Subject: Re: [PATCH] KVM: Move gfn_to_memslot() to kvm_host.h

From: Avi Kivity <[email-masked]>
Date: Thu, 12 Jan 2012 17:47:19 +0200

On 01/12/2012 12:41 PM, Paul Mackerras wrote:
> This moves __gfn_to_memslot() and search_memslots() from kvm_main.c to
> kvm_host.h to reduce the code duplication caused by the need for
> non-modular code in arch/powerpc/kvm/book3s_hv_rm_mmu.c to call
> gfn_to_memslot() in real mode.
>
> Rather than putting gfn_to_memslot() itself in a header, which would
> lead to increased code size, this puts __gfn_to_memslot() in a header.
> Then, the non-modular uses of gfn_to_memslot() are changed to call
> __gfn_to_memslot() instead.  This way there is only one place in the
> source code that needs to be changed should the gfn_to_memslot()
> implementation need to be modified.
>
> On powerpc, the Book3S HV style of KVM has code that is called from
> real mode which needs to call gfn_to_memslot() and thus needs this.
> (Module code is allocated in the vmalloc region, which can't be
> accessed in real mode.)
>
>  
> +static inline struct kvm_memory_slot *
> +search_memslots(struct kvm_memslots *slots, gfn_t gfn)
> +{
> +	struct kvm_memory_slot *memslot;
> +
> +	kvm_for_each_memslot(memslot, slots)
> +		if (gfn >= memslot->base_gfn &&
> +		      gfn < memslot->base_gfn + memslot->npages)
> +			return memslot;
> +
> +	return NULL;
> +}
> +
> +static inline struct kvm_memory_slot *
> +__gfn_to_memslot(struct kvm_memslots *slots, gfn_t gfn)
> +{
> +	return search_memslots(slots, gfn);
> +}

Please add a comment here explaining why these functions are inlined. 
There's also the call to kvm_gfn_to_hva_cache_init(), which should be
changed to gfn_to_memslot(), to avoid code bloat.

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