Re: [Qemu-devel] Regression caused by d2f39ad "exec.c: Ensure right alignment also for file backed ram"

[Dominik Dingel]

> Am 24.10.2016 um 13:44 schrieb Igor Mammedov <imamm...@redhat.com>:
> 
>> 
>> modified   exec.c
>> @@ -1254,7 +1254,11 @@ static void *file_ram_alloc(RAMBlock *block,
>>     }
>> 
>>     block->page_size = qemu_fd_getpagesize(fd);
>> +#if defined(__x86_64__) || defined(__i386__)
>> +    block->mr->align = block->page_size;
>> +#else
>>     block->mr->align = MAX(block->page_size, QEMU_VMALLOC_ALIGN);
> maybe it's worth to do other way around i.e. for special s390 case
> do above and for the rest leave page_size alignment?
> 


That should work, now the question would be why on x86 file backed memory 
allocations differ to anonymous allocations?

On s390 all allocations used for KVM should be aligned on a segment basis.

> SPAPR supports mem hotplug so it's also affected

As power does not specialize QEMU_VMALLOC_ALIGN it shouldn’t be affected.

Thanks,
        Dominik