Commit-ID: 8c3e44bde7fd1b8291515f046008225711ac7beb
Gitweb: https://git.kernel.org/tip/8c3e44bde7fd1b8291515f046008225711ac7beb
Author: Maya Nakamura <m.maya.nakamura@xxxxxxxxx>
AuthorDate: Fri, 12 Jul 2019 08:21:25 +0000
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Mon, 22 Jul 2019 11:06:45 +0200
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: Maya Nakamura <m.maya.nakamura@xxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Reviewed-by: Michael Kelley <mikelley@xxxxxxxxxxxxx>
Reviewed-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
Link: https://lore.kernel.org/lkml/alpine.DEB.2.21.1906272334560.32342@xxxxxxxxxxxxxxxxxxxxxxx/
Link: https://lore.kernel.org/lkml/87muindr9c.fsf@xxxxxxxxxxxxxxxxxxxx/
Link: https://lkml.kernel.org/r/706b2e71eb3e587b5f8801e50f090fae2a00e35d.1562916939.git.m.maya.nakamura@xxxxxxxxx
---
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 0d258688c8cf..d314cf1e15fd 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 2ef31cc8c529..f4138aeb4280 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) {};
|