hv: Do not reset vcpu thread's stack when reset_vcpu

vcpu thread's stack shouldn't follow reset_vcpu to reset.
There is also a bug here:
while vcpu B thread set vcpu->running to false, other vcpu A thread
will treat the vcpu B is paused while it has not been switch out
completely, then reset_vcpu will reset the vcpu B thread's stack and
corrupt its running context.

This patch will remove the vcpu thread's stack reset from reset_vcpu.
With the change, we need do init_vmcs between vcpu startup address be
settled and scheduled in. And switch_to_idle() is not needed anymore
as S3 thread's stack will not be reset.

Tracked-On: #3813
Signed-off-by: Fengwei Yin <fengwei.yin@intel.com>
Signed-off-by: Shuo A Liu <shuo.a.liu@intel.com>

Author: Shuo A Liu

hypervisor/arch/x86/guest/vcpu.c

@@ -639,7 +639,6 @@ void reset_vcpu(struct acrn_vcpu *vcpu)
 		vcpu->arch.exception_info.exception = VECTOR_INVALID;
 		vcpu->arch.cur_context = NORMAL_WORLD;
 		vcpu->arch.irq_window_enabled = false;
-		vcpu->thread_obj.host_sp = build_stack_frame(vcpu);
 		(void)memset((void *)vcpu->arch.vmcs, 0U, PAGE_SIZE);
 
 		for (i = 0; i < NR_WORLD; i++) {

hypervisor/arch/x86/guest/vlapic.c

@@ -1170,6 +1170,8 @@ vlapic_process_init_sipi(struct acrn_vcpu* target_vcpu, uint32_t mode, uint32_t
 					target_vcpu->vcpu_id,
 					target_vcpu->vm->vm_id);
 				set_vcpu_startup_entry(target_vcpu, (icr_low & APIC_VECTOR_MASK) << 12U);
+				/* init vmcs after set_vcpu_startup_entry */
+				init_vmcs(target_vcpu);
 				schedule_vcpu(target_vcpu);
 			}
 		}

hypervisor/arch/x86/guest/vm.c

@@ -647,6 +647,7 @@ void start_vm(struct acrn_vm *vm)
 
 	/* Only start BSP (vid = 0) and let BSP start other APs */
 	bsp = vcpu_from_vid(vm, BOOT_CPU_ID);
+	init_vmcs(bsp);
 	schedule_vcpu(bsp);
 }
 
@@ -772,7 +773,6 @@ void resume_vm_from_s3(struct acrn_vm *vm, uint32_t wakeup_vec)
 
 	init_vmcs(bsp);
 	schedule_vcpu(bsp);
-	switch_to_idle(default_idle);
 }
 
 /**

hypervisor/arch/x86/guest/vmcs.c

@@ -496,10 +496,7 @@ static void init_exit_ctrl(const struct acrn_vcpu *vcpu)
 	exec_vmwrite64(VMX_EXIT_MSR_LOAD_ADDR_FULL, hva2hpa((void *)vcpu->arch.msr_area.host));
 }
 
-/**
- * @pre vcpu != NULL
- */
-void init_vmcs(struct acrn_vcpu *vcpu)
+static void do_init_vmcs(struct acrn_vcpu *vcpu)
 {
 	uint64_t vmx_rev_id;
 	uint64_t vmcs_pa;
@@ -532,6 +529,20 @@ void init_vmcs(struct acrn_vcpu *vcpu)
 	init_exit_ctrl(vcpu);
 }
 
+/**
+ * @pre vcpu != NULL
+ */
+void init_vmcs(struct acrn_vcpu *vcpu)
+{
+	uint16_t pcpu_id = vcpu->pcpu_id;
+
+	if (pcpu_id == get_pcpu_id()) {
+		do_init_vmcs(vcpu);
+	} else {
+		smp_call_function((1UL << pcpu_id), (smp_call_func_t)do_init_vmcs, vcpu);
+	}
+}
+
 void switch_apicv_mode_x2apic(struct acrn_vcpu *vcpu)
 {
 	uint32_t value32;

hypervisor/common/hv_main.c

@@ -21,11 +21,6 @@ void vcpu_thread(struct thread_object *obj)
 	int32_t ret = 0;
 
 	do {
-		/* If vcpu is not launched, we need to do init_vmcs first */
-		if (!vcpu->launched) {
-			init_vmcs(vcpu);
-		}
-
 		if (!is_lapic_pt_enabled(vcpu)) {
 			CPU_IRQ_DISABLE();
 		}