From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752419AbcKRJpX (ORCPT ); Fri, 18 Nov 2016 04:45:23 -0500 Received: from mx1.redhat.com ([209.132.183.28]:40226 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751180AbcKRJpU (ORCPT ); Fri, 18 Nov 2016 04:45:20 -0500 Subject: Re: [PATCH 1/3] virtio: Basic implementation of virtio pstore driver To: Namhyung Kim References: <20160820080744.10344-1-namhyung@kernel.org> <20161110182611-mutt-send-email-mst@kernel.org> <20161115045021.GA15992@danjae.aot.lge.com> <20161115065658-mutt-send-email-mst@kernel.org> <20161115143629.GA29740@danjae.aot.lge.com> <1627682877.13077005.1479298236793.JavaMail.zimbra@redhat.com> <20161118033206.GA15698@danjae.aot.lge.com> Cc: "Michael S. Tsirkin" , virtio-dev@lists.oasis-open.org, Tony Luck , Kees Cook , KVM , =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= , Anton Vorontsov , LKML , Steven Rostedt , qemu-devel , Minchan Kim , Anthony Liguori , Colin Cross , virtualization@lists.linux-foundation.org, Ingo Molnar From: Paolo Bonzini Message-ID: <213903eb-5f1b-f38f-bd10-04402333777d@redhat.com> Date: Fri, 18 Nov 2016 10:45:12 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.4.0 MIME-Version: 1.0 In-Reply-To: <20161118033206.GA15698@danjae.aot.lge.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Fri, 18 Nov 2016 09:45:20 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 18/11/2016 04:32, Namhyung Kim wrote: >> In addition, the firmware will need to reserve a few KB of RAM for the error log >> address range (I checked a real system and it reserves 8KB). The first eight >> bytes are needed for the record identifier interface, because there's no such >> thing as 64-bit I/O ports, and the rest can be used for the actual buffer. > > Is there a limit on the size? It'd be great if it can use a few MB.. Yes, you can make it customizable. >>> Also I need to control pstore driver like using bigger buffer, >>> enabling specific message types and so on if ERST supports. Is it >>> possible for ERST to provide such information? >> >> It's the normal pstore driver, same as on a real server. What exactly do you >> need? > > Well, I don't want to send additional pstore messages to the device if > it cannot handle them properly - for example, ftrace message should not > overwrite kmsg dump. It'd be great if device somehow could expose > acceptable message types to the driver IMHO. This is something that you have to do in the usual kernel pstore infrastructure. It should not be specific to virtualization. Paolo > Btw I prefer using the kvmtool for my kernel work since it's much more > simpler..