hv:fix rtvm hang with maxcpus=0/1 in bootargs

RTVM (with lapic PT) boots hang when maxcpus is
 assigned a value less than the CPU number configured
 in hypervisor.

 In this case, vlapic_state(per VM) is left in TRANSITION
 state after BSP boot, which blocks interupts to be injected
 to this UOS.

Tracked-On: #4803
Signed-off-by: Yonghua Huang <yonghua.huang@intel.com>
Reviewed-by: Li, Fei <fei1.li@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>

hypervisor/arch/x86/guest/vcpu.c

@@ -513,7 +513,7 @@ int32_t create_vcpu(uint16_t pcpu_id, struct acrn_vm *vm, struct acrn_vcpu **rtn
 
 		/* Populate the return handle */
 		*rtn_vcpu_handle = vcpu;
-		vcpu->state = VCPU_INIT;
+		vcpu_set_state(vcpu, VCPU_INIT);
 
 		init_xsave(vcpu);
 		vcpu_reset_internal(vcpu, POWER_ON_RESET);
@@ -670,7 +670,7 @@ void offline_vcpu(struct acrn_vcpu *vcpu)
 	/* This operation must be atomic to avoid contention with posted interrupt handler */
 	per_cpu(vcpu_array, pcpuid_from_vcpu(vcpu))[vcpu->vm->vm_id] = NULL;
 
-	vcpu->state = VCPU_OFFLINE;
+	vcpu_set_state(vcpu, VCPU_OFFLINE);
 }
 
 void kick_vcpu(const struct acrn_vcpu *vcpu)
@@ -716,7 +716,7 @@ void reset_vcpu(struct acrn_vcpu *vcpu, enum reset_mode mode)
 	pr_dbg("vcpu%hu reset", vcpu->vcpu_id);
 
 	vcpu_reset_internal(vcpu, mode);
-	vcpu->state = VCPU_INIT;
+	vcpu_set_state(vcpu, VCPU_INIT);
 }
 
 void pause_vcpu(struct acrn_vcpu *vcpu, enum vcpu_state new_state)
@@ -727,7 +727,7 @@ void pause_vcpu(struct acrn_vcpu *vcpu, enum vcpu_state new_state)
 
 	if (((vcpu->state == VCPU_RUNNING) || (vcpu->state == VCPU_INIT)) && (new_state == VCPU_ZOMBIE)) {
 		vcpu->prev_state = vcpu->state;
-		vcpu->state = new_state;
+		vcpu_set_state(vcpu, new_state);
 
 		if (vcpu->prev_state == VCPU_RUNNING) {
 			sleep_thread(&vcpu->thread_obj);
@@ -747,7 +747,7 @@ int32_t resume_vcpu(struct acrn_vcpu *vcpu)
 	pr_dbg("vcpu%hu resumed", vcpu->vcpu_id);
 
 	if (vcpu->state == VCPU_PAUSED) {
-		vcpu->state = vcpu->prev_state;
+		vcpu_set_state(vcpu, vcpu->prev_state);
 		if (vcpu->state == VCPU_RUNNING) {
 			wake_thread(&vcpu->thread_obj);
 		}
@@ -818,7 +818,7 @@ void launch_vcpu(struct acrn_vcpu *vcpu)
 	uint16_t pcpu_id = pcpuid_from_vcpu(vcpu);
 
 	pr_dbg("vcpu%hu scheduled on pcpu%hu", vcpu->vcpu_id, pcpu_id);
-	vcpu->state = VCPU_RUNNING;
+	vcpu_set_state(vcpu, VCPU_RUNNING);
 	wake_thread(&vcpu->thread_obj);
 
 }
@@ -922,3 +922,17 @@ void vcpu_handle_pi_notification(uint32_t vcpu_index)
 		}
 	}
 }
+
+/*
+ * @brief Update the state of vCPU and state of vlapic
+ *
+ * The vlapic state of VM shall be updated for some vCPU
+ * state update cases, such as from VCPU_INIT to VCPU_RUNNING.
+
+ * @pre (vcpu != NULL)
+ */
+void vcpu_set_state(struct acrn_vcpu *vcpu, enum vcpu_state new_state)
+{
+	vcpu->state = new_state;
+	update_vm_vlapic_state(vcpu->vm);
+}

hypervisor/arch/x86/guest/vlapic.c

@@ -1135,6 +1135,7 @@ vlapic_process_init_sipi(struct acrn_vcpu* target_vcpu, uint32_t mode, uint32_t
 				pr_err("Start Secondary VCPU%hu for VM[%d]...",
 					target_vcpu->vcpu_id,
 					target_vcpu->vm->vm_id);
+
 				set_vcpu_startup_entry(target_vcpu, (icr_low & APIC_VECTOR_MASK) << 12U);
 				vcpu_make_request(target_vcpu, ACRN_REQUEST_INIT_VMCS);
 				launch_vcpu(target_vcpu);

hypervisor/arch/x86/guest/vm.c

@@ -801,9 +801,6 @@ void launch_vms(uint16_t pcpu_id)
  * VM_VLAPIC_DISABLED - All the online vCPUs/vLAPICs of this VM are in Disabled mode
  * VM_VLAPIC_TRANSITION - Online vCPUs/vLAPICs of this VM are in between transistion
  *
- * TODO: offline_vcpu need to call this API to reflect the status of rest of the
- * vLAPICs that are online.
- *
  * @pre vm != NULL
  */
 void update_vm_vlapic_state(struct acrn_vm *vm)
@@ -817,14 +814,17 @@ void update_vm_vlapic_state(struct acrn_vm *vm)
 	vcpus_in_xapic = 0U;
 	spinlock_obtain(&vm->vm_lock);
 	foreach_vcpu(i, vm, vcpu) {
-		if (is_x2apic_enabled(vcpu_vlapic(vcpu))) {
+		/* Skip vCPU in state outside of VCPU_RUNNING as it may be offline. */
-			vcpus_in_x2apic++;
+		if (vcpu->state == VCPU_RUNNING) {
-		} else if (is_xapic_enabled(vcpu_vlapic(vcpu))) {
+			if (is_x2apic_enabled(vcpu_vlapic(vcpu))) {
-			vcpus_in_xapic++;
+				vcpus_in_x2apic++;
-		} else {
+			} else if (is_xapic_enabled(vcpu_vlapic(vcpu))) {
-			/*
+				vcpus_in_xapic++;
-			 * vCPU is using vLAPIC in Disabled mode
+			} else {
-			 */
+				/*
+				 * vCPU is using vLAPIC in Disabled mode
+				 */
+			}
 		}
 	}
 

hypervisor/include/arch/x86/guest/vcpu.h

@@ -715,6 +715,17 @@ bool is_lapic_pt_enabled(struct acrn_vcpu *vcpu);
  * @return None
  */
 void vcpu_handle_pi_notification(uint32_t vcpu_index);
+
+/*
+ * @brief Update the state of vCPU and state of vlapic
+ *
+ * The vlapic state of VM shall be updated for some vCPU
+ * state update cases, such as from VCPU_INIT to VCPU_RUNNING.
+
+ * @pre (vcpu != NULL)
+ */
+void vcpu_set_state(struct acrn_vcpu *vcpu, enum vcpu_state new_state);
+
 /**
  * @}
  */