From 81935737ff01b7ce7def5c63629ca41b62b3adbc Mon Sep 17 00:00:00 2001
From: Haiwei Li <haiwei.li@intel.com>
Date: Sat, 9 Sep 2023 05:45:42 +0800
Subject: [PATCH] hv: s3: reset vm after resume

Now only BSP is reset. After Service VM OS resumes from s3, APs'
apic_base_msr are incorrect with x2apic bit en.

To avoid incorrect states, do `reset_vm` after resume.

Tracked-On: #8623
Signed-off-by: Haiwei Li <haiwei.li@intel.com>
---
 hypervisor/arch/x86/guest/vm.c             | 11 ++++-------
 hypervisor/common/hypercall.c              |  2 +-
 hypervisor/include/arch/x86/asm/guest/vm.h |  3 ++-
 3 files changed, 7 insertions(+), 9 deletions(-)

diff --git a/hypervisor/arch/x86/guest/vm.c b/hypervisor/arch/x86/guest/vm.c
index 1ab7eb312..f4a247be8 100644
--- a/hypervisor/arch/x86/guest/vm.c
+++ b/hypervisor/arch/x86/guest/vm.c
@@ -995,7 +995,7 @@ void start_vm(struct acrn_vm *vm)
  * @pre vm != NULL
  * @pre vm->state == VM_PAUSED
  */
-int32_t reset_vm(struct acrn_vm *vm)
+int32_t reset_vm(struct acrn_vm *vm, enum reset_mode mode)
 {
 	uint16_t i;
 	uint64_t mask;
@@ -1016,7 +1016,7 @@ int32_t reset_vm(struct acrn_vm *vm)
 	 */
 	vm->arch_vm.vlapic_mode = VM_VLAPIC_XAPIC;
 
-	if (is_service_vm(vm)) {
+	if ((mode == POWER_ON_RESET) && is_service_vm(vm)) {
 		(void)prepare_os_image(vm);
 	}
 
@@ -1078,17 +1078,14 @@ void resume_vm_from_s3(struct acrn_vm *vm, uint32_t wakeup_vec)
 {
 	struct acrn_vcpu *bsp = vcpu_from_vid(vm, BSP_CPU_ID);
 
-	vm->state = VM_RUNNING;
-
-	reset_vcpu(bsp, POWER_ON_RESET);
+	reset_vm(vm, RESUME_FROM_S3);
 
 	/* When Service VM resume from S3, it will return to real mode
 	 * with entry set to wakeup_vec.
 	 */
 	set_vcpu_startup_entry(bsp, wakeup_vec);
 
-	init_vmcs(bsp);
-	launch_vcpu(bsp);
+	start_vm(vm);
 }
 
 static uint8_t loaded_pre_vm_nr = 0U;
diff --git a/hypervisor/common/hypercall.c b/hypervisor/common/hypercall.c
index 12bf26880..bf4d74d5c 100644
--- a/hypervisor/common/hypercall.c
+++ b/hypervisor/common/hypercall.c
@@ -348,7 +348,7 @@ int32_t hcall_reset_vm(__unused struct acrn_vcpu *vcpu, struct acrn_vm *target_v
 
 	if (is_paused_vm(target_vm)) {
 		/* TODO: check target_vm guest_flags */
-		ret = reset_vm(target_vm);
+		ret = reset_vm(target_vm, COLD_RESET);
 	}
 	return ret;
 }
diff --git a/hypervisor/include/arch/x86/asm/guest/vm.h b/hypervisor/include/arch/x86/asm/guest/vm.h
index 0503ed8b4..5bb5deea0 100644
--- a/hypervisor/include/arch/x86/asm/guest/vm.h
+++ b/hypervisor/include/arch/x86/asm/guest/vm.h
@@ -39,6 +39,7 @@ enum reset_mode {
 	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 */
+	RESUME_FROM_S3,		/* reset core states after resuming from S3 */
 };
 
 struct vm_hw_info {
@@ -239,7 +240,7 @@ void poweroff_if_rt_vm(struct acrn_vm *vm);
 void pause_vm(struct acrn_vm *vm);
 void resume_vm_from_s3(struct acrn_vm *vm, uint32_t wakeup_vec);
 void start_vm(struct acrn_vm *vm);
-int32_t reset_vm(struct acrn_vm *vm);
+int32_t reset_vm(struct acrn_vm *vm, enum reset_mode mode);
 int32_t create_vm(uint16_t vm_id, uint64_t pcpu_bitmap, struct acrn_vm_config *vm_config, struct acrn_vm **rtn_vm);
 int32_t prepare_vm(uint16_t vm_id, struct acrn_vm_config *vm_config);
 void launch_vms(uint16_t pcpu_id);