Re: [PATCH] KVM: MIPS: fix compilation

[maobibo]

On 04/01/2020 12:33 AM, Paolo Bonzini wrote:
> On 31/03/20 18:07, Mike Rapoport wrote:
>> On Tue, Mar 31, 2020 at 11:47:49AM -0400, Paolo Bonzini wrote:
>>> Commit 31168f033e37 is correct that pud_index() & __pud_offset() are the same
>>> when pud_index() is actually provided, however it does not take into account
>>> the __PAGETABLE_PUD_FOLDED case.  Provide kvm_pud_index so that MIPS KVM
>>> compiles.
>>>
>>> Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
>>> ---
>>>  arch/mips/kvm/mmu.c | 18 ++++++++++++------
>>>  1 file changed, 12 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/arch/mips/kvm/mmu.c b/arch/mips/kvm/mmu.c
>>> index 7dad7a293eae..ccf98c22fd2c 100644
>>> --- a/arch/mips/kvm/mmu.c
>>> +++ b/arch/mips/kvm/mmu.c
>>> @@ -25,6 +25,12 @@
>>>  #define KVM_MMU_CACHE_MIN_PAGES 2
>>>  #endif
>>>  
>>> +#if defined(__PAGETABLE_PUD_FOLDED)
>>> +#define kvm_pud_index(gva) 0
>>> +#else
>>> +#define kvm_pud_index(gva) pud_index(gva)
>>> +#endif
>>> +
>>
>> I'd prefer simply making pud_index() always defined. When pud level is
>> folded asm-generic/pgtable-nopud.h will define PTRS_PER_PUD to 1 and
>> pud_index() will evaluate to 0 anyway.
> 
> I won't queue this patch for now, let's wait for the MIPS people to say
> what they prefer.  Thanks!
Hi Paolo,

Thanks for patch, it passes to compile on my loongson64 box. I prefer to
the second method, since pgd_inde/pmd_index is already defined in
pgtable-64.h :)

> 
> Paolo

> 
>> diff --git a/arch/mips/include/asm/pgtable-64.h b/arch/mips/include/asm/pgtable-64.h
>> index f92716cfa4f4..ee5dc0c145b9 100644
>> --- a/arch/mips/include/asm/pgtable-64.h
>> +++ b/arch/mips/include/asm/pgtable-64.h
>> @@ -172,6 +172,8 @@
>>  
>>  extern pte_t invalid_pte_table[PTRS_PER_PTE];
>>  
>> +#define pud_index(address)	(((address) >> PUD_SHIFT) & (PTRS_PER_PUD - 1))
>> +
>>  #ifndef __PAGETABLE_PUD_FOLDED
>>  /*
>>   * For 4-level pagetables we defines these ourselves, for 3-level the
>> @@ -210,8 +212,6 @@ static inline void p4d_clear(p4d_t *p4dp)
>>  	p4d_val(*p4dp) = (unsigned long)invalid_pud_table;
>>  }
>>  
>> -#define pud_index(address)	(((address) >> PUD_SHIFT) & (PTRS_PER_PUD - 1))
>> -
>>  static inline unsigned long p4d_page_vaddr(p4d_t p4d)
>>  {
>>  	return p4d_val(p4d);
>>
>>>  static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache,
>>>  				  int min, int max)
>>>  {
>>> @@ -234,8 +240,8 @@ static bool kvm_mips_flush_gpa_pud(pud_t *pud, unsigned long start_gpa,
>>>  {
>>>  	pmd_t *pmd;
>>>  	unsigned long end = ~0ul;
>>> -	int i_min = pud_index(start_gpa);
>>> -	int i_max = pud_index(end_gpa);
>>> +	int i_min = kvm_pud_index(start_gpa);
>>> +	int i_max = kvm_pud_index(end_gpa);
>>>  	bool safe_to_remove = (i_min == 0 && i_max == PTRS_PER_PUD - 1);
>>>  	int i;
>>>  
>>> @@ -361,8 +367,8 @@ static int kvm_mips_##name##_pud(pud_t *pud, unsigned long start,	\
>>>  	int ret = 0;							\
>>>  	pmd_t *pmd;							\
>>>  	unsigned long cur_end = ~0ul;					\
>>> -	int i_min = pud_index(start);				\
>>> -	int i_max = pud_index(end);					\
>>> +	int i_min = kvm_pud_index(start);				\
>>> +	int i_max = kvm_pud_index(end);					\
>>>  	int i;								\
>>>  									\
>>>  	for (i = i_min; i <= i_max; ++i, start = 0) {			\
>>> @@ -896,8 +902,8 @@ static bool kvm_mips_flush_gva_pud(pud_t *pud, unsigned long start_gva,
>>>  {
>>>  	pmd_t *pmd;
>>>  	unsigned long end = ~0ul;
>>> -	int i_min = pud_index(start_gva);
>>> -	int i_max = pud_index(end_gva);
>>> +	int i_min = kvm_pud_index(start_gva);
>>> +	int i_max = kvm_pud_index(end_gva);
>>>  	bool safe_to_remove = (i_min == 0 && i_max == PTRS_PER_PUD - 1);
>>>  	int i;
>>>  
>>> -- 
>>> 2.18.2
>>>
>>