From mboxrd@z Thu Jan  1 00:00:00 1970
From: Sasha Levin <levinsasha928@gmail.com>
Subject: Re: [RFC PATCH 13/16] kvm tools: keep track of registered memory
 banks in struct kvm
Date: Tue, 13 Nov 2012 11:09:05 -0500
Message-ID: <50A270A1.8020305@gmail.com>
References: <1352721450-11340-1-git-send-email-will.deacon@arm.com> <1352721450-11340-14-git-send-email-will.deacon@arm.com> <50A1CE92.6060803@gmail.com> <20121113121605.GC5493@mudshark.cambridge.arm.com>
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Cc: "kvm@vger.kernel.org" <kvm@vger.kernel.org>,
	"penberg@kernel.org" <penberg@kernel.org>,
	Marc Zyngier <Marc.Zyngier@arm.com>,
	"c.dall@virtualopensystems.com" <c.dall@virtualopensystems.com>,
	Matt Evans <Matt.Evans@arm.com>,
	"peter.maydell@linaro.org" <peter.maydell@linaro.org>
To: Will Deacon <will.deacon@arm.com>
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On 11/13/2012 07:16 AM, Will Deacon wrote:
> On Tue, Nov 13, 2012 at 04:37:38AM +0000, Sasha Levin wrote:
>> On 11/12/2012 06:57 AM, Will Deacon wrote:
>>> +struct kvm_mem_bank {
>>> +	struct list_head	list;
>>> +	unsigned long		guest_phys_addr;
>>> +	void			*host_addr;
>>> +	unsigned long		size;
>>> +};
>>
>> Can we just reuse struct kvm_userspace_memory_region here? We're also using different
>> data types for guest_phys_addr and size than whats in kvm_userspace_memory_region - that
>> can't be good.
> 
> I looked briefly at doing that when I wrote the multi-bank stuff, but I hit
> a couple of issues:
> 
> 	- kvmtool itself tends to use void * for host addresses, rather than
> 	  the __u64 userspace_addr in kvm_userspace_memory_region
> 
> 	- kvm_userspace_memory_region is a superset of what we need (not the
> 	  end of the world I guess)
> 
> so you end up casting address types a fair amount. Still, I'll revisit it
> and see if I can come up with something cleaner.

That's a good point. We used void* while the kernel side is using u64, which
looks odd.

In that case, let's get everything moved to u64 (obviously not in the scope of
this patch series).


Thanks,
Sasha