From mboxrd@z Thu Jan  1 00:00:00 1970
From: Paolo Bonzini <pbonzini@redhat.com>
Subject: Re: Documentation of the kvm->srcu lock
Date: Mon, 09 Sep 2013 14:13:33 +0200
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References: <20130909140032.3fb22a4a@thhw500>
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Cc: kvm@vger.kernel.org,
	Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
To: Thomas Huth <thuth@linux.vnet.ibm.com>
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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?

Paolo