Re: [PATCH 6/7] kvm mmu: enabling 1GB pages by extending backing_size funtion

[Avi Kivity <avi@redhat.com>]

Joerg Roedel wrote:
> This patch enables support for 1GB pages in KVM by implementing
> the support in backing_size().
>
> @@ -490,18 +492,30 @@ static enum kvm_page_size host_page_size(struct kvm *kvm, gfn_t gfn)
>  static enum kvm_page_size backing_size(struct kvm_vcpu *vcpu, gfn_t gfn)
>  {
>  	struct kvm_memory_slot *slot;
> -
> -	if (has_wrprotected_page(vcpu->kvm, gfn))
> -		return KVM_PAGE_SIZE_4k;
> -
> -	if (host_page_size(vcpu->kvm, gfn) < KVM_PAGE_SIZE_2M)
> -		return KVM_PAGE_SIZE_4k;
> +	enum kvm_page_size host_size, ret;
>  
>  	slot = gfn_to_memslot(vcpu->kvm, gfn);
>  	if (slot && slot->dirty_bitmap)
>  		return KVM_PAGE_SIZE_4k;
>  
> -	return KVM_PAGE_SIZE_2M;
> +	host_size = host_page_size(vcpu->kvm, gfn);
> +
> +	switch (host_size) {
> +	case KVM_PAGE_SIZE_1G:
> +		if (!has_wrprotected_largepage(vcpu->kvm, gfn)) {
> +			ret = KVM_PAGE_SIZE_1G;
> +			break;
> +		}
>   

What if there's a wrprotected_page in there?

> +	case KVM_PAGE_SIZE_2M:
> +		if (!has_wrprotected_page(vcpu->kvm, gfn)) {
> +			ret = KVM_PAGE_SIZE_2M;
> +			break;
> +		}
> +	default:
> +		ret = KVM_PAGE_SIZE_4k;
> +	}
> +
> +	return ret;
>  }
>  
>  /*
>   


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