Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758096Ab3EGMMk (ORCPT ); Tue, 7 May 2013 08:12:40 -0400 Received: from ozlabs.org ([203.10.76.45]:41365 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757385Ab3EGMMi (ORCPT ); Tue, 7 May 2013 08:12:38 -0400 From: Rusty Russell To: Peter Maydell Cc: Alexander Graf , Pranavkumar Sawargaonkar , "linux-arm-kernel\@lists.infradead.org" , "linaro-kernel\@lists.linaro.org" , "patches\@linaro.org" , "linux-kernel\@vger.kernel.org List" , "kvmarm\@lists.cs.columbia.edu" , Amit Shah Subject: Re: [PATCH 0/2] Early printk support for virtio console devices. In-Reply-To: References: <1366974299-17877-1-git-send-email-pranavkumar@linaro.org> <87obcyc9sh.fsf@rustcorp.com.au> <336C59AA-D5D7-472E-A8DA-EEB413DD6C68@suse.de> <87sj27xxjr.fsf@rustcorp.com.au> <87ip2wr8tp.fsf@rustcorp.com.au> User-Agent: Notmuch/0.15.2+81~gd2c8818 (http://notmuchmail.org) Emacs/23.4.1 (i686-pc-linux-gnu) Date: Tue, 07 May 2013 14:16:22 +0930 Message-ID: <87txmfo0rl.fsf@rustcorp.com.au> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1174 Lines: 29 Peter Maydell writes: > On 6 May 2013 06:11, Rusty Russell wrote: >> Peter Maydell writes: >>> To be actually useful we need to also specify something in >>> the device tree to say "here is where you will find your >>> emergency output and what it is". >> >> Hmm, I'm not sure that's true. It looks like it needs: >> >> 1) An enhancment to the vdev->set_config callback to pass through (at >> least) an offset, probably offset and length. >> >> 2) An emerg_write() function ptr which can be called at any time, set by >> virtio_console.c's class_init: > > That all looks like sensible QEMU implementation possibilities > but it seems to be a bit of a non-sequitur from "how do we > tell the kernel to actually use this?" You enable the feature in the virtio console device, and a kernel compiled with EARLY_PRINTK will use it? Cheers, Rusty. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/