[PATCH 01/17] KVM: arm64: Add __pkvm_private_range_pa

[Vincent Donnefort]

Mappings in the pKVM private range are not identity mapped, making the
standard __hyp_pa() unsuitable for translating these addresses.

Introduce __pkvm_private_range_pa() to resolve physical addresses for
this range by walking the hypervisor page-table. This will be useful for
the upcoming pKVM heap allocator.

Signed-off-by: Vincent Donnefort <vdonnefort at google.com>

diff --git a/arch/arm64/kvm/hyp/include/nvhe/mm.h b/arch/arm64/kvm/hyp/include/nvhe/mm.h
index 6e83ce35c2f2..d3137c16b632 100644
--- a/arch/arm64/kvm/hyp/include/nvhe/mm.h
+++ b/arch/arm64/kvm/hyp/include/nvhe/mm.h
@@ -30,5 +30,6 @@ int __pkvm_create_private_mapping(phys_addr_t phys, size_t size,
 				  unsigned long *haddr);
 int pkvm_create_stack(phys_addr_t phys, unsigned long *haddr);
 int pkvm_alloc_private_va_range(size_t size, unsigned long *haddr);
+phys_addr_t __pkvm_private_range_pa(void *va);
 
 #endif /* __KVM_HYP_MM_H */
diff --git a/arch/arm64/kvm/hyp/nvhe/mm.c b/arch/arm64/kvm/hyp/nvhe/mm.c
index 3b0bee496bff..773426a68d2d 100644
--- a/arch/arm64/kvm/hyp/nvhe/mm.c
+++ b/arch/arm64/kvm/hyp/nvhe/mm.c
@@ -502,3 +502,17 @@ int refill_memcache(struct kvm_hyp_memcache *mc, unsigned long min_pages,
 
 	return ret;
 }
+
+phys_addr_t __pkvm_private_range_pa(void *va)
+{
+	kvm_pte_t pte = 0;
+	s8 level;
+
+	hyp_spin_lock(&pkvm_pgd_lock);
+	WARN_ON(kvm_pgtable_get_leaf(&pkvm_pgtable, (u64)va, &pte, &level));
+	hyp_spin_unlock(&pkvm_pgd_lock);
+
+	WARN_ON(!kvm_pte_valid(pte));
+
+	return kvm_pte_to_phys(pte) + offset_in_page(va);
+}
-- 
2.54.0.631.ge1b05301d1-goog