Re: [PATCH v2 4/9] KVM: s390: Fix dirty marking in adapter_indicators_set*()

[Christian Borntraeger]

Am 12.08.26 um 12:44 schrieb Claudio Imbrenda:

> @@ -3017,26 +3017,30 @@ static int adapter_indicators_set_fast(struct kvm *kvm,
>   				       struct kvm_s390_adapter_int *adapter_int,
>   				       int setbit)
>   {
> +	struct s390_map_info *ind_info, *summary_info;
>   	unsigned long bit;
>   	int summary_set;
> -	struct s390_map_info *ind_info, *summary_info;
>   	void *map;
>   
> -	spin_lock(&adapter->maps_lock);
> +	guard(srcu)(&kvm->srcu);
> +	guard(spinlock)(&adapter->maps_lock);
> +
>   	ind_info = get_map_info(adapter, adapter_int->ind_addr);
> -	if (!ind_info) {
> -		spin_unlock(&adapter->maps_lock);
> +	if (!ind_info)
>   		return -EWOULDBLOCK;
> -	}
> +
>   	map = page_address(ind_info->page);
>   	bit = get_ind_bit(ind_info->addr, adapter_int->ind_offset, adapter->swap);
> -	if (setbit)
> +	if (setbit) {
> +		mark_page_dirty(kvm, gpa_to_gfn(adapter_int->ind_gaddr));
> +		set_page_dirty(ind_info->page);
>   		set_bit(bit, map);
> +	}

This marks the indicator page dirty before writing it.
The summary twenty lines below does it the other way round and so do both
slow-path branches.
The order matters because kvm_get_dirty_log_protect() harvests destructively.