Re: [PATCH 1/2] KVM: MMU: Do not treat ZONE_DEVICE pages as being reserved

[Paolo Bonzini]

On 06/11/19 18:07, Sean Christopherson wrote:
>  void kvm_get_pfn(kvm_pfn_t pfn)
>  {
> -	if (!kvm_is_reserved_pfn(pfn))
> +	if (!kvm_is_reserved_pfn(pfn) && !WARN_ON(kvm_is_zone_device_pfn(pfn)))
>  		get_page(pfn_to_page(pfn));
>  }
>  EXPORT_SYMBOL_GPL(kvm_get_pfn);

Can you call remap_pfn_range with a source address that is ZONE_DEVICE?
 If so, you would get a WARN from the kvm_get_pfn call in
hva_to_pfn_remapped.

Paolo