuff there? But again no
> improvement?.
> 
> 
> How can I debug this further? What should I try next?
> 
> thanks,
> -natevw
> 
> 
> --- the test.xml domain configuration I am trying ---
> 
> <domain type="qemu"
xmlns:qemu="http://libvirt.org/schemas/domain/qemu/1.0">
>   <name>test1</name>
>   <uuid>D45FCA3E-B873-4608-A0B8-3D8529E7CFB7</uuid>
>   <memory unit="MiB">2048</memory>
>   <cpu mode="host-model" check="partial" />
>   <vcpu>2</vcpu>
>   <clock offset="utc"/>
>   <qemu:commandline>
>     <qemu:arg value='-accel'/>
>     <qemu:arg value='hvf'/>
>   </qemu:commandline>
>   <os firmware="efi">
Since you are providing the path to both UEFI image and varstore you can
drop this 'firmware="efi"' attribute. It's what's
causing troubles here.

A short trip into not so distant past. UEFI was introduced to QEMU, so
libvirt came up with <loader
type="pflash>/path/to/uefi</loader> and
<nvram/> combo. This was suboptimal, because now users had to guess
which FW to select (because it depends on guest arch, secure boot
enabled, SMM mode, ...). So QEMU started shipping small, machine
readable files to each BIOS/UEFI image, which libvirt would parse and
pick the best one for given domain XML. And this is what firmware='efi'
controls. IOW, using firmware='efi' is incompatible with specifying
paths in <loader/> and <nvram/> and if you define this XML you'd
see
that the paths are not formatted back (e.g. in virsh dumpxml).
>     <type arch="aarch64"
machine="virt">hvm</type>
>     <loader readonly="yes" secure="no"
>
type="pflash">/opt/homebrew/share/qemu/edk2-aarch64-code.fd</loader>
>     <nvram
template="/opt/homebrew/share/qemu/edk2-arm-vars.fd">/Users/me/vm_testing/vm-test1.efi.fd</nvram>
>     <bootmenu enable="no"/>
>     <boot dev="hd"/>
>   </os>
>   <features>
>     <acpi/>
>     <gic version="3"/>
>     <pae/>
>   </features>
>   <devices>
>     <emulator>/opt/homebrew/bin/qemu-system-aarch64</emulator>
>     <disk type="file" device="disk">
>       <driver name="qemu" type="qcow2"/>
>       <source file="/Users/me/vm_testing/vm-test1.qcow2"/>
>       <target dev="vda" bus="virtio"/>
>     </disk>
>     <interface type="network">
>       <source network="default"/>
>       <model type="virtio"/>
>     </interface>
>     <console type="pty">
>       <target type="serial" port="0"/>
>     </console>
>     <rng model="virtio">
>       <backend model="random">/dev/urandom</backend>
>     </rng>
>   </devices>
> </domain>
> 
> 
Michal

On Fri, Nov 26, 2021 at 11:08 PM Michal Pr?vozn?k <mprivozn at redhat.com>
wrote:
> Since you are providing the path to both UEFI image and varstore you can
> drop this 'firmware="efi"' attribute. It's what's
causing troubles here.
Thank you, yes!
> A short trip into not so distant past. UEFI was introduced to QEMU, so
> libvirt came up with <loader
type="pflash>/path/to/uefi</loader> and
> <nvram/> combo. This was suboptimal, because now users had to guess
> which FW to select (because it depends on guest arch, secure boot
> enabled, SMM mode, ...). So QEMU started shipping small, machine
> readable files to each BIOS/UEFI image, which libvirt would parse and
> pick the best one for given domain XML. And this is what
firmware='efi'
> controls. IOW, using firmware='efi' is incompatible with specifying
> paths in <loader/> and <nvram/> and if you define this XML
you'd see
> that the paths are not formatted back (e.g. in virsh dumpxml).
Okay, yes this was unclear. It's not in the documentation afaict and I
saw some threads making it sound like it was the mere presence of the
JSON config files that made libvirt ignore any loader/nvram
configuration. But dropping the firmware attribute on the os element
was indeed the trick to get rid of the EFI error. Thanks for the
clarification!

regards,
-natevw