diff --git a/hypervisor/arch/x86/guest/vmexit.c b/hypervisor/arch/x86/guest/vmexit.c
index 9f35941b6..9917c2ece 100644
--- a/hypervisor/arch/x86/guest/vmexit.c
+++ b/hypervisor/arch/x86/guest/vmexit.c
@@ -384,7 +384,7 @@ static int32_t wbinvd_vmexit_handler(struct acrn_vcpu *vcpu)
 	struct acrn_vcpu *other;
 
 	/* GUEST_FLAG_RT has not set in post-launched RTVM before it has been created */
-	if ((is_psram_initialized) || (has_rt_vm() == false)) {
+	if ((!is_psram_initialized) && (has_rt_vm() == false)) {
 		cache_flush_invalidate_all();
 	} else {
 		if (is_rt_vm(vcpu->vm)) {
diff --git a/hypervisor/common/hypercall.c b/hypervisor/common/hypercall.c
index e2bc08cb8..ed3f90647 100644
--- a/hypervisor/common/hypercall.c
+++ b/hypervisor/common/hypercall.c
@@ -22,6 +22,7 @@
 #include <mmio_dev.h>
 #include <ivshmem.h>
 #include <vmcs9900.h>
+#include <ptcm.h>
 
 #define DBG_LEVEL_HYCALL	6U
 
@@ -577,6 +578,16 @@ static int32_t add_vm_memory_region(struct acrn_vm *vm, struct acrn_vm *target_v
 			} else {
 				prot |= EPT_UNCACHED;
 			}
+			/* If pSRAM is initialized, and HV received a request to map pSRAM area to guest,
+			 * we should add EPT_WB flag to make pSRAM effective.
+			 * Assumption: SOS must assign the PSRAM area as a whole and as a separate memory
+			 * region whose base address is PSRAM_BASE_HPA
+			 * TODO: We can enforce WB for any region has overlap with pSRAM, for simplicity,
+			 * and leave it to SOS to make sure it won't violate.
+			 */
+			if (hpa == PSRAM_BASE_HPA && is_psram_initialized == true) {
+				prot |= EPT_WB;
+			}
 			/* create gpa to hpa EPT mapping */
 			ept_add_mr(target_vm, pml4_page, hpa,
 					region->gpa, region->size, prot);