Re: [Qemu-devel] [PATCH v3 00/32] implement vNVDIMM

[Xiao Guangrong]

On 10/13/2015 02:36 PM, Dan Williams wrote:
> On Mon, Oct 12, 2015 at 10:49 PM, Xiao Guangrong
> <address@hidden> wrote:
> > On 10/13/2015 11:38 AM, Dan Williams wrote:
> > > On Mon, Oct 12, 2015 at 8:14 PM, Xiao Guangrong
> > > <address@hidden> wrote:
> > > > On 10/13/2015 12:36 AM, Dan Williams wrote:
> > > > > Static namespaces can be emitted without a label.  Linux needs this to
> > > > > support existing "label-less" bare metal NVDIMMs.
> > > >
> > > >
> > > >
> > > > This is Linux specific? As i did not see it has been documented in the
> > > > spec...
> > >
> > >
> > > I expect most NVDIMMs, especially existing ones available today, do
> > > not have a label area.  This is not Linux specific and ACPI 6 does not
> > > specify a label area, only the Intel DSM Interface Example.
> >
> > Yup, label data is accessed via DSM interface, the spec I mentioned
> > is Intel DSM Interface Example.
> >
> > However, IIRC Linux NVDIMM driver refused to use the device if no
> > DSM GET_LABEL support, are you going to update it?
>
> Label-less DIMMs are tested as part of the unit test [1] and the
> "memmap=nn!ss" kernel parameter that registers a persistent-memory
> address range without a DIMM.  What error do you see when label
> support is disabled?
>
> [1]: https://github.com/pmem/ndctl/blob/master/README.md

After revert my commits on NVDIMM driver, yeah, it works.

Okay, i will drop the namespace part and make it as label-less
instead.

Thank you, Dan!