1 files changed, 30 insertions, 2 deletions

diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index cfecc2272f2d..4c431e1c1eff 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -91,12 +91,19 @@ EXPORT_SYMBOL_GPL(hv_vp_index);
 struct hv_vp_assist_page **hv_vp_assist_page;
 EXPORT_SYMBOL_GPL(hv_vp_assist_page);
 
+void  __percpu **hyperv_pcpu_input_arg;
+EXPORT_SYMBOL_GPL(hyperv_pcpu_input_arg);
+
 u32 hv_max_vp_index;
 
 static int hv_cpu_init(unsigned int cpu)
 {
         u64 msr_vp_index;
         struct hv_vp_assist_page **hvp = &hv_vp_assist_page[smp_processor_id()];
+        void **input_arg;
+
+        input_arg = (void **)this_cpu_ptr(hyperv_pcpu_input_arg);
+        *input_arg = page_address(alloc_page(GFP_KERNEL));
 
         hv_get_vp_index(msr_vp_index);
 
@@ -217,6 +224,16 @@ static int hv_cpu_die(unsigned int cpu)
 {
         struct hv_reenlightenment_control re_ctrl;
         unsigned int new_cpu;
+        unsigned long flags;
+        void **input_arg;
+        void *input_pg = NULL;
+
+        local_irq_save(flags);
+        input_arg = (void **)this_cpu_ptr(hyperv_pcpu_input_arg);
+        input_pg = *input_arg;
+        *input_arg = NULL;
+        local_irq_restore(flags);
+        free_page((unsigned long)input_pg);
 
         if (hv_vp_assist_page && hv_vp_assist_page[cpu])
                 wrmsrl(HV_X64_MSR_VP_ASSIST_PAGE, 0);
@@ -242,8 +259,9 @@ static int hv_cpu_die(unsigned int cpu)
  *
  * 1. Setup the hypercall page.
  * 2. Register Hyper-V specific clocksource.
+ * 3. Setup Hyper-V specific APIC entry points.
  */
-void hyperv_init(void)
+void __init hyperv_init(void)
 {
         u64 guest_id, required_msrs;
         union hv_x64_msr_hypercall_contents hypercall_msr;
@@ -259,6 +277,16 @@ void hyperv_init(void)
         if ((ms_hyperv.features & required_msrs) != required_msrs)
                 return;
 
+        /*
+         * Allocate the per-CPU state for the hypercall input arg.
+         * If this allocation fails, we will not be able to setup
+         * (per-CPU) hypercall input page and thus this failure is
+         * fatal on Hyper-V.
+         */
+        hyperv_pcpu_input_arg = alloc_percpu(void  *);
+
+        BUG_ON(hyperv_pcpu_input_arg == NULL);
+
         /* Allocate percpu VP index */
         hv_vp_index = kmalloc_array(num_possible_cpus(), sizeof(*hv_vp_index),
                                     GFP_KERNEL);
@@ -296,7 +324,7 @@ void hyperv_init(void)
         hypercall_msr.guest_physical_address = vmalloc_to_pfn(hv_hypercall_pg);
         wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
 
-        hyper_alloc_mmu();
+        hv_apic_init();
 
         /*
          * Register Hyper-V specific clocksource.