Re: [PATCH] x86/apic: Don't disable x2APIC if locked

From: "Huang, Kai" <kai.huang@intel.com>
To: "Hansen, Dave" <dave.hansen@intel.com>,
	"x86@kernel.org" <x86@kernel.org>,
	"dave.hansen@linux.intel.com" <dave.hansen@linux.intel.com>,
	"bp@alien8.de" <bp@alien8.de>,
	"mingo@redhat.com" <mingo@redhat.com>,
	"tglx@linutronix.de" <tglx@linutronix.de>,
	"Shutemov, Kirill" <kirill.shutemov@intel.com>,
	"daniel.sneddon@linux.intel.com" <daniel.sneddon@linux.intel.com>
Cc: "hpa@zytor.com" <hpa@zytor.com>,
	"pawan.kumar.gupta@linux.intel.com" 
	<pawan.kumar.gupta@linux.intel.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"Gomez Iglesias, Antonio" <antonio.gomez.iglesias@intel.com>
Subject: Re: [PATCH] x86/apic: Don't disable x2APIC if locked
Date: Thu, 11 Aug 2022 08:29:37 +0000	[thread overview]
Message-ID: <76b3c2703d13252d1dba1b7f32675951d6b27e28.camel@intel.com> (raw)
In-Reply-To: <ba80b303-31bf-d44a-b05d-5c0f83038798@intel.com>

On Wed, 2022-08-10 at 16:09 -0700, Dave Hansen wrote:
> On 8/10/22 16:03, Daniel Sneddon wrote:
> > On 8/10/22 15:06, Thomas Gleixner wrote:
> > > So this affects already deployed systems and we have to
> > > 
> > >   - backport the x2apic lock changes
> > > 
> > >   - provide proper diagnostics
> > > 
> > >   - make SGX and TDX depend on X2APIC support
> > I'll add the comments Dave mentioned earlier, and will make SGX and TDX depend
> > on X2APIC since that makes sense regardless of what hw ends up with this change.
> >  Unless we want to get rid of CONFIG_X86_X2APIC like Dave mentioned?
> 
> The TDX guest support in the kernel isn't _actually_ related to this*.
> It's the host-side support that matters and that isn't merged yet.  I've
> cc'd Kai so he doesn't forget to do this.
> 
> 

Hi Dave,

Thanks for the info.  I'll address this before sending out next version.

-- 
Thanks,
-Kai