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Date:   Thu, 2 Sep 2021 14:29:50 +0200
From:   Joerg Roedel <jroedel@suse.de>
To:     Lai Jiangshan <laijs@linux.alibaba.com>
Cc:     Peter Zijlstra <peterz@infradead.org>,
        Lai Jiangshan <jiangshanlai@gmail.com>,
        linux-kernel@vger.kernel.org, Andy Lutomirski <luto@kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
        Youquan Song <youquan.song@intel.com>,
        Tony Luck <tony.luck@intel.com>
Subject: Re: [PATCH 22/24] x86/entry: Implement and use do_paranoid_entry()
 and paranoid_exit()
Message-ID: <YTDDvnvslnjjok2H@suse.de>
References: <20210831175025.27570-1-jiangshanlai@gmail.com>
 <20210831175025.27570-23-jiangshanlai@gmail.com>
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 <44e08066-bbfb-222e-dffc-63e5b64f125f@linux.alibaba.com>
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On Thu, Sep 02, 2021 at 07:58:51PM +0800, Lai Jiangshan wrote:
> Oh, #VC will need to switch stack.  I think we need ASM code to switch
> stack since the original stack need to be "free" for next #VC.

Right, #VC switches off its IST stack to make it free for subsequent
#VCs. The switch mostly happens in C code already, see
vc_switch_off_ist(), only the actual RSP update is still ASM.

Regards,

	Joerg