Re: [Qemu-devel] [PATCH 2/5] exec.c: use refcnt to protect device during dispatching

[Avi Kivity]

On 07/25/2012 01:58 PM, Avi Kivity wrote:
>>      while (len > 0) {
>>          page = addr & TARGET_PAGE_MASK;
>>          l = (page + TARGET_PAGE_SIZE) - addr;
>>          if (l > len)
>>              l = len;
>> +
>> +        qemu_rwlock_rdlock_devtree();
>>          section = phys_page_find(page >> TARGET_PAGE_BITS);
> 
> Does the devtree lock also protect the data structures accessed by
> phys_page_find()?  Seems wrong.

The right way is to object_ref() in core_region_add() and object_unref()
in core_region_del().  We're guaranteed that mr->object is alive during
_add(), and DeviceClass::unmap() ensures that the extra ref doesn't
block destruction.

-- 
error compiling committee.c: too many arguments to function