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SubjectRe: [PATCH V2 0/4] Fix kvm misconceives NVDIMM pages as reserved mmio
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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(-)
>>>
>>

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