Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754028AbZI2MUq (ORCPT ); Tue, 29 Sep 2009 08:20:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753891AbZI2MUp (ORCPT ); Tue, 29 Sep 2009 08:20:45 -0400 Received: from mx1.redhat.com ([209.132.183.28]:23977 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753733AbZI2MUp (ORCPT ); Tue, 29 Sep 2009 08:20:45 -0400 Date: Tue, 29 Sep 2009 17:50:06 +0530 From: Amit Shah To: Christian Borntraeger Cc: Rusty Russell , Alan Cox , virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] virtio_console: Add support for multiple ports for generic guest and host communication Message-ID: <20090929122006.GB3766@amit-x200.redhat.com> References: <1252678386-17404-1-git-send-email-amit.shah@redhat.com> <20090922154549.GA11379@amit-x200.redhat.com> <20090929092431.GA3368@amit-x200.redhat.com> <200909291403.08547.borntraeger@de.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200909291403.08547.borntraeger@de.ibm.com> User-Agent: Mutt/1.5.19 (2009-01-05) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3706 Lines: 109 On (Tue) Sep 29 2009 [14:03:08], Christian Borntraeger wrote: > Am Dienstag 29 September 2009 11:24:31 schrieb Amit Shah: > > -static void hvc_handle_input(struct virtqueue *vq) > > +/* The operations for our console. */ > > +static struct hv_ops virtio_cons = { > > + .get_chars = cons_get_chars, > > + .put_chars = cons_put_chars, > > + .notifier_add = cons_notifier_add_vio, > > + .notifier_del = cons_notifier_del_vio, > > + .notifier_hangup = cons_notifier_del_vio, > > +}; > [...] > > +int __init virtio_cons_early_init(int (*put_chars)(u32, const char *, int)) > > +{ > > + virtio_cons.put_chars = put_chars; > > + return hvc_instantiate(0, 0, &virtio_cons); > > +} > [...] > > +static int __devinit virtcons_probe(struct virtio_device *vdev) > [...] > > - /* Start using the new console output. */ > > - virtio_cons.get_chars = get_chars; > > - virtio_cons.put_chars = put_chars; > > Ok, that wont work for systems that use virtio_cons_early_init. The early > put_chars method was replaced by the final one, but these hunks changed that > behaviour. Something like the following restores the old behaviour: (only > tested on s390) Thanks for the testing as well as the patch! Sadly I can only test this on qemu and x86, so this is very welcome. However: > Signed-off-by: Christian Borntraeger > If you agree, you can merge this snipped into your big patch. > > --- > drivers/char/virtio_console.c | 3 +++ > 1 file changed, 3 insertions(+) > > Index: linux-2.6/drivers/char/virtio_console.c > =================================================================== > --- linux-2.6.orig/drivers/char/virtio_console.c > +++ linux-2.6/drivers/char/virtio_console.c > @@ -590,6 +590,9 @@ int init_port_console(struct virtio_cons > pr_err("%s: Could not alloc hvc for virtio console port, ret = %d\n", > __func__, ret); > port->hvc = NULL; > + } else { > + /* get rid of early put char variants */ > + virtio_cons.put_chars = cons_put_chars; > } > return ret; > } I changed it to look like this, which initializes the final value even when hvc_alloc fails. It should work for you I guess. I'll merge this in my patch when I send it next. Can you please ack the patch? Thanks, Amit >From 462aa408c2a1140137d0890ca8043f37b447410d Mon Sep 17 00:00:00 2001 From: Amit Shah Date: Tue, 29 Sep 2009 17:46:41 +0530 Subject: [PATCH] virtio_console: fix put_chars after early-init Christian tested the patch on s390 and found that the output was very slow. He tracked it down to put_chars never getting init'ed to the final value. Signed-off-by: Amit Shah --- drivers/char/virtio_console.c | 8 ++++++++ 1 files changed, 8 insertions(+), 0 deletions(-) diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c index 37513e8..598bc0d 100644 --- a/drivers/char/virtio_console.c +++ b/drivers/char/virtio_console.c @@ -571,6 +571,14 @@ int init_port_console(struct virtio_console_port *port) * The Host's telling us this port is a console port. Hook it * up with an hvc console. * + * We had set the virtio_cons put_chars implementation to + * put_chars for early_init. Now that we're done with the + * early init phase, replace it with our cons_put_chars + * implementation. + */ + virtio_cons.put_chars = cons_put_chars; + + /* * To set up and manage our virtual console, we call * hvc_alloc(). * -- 1.6.2.5 -- 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/