From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.alien8.de (mail.alien8.de [65.109.113.108]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CB9B145038; Fri, 9 May 2025 17:32:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=65.109.113.108 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746811972; cv=none; b=QLAJSlLL6CPZEmkiZCRDaj9xvgME/wXt3NAEw6cYMnPOiWVE/h1hKzB3eZUnR0jswYPVTcgpsVyGhwfJllUruV3gfwgzbXiu55GBpJGBYIPdxQY5yIh7+shtspZyMyn4GH93WdUNzH/tQ2S1vc1sXBHCiiIewzSf6WM3UMoogFc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746811972; c=relaxed/simple; bh=BYghYgLKz845p/XJUOgV5+fweGgy0oL4oXzWYAfXIGc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=SbGeLLPk4IBESx4hWo6dcnDG+p+sXjgPRZR5FAhkX1jvj/QtBxL77a85RcD+hM+LCeKBcg1Yhb44sugpQoqXk7/HZJ2IjD0Hwui2tTTKbz8r3KReg//NiicknJp89hb/p3BmLR7JllCXz5oqUhtNUO1DO8pCWnZsYU3SvZPuE0M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=alien8.de; spf=pass smtp.mailfrom=alien8.de; dkim=pass (4096-bit key) header.d=alien8.de header.i=@alien8.de header.b=HuZzubWh; arc=none smtp.client-ip=65.109.113.108 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=alien8.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=alien8.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (4096-bit key) header.d=alien8.de header.i=@alien8.de header.b="HuZzubWh" Received: from localhost (localhost.localdomain [127.0.0.1]) by mail.alien8.de (SuperMail on ZX Spectrum 128k) with ESMTP id 1914640E01CF; Fri, 9 May 2025 17:32:47 +0000 (UTC) X-Virus-Scanned: Debian amavisd-new at mail.alien8.de Authentication-Results: mail.alien8.de (amavisd-new); dkim=pass (4096-bit key) header.d=alien8.de Received: from mail.alien8.de ([127.0.0.1]) by localhost (mail.alien8.de [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id QP-XzlRqnOfZ; Fri, 9 May 2025 17:32:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=alien8; t=1746811962; bh=92FBgt9X64NNgwgndLEy21ZDonQ9gW2RlXVeTWQ7YCs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=HuZzubWhBj+bfLZE+YRtp8iBNxxFiR2Eg98G0JtYkLbtOzksG7IyiPCeOqSbwJXJT E1zyb7RSbovxsFzasq4gZluAvNeGCMO5XVm77neg5V525PpR7XULkoHwH1NpjOqgW4 MMA57bP5OEYUovC8rtePBK9wFDWHIQWRLP3zED04BGf1Furmj30FfQHettBLsXNKZt I7mxnaW+vXqcslYDEgfw0bt0sOniuPjgXKU/WHMmvzf9pmVYJ9ez3VuFask7KJSRB6 HrnNTCCpQAqzSjxiqxTNHjTBt2McSg+ANrdOAPUXPep69mCtnWzKSc4D986dueIemK bZIwTJC+l0UQR23Ig1WuX6U29+fEr/+QQ9icYFxKQR9QEJsgHposZRJ2DPAd6fMjkh anaA9ATNvLJndcc3euJ/jIqLIHigYe2QSvXq5bfMA5djQKZc64B8+HnlPOhHkJ4x9g NAyiVEMeOCx/JMAcMwpX7PUxGgn8MIZQ8IRzSsbGD93vBpDVOUFxTJ1LqBIG01hwfy UjF3JmvoPEowqyt8A/4YVILdIpngBLMHD+MYO7Mh0PcoVRurByZS/Kd11zRiFkJVR7 dDq4BAZ1nRE30tKAbFWQY7c0t62lV+EdfRwBDw/eojza9yHgwUrg3LxC4VjaaxlxeZ fQmznck9KvdSAV6aEz/PVdHA= Received: from zn.tnic (p579690ee.dip0.t-ipconnect.de [87.150.144.238]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature ECDSA (P-256) server-digest SHA256) (No client certificate requested) by mail.alien8.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 3288C40E0222; Fri, 9 May 2025 17:32:31 +0000 (UTC) Date: Fri, 9 May 2025 19:32:25 +0200 From: Borislav Petkov To: Jiaqing Zhao Cc: Thomas Gleixner , Ingo Molnar , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Bernhard Kaindl , Andi Kleen , Li Fei , stable@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] x86/mtrr: Check if fixed-range MTRR exists in mtrr_save_fixed_ranges() Message-ID: <20250509173225.GDaB48KZvZSA9QLUaR@fat_crate.local> References: <20250509170633.3411169-2-jiaqing.zhao@linux.intel.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20250509170633.3411169-2-jiaqing.zhao@linux.intel.com> On Fri, May 09, 2025 at 05:06:33PM +0000, Jiaqing Zhao wrote: > When suspending, save_processor_state() calls mtrr_save_fixed_ranges() > to save fixed-range MTRRs. On platforms without fixed-range MTRRs, > accessing these MSRs will trigger unchecked MSR access error. Make > sure fixed-range MTRRs are supported before access to prevent such > error. > > Since mtrr_state.have_fixed is only set when MTRRs are present and > enabled, checking the CPU feature flag in mtrr_save_fixed_ranges() > is unnecessary. > > Fixes: 3ebad5905609 ("[PATCH] x86: Save and restore the fixed-range MTRRs of the BSP when suspending") > Cc: stable@vger.kernel.org > Signed-off-by: Jiaqing Zhao Next question: this is CC:stable, meaning it'll go to Linus now. What exactly is it fixing? Because the patch in Fixes: is from 2007. :-\ -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette