Re: [PATCH V3 1/2] x86/tdx: Route safe halt execution via tdx_safe_halt()

[Vishal Annapurve]

On Tue, Feb 11, 2025 at 3:46 PM Dave Hansen <dave.hansen@xxxxxxxxx> wrote:
>
> On 2/11/25 00:32, Kirill A. Shutemov wrote:
> >> If CONFIG_PARAVIRT_XXL is disabled, "sti;hlt" sequences can still get
> >> executed from TDX VMs via paths like:
> >>         acpi_safe_halt() =>
> >>         raw_safe_halt()  =>
> >>         arch_safe_halt() =>
> >>      native_safe_halt()
> >> There is a long term plan to fix these paths by carving out
> >> irq.safe_halt() outside paravirt framework.
> > I don't think it is acceptable to keep !PARAVIRT_XXL (read no-Xen) config
> > broken.
>
> Oh, I thought it took PARAVIRT_XXL=y to even trigger this issue. Was I
> just confused?

Original issue with unsafe "sti;hlt" execution for TDX VMs doesn't
need PARAVIRT_XXL to be enabled in theory. Any caller just needs to
reach native*halt() to trigger the issue.