Re: [PATCHv2 19/29] x86/topology: Disable CPU online/offline control for TDX guests

[Thomas Gleixner]

On Thu, Feb 03 2022 at 16:00, Borislav Petkov wrote:
> On Wed, Feb 02, 2022 at 01:11:56AM +0100, Thomas Gleixner wrote:
>> On Wed, Feb 02 2022 at 01:09, Thomas Gleixner wrote:
>> 
>> > On Mon, Jan 24 2022 at 18:02, Kirill A. Shutemov wrote:
>> >>  static bool intel_cc_platform_has(enum cc_attr attr)
>> >>  {
>> >> -	if (attr == CC_ATTR_GUEST_UNROLL_STRING_IO)
>> >> +	switch (attr) {
>> >> +	case CC_ATTR_GUEST_UNROLL_STRING_IO:
>> >> +	case CC_ATTR_HOTPLUG_DISABLED:
>> 
>> Not that I care much, but I faintly remember that I suggested that in
>> one of the gazillion of threads.
>
> Right, and yeah, adding a separate attribute is ok too but we already
> have a hotplug disable method. Why can't this call
>
> 	cpu_hotplug_disable()
>
> on the TDX init path somewhere and have this be even simpler?

That's daft. I rather have this explicit control which makes it obvious
what's going on.

Thanks,

        tglx