From mboxrd@z Thu Jan 1 00:00:00 1970 From: Keir Fraser Subject: Re: [PATCH] x86: fix cache flushing condition in map_pages_to_xen() Date: Wed, 17 Jul 2013 17:31:41 +0100 Message-ID: References: <51E6CFC802000078000E5AB8@nat28.tlf.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta5.messagelabs.com ([195.245.231.135]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1UzUdo-0001Hq-SL for xen-devel@lists.xenproject.org; Wed, 17 Jul 2013 16:31:49 +0000 Received: by mail-wi0-f175.google.com with SMTP id m6so5659960wiv.2 for ; Wed, 17 Jul 2013 09:31:47 -0700 (PDT) In-Reply-To: <51E6CFC802000078000E5AB8@nat28.tlf.novell.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Jan Beulich , xen-devel List-Id: xen-devel@lists.xenproject.org On 17/07/2013 16:09, "Jan Beulich" wrote: > This fixes yet another shortcoming of the function (exposed by 8bfaa2c2 > ["x86: add locking to map_pages_to_xen()"]'s adjustment to > msix_put_fixmap()): It must not flush caches when transitioning to a > non-present mapping. Doing so causes the CLFLUSH to fault, if used in > favor of WBINVD. > > To help code readability, factor out the whole flush flags updating > in map_pages_to_xen() into a helper macro. > > Signed-off-by: Jan Beulich I'd prefer the macro modified as I just posted, but either way: Acked-by: Keir Fraser