[PATCH 0/2] add vNVDIMM support for Xen

[Haozhong Zhang <haozhong.zhang@intel.com>]

This patch series extends current vNVDIMM implementation to provide
vNVDIMM to HVM domains when QEMU is used as the device model of Xen.

This patch series is based on upstream qemu rather of qemu-xen,
because vNVDIMM support has not been in qemu-xen (commit f165e58).

* Following two problem that prevent Xen from directly using current
  implementation are solved by this patch series.

 (1) The current way to allocate memory for pc-dimm based vNVDIMM
     through file-backend device is not compatible with Xen. Patch 2
     adds another pc-nvdimm device to manage vNVDIMM's memory by
     itself.
    
     A pc-nvdimm device can be used only with Xen and is specified by
     parameters like
            -device pc-nvdimm,file=/dev/pmem0,size=MBYTES
	    
 (2) Xen uses its hvmloader rather than QEMU to build guest ACPI
     tables. In order to reuse as much code as possible, patch 2 calls
     the existing QEMU code to build guest ACPI tables for pc-nvdimm
     devices and passes them to hvmloader.

* Test
 (1) A patched Xen is used for test. Xen patch series is sent
     separately with title "[PATCH 0/4] add support for vNVDIMM".
      
 (2) Prepare a memory backend file:
            dd if=/dev/zero of=/tmp/nvm0 bs=1G count=10

 (3) Add the following line to a HVM domain's configuration xl.cfg:
            nvdimm =[ 'file=/tmp/nvm0,size=10240' ]

 (4) Launch a HVM domain from above xl.cfg.

 (5) If guest Linux kernel is 4.2 or newer and kernel modules
     libnvdimm, nfit, nd_btt and nd_pmem are loaded, then you will see
     the whole nvdimm device used as a single namespace and /dev/pmem0
     will appear.



Haozhong Zhang (2):
  pc-nvdimm: implement pc-nvdimm device abstract
  pc-nvdimm acpi: build ACPI tables for pc-nvdimm devices

 hw/acpi/nvdimm.c           |   5 +-
 hw/i386/pc.c               |   6 +-
 hw/mem/Makefile.objs       |   1 +
 hw/mem/pc-nvdimm.c         | 239 +++++++++++++++++++++++++++++++++++++++++++++
 include/hw/mem/pc-nvdimm.h |  49 ++++++++++
 include/hw/xen/xen.h       |   2 +
 xen-hvm.c                  |  73 ++++++++++++++
 7 files changed, 373 insertions(+), 2 deletions(-)
 create mode 100644 hw/mem/pc-nvdimm.c
 create mode 100644 include/hw/mem/pc-nvdimm.h

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2.4.8