Re: [PATCH] x86/tdx: Remove the early #VE handler

[Verma, Vishal L]

On Fri, 2026-09-11 at 11:37 +0100, Kiryl Shutsemau wrote:
> 
> Rick, could you actually test it?
> 
> Are we sure there's no other port I/O in before idt_setup_early_traps()?
> 
> I don't see anything direct, but exception path is different story.
> 
> native_machine_emergency_restart() does port I/O for BOOT_KBD which
> seems to be reachable and leads to #VE with the patch:
> 
> machine_emergency_restart()
>   __machine_emergency_restart(1)
>     machine_ops.emergency_restart()
>       native_machine_emergency_restart()
>         reboot_type == BOOT_ACPI (default)
> 	acpi_reboot()
> 	reboot_type = BOOT_KBD
>   	  kb_wait()
>             inb(0x64) --> #VE
> 
> Could you check if the patch changes panic() behaviour in the window
> before idt_setup_early_traps()?

Hi Kiryl - not sure how I would test this - but looking at it a bit
more - 

vpanic() only goes to the machine_emergency_restart() path if
CONFIG_PANIC_TIMEOUT is something other than 0. Distros and Kconfig
both default it to 0. This could be overridden by panic=N on the
command line, but that is parsed after idt_setup_early_traps(), so that
would behave normally.

So at least this path should, in practice, never cause a problem.