From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 0F170238178 for ; Mon, 26 Jan 2026 21:24:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769462692; cv=none; b=AYPCuYnU49XQF5XRfaYSuhkEPeAEO+cyT6rGYQShb8yH93KHiVzs9roByiCSqDfQIsU+uzu7EHDHosbN+0VzWANyjEQ33eGZGT2jEqiRxtcOm1qWy89Wl11hKS56fg+eI8SJVxzJo9beoHpxnSUZfQdkP5/ZyLD6cNiJqSnea40= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769462692; c=relaxed/simple; bh=4PH2D+60YcpzT9jCqRLgPAPA7fUQOZpdmPC1qBSMwEA=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=IU3H70olSmkA2zJfHAOhSpNs8gPIqg5FJGUo5YMieKvUj8TNkwEAD8CVEMlCozbFWqs1r/Q/bo5hDF9nPC09eDKk6Uvq2uMgdaE0B0OFZaDarzBuPbc/edukLT9nckiSk11UdFitomFSVnnVcv37HVussGD/xAyLbXDXD8XpsG8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=RIk/EXZ0; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="RIk/EXZ0" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6129FC116C6; Mon, 26 Jan 2026 21:24:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1769462691; bh=4PH2D+60YcpzT9jCqRLgPAPA7fUQOZpdmPC1qBSMwEA=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=RIk/EXZ0vSV6QoJWOTruoWEqsSTitC/yThQPQ9Woyr7A+l8X1lmOd1zv2U4c8OYdm yjzrfNXDd4u2fk5OkluqNpLIRahyypIvqNacYPtLroBAFaRJDhSQ6O59Uy+kzyCBNT rxHiGrIGNxbFUOE9vNFFXV3BxXwAUx/bHUHilpjo= Date: Mon, 26 Jan 2026 13:24:50 -0800 From: Andrew Morton To: Andrew Cooper Cc: LKML , Ryusuke Konishi , Alexander Potapenko , Marco Elver , Dmitry Vyukov , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Jann Horn , kasan-dev@googlegroups.com Subject: Re: [PATCH v2] x86/kfence: Fix booting on 32bit non-PAE systems Message-Id: <20260126132450.fe903384a227a558fab50536@linux-foundation.org> In-Reply-To: <20260126211046.2096622-1-andrew.cooper3@citrix.com> References: <20260126211046.2096622-1-andrew.cooper3@citrix.com> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) 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=US-ASCII Content-Transfer-Encoding: 7bit On Mon, 26 Jan 2026 21:10:46 +0000 Andrew Cooper wrote: > The original patch inverted the PTE unconditionally to avoid > L1TF-vulnerable PTEs, but Linux doesn't make this adjustment in 2-level > paging. > > Adjust the logic to use the flip_protnone_guard() helper, which is a nop on > 2-level paging but inverts the address bits in all other paging modes. > > This doesn't matter for the Xen aspect of the original change. Linux no > longer supports running 32bit PV under Xen, and Xen doesn't support running > any 32bit PV guests without using PAE paging. Great thanks. I'll add Tested-by: Ryusuke Konishi and, importantly, Cc: to help everything get threaded together correctly. I'll queue this as a 6.19-rcX hotfix.