Re: [PATCH v4 1/3] KVM: s390: Add map/unmap ioctl and clean mappings post-guest

[Claudio Imbrenda <imbrenda@linux.ibm.com>]

On Wed, 29 Apr 2026 10:44:51 -0400
Matthew Rosato <mjrosato@linux.ibm.com> wrote:

[...]

> 
> > +		if (locked)
> > +			mmap_read_unlock(mm);
> > +		mmput(mm);
> > +	}
> > +
> > +	return page;
> > +}
> > +
> > +static int kvm_s390_adapter_map(struct kvm *kvm, unsigned int id, __u64 addr)
> > +{
> > +	struct s390_io_adapter *adapter = get_io_adapter(kvm, id);
> > +	struct s390_map_info *map;
> > +	unsigned long flags;
> > +	__u64 host_addr;
> > +	int ret, idx;
> > +
> > +	if (!adapter || !addr)
> > +		return -EINVAL;
> > +
> > +	map = kzalloc_obj(*map, GFP_KERNEL_ACCOUNT);
> > +	if (!map)
> > +		return -ENOMEM;
> > +
> > +	INIT_LIST_HEAD(&map->list);
> > +	idx = srcu_read_lock(&kvm->srcu);
> > +	host_addr = gpa_to_hva(kvm, addr);
> > +	if (kvm_is_error_hva(host_addr)) {
> > +		srcu_read_unlock(&kvm->srcu, idx);
> > +		kfree(map);  
> 
> Drop this kfree(), you already do this when you goto out

have you considered using __free(kvfree) and let the compiler free map
for you automatically? (or it doesn't work here?)

[...]