From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: [PATCH v13 0/8] pv event interface between host and guest Date: Mon, 04 Mar 2013 13:21:10 +0100 Message-ID: <513491B6.6050706@redhat.com> References: <20130303091738.GB23616@redhat.com> <513471F1.5020702@redhat.com> <20130304102131.GK23616@redhat.com> <51347735.9090204@redhat.com> <20130304104301.GL23616@redhat.com> <51347C23.8080802@redhat.com> <20130304105928.GM23616@redhat.com> <51348142.4070206@redhat.com> <20130304112023.GN23616@redhat.com> <513486EC.1050709@redhat.com> <20130304115207.GO23616@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Peter Maydell , kvm list , "Michael S. Tsirkin" , Hu Tao , qemu-devel , Markus Armbruster , Blue Swirl , Orit Wasserman , Juan Quintela , Alexander Graf , Jan Kiszka , Andrew Jones , Alex Williamson , Sasha Levin , Stefan Hajnoczi , Luiz Capitulino , KAMEZAWA Hiroyuki , Kevin Wolf , Anthony Liguori , Marcelo Tosatti , "linux-kernel@vger.kernel.org" To: Gleb Natapov Return-path: In-Reply-To: <20130304115207.GO23616@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org Sender: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org List-Id: kvm.vger.kernel.org Il 04/03/2013 12:52, Gleb Natapov ha scritto: > > Same here, you can remove the panic event port and add debugcon at > > 0x505. That's the problematic case. But if the user goes to that > > length, I think we can honestly say we don't care. > > IMO there is a big difference between well know serial ISA ports and > PIO ports we allocate for our devices. Later have to be discoverable > without resorting to probing. On CPU level we do the same with CPUID > bits instead of relaying on MSRs #GP. On KVM API level we do the same > with capabilities instead of relying on ioctls returning errors. This > is not different. Ok, I see your point now. Yes, this is a good reason why patching is better in the long run. Paolo From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756858Ab3CDMWv (ORCPT ); Mon, 4 Mar 2013 07:22:51 -0500 Received: from mx1.redhat.com ([209.132.183.28]:56515 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756496Ab3CDMWt (ORCPT ); Mon, 4 Mar 2013 07:22:49 -0500 Message-ID: <513491B6.6050706@redhat.com> Date: Mon, 04 Mar 2013 13:21:10 +0100 From: Paolo Bonzini User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130110 Thunderbird/17.0.2 MIME-Version: 1.0 To: Gleb Natapov CC: Hu Tao , kvm list , qemu-devel , "linux-kernel@vger.kernel.org" , "Daniel P. Berrange" , KAMEZAWA Hiroyuki , Jan Kiszka , Blue Swirl , Eric Blake , Andrew Jones , Marcelo Tosatti , Sasha Levin , Luiz Capitulino , Anthony Liguori , Markus Armbruster , Stefan Hajnoczi , Juan Quintela , Orit Wasserman , Kevin Wolf , Wen Congyang , "Michael S. Tsirkin" , Alexander Graf , Alex Williamson , Peter Maydell Subject: Re: [PATCH v13 0/8] pv event interface between host and guest References: <20130303091738.GB23616@redhat.com> <513471F1.5020702@redhat.com> <20130304102131.GK23616@redhat.com> <51347735.9090204@redhat.com> <20130304104301.GL23616@redhat.com> <51347C23.8080802@redhat.com> <20130304105928.GM23616@redhat.com> <51348142.4070206@redhat.com> <20130304112023.GN23616@redhat.com> <513486EC.1050709@redhat.com> <20130304115207.GO23616@redhat.com> In-Reply-To: <20130304115207.GO23616@redhat.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Il 04/03/2013 12:52, Gleb Natapov ha scritto: > > Same here, you can remove the panic event port and add debugcon at > > 0x505. That's the problematic case. But if the user goes to that > > length, I think we can honestly say we don't care. > > IMO there is a big difference between well know serial ISA ports and > PIO ports we allocate for our devices. Later have to be discoverable > without resorting to probing. On CPU level we do the same with CPUID > bits instead of relaying on MSRs #GP. On KVM API level we do the same > with capabilities instead of relying on ioctls returning errors. This > is not different. Ok, I see your point now. Yes, this is a good reason why patching is better in the long run. Paolo From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:44743) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UCUOf-0000H9-HU for qemu-devel@nongnu.org; Mon, 04 Mar 2013 07:21:38 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UCUOa-00029u-QH for qemu-devel@nongnu.org; Mon, 04 Mar 2013 07:21:37 -0500 Received: from mx1.redhat.com ([209.132.183.28]:48102) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UCUOa-00029f-In for qemu-devel@nongnu.org; Mon, 04 Mar 2013 07:21:32 -0500 Message-ID: <513491B6.6050706@redhat.com> Date: Mon, 04 Mar 2013 13:21:10 +0100 From: Paolo Bonzini MIME-Version: 1.0 References: <20130303091738.GB23616@redhat.com> <513471F1.5020702@redhat.com> <20130304102131.GK23616@redhat.com> <51347735.9090204@redhat.com> <20130304104301.GL23616@redhat.com> <51347C23.8080802@redhat.com> <20130304105928.GM23616@redhat.com> <51348142.4070206@redhat.com> <20130304112023.GN23616@redhat.com> <513486EC.1050709@redhat.com> <20130304115207.GO23616@redhat.com> In-Reply-To: <20130304115207.GO23616@redhat.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v13 0/8] pv event interface between host and guest List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Gleb Natapov Cc: Peter Maydell , kvm list , "Michael S. Tsirkin" , Hu Tao , qemu-devel , Markus Armbruster , Blue Swirl , Orit Wasserman , Juan Quintela , Alexander Graf , Jan Kiszka , Andrew Jones , Alex Williamson , Sasha Levin , Stefan Hajnoczi , Luiz Capitulino , KAMEZAWA Hiroyuki , Kevin Wolf , Anthony Liguori , Marcelo Tosatti , "linux-kernel@vger.kernel.org" Il 04/03/2013 12:52, Gleb Natapov ha scritto: > > Same here, you can remove the panic event port and add debugcon at > > 0x505. That's the problematic case. But if the user goes to that > > length, I think we can honestly say we don't care. > > IMO there is a big difference between well know serial ISA ports and > PIO ports we allocate for our devices. Later have to be discoverable > without resorting to probing. On CPU level we do the same with CPUID > bits instead of relaying on MSRs #GP. On KVM API level we do the same > with capabilities instead of relying on ioctls returning errors. This > is not different. Ok, I see your point now. Yes, this is a good reason why patching is better in the long run. Paolo