Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for Xen

From	"Jan Beulich" <JBeulich@suse.com>
Newsgroups	linux.kernel
Subject	Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for Xen
Date	2016-10-12 09:30 +0200
Message-ID	<srm9b-19E-3@gated-at.bofh.it> (permalink)
References	<sqwNj-2FC-3@gated-at.bofh.it> <sqLW2-3yz-37@gated-at.bofh.it> <sr4YG-77t-15@gated-at.bofh.it> <sr7Dc-84-1@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw

>>> On 11.10.16 at 17:53, <dan.j.williams@intel.com> wrote:
> On Tue, Oct 11, 2016 at 6:08 AM, Jan Beulich <jbeulich@suse.com> wrote:
>>>>> Andrew Cooper <andrew.cooper3@citrix.com> 10/10/16 6:44 PM >>>
>>>On 10/10/16 01:35, Haozhong Zhang wrote:
>>>> Xen hypervisor needs assistance from Dom0 Linux kernel for following tasks:
>>>> 1) Reserve an area on NVDIMM devices for Xen hypervisor to place
>>>>    memory management data structures, i.e. frame table and M2P table.
>>>> 2) Report SPA ranges of NVDIMM devices and the reserved area to Xen
>>>>    hypervisor.
>>>
>>>However, I can't see any justification for 1).  Dom0 should not be
>>>involved in Xen's management of its own frame table and m2p.  The mfns
>>>making up the pmem/pblk regions should be treated just like any other
>>>MMIO regions, and be handed wholesale to dom0 by default.
>>
>> That precludes the use as RAM extension, and I thought earlier rounds of
>> discussion had got everyone in agreement that at least for the pmem case
>> we will need some control data in Xen.
> 
> The missing piece for me is why this reservation for control data
> needs to be done in the libnvdimm core?  I would expect that any dax
> capable file could be mapped and made available to a guest.  This
> includes /dev/ramX devices that are dax capable, but are external to
> the libnvdimm sub-system.

Despite me being the only one on the To list, I don't think the question
was really meant to be directed to me.

Jan

Back to linux.kernel | Previous | Next — Previous in thread | Find similar | Unroll thread

Thread

[RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for Xen Haozhong Zhang <haozhong.zhang@intel.com> - 2016-10-10 02:40 +0200
  Re: [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for Xen Dan Williams <dan.j.williams@intel.com> - 2016-10-10 05:50 +0200
    Re: [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for Xen Haozhong Zhang <haozhong.zhang@intel.com> - 2016-10-10 08:40 +0200
      Re: [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for Xen Dan Williams <dan.j.williams@intel.com> - 2016-10-10 18:30 +0200
        Re: [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for Xen Haozhong Zhang <haozhong.zhang@intel.com> - 2016-10-11 09:20 +0200
  Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for  Xen Andrew Cooper <andrew.cooper3@citrix.com> - 2016-10-10 18:50 +0200
    Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for  Xen Haozhong Zhang <haozhong.zhang@intel.com> - 2016-10-11 08:00 +0200
      Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for  Xen Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> - 2016-10-11 20:50 +0200
      Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for  Xen Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> - 2016-10-11 21:00 +0200
      Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for  Xen Andrew Cooper <andrew.cooper3@citrix.com> - 2016-10-11 21:00 +0200
    Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support  for Xen "Jan Beulich" <jbeulich@suse.com> - 2016-10-11 15:10 +0200
      Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for Xen Dan Williams <dan.j.williams@intel.com> - 2016-10-11 18:00 +0200
        Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for  Xen Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> - 2016-10-11 19:00 +0200
          Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for Xen Dan Williams <dan.j.williams@intel.com> - 2016-10-11 20:00 +0200
            Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for  Xen Andrew Cooper <andrew.cooper3@citrix.com> - 2016-10-11 20:30 +0200
              Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for  Xen Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> - 2016-10-11 20:50 +0200
                Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for  Xen Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> - 2016-10-11 21:50 +0200
            Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for  Xen Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> - 2016-10-11 20:40 +0200
              Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for Xen Dan Williams <dan.j.williams@intel.com> - 2016-10-11 21:30 +0200
                Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for  Xen Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> - 2016-10-11 22:00 +0200
                Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for  Xen Andrew Cooper <andrew.cooper3@citrix.com> - 2016-10-11 22:20 +0200
                Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for Xen Dan Williams <dan.j.williams@intel.com> - 2016-10-11 22:20 +0200
                Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for  Xen Haozhong Zhang <haozhong.zhang@intel.com> - 2016-10-12 12:40 +0200
                Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support  for Xen "Jan Beulich" <JBeulich@suse.com> - 2016-10-12 13:40 +0200
                Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for  Xen Haozhong Zhang <haozhong.zhang@intel.com> - 2016-10-12 17:10 +0200
                Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support  for Xen "Jan Beulich" <JBeulich@suse.com> - 2016-10-12 17:40 +0200
                Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for Xen Dan Williams <dan.j.williams@intel.com> - 2016-10-12 17:50 +0200
                Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support  for Xen "Jan Beulich" <JBeulich@suse.com> - 2016-10-12 18:30 +0200
                Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for Xen Dan Williams <dan.j.williams@intel.com> - 2016-10-12 18:30 +0200
        Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support  for Xen "Jan Beulich" <JBeulich@suse.com> - 2016-10-12 09:30 +0200

csiph-web