HV: refine reset_vcpu api

The patch abstract a vcpu_reset_internal() api for internal usage, the
function would not touch any vcpu state transition and just do vcpu reset
processing. It will be called by create_vcpu() and reset_vcpu().

The reset_vcpu() will act as a public api and should be called
only when vcpu receive INIT or vm reset/resume from S3. It should not be
called when do shutdown_vm() or hcall_sos_offline_cpu(), so the patch remove
reset_vcpu() in shutdown_vm() and hcall_sos_offline_cpu().

The patch also introduced reset_mode enum so that vcpu and vlapic could do
different context operation according to different reset mode;

Tracked-On: #4267

Signed-off-by: Victor Sun <victor.sun@intel.com>
Reviewed-by: Jason Chen CJ <jason.cj.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>

hypervisor/arch/x86/guest/vcpu.c

@@ -193,6 +193,35 @@ void vcpu_reset_eoi_exit_bitmaps(struct acrn_vcpu *vcpu)
 	vcpu_make_request(vcpu, ACRN_REQUEST_EOI_EXIT_BITMAP_UPDATE);
 }
 
+/* As a vcpu reset internal API, DO NOT touch any vcpu state transition in this function. */
+static void vcpu_reset_internal(struct acrn_vcpu *vcpu, __unused enum reset_mode mode)
+{
+	int32_t i;
+	struct acrn_vlapic *vlapic;
+
+	vcpu->launched = false;
+	vcpu->running = false;
+	vcpu->arch.nr_sipi = 0U;
+
+	vcpu->arch.exception_info.exception = VECTOR_INVALID;
+	vcpu->arch.cur_context = NORMAL_WORLD;
+	vcpu->arch.irq_window_enabled = false;
+	(void)memset((void *)vcpu->arch.vmcs, 0U, PAGE_SIZE);
+
+	for (i = 0; i < NR_WORLD; i++) {
+		(void)memset((void *)(&vcpu->arch.contexts[i]), 0U,
+			sizeof(struct run_context));
+	}
+
+	/* TODO: we may need to add one scheduler->reset_data to reset the thread_obj */
+	vcpu->thread_obj.notify_mode = SCHED_NOTIFY_IPI;
+
+	vlapic = vcpu_vlapic(vcpu);
+	vlapic_reset(vlapic, apicv_ops);
+
+	reset_vcpu_regs(vcpu);
+}
+
 struct acrn_vcpu *get_running_vcpu(uint16_t pcpu_id)
 {
 	struct thread_object *curr = sched_get_current(pcpu_id);
@@ -445,12 +474,6 @@ int32_t create_vcpu(uint16_t pcpu_id, struct acrn_vm *vm, struct acrn_vcpu **rtn
 		 */
 		vcpu->arch.vpid = 1U + (vm->vm_id * MAX_VCPUS_PER_VM) + vcpu->vcpu_id;
 
-		/* Initialize exception field in VCPU context */
-		vcpu->arch.exception_info.exception = VECTOR_INVALID;
-
-		/* Initialize cur context */
-		vcpu->arch.cur_context = NORMAL_WORLD;
-
 		/* Create per vcpu vlapic */
 		vlapic_create(vcpu);
 
@@ -460,14 +483,10 @@ 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->launched = false;
-		vcpu->running = false;
-		vcpu->arch.nr_sipi = 0U;
 		vcpu->state = VCPU_INIT;
 
 		init_xsave(vcpu);
-		reset_vcpu_regs(vcpu);
+		vcpu_reset_internal(vcpu, POWER_ON_RESET);
 		(void)memset((void *)&vcpu->req, 0U, sizeof(struct io_request));
 		vm->hw.created_vcpus++;
 		ret = 0;
@@ -655,40 +674,15 @@ static uint64_t build_stack_frame(struct acrn_vcpu *vcpu)
 /* NOTE:
  * vcpu should be paused before call this function.
  */
-void reset_vcpu(struct acrn_vcpu *vcpu)
+void reset_vcpu(struct acrn_vcpu *vcpu, enum reset_mode mode)
 {
-	int32_t i;
-	struct acrn_vlapic *vlapic;
-
 	pr_dbg("vcpu%hu reset", vcpu->vcpu_id);
 	ASSERT(vcpu->state != VCPU_RUNNING,
 			"reset vcpu when it's running");
 
 	if (vcpu->state != VCPU_INIT) {
+		vcpu_reset_internal(vcpu, mode);
 		vcpu->state = VCPU_INIT;
-
-		vcpu->launched = false;
-		vcpu->running = false;
-		vcpu->arch.nr_sipi = 0U;
-
-		vcpu->arch.exception_info.exception = VECTOR_INVALID;
-		vcpu->arch.cur_context = NORMAL_WORLD;
-		vcpu->arch.irq_window_enabled = false;
-		(void)memset((void *)vcpu->arch.vmcs, 0U, PAGE_SIZE);
-
-		for (i = 0; i < NR_WORLD; i++) {
-			(void)memset((void *)(&vcpu->arch.contexts[i]), 0U,
-				sizeof(struct run_context));
-		}
-		vcpu->arch.cur_context = NORMAL_WORLD;
-
-		/* TODO: we may need to add one scheduler->reset_data to reset the thread_obj */
-		vcpu->thread_obj.notify_mode = SCHED_NOTIFY_IPI;
-
-		vlapic = vcpu_vlapic(vcpu);
-		vlapic_reset(vlapic, apicv_ops);
-
-		reset_vcpu_regs(vcpu);
 	}
 }
 
