x86/hyperv: Add functions to allocate/deallocate page for Hyper-V (8c3e44bd) · Commits · 戴 / test

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. Signed-off-by:

Maya Nakamura <m.maya.nakamura@gmail.com> Signed-off-by:

Thomas Gleixner <tglx@linutronix.de> Reviewed-by:

Michael Kelley <mikelley@microsoft.com> Reviewed-by:

Vitaly Kuznetsov <vkuznets@redhat.com> Link: https://lore.kernel.org/lkml/alpine.DEB.2.21.1906272334560.32342@nanos.tec.linutronix.de/ Link: https://lore.kernel.org/lkml/87muindr9c.fsf@vitty.brq.redhat.com/ Link: https://lkml.kernel.org/r/706b2e71eb3e587b5f8801e50f090fae2a00e35d.1562916939.git.m.maya.nakamura@gmail.com

arch/x86/hyperv/hv_init.c

+14 −0

Original line number	Diff line number	Diff line
		@@ -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;

arch/x86/include/asm/mshyperv.h

+4 −1

Original line number	Diff line number	Diff line
		@@ -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) {};

Admin message