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Date:   Wed, 25 Oct 2023 08:27:54 -0700
From:   Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
To:     Peter Zijlstra <peterz@infradead.org>
Cc:     Andrew Cooper <andrew.cooper3@citrix.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        Dave Hansen <dave.hansen@linux.intel.com>, x86@kernel.org,
        "H. Peter Anvin" <hpa@zytor.com>,
        Josh Poimboeuf <jpoimboe@kernel.org>,
        Andy Lutomirski <luto@kernel.org>,
        Jonathan Corbet <corbet@lwn.net>,
        Sean Christopherson <seanjc@google.com>,
        Paolo Bonzini <pbonzini@redhat.com>, tony.luck@intel.com,
        ak@linux.intel.com, tim.c.chen@linux.intel.com,
        linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org,
        kvm@vger.kernel.org,
        Alyssa Milburn <alyssa.milburn@linux.intel.com>,
        Daniel Sneddon <daniel.sneddon@linux.intel.com>,
        antonio.gomez.iglesias@linux.intel.com,
        Alyssa Milburn <alyssa.milburn@intel.com>
Subject: Re: [RESEND][PATCH 1/6] x86/bugs: Add asm helpers for executing VERW
Message-ID: <20231025152449.w6xre33cs7tkex7k@desk>
References: <20231020-delay-verw-v1-0-cff54096326d@linux.intel.com>
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On Wed, Oct 25, 2023 at 09:22:55AM +0200, Peter Zijlstra wrote:
 
> I'm thinking you need to at the very least stay in a section that's
> actually still mapped with PTI :-)
> 
> .entry.text is the only thing that is reliably mapped with PTI (IIRC),
> some configs also get a chunk of the kernel image, but not all.
> 
> Something like the below should do I suppose.

Thanks, will do this with Andrew's improvements.

> ---
>  arch/x86/entry/entry.S | 15 +++++++++++++++