@@ -806,7 +800,7 @@ int32_t prepare_vcpu(struct acrn_vm *vm, uint16_t pcpu_id)
 		vcpu->thread_obj.sched_ctl = &per_cpu(sched_ctl, pcpu_id);
 		vcpu->thread_obj.thread_entry = vcpu_thread;
 		vcpu->thread_obj.pcpu_id = pcpu_id;
-		vcpu->thread_obj.notify_mode = SCHED_NOTIFY_IPI;
+		/* vcpu->thread_obj.notify_mode is initialized in vcpu_reset_internal() when create vcpu */
 		vcpu->thread_obj.host_sp = build_stack_frame(vcpu);
 		vcpu->thread_obj.switch_out = context_switch_out;
 		vcpu->thread_obj.switch_in = context_switch_in;

hypervisor/arch/x86/guest/vlapic.c

@@ -1163,7 +1163,7 @@ vlapic_process_init_sipi(struct acrn_vcpu* target_vcpu, uint32_t mode, uint32_t
 
 			/* put target vcpu to INIT state and wait for SIPI */
 			pause_vcpu(target_vcpu, VCPU_PAUSED);
-			reset_vcpu(target_vcpu);
+			reset_vcpu(target_vcpu, INIT_RESET);
 			/* new cpu model only need one SIPI to kick AP run,
 			 * the second SIPI will be ignored as it move out of
 			 * wait-for-SIPI state.
@@ -1686,8 +1686,6 @@ void
 vlapic_init(struct acrn_vlapic *vlapic)
 {
 	vlapic_init_timer(vlapic);
-
-	vlapic_reset(vlapic, apicv_ops);
 }
 
 void vlapic_restore(struct acrn_vlapic *vlapic, const struct lapic_regs *regs)

hypervisor/arch/x86/guest/vm.c

@@ -650,7 +650,6 @@ int32_t shutdown_vm(struct acrn_vm *vm)
 		}
 
 		foreach_vcpu(i, vm, vcpu) {
-			reset_vcpu(vcpu);
 			offline_vcpu(vcpu);
 
 			if (bitmap_test(pcpuid_from_vcpu(vcpu), &mask)) {
@@ -737,7 +736,7 @@ int32_t reset_vm(struct acrn_vm *vm)
 		}
 
 		foreach_vcpu(i, vm, vcpu) {
-			reset_vcpu(vcpu);
+			reset_vcpu(vcpu, COLD_RESET);
 
 			if (bitmap_test(pcpuid_from_vcpu(vcpu), &mask)) {
 				make_pcpu_offline(pcpuid_from_vcpu(vcpu));
@@ -824,7 +823,7 @@ void resume_vm_from_s3(struct acrn_vm *vm, uint32_t wakeup_vec)
 
 	vm->state = VM_STARTED;
 
-	reset_vcpu(bsp);
+	reset_vcpu(bsp, POWER_ON_RESET);
 
 	/* When SOS resume from S3, it will return to real mode
 	 * with entry set to wakeup_vec.

hypervisor/common/hypercall.c

@@ -64,7 +64,6 @@ int32_t hcall_sos_offline_cpu(struct acrn_vm *vm, uint64_t lapicid)
 				break;
 			}
 			pause_vcpu(vcpu, VCPU_ZOMBIE);
-			reset_vcpu(vcpu);
 			offline_vcpu(vcpu);
 		}
 	}

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

@@ -146,6 +146,7 @@ enum vm_cpu_mode {
 	CPU_MODE_64BIT,			/* IA-32E mode (CS.L = 1) */
 };
 
+enum reset_mode;
 
 /* 2 worlds: 0 for Normal World, 1 for Secure World */
 #define NR_WORLD	2
@@ -600,10 +601,11 @@ void offline_vcpu(struct acrn_vcpu *vcpu);
  * Reset all fields in a vCPU instance, the vCPU state is reset to VCPU_INIT.
  *
  * @param[inout] vcpu pointer to vcpu data structure
+ * @param[in] mode the reset mode
  *
  * @return None
  */
-void reset_vcpu(struct acrn_vcpu *vcpu);
+void reset_vcpu(struct acrn_vcpu *vcpu, enum reset_mode mode);
 
 /**
  * @brief pause the vcpu and set new state

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

@@ -30,6 +30,14 @@
 #include <hyperv.h>
 #endif
 
+enum reset_mode {
+	POWER_ON_RESET,		/* reset by hardware Power-on */
+	COLD_RESET,		/* hardware cold reset */
+	WARM_RESET,		/* behavior slightly differ from cold reset, that some MSRs might be retained. */
+	INIT_RESET,		/* reset by INIT */
+	SOFTWARE_RESET,		/* reset by software disable<->enable */
+};
+
 struct vm_hw_info {
 	/* vcpu array of this VM */
 	struct acrn_vcpu vcpu_array[MAX_VCPUS_PER_VM];