3 files changed, 72 insertions, 30 deletions

diff --git a/arch/arm64/kvm/hyp/include/nvhe/mm.h b/arch/arm64/kvm/hyp/include/nvhe/mm.h
index 2d08510c6cc1..42d8eb9bfe72 100644
--- a/arch/arm64/kvm/hyp/include/nvhe/mm.h
+++ b/arch/arm64/kvm/hyp/include/nvhe/mm.h
@@ -19,8 +19,10 @@ int hyp_back_vmemmap(phys_addr_t phys, unsigned long size, phys_addr_t back);
 int pkvm_cpu_set_vector(enum arm64_hyp_spectre_vector slot);
 int pkvm_create_mappings(void *from, void *to, enum kvm_pgtable_prot prot);
 int pkvm_create_mappings_locked(void *from, void *to, enum kvm_pgtable_prot prot);
-unsigned long __pkvm_create_private_mapping(phys_addr_t phys, size_t size,
-					    enum kvm_pgtable_prot prot);
+int __pkvm_create_private_mapping(phys_addr_t phys, size_t size,
+				  enum kvm_pgtable_prot prot,
+				  unsigned long *haddr);
+int pkvm_alloc_private_va_range(size_t size, unsigned long *haddr);
 
 static inline void hyp_vmemmap_range(phys_addr_t phys, unsigned long size,
 				     unsigned long *start, unsigned long *end)
diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
index 5e2197db0d32..3cea4b6ac23e 100644
--- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c
+++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
@@ -160,7 +160,23 @@ static void handle___pkvm_create_private_mapping(struct kvm_cpu_context *host_ct
 	DECLARE_REG(size_t, size, host_ctxt, 2);
 	DECLARE_REG(enum kvm_pgtable_prot, prot, host_ctxt, 3);
 
-	cpu_reg(host_ctxt, 1) = __pkvm_create_private_mapping(phys, size, prot);
+	/*
+	 * __pkvm_create_private_mapping() populates a pointer with the
+	 * hypervisor start address of the allocation.
+	 *
+	 * However, handle___pkvm_create_private_mapping() hypercall crosses the
+	 * EL1/EL2 boundary so the pointer would not be valid in this context.
+	 *
+	 * Instead pass the allocation address as the return value (or return
+	 * ERR_PTR() on failure).
+	 */
+	unsigned long haddr;
+	int err = __pkvm_create_private_mapping(phys, size, prot, &haddr);
+
+	if (err)
+		haddr = (unsigned long)ERR_PTR(err);
+
+	cpu_reg(host_ctxt, 1) = haddr;
 }
 
 static void handle___pkvm_prot_finalize(struct kvm_cpu_context *host_ctxt)
diff --git a/arch/arm64/kvm/hyp/nvhe/mm.c b/arch/arm64/kvm/hyp/nvhe/mm.c
index cdbe8e246418..96193cb31a39 100644
--- a/arch/arm64/kvm/hyp/nvhe/mm.c
+++ b/arch/arm64/kvm/hyp/nvhe/mm.c
@@ -37,36 +37,60 @@ static int __pkvm_create_mappings(unsigned long start, unsigned long size,
 	return err;
 }
 
-unsigned long __pkvm_create_private_mapping(phys_addr_t phys, size_t size,
-					    enum kvm_pgtable_prot prot)
+/**
+ * pkvm_alloc_private_va_range - Allocates a private VA range.
+ * @size:	The size of the VA range to reserve.
+ * @haddr:	The hypervisor virtual start address of the allocation.
+ *
+ * The private virtual address (VA) range is allocated above __io_map_base
+ * and aligned based on the order of @size.
+ *
+ * Return: 0 on success or negative error code on failure.
+ */
+int pkvm_alloc_private_va_range(size_t size, unsigned long *haddr)
 {
-	unsigned long addr;
-	int err;
+	unsigned long base, addr;
+	int ret = 0;
 
 	hyp_spin_lock(&pkvm_pgd_lock);
 
-	size = PAGE_ALIGN(size + offset_in_page(phys));
-	addr = __io_map_base;
-	__io_map_base += size;
+	/* Align the allocation based on the order of its size */
+	addr = ALIGN(__io_map_base, PAGE_SIZE << get_order(size));
 
-	/* Are we overflowing on the vmemmap ? */
-	if (__io_map_base > __hyp_vmemmap) {
-		__io_map_base -= size;
-		addr = (unsigned long)ERR_PTR(-ENOMEM);
-		goto out;
-	}
+	/* The allocated size is always a multiple of PAGE_SIZE */
+	base = addr + PAGE_ALIGN(size);
 
-	err = kvm_pgtable_hyp_map(&pkvm_pgtable, addr, size, phys, prot);
-	if (err) {
-		addr = (unsigned long)ERR_PTR(err);
-		goto out;
+	/* Are we overflowing on the vmemmap ? */
+	if (!addr || base > __hyp_vmemmap)
+		ret = -ENOMEM;
+	else {
+		__io_map_base = base;
+		*haddr = addr;
 	}
 
-	addr = addr + offset_in_page(phys);
-out:
 	hyp_spin_unlock(&pkvm_pgd_lock);
 
-	return addr;
+	return ret;
+}
+
+int __pkvm_create_private_mapping(phys_addr_t phys, size_t size,
+				  enum kvm_pgtable_prot prot,
+				  unsigned long *haddr)
+{
+	unsigned long addr;
+	int err;
+
+	size = PAGE_ALIGN(size + offset_in_page(phys));
+	err = pkvm_alloc_private_va_range(size, &addr);
+	if (err)
+		return err;
+
+	err = __pkvm_create_mappings(addr, size, phys, prot);
+	if (err)
+		return err;
+
+	*haddr = addr + offset_in_page(phys);
+	return err;
 }
 
 int pkvm_create_mappings_locked(void *from, void *to, enum kvm_pgtable_prot prot)
@@ -146,7 +170,8 @@ int pkvm_cpu_set_vector(enum arm64_hyp_spectre_vector slot)
 int hyp_map_vectors(void)
 {
 	phys_addr_t phys;
-	void *bp_base;
+	unsigned long bp_base;
+	int ret;
 
 	if (!kvm_system_needs_idmapped_vectors()) {
 		__hyp_bp_vect_base = __bp_harden_hyp_vecs;
@@ -154,13 +179,12 @@ int hyp_map_vectors(void)
 	}
 
 	phys = __hyp_pa(__bp_harden_hyp_vecs);
-	bp_base = (void *)__pkvm_create_private_mapping(phys,
-							__BP_HARDEN_HYP_VECS_SZ,
-							PAGE_HYP_EXEC);
-	if (IS_ERR_OR_NULL(bp_base))
-		return PTR_ERR(bp_base);
+	ret = __pkvm_create_private_mapping(phys, __BP_HARDEN_HYP_VECS_SZ,
+					    PAGE_HYP_EXEC, &bp_base);
+	if (ret)
+		return ret;
 
-	__hyp_bp_vect_base = bp_base;
+	__hyp_bp_vect_base = (void *)bp_base;
 
 	return 0;
 }