On 2018年08月09日 17:02, Jan Kara wrote: > On Thu 09-08-18 18:52:48, 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: >> https://lkml.org/lkml/2018/7/10/135 >> >> V3: >> [PATCH V3 1/4] Needs Comments. >> [PATCH V3 2/4] Update the description of MEMORY_DEVICE_DEV_DAX: Jan >> [PATCH V3 3/4] Acked-by: Jan in V2 > Hum, but it is not the the patch... > > Honza Sorry, I missed that, will add in the next version, thanks for your review
