[SOLVED] Suddenly getting "No more image in the PCI ROM" in logs, passthrough still works but no Tiancore boot

[marcosscriven]

EDIT - Fixed turning of CSM support (somehow it turned on randomly in BIOS). However, still want to understand the behaviour

Original Post:

I've suddenly started noticing, when booting a Windows 10 VM, that I don't see the Proxmox/Tianco core boot screen.

I do however still see Windows once it has booted. In system logs I see:

[Wed Apr 26 14:33:43 2023] vfio-pci 0000:07:00.0: vfio_ecap_init: hiding ecap 0x1e@0x258
[Wed Apr 26 14:33:43 2023] vfio-pci 0000:07:00.0: vfio_ecap_init: hiding ecap 0x19@0x900
[Wed Apr 26 14:33:43 2023] vfio-pci 0000:07:00.0: vfio_ecap_init: hiding ecap 0x26@0xc1c
[Wed Apr 26 14:33:43 2023] vfio-pci 0000:07:00.0: vfio_ecap_init: hiding ecap 0x27@0xd00
[Wed Apr 26 14:33:43 2023] vfio-pci 0000:07:00.0: vfio_ecap_init: hiding ecap 0x25@0xe00
[Wed Apr 26 14:33:43 2023] vfio-pci 0000:07:00.0: No more image in the PCI ROM
[Wed Apr 26 14:33:43 2023] vfio-pci 0000:07:00.1: vfio_ecap_init: hiding ecap 0x25@0x160
[Wed Apr 26 14:33:49 2023] vfio-pci 0000:07:00.0: No more image in the PCI ROM
[Wed Apr 26 14:33:49 2023] vfio-pci 0000:07:00.0: No more image in the PCI ROM

I don't think I've updated any software - this is just Proxmox 7.4.3 - I've completely reinstalled to see if I can get back to previous state, and still seeing this.

I'm using an OVMF/UEFI BIOS, with q35 7.2 machine.

Any ideas why this change? All I could find on this is https://www.reddit.com/r/VFIO/comments/wkggfb/single_gpu_passthrough_not_working_no_more_image/

 

[marcosscriven]

Ok - I can answer my own question - somehow my BIOS flipped CSM support on (which I believe means legacy rather than UEFI boot).

Now I've turned that off again, I see the Tianocore boot screen again, and the "No more image in the PCI ROM" message is gone.

I don't really understand what that means though, and why it still sort of works?

 

[leesteken]

It behaves similar to a GPU with no UEFI firmware, which will only show output after the driver is loaded when booting a VM in UEFI mode. That probably explains why you get the message that it runs out of images in the PCI ROM (before finding a suitable UEFI firmware). Maybe booting with CSM hides the UEFI firmware?

 

[marcosscriven]

It behaves similar to a GPU with no UEFI firmware, which will only show output after the driver is loaded when booting a VM in UEFI mode. That probably explains why you get the message that it runs out of images in the PCI ROM (before finding a suitable UEFI firmware). Maybe booting with CSM hides the UEFI firmware?

Probably - although when on in BIOS, it enables some sub-options, including "Other PCI Device ROM Priority", which is set to UEFI only. That sounds like an attempt, at least, to ensure the UEFI firmware is still available even if in CSM mode.

 

[leesteken]

Probably - although when on in BIOS, it enables some sub-options, including "Other PCI Device ROM Priority", which is set to UEFI only. That sounds like an attempt, at least, to ensure the UEFI firmware is still available even if in CSM mode.

Or maybe it means that the motherboard will initialize the device only when booting in UEFI mode?