Re: [Qemu-devel] [PATCH 2/3] update kvm related the head file from kernel

[Xiao Guangrong]

Hi Jan,

Thanks for your review.

On 09/07/2012 04:49 PM, Jan Kiszka wrote:

>> +#ifdef __KVM_HAVE_READONLY_MEM
>> +                    __u8 write_readonly_mem;
>> +#endif
>>              } mmio;
>>              /* KVM_EXIT_HYPERCALL */
>>              struct {
>> @@ -618,6 +625,9 @@ struct kvm_ppc_smmu_info {
>>  #define KVM_CAP_PPC_GET_SMMU_INFO 78
>>  #define KVM_CAP_S390_COW 79
>>  #define KVM_CAP_PPC_ALLOC_HTAB 80
>> +#ifdef __KVM_HAVE_READONLY_MEM
>> +#define KVM_CAP_READONLY_MEM 81
>> +#endif
> 
> Sorry for commenting on the wrong patch, this must be fixed in the
> kernel: no more conditional CAPs, please. 

There are some common code depend on KVM_CAP_READONLY_MEM, such as,
check_memory_region_flags() and write_readonly_mem field in mmio-exit-info.

Yes, we can use #ifdef CONFIG_X86 to enable it only on x86, but it
is hard to expand this feather to other arches in the further.

So, i used __KVM_HAVE_READONLY_MEM and only defined it on x86. :)