From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34198) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1c6erf-0006fP-N7 for qemu-devel@nongnu.org; Tue, 15 Nov 2016 09:37:36 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1c6erc-0002gR-Jt for qemu-devel@nongnu.org; Tue, 15 Nov 2016 09:37:35 -0500 Received: from mail-pg0-x244.google.com ([2607:f8b0:400e:c05::244]:36824) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1c6erc-0002fu-CO for qemu-devel@nongnu.org; Tue, 15 Nov 2016 09:37:32 -0500 Received: by mail-pg0-x244.google.com with SMTP id x23so11999795pgx.3 for ; Tue, 15 Nov 2016 06:37:32 -0800 (PST) Sender: Namhyung Kim Date: Tue, 15 Nov 2016 23:36:29 +0900 From: Namhyung Kim Message-ID: <20161115143629.GA29740@danjae.aot.lge.com> References: <20160820080744.10344-1-namhyung@kernel.org> <20160820080744.10344-2-namhyung@kernel.org> <20161110182611-mutt-send-email-mst@kernel.org> <20161115045021.GA15992@danjae.aot.lge.com> <20161115065658-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Subject: Re: [Qemu-devel] [PATCH 1/3] virtio: Basic implementation of virtio pstore driver List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini Cc: "Michael S. Tsirkin" , virtio-dev@lists.oasis-open.org, Tony Luck , Kees Cook , kvm@vger.kernel.org, Radim =?utf-8?B?S3LEjW3DocWZ?= , Anton Vorontsov , LKML , Steven Rostedt , qemu-devel@nongnu.org, Minchan Kim , Anthony Liguori , Colin Cross , virtualization@lists.linux-foundation.org, Ingo Molnar Hi, On Tue, Nov 15, 2016 at 10:57:29AM +0100, Paolo Bonzini wrote: > > > On 15/11/2016 06:06, Michael S. Tsirkin wrote: > > On Tue, Nov 15, 2016 at 01:50:21PM +0900, Namhyung Kim wrote: > >> Hi Michael, > >> > >> On Thu, Nov 10, 2016 at 06:39:55PM +0200, Michael S. Tsirkin wrote: > >>> On Sat, Aug 20, 2016 at 05:07:42PM +0900, Namhyung Kim wrote: > >>>> The virtio pstore driver provides interface to the pstore subsystem so > >>>> that the guest kernel's log/dump message can be saved on the host > >>>> machine. Users can access the log file directly on the host, or on the > >>>> guest at the next boot using pstore filesystem. It currently deals with > >>>> kernel log (printk) buffer only, but we can extend it to have other > >>>> information (like ftrace dump) later. > >>>> > >>>> It supports legacy PCI device using single order-2 page buffer. > >>> > >>> Do you mean a legacy virtio device? I don't see why > >>> you would want to support pre-1.0 mode. > >>> If you drop that, you can drop all cpu_to_virtio things > >>> and just use __le accessors. > >> > >> I was thinking about the kvmtools which lacks 1.0 support AFAIK. > > > > Unless kvmtools wants to be left behind it has to go 1.0. > > And it also has to go ACPI. Is there any reason, apart from kvmtool, to > make a completely new virtio device, with no support in existing guests, > rather than implement ACPI ERST? Well, I know nothing about ACPI. It looks like a huge spec and I don't want to dig into it just for this. What I want is to speed up dumping guest kernel message (especially for ftrace dump). Thanks, Namhyung