Message ID | 2b7856596e519130946c834d5d61b00b7f592770.1533811181.git.yi.z.zhang@linux.intel.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | Fix kvm misconceives NVDIMM pages as reserved mmio | expand |
> > DAX driver hotplug the device memory and move it to memory zone, these > pages will be marked reserved flag, however, some other kernel componet > will misconceive these pages are reserved mmio (ex: we map these dev_dax > or fs_dax pages to kvm for DIMM/NVDIMM backend). Together with the type > MEMORY_DEVICE_FS_DAX, we can use is_dax_page() to differentiate the pages > is DAX device memory or not. > > Signed-off-by: Zhang Yi <yi.z.zhang@linux.intel.com> > Signed-off-by: Zhang Yu <yu.c.zhang@linux.intel.com> > --- > include/linux/mm.h | 12 ++++++++++++ > 1 file changed, 12 insertions(+) > > diff --git a/include/linux/mm.h b/include/linux/mm.h > index 68a5121..de5cbc3 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -889,6 +889,13 @@ static inline bool is_device_public_page(const struct > page *page) > page->pgmap->type == MEMORY_DEVICE_PUBLIC; > } > > +static inline bool is_dax_page(const struct page *page) > +{ > + return is_zone_device_page(page) && > + (page->pgmap->type == MEMORY_DEVICE_FS_DAX || > + page->pgmap->type == MEMORY_DEVICE_DEV_DAX); > +} I think question from Dan for KVM VM with 'MEMORY_DEVICE_PUBLIC' still holds? I am also interested to know if there is any use-case. Thanks, Pankaj > + > #else /* CONFIG_DEV_PAGEMAP_OPS */ > static inline void dev_pagemap_get_ops(void) > { > @@ -912,6 +919,11 @@ static inline bool is_device_public_page(const struct > page *page) > { > return false; > } > + > +static inline bool is_dax_page(const struct page *page) > +{ > + return false; > +} > #endif /* CONFIG_DEV_PAGEMAP_OPS */ > > static inline void get_page(struct page *page) > -- > 2.7.4 > >
On Tue, Aug 14, 2018 at 01:41:40AM +0800, Zhang,Yi wrote: > > > On 2018年08月09日 17:23, Pankaj Gupta wrote: > >> DAX driver hotplug the device memory and move it to memory zone, these > >> pages will be marked reserved flag, however, some other kernel componet > >> will misconceive these pages are reserved mmio (ex: we map these dev_dax > >> or fs_dax pages to kvm for DIMM/NVDIMM backend). Together with the type > >> MEMORY_DEVICE_FS_DAX, we can use is_dax_page() to differentiate the pages > >> is DAX device memory or not. > >> > >> Signed-off-by: Zhang Yi <yi.z.zhang@linux.intel.com> > >> Signed-off-by: Zhang Yu <yu.c.zhang@linux.intel.com> > >> --- > >> include/linux/mm.h | 12 ++++++++++++ > >> 1 file changed, 12 insertions(+) > >> > >> diff --git a/include/linux/mm.h b/include/linux/mm.h > >> index 68a5121..de5cbc3 100644 > >> --- a/include/linux/mm.h > >> +++ b/include/linux/mm.h > >> @@ -889,6 +889,13 @@ static inline bool is_device_public_page(const struct > >> page *page) > >> page->pgmap->type == MEMORY_DEVICE_PUBLIC; > >> } > >> > >> +static inline bool is_dax_page(const struct page *page) > >> +{ > >> + return is_zone_device_page(page) && > >> + (page->pgmap->type == MEMORY_DEVICE_FS_DAX || > >> + page->pgmap->type == MEMORY_DEVICE_DEV_DAX); > >> +} > > I think question from Dan for KVM VM with 'MEMORY_DEVICE_PUBLIC' still holds? > > I am also interested to know if there is any use-case. > > > > Thanks, > > Pankaj > Yes, it is, thanks for your remind, Pankaj. > Adding Jerome for Dan's questions on V1: > [Dan]: > > Jerome, might there be any use case