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Date: Sun, 26 Nov 2017 16:13:30 +0100
From: Ingo Molnar <mingo@kernel.org>
To: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>, linux-kernel@vger.kernel.org,
        Andy Lutomirski <luto@amacapital.net>,
        Thomas Gleixner <tglx@linutronix.de>,
        "H . Peter Anvin" <hpa@zytor.com>, Borislav Petkov <bp@alien8.de>,
        Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: [PATCH 25/43] x86/mm/kaiser: Unmap kernel from userspace page
 tables (core patch)
Message-ID: <20171126151330.otk6576fi5aae64h@gmail.com>
References: <20171124091448.7649-1-mingo@kernel.org>
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 <20171124121638.ej2flgfvctw2cqer@hirez.programming.kicks-ass.net>
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* Dave Hansen <dave.hansen@linux.intel.com> wrote:

> On 11/24/2017 04:16 AM, Peter Zijlstra wrote:
> > On Fri, Nov 24, 2017 at 10:14:30AM +0100, Ingo Molnar wrote:
> >> +The minimalistic kernel portion of the user page tables try to
> >> +map only what is needed to enter/exit the kernel such as the
> >> +entry/exit functions themselves and the interrupt descriptor
> >> +table (IDT).  
> > 
> >                 There are a few unnecessary things that get mapped
> >> +such as the first C function when entering an interrupt (see
> >> +comments in kaiser.c).
> > 
> > If I understood Andy's patches correctly, this should no longer be
> > required. Is this text still correct?
> 
> It is out of date.  We were able to remove the irq handler mappings.

I have updated the Documentation/x86/kaiser.txt file accordingly.

Thanks,

	Ingo