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Sender: Namhyung Kim <namhyung@gmail.com>
Date: Tue, 15 Nov 2016 15:23:36 +0900
From: Namhyung Kim <namhyung@kernel.org>
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Subject: Re: [Qemu-devel] [PATCH 2/3] qemu: Implement virtio-pstore device
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To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: virtio-dev@lists.oasis-open.org, kvm@vger.kernel.org, qemu-devel@nongnu.org, virtualization@lists.linux-foundation.org, LKML <linux-kernel@vger.kernel.org>, Paolo Bonzini <pbonzini@redhat.com>, Radim =?utf-8?B?S3LEjW3DocWZ?= <rkrcmar@redhat.com>, Anthony Liguori <aliguori@amazon.com>, Anton Vorontsov <anton@enomsg.org>, Colin Cross <ccross@android.com>, Kees Cook <keescook@chromium.org>, Tony Luck <tony.luck@intel.com>, Steven Rostedt <rostedt@goodmis.org>, Ingo Molnar <mingo@kernel.org>, Minchan Kim <minchan@kernel.org>, "Daniel P . Berrange" <berrange@redhat.com>

On Fri, Nov 11, 2016 at 12:50:03AM +0200, Michael S. Tsirkin wrote:
> On Fri, Sep 16, 2016 at 07:05:47PM +0900, Namhyung Kim wrote:
> > On Tue, Sep 13, 2016 at 06:57:10PM +0300, Michael S. Tsirkin wrote:
> > > On Sat, Aug 20, 2016 at 05:07:43PM +0900, Namhyung Kim wrote:
> > > > +
> > > > +/* the index should match to the type value */
> > > > +static const char *virtio_pstore_file_prefix[] = {
> > > > +    "unknown-",		/* VIRTIO_PSTORE_TYPE_UNKNOWN */
> > > 
> > > Is there value in treating everything unexpected as "unknown"
> > > and rotating them as if they were logs?
> > > It might be better to treat everything that's not known
> > > as guest error.
> > 
> > I was thinking about the version mismatch between the kernel and qemu.
> > I'd like to make the device can deal with a new kernel version which
> > might implement a new pstore message type.  It will be saved as
> > unknown but the kernel can read it properly later.
> 
> Well it'll have a different prefix. E.g. if kernel has
> two different types they will end up in the same
> file, hardly what was wanted.

Right, I think it needs to add 'type' info to the filename for unknown
type.

Thanks,
Namhyung