Re: [PATCH v12 09/22] x86/virt/tdx: Use all system memory when initializing TDX module as TDX memory

[Huang, Kai]

On Wed, 2023-06-28 at 16:17 +0200, Peter Zijlstra wrote:
> On Tue, Jun 27, 2023 at 02:12:39AM +1200, Kai Huang wrote:
> 
> > +static int tdx_memory_notifier(struct notifier_block *nb, unsigned long action,
> > +			       void *v)
> > +{
> > +	struct memory_notify *mn = v;
> > +
> > +	if (action != MEM_GOING_ONLINE)
> > +		return NOTIFY_OK;
> 
> So offlining TDX memory is ok?

Yes.  We want to support normal software memory hotplug logic even TDX is
enabled.  User can offline part of memory and then online again.

> 
> > +
> > +	/*
> > +	 * Empty list means TDX isn't enabled.  Allow any memory
> > +	 * to go online.
> > +	 */
> > +	if (list_empty(&tdx_memlist))
> > +		return NOTIFY_OK;
> > +
> > +	/*
> > +	 * The TDX memory configuration is static and can not be
> > +	 * changed.  Reject onlining any memory which is outside of
> > +	 * the static configuration whether it supports TDX or not.
> > +	 */
> > +	return is_tdx_memory(mn->start_pfn, mn->start_pfn + mn->nr_pages) ?
> > +		NOTIFY_OK : NOTIFY_BAD;
> 
> 	if (is_tdx_memory(...))
> 		return NOTIFY_OK;
> 
> 	return NOTIFY_BAD;
> 

Sure will do.  Thanks!
>