Maya, On Tue, 18 Jun 2019, Maya Nakamura wrote: > diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c > index 0e033ef11a9f..e8960a83add7 100644 > --- a/arch/x86/hyperv/hv_init.c > +++ b/arch/x86/hyperv/hv_init.c > @@ -37,6 +37,20 @@ EXPORT_SYMBOL_GPL(hyperv_pcpu_input_arg); > u32 hv_max_vp_index; > EXPORT_SYMBOL_GPL(hv_max_vp_index); > > +void *hv_alloc_hyperv_page(void) > +{ > + BUILD_BUG_ON(PAGE_SIZE != HV_HYP_PAGE_SIZE); > + > + return (void *)__get_free_page(GFP_KERNEL); > +} > +EXPORT_SYMBOL_GPL(hv_alloc_hyperv_page); > + > +void hv_free_hyperv_page(unsigned long addr) > +{ > + free_page(addr); > +} > +EXPORT_SYMBOL_GPL(hv_free_hyperv_page); These functions need to be declared in a header file. Thanks, tglx