On Tue, Jul 29, 2025 at 03:28:49PM -0600, Jim Fehlig wrote:
On 5/13/25 14:25, Jim Fehlig wrote:
On 4/24/25 14:18, Jim Fehlig wrote:
On 4/24/25 04:59, Daniel P. Berrangé wrote:
On Mon, Apr 21, 2025 at 01:38:35PM -0600, Jim Fehlig via Devel wrote:
Hi All,
While investigating an internal bug report, we noticed that a minimal firmware auto-selection configuration along with SEV* fails to find a match. E.g. the following config
<domain type="kvm"> <os firmware="efi"> <type arch="x86_64" machine="q35">hvm</type> <boot dev="hd"/> </os> <launchSecurity type="sev"> <policy>0x07</policy> </launchSecurity> ... </domain>
Fails with "Unable to find 'efi' firmware that is compatible with the current configuration". A firmware that should match has the following json description
{ "description": "UEFI firmware for x86_64, with AMD SEV", "interface-types": [ "uefi" ], "mapping": { "device": "flash", "mode": "stateless", "executable": { "filename": "/usr/share/qemu/ovmf-x86_64-sev.bin", "format": "raw" } }, "targets": [ { "architecture": "x86_64", "machines": [ "pc-q35-*" ] } ], "features": [ "acpi-s4", "amd-sev", "amd-sev-es", "amd-sev-snp", "verbose-dynamic" ], "tags": [
] }
Auto-selection works fine if I specify a 'stateless' firmware, e.g. amend the above config with
<os firmware="efi"> <type arch="x86_64" machine="q35">hvm</type> <loader stateless="yes"/> <boot dev="hd"/> </os>
Being unfamiliar with the firmware auto-selection code, I tried the below naive hack, which only led to test failures and the subsequent runtime error "unable to find any master var store for loader: /usr/share/qemu/ovmf-x86_64-sev.bin". Should auto-selection work with the minimal config, or is it expected that user also specify a stateless firmware?
Andrea,
Having spent a fair bit of time in the firmware auto-selection code, perhaps you have an opinion about this?
Sorry to keep nagging about this, but I still see the issue with latest git master using a json descriptor identical to the latest Fedora one. When omitting the 'stateless' attribute, autoselection fails with
operation failed: Unable to find 'efi' firmware that is compatible with the current configuration
With debug enabled, I can see the firmware is not even considered since it's not "split"
2025-07-29 21:02:05.517+0000: 32187: debug : qemuFirmwareMatchDomain:1310 : Discarding loader without split flash
I would need to install Fedora and verify myself, but I'd be surprised if it didn't encounter the same issue. Without the 'stateless' attribute, the following test would fail
https://gitlab.com/libvirt/libvirt/-/blob/master/src/qemu/qemu_firmware.c?re...
executing the else condition, and failing similarly since the firmware is not split.
So I've tested the scenario I mentioned before, and in fact see the same behaviour as you describe error: operation failed: Unable to find 'efi' firmware that is compatible with the current configuration which confuses me, because I'm sure I used virt-install to provision SNP guests before, without expanding the args to --boot uefi,loader.stateless=on With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|