From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexander Graf Subject: Re: [PATCH 5/5] KVM: s390: Split out early console code. Date: Tue, 30 Oct 2012 14:43:10 +0100 Message-ID: <508FD96E.1010209@suse.de> References: <1351516046-30037-1-git-send-email-cornelia.huck@de.ibm.com> <1351516046-30037-6-git-send-email-cornelia.huck@de.ibm.com> <1440F0DC-0DC5-40FB-88E2-EE203A7C5F66@suse.de> <20121030135926.2db07255@BR9GNB5Z> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Avi Kivity , Marcelo Tosatti , KVM , linux-s390 , Christian Borntraeger , Carsten Otte , Heiko Carstens , Martin Schwidefsky , Sebastian Ott To: Cornelia Huck Return-path: Received: from cantor2.suse.de ([195.135.220.15]:54835 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932305Ab2J3NnO (ORCPT ); Tue, 30 Oct 2012 09:43:14 -0400 In-Reply-To: <20121030135926.2db07255@BR9GNB5Z> Sender: kvm-owner@vger.kernel.org List-ID: On 10/30/2012 01:59 PM, Cornelia Huck wrote: > On Mon, 29 Oct 2012 19:14:19 +0100 > Alexander Graf wrote: > >> On 29.10.2012, at 14:07, Cornelia Huck wrote: >> >>> This code is transport agnostic and can be used by both the legacy >>> virtio code and virtio_ccw. >> Would it be possible to actually send real virtio or sclp console commands for early printk? That'd make things a lot easier on the user space end. Combining two completely separate character channels (early printk + sclp or early printk + virtio-console) is really tricky. >> > This code is only used if we use a virtio console device. The sclp > code path is completely different. Ah, so the sclp early console works differently? > What do you mean with "real virtio console commands"? The message is > just put on the output queue anyway. For virtio-console, yes. For the early printk it is sent to the hypervisor using a hypercall, not through the virtio queue. So it arrives at a completely different end point that usually has no knowledge of the virtio-console output driver. Alex