to pass MEMORY_DEVICE_PUBLIC > memory to a guest vm? Yes and no, i am not sure how we are going to do it. But being able to share GPU among multiple VM is on TODO list and those GPU will have MEMORY_DEVICE_PUBLIC|PRIVATE depending on the platform. So either we pass down the real underlying resource to the guest, or we will pass down a fake one and have guest and host driver talk to each other so that the host driver can do overall resource management accross multiple guests. So i would say that for now you can ignore MEMORY_DEVICE_PUBLIC and when we get to the KVM guest sharing of those and decide how we want to do it then we can update kvm to properly interpret those. Cheers, Jérôme
On 2018年08月09日 17:23, Pankaj Gupta wrote: >> DAX driver hotplug the device memory and move it to memory zone, these >> pages will be marked reserved flag, however, some other kernel componet >> will misconceive these pages are reserved mmio (ex: we map these dev_dax >> or fs_dax pages to kvm for DIMM/NVDIMM backend). Together with the type >> MEMORY_DEVICE_FS_DAX, we can use is_dax_page() to differentiate the pages >> is DAX device memory or not. >> >> Signed-off-by: Zhang Yi <yi.z.zhang@linux.intel.com> >> Signed-off-by: Zhang Yu <yu.c.zhang@linux.intel.com> >> --- >> include/linux/mm.h | 12 ++++++++++++ >> 1 file changed, 12 insertions(+) >> >> diff --git a/include/linux/mm.h b/include/linux/mm.h >> index 68a5121..de5cbc3 100644 >> --- a/include/linux/mm.h >> +++ b/include/linux/mm.h >> @@ -889,6 +889,13 @@ static inline bool is_device_public_page(const struct >> page *page) >> page->pgmap->type == MEMORY_DEVICE_PUBLIC; >> } >> >> +static inline bool is_dax_page(const struct page *page) >> +{ >> + return is_zone_device_page(page) && >> + (page->pgmap->type == MEMORY_DEVICE_FS_DAX || >> + page->pgmap->type == MEMORY_DEVICE_DEV_DAX); >> +} > I think question from Dan for KVM VM with 'MEMORY_DEVICE_PUBLIC' still holds? > I am also interested to know if there is any use-case. > > Thanks, > Pankaj Yes, it is, thanks for your remind, Pankaj. Adding Jerome for Dan's questions on V1: [Dan]: Jerome, might there be any use case to pass MEMORY_DEVICE_PUBLIC memory to a guest vm? > >> + >> #else /* CONFIG_DEV_PAGEMAP_OPS */ >> static inline void dev_pagemap_get_ops(void) >> { >> @@ -912,6 +919,11 @@ static inline bool is_device_public_page(const struct >> page *page) >> { >> return false; >> } >> + >> +static inline bool is_dax_page(const struct page *page) >> +{ >> + return false; >> +} >> #endif /* CONFIG_DEV_PAGEMAP_OPS */ >> >> static inline void get_page(struct page *page) >> -- >> 2.7.4 >> >>
diff --git a/include/linux/mm.h b/include/linux/mm.h index 68a5121..de5cbc3 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -889,6 +889,13 @@ static inline bool is_device_public_page(const struct page *page) page->pgmap->type == MEMORY_DEVICE_PUBLIC; } +static inline bool is_dax_page(const struct page *page) +{ + return is_zone_device_page(page) && + (page->pgmap->type == MEMORY_DEVICE_FS_DAX || + page->pgmap->type == MEMORY_DEVICE_DEV_DAX); +} + #else /* CONFIG_DEV_PAGEMAP_OPS */ static inline void dev_pagemap_get_ops(void) { @@ -912,6 +919,11 @@ static inline bool is_device_public_page(const struct page *page) { return false; } + +static inline bool is_dax_page(const struct page *page) +{ + return false; +} #endif /* CONFIG_DEV_PAGEMAP_OPS */ static inline void get_page(struct page *page)