On 13.07.2018 09:52, Pankaj Gupta wrote: > This is RFC V3 for 'fake DAX' flushing interface sharing > for review. This patchset has two parts: > > - Guest virtio-pmem driver > Guest driver reads persistent memory range from paravirt device > and registers with 'nvdimm_bus'. 'nvdimm/pmem' driver uses this > information to allocate persistent memory range. Also, we have > implemented guest side of VIRTIO flushing interface. > > - Qemu virtio-pmem device > It exposes a persistent memory range to KVM guest which at host > side is file backed memory and works as persistent memory device. > In addition to this it provides virtio device handling of flushing > interface. KVM guest performs Qemu side asynchronous sync using > this interface. > > Changes from RFC v2: > - Add flush function in the nd_region in place of switching > on a flag - Dan & Stefan > - Add flush completion function with proper locking and wait > for host side flush completion - Stefan & Dan > - Keep userspace API in uapi header file - Stefan, MST > - Use LE fields & New device id - MST > - Indentation & spacing suggestions - MST & Eric > - Remove extra header files & add licensing - Stefan > > Changes from RFC v1: > - Reuse existing 'pmem' code for registering persistent > memory and other operations instead of creating an entirely > new block driver. > - Use VIRTIO driver to register memory information with > nvdimm_bus and create region_type accordingly. > - Call VIRTIO flush from existing pmem driver. > > Details of project idea for 'fake DAX' flushing interface is > shared [2] & [3]. > > Pankaj Gupta (2): > Add virtio-pmem guest driver > pmem: device flush over VIRTIO > > [1] https://marc.info/?l=linux-mm&m=150782346802290&w=2 > [2] https://www.spinics.net/lists/kvm/msg149761.html > [3] https://www.spinics.net/lists/kvm/msg153095.html > > drivers/nvdimm/nd.h | 1 > drivers/nvdimm/pmem.c | 4 > drivers/nvdimm/region_devs.c | 24 +++- > drivers/virtio/Kconfig | 9 + > drivers/virtio/Makefile | 1 > drivers/virtio/virtio_pmem.c | 190 +++++++++++++++++++++++++++++++++++++++ > include/linux/libnvdimm.h | 5 - > include/linux/virtio_pmem.h | 44 +++++++++ > include/uapi/linux/virtio_ids.h | 1 > include/uapi/linux/virtio_pmem.h | 40 ++++++++ > 10 files changed, 310 insertions(+), 9 deletions(-) > Hi Pankaj, do you have a branch for the QEMU part somewhere available? I want to see how this works with MemoryDevice changes. -- Thanks, David / dhildenb
