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Commit 8c3e44bd authored by Maya Nakamura's avatar Maya Nakamura Committed by Thomas Gleixner
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x86/hyperv: Add functions to allocate/deallocate page for Hyper-V 



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: default avatarMaya Nakamura <m.maya.nakamura@gmail.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Reviewed-by: default avatarMichael Kelley <mikelley@microsoft.com>
Reviewed-by: default avatarVitaly 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
parent fcd3f622

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) {};