Thanks Paolo, let's wait Jan&Dan 's comments. Thank you, Paolo. Regards Yi On 2018年07月20日 16:32, Paolo Bonzini wrote: > On 20/07/2018 16:11, Zhang,Yi wrote: >> Added Jiang,Dave, >> >> Ping for further review, comments. > I need an Acked-by from the MM people to merge this. Jan, Dan? > > Paolo > >> 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(-) >>> >>
