ANDROID: KVM: arm64: iommu: Add owner to domains

Add an owner to each domain either host or a VM which is set at alloc
time, and all other IOMMU operations would be allowed only from the
domain owner.
The new vm member is protected by kvm_iommu_domain_lock while
set/cleared in alloc/free, and the check is done only after the domain
refcount is elevated to avoid racing with alloc.

Bug: 357781595
Bug: 348382247
Bug: 236685427
Change-Id: Ie23379d958922368ec3be2127ba90393709a77bb
Signed-off-by: Mostafa Saleh <smostafa@google.com>

include/kvm/iommu.h

@@ -21,6 +21,7 @@ struct kvm_hyp_iommu_domain {
 	atomic_t		refs;
 	pkvm_handle_t		domain_id;
 	void			*priv;
+	void			*vm;
 	ANDROID_KABI_RESERVE(1);
 	ANDROID_KABI_RESERVE(2);
 };