diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 097356603e13fa0036f77fff1500e2e1b6de96c0..23fe0fd3fe74b912592ae3d8374f8c2ad8ee5002 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -234,6 +234,7 @@ config ARM64
 	select HAVE_KRETPROBES
 	select HAVE_GENERIC_VDSO
 	select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU
+	select HOTPLUG_SMT if (SMP && HOTPLUG_CPU)
 	select IRQ_DOMAIN
 	select IRQ_FORCED_THREADING
 	select KASAN_VMALLOC if KASAN
diff --git a/arch/arm64/configs/openeuler_defconfig b/arch/arm64/configs/openeuler_defconfig
index 597c09d37bf8dc2c36f192a1d70775681b3dec9d..b80368a02d838e3f350bf80a21fb5e2314d7d8fb 100644
--- a/arch/arm64/configs/openeuler_defconfig
+++ b/arch/arm64/configs/openeuler_defconfig
@@ -708,6 +708,7 @@ CONFIG_KVM=y
 #
 # General architecture-dependent options
 #
+CONFIG_HOTPLUG_SMT=y
 CONFIG_HOTPLUG_CORE_SYNC=y
 CONFIG_HOTPLUG_CORE_SYNC_DEAD=y
 CONFIG_KPROBES=y
diff --git a/arch/arm64/kernel/topology.c b/arch/arm64/kernel/topology.c
index 817d788cd86669439cf4b55af45214f016cc5efb..0dc360c32ec82d68d68c6b741588fb9089b43ac9 100644
--- a/arch/arm64/kernel/topology.c
+++ b/arch/arm64/kernel/topology.c
@@ -17,6 +17,7 @@
 #include <linux/cpufreq.h>
 #include <linux/init.h>
 #include <linux/percpu.h>
+#include <linux/xarray.h>
 
 #include <asm/cpu.h>
 #include <asm/cputype.h>
@@ -43,11 +44,16 @@ static bool __init acpi_cpu_is_threaded(int cpu)
  */
 int __init parse_acpi_topology(void)
 {
+	int thread_num, max_smt_thread_num = 1;
+	struct xarray core_threads;
 	int cpu, topology_id;
+	void *entry;
 
 	if (acpi_disabled)
 		return 0;
 
+	xa_init(&core_threads);
+
 	for_each_possible_cpu(cpu) {
 		topology_id = find_acpi_cpu_topology(cpu, 0);
 		if (topology_id < 0)
@@ -57,6 +63,20 @@ int __init parse_acpi_topology(void)
 			cpu_topology[cpu].thread_id = topology_id;
 			topology_id = find_acpi_cpu_topology(cpu, 1);
 			cpu_topology[cpu].core_id   = topology_id;
+
+			entry = xa_load(&core_threads, topology_id);
+			if (!entry) {
+				xa_store(&core_threads, topology_id,
+					 xa_mk_value(1), GFP_KERNEL);
+			} else {
+				thread_num = xa_to_value(entry);
+				thread_num++;
+				xa_store(&core_threads, topology_id,
+					 xa_mk_value(thread_num), GFP_KERNEL);
+
+				if (thread_num > max_smt_thread_num)
+					max_smt_thread_num = thread_num;
+			}
 		} else {
 			cpu_topology[cpu].thread_id  = -1;
 			cpu_topology[cpu].core_id    = topology_id;
@@ -67,6 +87,9 @@ int __init parse_acpi_topology(void)
 		cpu_topology[cpu].package_id = topology_id;
 	}
 
+	topology_smt_set_num_threads(max_smt_thread_num);
+
+	xa_destroy(&core_threads);
 	return 0;
 }
 #endif
diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c
index b741b5ba82bd6e53c216e9338cec8bfdd0dd3e27..252a436e0c1b7382a5351115012f7bb6415e98e0 100644
--- a/drivers/base/arch_topology.c
+++ b/drivers/base/arch_topology.c
@@ -526,6 +526,13 @@ static int __init parse_core(struct device_node *core, int package_id,
 		i++;
 	} while (t);
 
+	/*
+	 * We've already gotten threads number in this core, update the SMT
+	 * threads number when necessary.
+	 */
+	if (i > topology_smt_get_num_threads())
+		topology_smt_set_num_threads(i);
+
 	cpu = get_cpu_for_node(core);
 	if (cpu >= 0) {
 		if (!leaf) {
@@ -729,6 +736,36 @@ const struct cpumask *cpu_clustergroup_mask(int cpu)
 	return &cpu_topology[cpu].cluster_sibling;
 }
 
+#ifdef CONFIG_HOTPLUG_SMT
+
+/* Maximum threads number per-Core */
+static unsigned int topology_smt_num_threads = 1;
+
+void __init topology_smt_set_num_threads(unsigned int num_threads)
+{
+	topology_smt_num_threads = num_threads;
+}
+
+unsigned int __init topology_smt_get_num_threads(void)
+{
+	return topology_smt_num_threads;
+}
+
+/*
+ * On SMT Hotplug the primary thread of the SMT won't be disabled. For x86 they
+ * seem to have a primary thread for special purpose. For other arthitectures
+ * like arm64 there's no such restriction for a primary thread, so make the
+ * first thread in the SMT as the primary thread.
+ */
+bool topology_is_primary_thread(unsigned int cpu)
+{
+	if (cpu == cpumask_first(topology_sibling_cpumask(cpu)))
+		return true;
+
+	return false;
+}
+#endif
+
 void update_siblings_masks(unsigned int cpuid)
 {
 	struct cpu_topology *cpu_topo, *cpuid_topo = &cpu_topology[cpuid];
@@ -841,6 +878,14 @@ void __init init_cpu_topology(void)
 		reset_cpu_topology();
 	}
 
+	/*
+	 * By this stage we get to know whether we support SMT or not, update
+	 * the information for the core. We don't support
+	 * CONFIG_SMT_NUM_THREADS_DYNAMIC so make the max_threads == num_threads.
+	 */
+	cpu_smt_set_num_threads(topology_smt_get_num_threads(),
+				topology_smt_get_num_threads());
+
 	for_each_possible_cpu(cpu) {
 		ret = fetch_cache_info(cpu);
 		if (!ret)
diff --git a/include/linux/arch_topology.h b/include/linux/arch_topology.h
index a07b510e7dc55960e83dca5542f9e937925c66d9..0367f3a61838a1104fac125fabc01ec9d59a745b 100644
--- a/include/linux/arch_topology.h
+++ b/include/linux/arch_topology.h
@@ -92,6 +92,20 @@ void update_siblings_masks(unsigned int cpu);
 void remove_cpu_topology(unsigned int cpuid);
 void reset_cpu_topology(void);
 int parse_acpi_topology(void);
+
+#ifdef CONFIG_HOTPLUG_SMT
+bool topology_is_primary_thread(unsigned int cpu);
+void topology_smt_set_num_threads(unsigned int num_threads);
+unsigned int topology_smt_get_num_threads(void);
+#else
+static inline bool topology_is_primary_thread(unsigned int cpu) { return false; }
+static inline void topology_smt_set_num_threads(unsigned int num_threads) { }
+static inline unsigned int topology_smt_get_num_threads(void)
+{
+	return 1;
+}
+#endif
+
 #endif
 
 #endif /* _LINUX_ARCH_TOPOLOGY_H_ */