On Wed, Apr 25, 2018 at 4:24 AM, Pankaj Gupta <pagupta@xxxxxxxxxx> wrote: > This patch adds virtio-pmem driver for KVM > guest. Minor nit, please expand your changelog line wrapping to 72 columns. > > Guest reads the persistent memory range > information from Qemu over VIRTIO and registers > it on nvdimm_bus. It also creates a nd_region > object with the persistent memory range > information so that existing 'nvdimm/pmem' > driver can reserve this into system memory map. > This way 'virtio-pmem' driver uses existing > functionality of pmem driver to register persistent > memory compatible for DAX capable filesystems. We need some additional enabling to disable MAP_SYNC for this configuration. In other words, if fsync() is required then we must disable the MAP_SYNC optimization. I think this should be a struct dax_device property looked up at mmap time in each MAP_SYNC capable ->mmap() file operation implementation.