From mboxrd@z Thu Jan  1 00:00:00 1970
From: Ingo Molnar <mingo@elte.hu>
Subject: Re: [PATCH 2/3 V2] kvm tools: Prevent PFN wraparound
Date: Wed, 11 May 2011 13:15:59 +0200
Message-ID: <20110511111559.GD18521@elte.hu>
References: <1305086951-31698-1-git-send-email-levinsasha928@gmail.com>
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Cc: penberg@kernel.org, asias.hejun@gmail.com,
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To: Sasha Levin <levinsasha928@gmail.com>
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* Sasha Levin <levinsasha928@gmail.com> wrote:

> +++ b/tools/kvm/include/kvm/virtio.h
> @@ -36,6 +36,11 @@ static inline bool virt_queue__available(struct virt_queue *vq)
>  	return vq->vring.avail->idx !=  vq->last_avail_idx;
>  }
>  
> +static inline void *guest_pfn_to_host(struct kvm *kvm, u32 pfn)
> +{
> +	return guest_flat_to_host(kvm, (unsigned long)pfn << 12);
> +}

We should at minimum document that on 32-bit hosts this will clip things at 
4GB.

Documenting such things helps, in case someone ventures into fixing this 
limitation in the future.

Thanks,

	Ingo