Introduce two new functions, hv_alloc_hyperv_page() and hv_free_hyperv_page(), to allocate/deallocate memory with the size and alignment that Hyper-V expects as a page. Although currently they are not used, they are ready to be used to allocate/deallocate memory on x86 when their ARM64 counterparts are implemented, keeping symmetry between architectures with potentially different guest page sizes. Link: https://lore.kernel.org/lkml/alpine.DEB.2.21.1906272334560.32342@xxxxxxxxxxxxxxxxxxxxxxx/ Link: https://lore.kernel.org/lkml/87muindr9c.fsf@xxxxxxxxxxxxxxxxxxxx/ Signed-off-by: Maya Nakamura <m.maya.nakamura@xxxxxxxxx> Reviewed-by: Michael Kelley <mikelley@xxxxxxxxxxxxx> Reviewed-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> --- arch/x86/hyperv/hv_init.c | 14 ++++++++++++++ arch/x86/include/asm/mshyperv.h | 5 ++++- 2 files changed, 18 insertions(+), 1 deletion(-) 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); + static int hv_cpu_init(unsigned int cpu) { u64 msr_vp_index; diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h index 2a793bf6ebb0..32ec9df39a99 100644 --- a/arch/x86/include/asm/mshyperv.h +++ b/arch/x86/include/asm/mshyperv.h @@ -218,7 +218,8 @@ static inline struct hv_vp_assist_page *hv_get_vp_assist_page(unsigned int cpu) void __init hyperv_init(void); void hyperv_setup_mmu_ops(void); - +void *hv_alloc_hyperv_page(void); +void hv_free_hyperv_page(unsigned long addr); void hyperv_reenlightenment_intr(struct pt_regs *regs); void set_hv_tscchange_cb(void (*cb)(void)); void clear_hv_tscchange_cb(void); @@ -241,6 +242,8 @@ static inline void hv_apic_init(void) {} #else /* CONFIG_HYPERV */ static inline void hyperv_init(void) {} static inline void hyperv_setup_mmu_ops(void) {} +static inline void *hv_alloc_hyperv_page(void) { return NULL; } +static inline void hv_free_hyperv_page(unsigned long addr) {} static inline void set_hv_tscchange_cb(void (*cb)(void)) {} static inline void clear_hv_tscchange_cb(void) {} static inline void hyperv_stop_tsc_emulation(void) {}; -- 2.17.1
