On Thu, Nov 06, 2025 at 02:38:28AM +0000, Kazuhiro Abe (Fujitsu) via Devel
wrote:
> Hi all,
>
> We are currently working on CCA support.
> Due to CCA specifications, we are unable to use pflash with QEMU.
> Therefore, we intend to enable ACPI by specifying the UEFI firmware using the
> QEMU -bios option as follows:
>
> -machine virt,acpi=on
> -bios /usr/share/qemu-efi-aarch64/QEMU_EFI.fd
>
> Using the above QEMU option, we can successfully boot VM.
> My understanding is that the above QEMU option could be translated by the
> following libvirt XML:
>
> <os>
> <type arch='aarch64' machine='virt-4.0'>hvm</type>
> <loader type="rom">/usr/share/qemu-efi-aarch64/QEMU_EFI.fd</loader>
> </os>
> <features>
> <acpi/>
> </features>
>
>
> However, this XML configuration results in a validation error.
> Specifically, the error occurs because def->os.firmware is
> VIR_DOMAIN_OS_DEF_FIRMWARE_NONE during the following check:
>
> src/qemu/qemu_validate.c: qemuValidateDomainDef()
>
> /* On aarch64, ACPI requires UEFI */
> if (def->features[VIR_DOMAIN_FEATURE_ACPI] == VIR_TRISTATE_SWITCH_ON &&
> def->os.arch == VIR_ARCH_AARCH64 &&
> (def->os.firmware != VIR_DOMAIN_OS_DEF_FIRMWARE_EFI &&
> !virDomainDefHasOldStyleUEFI(def))) {
> virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
> _("ACPI requires UEFI on this architecture"));
> return -1;
> }
>
> It appears that a configuration that successfully boots QEMU directly is
> being rejected by libvirt.
>
> Could you please explain if there's a specific reason for this strict
> validation?
> We are particularly interested in why VIR_DOMAIN_OS_DEF_FIRMWARE_NONE also
> becomes a condition for this error.
Historically this scenario was not supported, so libvirt blocked it to
give better error diagnose of configuration mistakes.
If CCA needs this configuration, the qemu_validate.c check should simply
be changed to allow the required config.
With regards,
Daniel
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