diff --git a/ostd/src/arch/riscv/irq/chip/mod.rs b/ostd/src/arch/riscv/irq/chip/mod.rs
index 9d1a8b4c4..42c2fd3e5 100644
--- a/ostd/src/arch/riscv/irq/chip/mod.rs
+++ b/ostd/src/arch/riscv/irq/chip/mod.rs
@@ -17,7 +17,6 @@ use crate::{
         boot::DEVICE_TREE,
         irq::{chip::plic::Plic, HwIrqLine, InterruptSource},
     },
-    cpu::CpuId,
     io::IoMemAllocatorBuilder,
     irq::IrqLine,
     sync::{LocalIrqDisabled, SpinLock},
@@ -92,9 +91,9 @@ impl IrqChip {
 
         plic.map_interrupt_source_to(interrupt_source_in_fdt.interrupt, &irq_line)?;
         plic.set_priority(interrupt_source_in_fdt.interrupt, 1);
-        // FIXME: Here we only enable external insterrupt on the BSP. We should
-        // enable it on APs as well when SMP is supported.
-        plic.set_interrupt_enabled(CpuId::bsp().into(), interrupt_source_in_fdt.interrupt, true);
+        plic.managed_harts().for_each(|hart| {
+            plic.set_interrupt_enabled(hart, interrupt_source_in_fdt.interrupt, true)
+        });
 
         Ok(MappedIrqLine {
             irq_line,
@@ -145,9 +144,8 @@ impl IrqChip {
         let InterruptSourceOnChip { index, interrupt } = &mapped_irq_line.interrupt_source_on_chip;
         let plic = &mut plics[*index];
 
-        // FIXME: Here we only disable external insterrupt on the BSP. We should
-        // disable it on APs as well when SMP is supported.
-        plic.set_interrupt_enabled(CpuId::bsp().into(), *interrupt, false);
+        plic.managed_harts()
+            .for_each(|hart| plic.set_interrupt_enabled(hart, *interrupt, false));
         plic.set_priority(*interrupt, 0);
         plic.unmap_interrupt_source(*interrupt);
     }
diff --git a/ostd/src/arch/riscv/irq/chip/plic.rs b/ostd/src/arch/riscv/irq/chip/plic.rs
index 976419460..fe46ac45a 100644
--- a/ostd/src/arch/riscv/irq/chip/plic.rs
+++ b/ostd/src/arch/riscv/irq/chip/plic.rs
@@ -108,6 +108,11 @@ impl Plic {
         unsafe { self.io_mem.write_once(offset, &interrupt_source) };
     }
 
+    /// Gets an iterator of harts managed by this PLIC.
+    pub(super) fn managed_harts(&self) -> impl Iterator<Item = u32> + use<'_> {
+        self.hart_to_target_mapping.keys().copied()
+    }
+
     /// Initializes the PLIC.
     pub(super) fn init(&mut self) {
         // Initialize priorities of all interrupt sources to 0.
@@ -115,20 +120,20 @@ impl Plic {
             self.set_priority(interrupt_source, 0);
         }
 
-        for hart in self.hart_to_target_mapping.keys() {
+        for hart in self.managed_harts() {
             // Disable all interrupt sources for all targets.
             for interrupt_source in 1..self.num_interrupt_sources() {
-                self.set_interrupt_enabled(*hart, interrupt_source, false);
+                self.set_interrupt_enabled(hart, interrupt_source, false);
             }
 
             // Set all targets' thresholds to 0 to allow all priority levels.
-            self.set_threshold(*hart, 0);
+            self.set_threshold(hart, 0);
 
             // Clear all pending claims.
-            while let irq_num = self.claim_interrupt(*hart)
+            while let irq_num = self.claim_interrupt(hart)
                 && irq_num != 0
             {
-                self.complete_interrupt(*hart, irq_num);
+                self.complete_interrupt(hart, irq_num);
             }
         }
     }
diff --git a/ostd/src/arch/riscv/irq/mod.rs b/ostd/src/arch/riscv/irq/mod.rs
index fa9e9bd8b..be70d97e6 100644
--- a/ostd/src/arch/riscv/irq/mod.rs
+++ b/ostd/src/arch/riscv/irq/mod.rs
@@ -12,7 +12,7 @@ pub(crate) use ipi::{send_ipi, HwCpuId};
 pub(crate) use ops::{disable_local, enable_local, enable_local_and_halt, is_local_enabled};
 pub(crate) use remapping::IrqRemapping;
 
-use crate::{arch::irq::chip::InterruptSourceOnChip, cpu::CpuId};
+use crate::arch::irq::chip::InterruptSourceOnChip;
 
 pub(crate) const IRQ_NUM_MIN: u8 = 0;
 pub(crate) const IRQ_NUM_MAX: u8 = 255;
@@ -51,7 +51,7 @@ impl HwIrqLine {
             InterruptSource::External(interrupt_source_on_chip) => {
                 IRQ_CHIP.get().unwrap().complete_interrupt(
                     // No races because we are in IRQs.
-                    CpuId::current_racy().into(),
+                    crate::arch::boot::smp::get_current_hart_id(),
                     *interrupt_source_on_chip,
                 );
             }
diff --git a/ostd/src/arch/riscv/trap/mod.rs b/ostd/src/arch/riscv/trap/mod.rs
index cc6428509..7e2779dad 100644
--- a/ostd/src/arch/riscv/trap/mod.rs
+++ b/ostd/src/arch/riscv/trap/mod.rs
@@ -21,7 +21,7 @@ use crate::{
         irq::{disable_local, enable_local, HwIrqLine, InterruptSource, IRQ_CHIP},
         timer::TIMER_IRQ_NUM,
     },
-    cpu::{CpuId, PrivilegeLevel},
+    cpu::PrivilegeLevel,
     ex_table::ExTable,
     irq::call_irq_callback_functions,
     mm::MAX_USERSPACE_VADDR,
@@ -115,9 +115,8 @@ pub(super) fn handle_irq(trap_frame: &TrapFrame, interrupt: Interrupt, priv_leve
             );
         }
         Interrupt::SupervisorExternal => {
-            // No races because we are in IRQs.
-            let current_cpu = CpuId::current_racy().into();
-            while let Some(hw_irq_line) = IRQ_CHIP.get().unwrap().claim_interrupt(current_cpu) {
+            let hart_id = crate::arch::boot::smp::get_current_hart_id();
+            while let Some(hw_irq_line) = IRQ_CHIP.get().unwrap().claim_interrupt(hart_id) {
                 call_irq_callback_functions(trap_frame, &hw_irq_line, priv_level);
             }
         }