Ping for further review, comments. Thanks All Regards Yi. On 2018年07月11日 01:01, Zhang Yi wrote: > For device specific memory space, when we move these area of pfn to > memory zone, we will set the page reserved flag at that time, some of > these reserved for device mmio, and some of these are not, such as > NVDIMM pmem. > > Now, we map these dev_dax or fs_dax pages to kvm for DIMM/NVDIMM > backend, since these pages are reserved. the check of > kvm_is_reserved_pfn() misconceives those pages as MMIO. Therefor, we > introduce 2 page map types, MEMORY_DEVICE_FS_DAX/MEMORY_DEVICE_DEV_DAX, > to indentify these pages are from NVDIMM pmem. and let kvm treat these > as normal pages. > > Without this patch, Many operations will be missed due to this > mistreatment to pmem pages. For example, a page may not have chance to > be unpinned for KVM guest(in kvm_release_pfn_clean); not able to be > marked as dirty/accessed(in kvm_set_pfn_dirty/accessed) etc. > > V1: > https://lkml.org/lkml/2018/7/4/91 > > V2: > *Add documentation for MEMORY_DEVICE_DEV_DAX memory type in comment block > *Add is_dax_page() in mm.h to differentiate the pages is from DAX device. > *Remove the function kvm_is_nd_pfn(). > > Zhang Yi (4): > kvm: remove redundant reserved page check > mm: introduce memory type MEMORY_DEVICE_DEV_DAX > mm: add a function to differentiate the pages is from DAX device > memory > kvm: add a check if pfn is from NVDIMM pmem. > > drivers/dax/pmem.c | 1 + > include/linux/memremap.h | 9 +++++++++ > include/linux/mm.h | 12 ++++++++++++ > virt/kvm/kvm_main.c | 16 ++++++++-------- > 4 files changed, 30 insertions(+), 8 deletions(-) >
