Re: [PATCH v2 2/2] KVM: x86/mmu: Check all address spaces before skipping unsync

[Paolo Bonzini]

On 7/21/26 12:35, Jinu Kim wrote:
> diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
> index 7757f0ad65c6f..1db6750992546 100644
> --- a/arch/x86/kvm/mmu/mmu.c
> +++ b/arch/x86/kvm/mmu/mmu.c
> @@ -725,6 +725,25 @@ static struct kvm_lpage_info *lpage_info_slot(gfn_t gfn,
>   	return &slot->arch.lpage_info[level - 2][idx];
>   }
>   
> +static bool kvm_gfn_is_lpage_allowed(struct kvm *kvm,
> +				     const struct kvm_memory_slot *slot,
> +				     gfn_t gfn, int level)
> +{
> +	const struct kvm_memory_slot *other_slot;
> +
> +	BUILD_BUG_ON(KVM_MAX_NR_ADDRESS_SPACES > 2);
> +
> +	if (lpage_info_slot(gfn, slot, level)->disallow_lpage)
> +		return false;
> +
> +	if (kvm_arch_nr_memslot_as_ids(kvm) == 1)
> +		return true;
> +
> +	other_slot = __gfn_to_memslot(__kvm_memslots(kvm, slot->as_id ^ 1), gfn);
> +	return !other_slot ||
> +	       !lpage_info_slot(gfn, other_slot, level)->disallow_lpage;
I have a slight preference for checking "> 1", for example:

	if (kvm_arch_nr_memslot_as_ids(kvm) > 1) {
		other_slot = __gfn_to_memslot(__kvm_memslots(kvm, slot->as_id ^ 1), gfn);
		if (other_slot && lpage_info_slot(gfn, other_slot, level)->disallow_lpage)
			return false;
	}
	return true;

I made the change and queued the two patches, thanks!

Paolo