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Date: Thu, 25 Jan 2018 12:50:16 +0100
From: Borislav Petkov <bp@alien8.de>
To: David Woodhouse <dwmw2@infradead.org>
Cc: arjan@linux.intel.com, tglx@linutronix.de, karahmed@amazon.de,
	x86@kernel.org, linux-kernel@vger.kernel.org,
	tim.c.chen@linux.intel.com, peterz@infradead.org,
	pbonzini@redhat.com, ak@linux.intel.com,
	torvalds@linux-foundation.org, gregkh@linux-foundation.org,
	dave.hansen@intel.com, gnomes@lxorguk.ukuu.org.uk,
	ashok.raj@intel.com, mingo@kernel.org
Subject: Re: [PATCH v4 7/7] x86/speculation: Add basic IBPB (Indirect Branch
 Prediction Barrier) support
Message-ID: <20180125115016.ov72ajqb6z7scdrc@pd.tnic>
References: <1516872189-16577-1-git-send-email-dwmw@amazon.co.uk>
 <1516872189-16577-8-git-send-email-dwmw@amazon.co.uk>
 <20180125114127.5iw4vy56bb2cs5mr@pd.tnic>
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On Thu, Jan 25, 2018 at 11:47:35AM +0000, David Woodhouse wrote:
> I did already do the explicit clobbers now you reminded me how to do
> them, but I elected not to use ASM_NO_INPUT_CLOBBER() because on
> balance, losing the MSR_IA32_PRED_CMD / PRED_CMD_IBPB definitions and
> having to hard-code the numbers was not so much of a win.

and I'm thinking exactly the opposite: if an alternative can lose a
bunch of inputs which don't change, then that's a good thing.

-- 
Regards/Gruss,
    Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.