Re: [PATCH 1/3] virtio: Basic implementation of virtio pstore driver

Hi,

On Tue, Nov 15, 2016 at 11:38 PM, Paolo Bonzini [off-list ref] wrote:

On 15/11/2016 15:36, Namhyung Kim wrote:

quoted

Hi,

On Tue, Nov 15, 2016 at 10:57:29AM +0100, Paolo Bonzini wrote:

quoted

On 15/11/2016 06:06, Michael S. Tsirkin wrote:

quoted

On Tue, Nov 15, 2016 at 01:50:21PM +0900, Namhyung Kim wrote:

quoted

Hi Michael,

On Thu, Nov 10, 2016 at 06:39:55PM +0200, Michael S. Tsirkin wrote:

quoted

On Sat, Aug 20, 2016 at 05:07:42PM +0900, Namhyung Kim wrote:

quoted

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.

ERST (error record serialization table) is a small subset of the ACPI spec.

Not sure how independent ERST is from ACPI and other specs.  It looks
like referencing UEFI spec at least.  Btw, is the ERST used for pstore
only (in Linux)?

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?

Thanks,
Namhyung