How to force Talos local console over iKVM?

[astro-stan]

I am running Talos on a motherboard with IPMI (Asus Pro WS W880-ACE SE) and have installed an Intel CPU with iGPU (270k Plus).

I want Talos to render its local console/dashboard over the iKVM, leaving the iGPU entirely for cluster workloads.

My config is the following (Talos v1.12.7):

...
    kernelModules:
      - name: nvme_tcp
      - name: vfio_pci
      - name: uio_pci_generic
    schematic:
        customization:
            extraKernelArgs:
              - net.ifnames=0
              - cpufreq.default_governor=performance 
            systemExtensions:
                officialExtensions:
                    - siderolabs/util-linux-tools
                    - siderolabs/i915
                    - siderolabs/intel-ucode
                    - siderolabs/mei

I can see the Talos bootloader screen over the iKVM, but as soon as an option is selected the iKVM screen goes completely black. I can see the Talos dashboard via talosctl, so I know the node is working fine.

I suspect the i915 driver hijacks the video output from the Aspeed graphics which are used by the iKVM.

I cannot figure out what cmdline options or extensions to I have to include to force Talos to display over the Aspeed graphics and leave the iGPU entirely to the cluster.

[astro-stan]

Ah, actually I think the ast driver isn't included in the built-in modules, and I don't see an extension either.

Should this be a feature request?

[astro-stan]

Hi again @smira.

I've played around with this for a few hours and I think I have an idea of what is going on.

So basically, I think the efifb always maps to iGPU.

Machine cmdline and extensions

Cmdline:

$ talosctl -n 10.1.10.2 read /proc/cmdline 
talos.platform=metal console=tty0 init_on_alloc=1 slab_nomerge pti=on consoleblank=0 nvme_core.io_timeout=4294967295 printk.devkmsg=on selinux=1 module.sig_enforce=1 lockdown=confidentiality net.ifnames=0 cpufreq.default_governor=performance

Extensions:

$ talosctl -n 10.1.10.2 get extensions
WARNING: 10.1.10.2: server version 1.12.7 is older than client version 1.13.0
NODE        NAMESPACE   TYPE              ID            VERSION   NAME               VERSION
10.1.10.2   runtime     ExtensionStatus   0             1         util-linux-tools   2.41.4
10.1.10.2   runtime     ExtensionStatus   1             1         intel-ucode        20260227
10.1.10.2   runtime     ExtensionStatus   2             1         mei                v1.12.7
10.1.10.2   runtime     ExtensionStatus   3             1         schematic          2cf424b7c52e9d5ce133986202627fd1e8af4b00ca98cf1dc10bbded49383138
10.1.10.2   runtime     ExtensionStatus   modules.dep   1         modules.dep        6.18.24-talos

NOTE: Notice I have removed the i915 driver.

The GPUs PCI addresses:

$ talosctl -n 10.1.10.2 get pcid | grep Display
WARNING: 10.1.10.2: server version 1.12.7 is older than client version 1.13.0
10.1.10.2   hardware    PCIDevice   0000:00:02.0   1         Display controller             VGA compatible controller        Intel Corporation            Arrow Lake-S [Intel Graphics]
10.1.10.2   hardware    PCIDevice   0000:87:00.0   1         Display controller             VGA compatible controller        ASPEED Technology, Inc.      ASPEED Graphics Family

I tested this with 3 cases:

1. Boot with HDMI connected and iKVM console open

$ talosctl -n 10.1.10.2 read /sys/class/tty/console/active
tty0
$ talosctl -n 10.1.10.2 read /proc/fb
0 EFI VGA
$ talosctl -n 10.1.10.2 read /proc/iomem | grep -E "efifb|0000:87:00.0"
  70800000-70afffff : efifb
      b4000000-b7ffffff : 0000:87:00.0
      b8000000-b803ffff : 0000:87:00.0
$ talosctl -n 10.1.10.2 dmesg | grep -E "vgaarb: setting as boot VGA device|vgaarb: VGA device added"
10.1.10.2: kern:    info: [2026-07-06T22:06:25.71396997Z]: pci 0000:00:02.0: vgaarb: setting as boot VGA device
10.1.10.2: kern:    info: [2026-07-06T22:06:25.713973465Z]: pci 0000:00:02.0: vgaarb: VGA device added: decodes=io+mem,owns=mem,locks=none
10.1.10.2: kern:    info: [2026-07-06T22:06:25.713976826Z]: pci 0000:87:00.0: vgaarb: VGA device added: decodes=io+mem,owns=none,locks=none

Notice the efifb region is outside the memory ranges mapped to the ASPEED chip.

With this setup, I can see the dashboard output via the HDMI but not via the iKVM.

2. Boot with HDMI disconnected and iKVM console open

Same command output as before, but interestingly, even if I plug in the HDMI at this point, nothing happens, and there is no output over the iKVM or HDMI.

3. Boot with the i915 extension

Adding the i915 extension back in causes the generic efifb to be replaced by the Intel driver layer:

talosctl -n 10.1.10.2 read /proc/fb
0 i915drmfb

As expected, no change otherwise - iKVM still shows a black screen.

---

I should also mention that the BIOS does not provide an option to set the primary display to be the Aspeed GPU - the Primary Display choices are limited to Auto and CPU Graphics. There is no BMC or Onboard ASPEED option to choose from (see screenshot at the bottom).

That being said I can see the bootloader screen over the iKVM so I am hoping there is some workaround here that can make this work on Talos without having to disable the iGPU in the BIOS.

[smira]

We do not plan to support anything beyond EFI console.

[astro-stan]

Hi again, not saying you should. Just trying to explain the issue.

I'm hoping there is a workaround/kernel option that I haven't thought of.

[smira]

EFI console is not part of the Linux kernel, it's managed by the computer firmware. Linux kernel should simply use whatever is set up by the firmware.

[astro-stan]

Yes I understand.

However, I don't understand why/how the bootloader screen (where you select whether to boot into Talos or wipe the state) is managing to output via the iKVM? By the time the bootloader screen is shown the EFI console must already be configured by the firmware, no? And if that's the case, what does the bootloader do differently? Perhaps i can replicate that in the Talos config?