Re: Documentation of the kvm->srcu lock

[Paolo Bonzini <pbonzini@redhat.com>]

Il 09/09/2013 14:47, Thomas Huth ha scritto:
> Am Mon, 09 Sep 2013 20:26:49 +0800
> schrieb Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>:
> 
>> On 09/09/2013 08:13 PM, Paolo Bonzini wrote:
>>> Il 09/09/2013 14:00, Thomas Huth ha scritto:
>>>>
>>>>  Hi all!
>>>>
>>>> I am quite new to KVM, and I recently had to struggle with the
>>>> kvm->srcu lock a little bit ... documentation for this lock seems
>>>> to be quite sparse, I've only found some descriptions in mailing
>>>> list archives (the description at the following URL is quite good:
>>>> http://www.mail-archive.com/kvm@vger.kernel.org/msg90003.html ).
>>>>
>>>> So I wonder whether it would be helpful for others, too, if some
>>>> information about this lock was added to the documentation file
>>>> Documentation/virtual/kvm/locking.txt for example? I'd like to
>>>> suggest the following text as a first draft (using some information
>>>> from the URL above):
>>>>
>>>>  Name:		kvm->srcu
>>>>  Type:		srcu lock
>>>>  Arch:		any
>>>>  Protects:	- kvm->memslots
>>>>  		- kvm->buses
>>>>  Comment:	The srcu read lock must be held while accessing memslots (e.g.
>>>>  		when using gfn_to_* functions) and while accessing in-kernel
>>>>  		MMIO/PIO address->device structure mapping (kvm->buses).
>>>>  		The srcu index can be stored in kvm_vcpu->srcu_idx per vcpu
>>>>  		if it is needed by multiple functions.
>>>>
>>>> What do you think? Since I am not an expert in this area, extension
>>>> and/or corrections are very welcome!
>>>
>>> Yes, this looks good.  Xiao, any suggestions?
>>
>> It's nice indeed! :)
>>
>> Reviewed-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
> 
> Great :-) ... ok, can you then simply pick up the above text or shall I
> submit a real patch for that file?

Sending a patch would be appreciated.

Paolo