From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754367AbcIFHDu (ORCPT ); Tue, 6 Sep 2016 03:03:50 -0400 Received: from mx1.redhat.com ([209.132.183.28]:58154 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753911AbcIFHDt (ORCPT ); Tue, 6 Sep 2016 03:03:49 -0400 Date: Tue, 6 Sep 2016 12:33:43 +0530 From: Amit Shah To: Andy Lutomirski Cc: x86@kernel.org, virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org, "Michael S. Tsirkin" Subject: Re: [PATCH] virtio_console: Stop doing DMA on the stack Message-ID: <20160906070343.GD3100@amit-lp.rh> References: <0afe68f9b4be6c95af9e7672b07acd0274c26dfe.1472569320.git.luto@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <0afe68f9b4be6c95af9e7672b07acd0274c26dfe.1472569320.git.luto@kernel.org> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Tue, 06 Sep 2016 07:03:48 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On (Tue) 30 Aug 2016 [08:04:15], Andy Lutomirski wrote: > virtio_console uses a small DMA buffer for control requests. Move > that buffer into heap memory. > > Doing virtio DMA on the stack is normally okay on non-DMA-API virtio > systems (which is currently most of them), but it breaks completely > if the stack is virtually mapped. > > Tested by typing both directions using picocom aimed at /dev/hvc0. > > Signed-off-by: Andy Lutomirski Looks fine, Reviewed-by: Amit Shah > --- > > Hi all- > > This is currently broken in tip:x86/asm. If you (Amit) like this patch, > would it make sense for Ingo to add it to -tip? Yes, I'm fine with that. Amit