For those making use of Open Virtual Machine Firmware (OVMF) such as for UEFI booting of VMs with KVM+QEMU, the upcoming Linux 6.17 kernel is set to offer a convenient new driver to help in debugging the system boot when needed.
Open Virtual Machine Firmware (OVMF) since edk2-stable202508 supports writing their debug log to a memory buffer. Coming with Linux 6.17 in turn is the “ovmf-debug-log” driver that when enabled via the new OVMF_DEBUG_LOG Kconfig switch will allow exposing that debug log memory buffer to system administrators via the Linux sysfs interface.
With the ovmf-debug-log driver, the debug log is exposed to user-space at /sys/firmware/efi/ovmf_debug_log for being able to conveniently capture that Open Virtual Machine Firmware debug log.
This driver is a little more than one hundred lines of code and authored by Red Hat. The driver has been queued up within the EFI.git codebase ahead of the upcoming Linux 6.17 merge window when this new driver is expected to land.