From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on
	aws-us-west-2-korg-lkml-1.web.codeaurora.org
Received: from vger.kernel.org (vger.kernel.org [23.128.96.18])
	by smtp.lore.kernel.org (Postfix) with ESMTP id 7D1C0CDB474
	for <linux-kernel@archiver.kernel.org>; Tue, 17 Oct 2023 10:19:49 +0000 (UTC)
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1343743AbjJQKTs (ORCPT
        <rfc822;linux-kernel@archiver.kernel.org>);
        Tue, 17 Oct 2023 06:19:48 -0400
Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39828 "EHLO
        lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S234974AbjJQKT1 (ORCPT
        <rfc822;linux-kernel@vger.kernel.org>);
        Tue, 17 Oct 2023 06:19:27 -0400
Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1])
        by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DBBDE12E;
        Tue, 17 Oct 2023 03:18:00 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed;
        d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version:
        References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To:
        Content-Transfer-Encoding:Content-ID:Content-Description;
        bh=fxvZNgF+It9/pkutyTdBwQ2drZbf8d9h7gItHyVyZtc=; b=UywmqRqXVi95xSI8PqvFWe4u1k
        Wxct0bmVsIzqbVqHIRow1Dv39c81o8Aw3R57nSINroRmme67pBE39wLzPEoIBW1w8GkpHoGa1GHQ3
        VcjF2ANQNyKIzBGqgpppAOdsA6GMmWW5jRSKIjeLzwaUL5YAHroY5o+n7yf4psX+UFP2kKbWX6dLc
        Ra/qER2vpnnWzDn3DLXaaNkKilQRvyq/tTKXrgLjDnV8ho677Gd8EbhwEh7kkGeDOQFfiyYxxIRI2
        SgEWk9gV0FBFju9II/84Bsf0T8uCgzD3NrBSXTtaRYr1HUMMLItbWzWm40hygwym22LIoJY6PaZ4N
        usMeJ3Xg==;
Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net)
        by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux))
        id 1qsh8Y-00Bjm7-Nd; Tue, 17 Oct 2023 10:17:18 +0000
Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000)
        id 15DE030058D; Tue, 17 Oct 2023 12:17:18 +0200 (CEST)
Date:   Tue, 17 Oct 2023 12:17:17 +0200
From:   Peter Zijlstra <peterz@infradead.org>
To:     Ard Biesheuvel <ardb@kernel.org>
Cc:     "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
        Matthew Wilcox <willy@infradead.org>,
        Borislav Petkov <bp@alien8.de>,
        Andy Lutomirski <luto@kernel.org>,
        Dave Hansen <dave.hansen@intel.com>,
        Sean Christopherson <seanjc@google.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Joerg Roedel <jroedel@suse.de>,
        Andi Kleen <ak@linux.intel.com>,
        Kuppuswamy Sathyanarayanan 
        <sathyanarayanan.kuppuswamy@linux.intel.com>,
        David Rientjes <rientjes@google.com>,
        Vlastimil Babka <vbabka@suse.cz>,
        Tom Lendacky <thomas.lendacky@amd.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Paolo Bonzini <pbonzini@redhat.com>,
        Ingo Molnar <mingo@redhat.com>,
        Dario Faggioli <dfaggioli@suse.com>,
        Mike Rapoport <rppt@kernel.org>,
        David Hildenbrand <david@redhat.com>,
        Mel Gorman <mgorman@techsingularity.net>,
        marcelo.cerri@canonical.com, tim.gardner@canonical.com,
        philip.cox@canonical.com, aarcange@redhat.com, peterx@redhat.com,
        x86@kernel.org, linux-mm@kvack.org, linux-coco@lists.linux.dev,
        linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org,
        stable@kernel.org, Nikolay Borisov <nik.borisov@suse.com>
Subject: Re: [PATCHv2] efi/unaccepted: Fix soft lockups caused by parallel
 memory acceptance
Message-ID: <20231017101717.GJ33217@noisy.programming.kicks-ass.net>
References: <20231016163122.12855-1-kirill.shutemov@linux.intel.com>
 <ZS15HZqK4hu5NjSh@casper.infradead.org>
 <20231016213932.6cscnn6tsnzsnvmf@box.shutemov.name>
 <CAMj1kXFc31N61=oQayLbnR+CrNT4=bfEisC3fwG4VNq2vJHV5w@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <CAMj1kXFc31N61=oQayLbnR+CrNT4=bfEisC3fwG4VNq2vJHV5w@mail.gmail.com>
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Tue, Oct 17, 2023 at 09:42:13AM +0200, Ard Biesheuvel wrote:

> One question I have is whether the sequence
> 
> spin_lock_irqsave(&unaccepted_memory_lock, flags);
> ...
> spin_unlock(&unaccepted_memory_lock);
> arch_accept_memory(phys_start, phys_end);
> spin_lock(&unaccepted_memory_lock);
> ...
> spin_unlock_irqrestore(&unaccepted_memory_lock, flags);
> 
> is considered sound and is supported by all architectures?

Yes.