Re: [PATCH v3 3/3] x86/acpi, x86/boot: Add multiprocessor wake-up support

[Rafael J. Wysocki]

On Mon, May 10, 2021 at 7:10 PM Kuppuswamy, Sathyanarayanan
<sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx> wrote:
>
>
>
> On 5/10/21 9:55 AM, Rafael J. Wysocki wrote:
> > I'm not sure how my comment regarding the fact that for a given CPU
> > this function is only usable once has been addressed.
> >
> > While it may not be a practical concern in the use case that you are
> > after (TDX), this is a generic mechanism and it needs to cover other
> > possible usage scenarios.
>
> For the same CPU, if we try to use mailbox again, firmware will not
> respond to it.

Well, theoretically, but what if it checks the mailbox every time for
all CPUs?  Or similar?

> So the command will timeout and return error.

If the firmware behaves as expected, but what if it doesn't?