diff --git a/hypervisor/arch/x86/guest/vm_reset.c b/hypervisor/arch/x86/guest/vm_reset.c
index 8f7e1f701..a15de301e 100644
--- a/hypervisor/arch/x86/guest/vm_reset.c
+++ b/hypervisor/arch/x86/guest/vm_reset.c
@@ -95,7 +95,7 @@ static bool handle_reset_reg_read(struct acrn_vcpu *vcpu, __unused uint16_t addr
 /**
  * @pre vm != NULL
  */
-static bool handle_common_reset_reg_write(struct acrn_vcpu *vcpu, bool reset)
+static bool handle_common_reset_reg_write(struct acrn_vcpu *vcpu, bool reset, bool warm)
 {
 	struct acrn_vm *vm = vcpu->vm;
 	bool ret = true;
@@ -105,7 +105,7 @@ static bool handle_common_reset_reg_write(struct acrn_vcpu *vcpu, bool reset)
 		poweroff_if_rt_vm(vm);
 
 		if (get_highest_severity_vm(true) == vm) {
-			reset_host();
+			reset_host(warm);
 		} else if (is_postlaunched_vm(vm)) {
 			/* re-inject to DM */
 			ret = false;
@@ -142,7 +142,7 @@ static bool handle_common_reset_reg_write(struct acrn_vcpu *vcpu, bool reset)
 static bool handle_kb_write(struct acrn_vcpu *vcpu, __unused uint16_t addr, size_t bytes, uint32_t val)
 {
 	/* ignore commands other than system reset */
-	return handle_common_reset_reg_write(vcpu, ((bytes == 1U) && (val == 0xfeU)));
+	return handle_common_reset_reg_write(vcpu, ((bytes == 1U) && (val == 0xfeU)), false);
 }
 
 static bool handle_kb_read(struct acrn_vcpu *vcpu, uint16_t addr, size_t bytes)
@@ -172,9 +172,9 @@ static bool handle_kb_read(struct acrn_vcpu *vcpu, uint16_t addr, size_t bytes)
  */
 static bool handle_cf9_write(struct acrn_vcpu *vcpu, __unused uint16_t addr, size_t bytes, uint32_t val)
 {
-	/* We don't differentiate among hard/soft/warm/cold reset */
 	return handle_common_reset_reg_write(vcpu,
-			((bytes == 1U) && ((val & 0x4U) == 0x4U) && ((val & 0xaU) != 0U)));
+			((bytes == 1U) && ((val & 0x4U) == 0x4U) && ((val & 0xaU) != 0U)),
+			((val & 0x8U) == 0U));
 }
 
 /**
@@ -189,7 +189,7 @@ static bool handle_reset_reg_write(struct acrn_vcpu *vcpu, uint16_t addr, size_t
 		struct acpi_reset_reg *reset_reg = get_host_reset_reg_data();
 
 		if (val == reset_reg->val) {
-			ret = handle_common_reset_reg_write(vcpu, true);
+			ret = handle_common_reset_reg_write(vcpu, true, false);
 		} else {
 			/*
 			 * ACPI defines the reset value but doesn't specify the meaning of other values.
diff --git a/hypervisor/arch/x86/pm.c b/hypervisor/arch/x86/pm.c
index 33705f7c7..3fb634d15 100644
--- a/hypervisor/arch/x86/pm.c
+++ b/hypervisor/arch/x86/pm.c
@@ -244,10 +244,10 @@ void host_enter_s3(const struct pm_s_state_data *sstate_data, uint32_t pm1a_cnt_
 	resume_console();
 }
 
-void reset_host(void)
+void reset_host(bool warm)
 {
 	struct acrn_acpi_generic_address *gas = &(host_reset_reg.reg);
-
+	uint8_t reboot_code = warm ? CF9_RESET_WARM : CF9_RESET_COLD;
 
 	/* TODO: gracefully shut down all guests before doing host reset. */
 
@@ -256,11 +256,6 @@ void reset_host(void)
 	 * The platform we are running must support at least one of reset method:
 	 *   - ACPI reset
 	 *   - 0xcf9 reset
-	 *
-	 * UEFI more likely sets the reset value as 0x6 (not 0xe) for 0xcf9 port.
-	 * This asserts PLTRST# to reset devices on the platform, but not the
-	 * SLP_S3#/4#/5# signals, which power down the systems. This might not be
-	 * enough for us.
 	 */
 	if ((gas->space_id == SPACE_SYSTEM_IO) &&
 		(gas->bit_width == 8U) && (gas->bit_offset == 0U) &&
@@ -270,7 +265,8 @@ void reset_host(void)
 		/* making sure bit 2 (RST_CPU) is '0', when the reset command is issued. */
 		pio_write8(0x2U, 0xcf9U);
 		udelay(50U);
-		pio_write8(0xeU, 0xcf9U);
+		pio_write8(reboot_code, 0xcf9U);
+		udelay(50U);
 	}
 
 	pr_fatal("%s(): can't reset host.", __func__);
diff --git a/hypervisor/debug/shell.c b/hypervisor/debug/shell.c
index fb850755e..cc3a7d5c6 100644
--- a/hypervisor/debug/shell.c
+++ b/hypervisor/debug/shell.c
@@ -1531,7 +1531,7 @@ static int32_t shell_cpuid(int32_t argc, char **argv)
 
 static int32_t shell_reboot(__unused int32_t argc, __unused char **argv)
 {
-	reset_host();
+	reset_host(false);
 	return 0;
 }
 
diff --git a/hypervisor/include/arch/x86/asm/host_pm.h b/hypervisor/include/arch/x86/asm/host_pm.h
index 6ee25e582..d70f504db 100644
--- a/hypervisor/include/arch/x86/asm/host_pm.h
+++ b/hypervisor/include/arch/x86/asm/host_pm.h
@@ -12,6 +12,9 @@
 #define	BIT_SLP_EN	13U
 #define	BIT_WAK_STS	15U
 
+#define CF9_RESET_WARM	0x6
+#define CF9_RESET_COLD	0xE
+
 struct cpu_state_info {
 	uint8_t			 	px_cnt;	/* count of all Px states */
 	const struct acrn_pstate_data	*px_data;
@@ -38,7 +41,7 @@ extern void asm_enter_s3(const struct pm_s_state_data *sstate_data, uint32_t pm1
 extern void restore_s3_context(void);
 struct cpu_state_info *get_cpu_pm_state_info(void);
 struct acpi_reset_reg *get_host_reset_reg_data(void);
-void reset_host(void);
+void reset_host(bool warm);
 void init_frequency_policy(void);
 void apply_frequency_policy(void);