[PATCH v3 03/17] KVM: arm64: Add pkvm_map_private_va_range

[Vincent Donnefort <vdonnefort@google.com>]

In preparation for the pKVM heap allocator, introduce
pkvm_map_private_va_range() to map a physical range into the pKVM
private range.

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

diff --git a/arch/arm64/kvm/hyp/include/nvhe/mm.h b/arch/arm64/kvm/hyp/include/nvhe/mm.h
index 00cadd13ee5d..ea97ea49820e 100644
--- a/arch/arm64/kvm/hyp/include/nvhe/mm.h
+++ b/arch/arm64/kvm/hyp/include/nvhe/mm.h
@@ -31,6 +31,7 @@ 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);
+int pkvm_map_private_va_range(void *haddr, phys_addr_t phys, size_t size);
 phys_addr_t pkvm_private_va_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 5cd2f1fe51e4..20e4445dd57b 100644
--- a/arch/arm64/kvm/hyp/nvhe/mm.c
+++ b/arch/arm64/kvm/hyp/nvhe/mm.c
@@ -25,6 +25,7 @@ struct memblock_region hyp_memory[HYP_MEMBLOCK_REGIONS];
 unsigned int hyp_memblock_nr;
 
 static u64 __io_map_base;
+static u64 __hyp_private_va_start;
 
 struct hyp_fixmap_slot {
 	u64 addr;
@@ -90,6 +91,31 @@ int pkvm_alloc_private_va_range(size_t size, unsigned long *haddr)
 	return ret;
 }
 
+/**
+ * pkvm_map_private_va_range() - Map a physical range into the private VA range
+ * @haddr:	The virtual address in the private range.
+ * @phys:	The physical address to map.
+ * @size:	The size of the range to map.
+ *
+ * The hypervisor VA @haddr must have been first allocated with pkvm_alloc_private_va_range()
+ *
+ * Return: 0 on success, negative error code on failure.
+ */
+int pkvm_map_private_va_range(void *haddr, phys_addr_t phys, size_t size)
+{
+	unsigned long addr = (unsigned long)haddr;
+
+	if (!PAGE_ALIGNED(addr | phys | size))
+		return -EINVAL;
+
+	guard(hyp_spinlock)(&pkvm_pgd_lock);
+
+	if (addr < __hyp_private_va_start || addr + size > __io_map_base)
+		return -EINVAL;
+
+	return kvm_pgtable_hyp_map(&pkvm_pgtable, addr, size, phys, PAGE_HYP);
+}
+
 phys_addr_t pkvm_private_va_range_pa(void *va)
 {
 	kvm_pte_t pte = 0;
@@ -450,6 +476,7 @@ int hyp_create_idmap(u32 hyp_va_bits)
 	 */
 	__io_map_base = start & BIT(hyp_va_bits - 2);
 	__io_map_base ^= BIT(hyp_va_bits - 2);
+	__hyp_private_va_start = __io_map_base;
 	__hyp_vmemmap = __io_map_base | BIT(hyp_va_bits - 3);
 
 	return __pkvm_create_mappings(start, end - start, start, PAGE_HYP_EXEC);
-- 
2.55.0.229.g6434b31f56-goog