>> +/*
>> + * Per-cpu array holding the tail pointer for the SynIC event ring buffer
>> + * for each SINT.
>> + *
>> + * We cannot maintain this in mshv driver because the tail pointer should
>> + * persist even if the mshv driver is unloaded.
>> + */
>> +u8 __percpu **hv_synic_eventring_tail;
>> +EXPORT_SYMBOL_GPL(hv_synic_eventring_tail);
>> +
>> /*
>> * Hyper-V specific initialization and shutdown code that is
>> * common across all architectures. Called from architecture
>> @@ -332,6 +342,8 @@ int __init hv_common_init(void)
>> if (hv_root_partition) {
>> hyperv_pcpu_output_arg = alloc_percpu(void *);
>> BUG_ON(!hyperv_pcpu_output_arg);
>> + hv_synic_eventring_tail = alloc_percpu(u8 *);
>> + BUG_ON(hv_synic_eventring_tail == NULL);
>> }
>>
>> hv_vp_index = kmalloc_array(num_possible_cpus(), sizeof(*hv_vp_index),
>> @@ -356,6 +368,7 @@ int __init hv_common_init(void)
>> int hv_common_cpu_init(unsigned int cpu)
>> {
>> void **inputarg, **outputarg;
>> + u8 **synic_eventring_tail;
>> u64 msr_vp_index;
>> gfp_t flags;
>> int pgcount = hv_root_partition ? 2 : 1;
>> @@ -371,6 +384,14 @@ int hv_common_cpu_init(unsigned int cpu)
>> if (hv_root_partition) {
>> outputarg = (void **)this_cpu_ptr(hyperv_pcpu_output_arg);
>> *outputarg = (char *)(*inputarg) + HV_HYP_PAGE_SIZE;
>> + synic_eventring_tail = (u8 **)this_cpu_ptr(hv_synic_eventring_tail);
>> + *synic_eventring_tail = kcalloc(HV_SYNIC_SINT_COUNT, sizeof(u8),
>> + flags);
>> +
>> + if (unlikely(!*synic_eventring_tail)) {
>> + kfree(*inputarg);
>> + return -ENOMEM;
>> + }
>> }
>>
>> msr_vp_index = hv_get_register(HV_MSR_VP_INDEX);
>> @@ -387,6 +408,7 @@ int hv_common_cpu_die(unsigned int cpu)
>> {
>> unsigned long flags;
>> void **inputarg, **outputarg;
>> + u8 **synic_eventring_tail;
>> void *mem;
>>
>> local_irq_save(flags);
>> @@ -398,6 +420,9 @@ int hv_common_cpu_die(unsigned int cpu)
>> if (hv_root_partition) {
>> outputarg = (void **)this_cpu_ptr(hyperv_pcpu_output_arg);
>> *outputarg = NULL;
>> + synic_eventring_tail = (u8 **)this_cpu_ptr(hv_synic_eventring_tail);
>> + kfree(*synic_eventring_tail);
>> + *synic_eventring_tail = NULL;
>
> The upstream code looks different now. See 9636be85cc.
>
Thanks, I have rebased for v2, and fixed this.
>> }
>>
>> local_irq_restore(flags);
>> diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
>> index 0c94d20b4d44..9118d678b27a 100644
>> --- a/include/asm-generic/mshyperv.h
>> +++ b/include/asm-generic/mshyperv.h
>> @@ -73,6 +73,8 @@ extern bool hv_nested;
>> extern void * __percpu *hyperv_pcpu_input_arg;
>> extern void * __percpu *hyperv_pcpu_output_arg;
>>
>> +extern u8 __percpu **hv_synic_eventring_tail;
>> +
>> extern u64 hv_do_hypercall(u64 control, void *inputaddr, void *outputaddr);
>> extern u64 hv_do_fast_hypercall8(u16 control, u64 input8);
>> extern bool hv_isolation_type_snp(void);
>> --
>> 2.25.1
>>
