diff --git a/drivers/virt/coco/pkvm-guest/arm-pkvm-guest.c b/drivers/virt/coco/pkvm-guest/arm-pkvm-guest.c
index e90e347ed457..9f8ada6dbbbd 100644
--- a/drivers/virt/coco/pkvm-guest/arm-pkvm-guest.c
+++ b/drivers/virt/coco/pkvm-guest/arm-pkvm-guest.c
@@ -63,6 +63,9 @@ static int arm_smccc_do_range(u32 func_id, phys_addr_t phys, int numpages,
 	size_t size = numpages * PAGE_SIZE;
 	int numgranules;
 
+	if (!IS_ALIGNED(phys, pkvm_granule))
+		return -EINVAL;
+
 	numgranules = DIV_ROUND_UP(size, pkvm_granule);
 	phys = ALIGN_DOWN(phys, pkvm_granule);
 
@@ -74,12 +77,18 @@ static int arm_smccc_do_range(u32 func_id, phys_addr_t phys, int numpages,
 
 static int pkvm_set_memory_encrypted(unsigned long addr, int numpages)
 {
+	if (!IS_ALIGNED(numpages * PAGE_SIZE, pkvm_granule))
+		return -EINVAL;
+
 	return arm_smccc_do_range(ARM_SMCCC_VENDOR_HYP_KVM_MEM_UNSHARE_FUNC_ID,
 				  virt_to_phys((void *)addr), numpages, pkvm_func_range);
 }
 
 static int pkvm_set_memory_decrypted(unsigned long addr, int numpages)
 {
+	if (!IS_ALIGNED(numpages * PAGE_SIZE, pkvm_granule))
+		return -EINVAL;
+
 	return arm_smccc_do_range(ARM_SMCCC_VENDOR_HYP_KVM_MEM_SHARE_FUNC_ID,
 				  virt_to_phys((void *)addr), numpages, pkvm_func_range);
 }
@@ -153,7 +162,7 @@ void pkvm_init_hyp_services(void)
 
 	arm_smccc_1_1_invoke(ARM_SMCCC_VENDOR_HYP_KVM_HYP_MEMINFO_FUNC_ID,
 			     0, 0, 0, &res);
-	if (res.a0 > PAGE_SIZE) /* Includes error codes */
+	if ((long)res.a0 < 0)
 		return;
 
 	pkvm_granule = res.a0;