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Date:   Mon, 29 Apr 2019 09:36:25 +0200
From:   Borislav Petkov <bp@alien8.de>
To:     "Zhao, Yakui" <yakui.zhao@intel.com>
Cc:     Ingo Molnar <mingo@kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "x86@kernel.org" <x86@kernel.org>,
        "tglx@linutronix.de" <tglx@linutronix.de>,
        "Chen, Jason CJ" <jason.cj.chen@intel.com>
Subject: Re: [RFC PATCH v5 4/4] x86/acrn: Add hypercall for ACRN guest
Message-ID: <20190429073625.GA2324@zn.tnic>
References: <1556067260-9128-1-git-send-email-yakui.zhao@intel.com>
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 <6dd021a9-e2c0-ee84-55fd-3e6dfb4bd944@intel.com>
 <20190425110025.GA16164@zn.tnic>
 <473d145c-4bfd-4ec8-34c3-8a26a78fe40d@intel.com>
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 <e04c43cf-029b-d459-e9d9-1a1f5c403dab@intel.com>
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On Mon, Apr 29, 2019 at 09:24:12AM +0800, Zhao, Yakui wrote:
> Yes. "movq" only indicates explicitly that it is 64-bit mov as ACRN guest
> only works under 64-bit mode.
> I also check the usage of "mov" and "movq" in this scenario. There is no
> difference except that the movq is an explicit 64-op.

Damn, I'm tired of explaining this: it is explicit only to the code
reader. gcc generates the *same* instruction no matter whether it has a
"q" suffix or not as long as the destination register is a 64-bit one.

If you prefer to have it explicit, sure, use "movq".

-- 
Regards/Gruss,
    Boris.

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