diff --git a/xen/arch/ppc/Makefile b/xen/arch/ppc/Makefile
index 71feb5e2c4..655d212f66 100644
--- a/xen/arch/ppc/Makefile
+++ b/xen/arch/ppc/Makefile
@@ -4,6 +4,7 @@ obj-$(CONFIG_EARLY_PRINTK) += early_printk.init.o
 obj-y += mm-radix.o
 obj-y += opal.o
 obj-y += setup.o
+obj-y += shutdown.o
 obj-y += stubs.o
 obj-y += tlb-radix.o
 
diff --git a/xen/arch/ppc/ppc64/opal-calls.S b/xen/arch/ppc/ppc64/opal-calls.S
index cc5de75c8a..69d07909d1 100644
--- a/xen/arch/ppc/ppc64/opal-calls.S
+++ b/xen/arch/ppc/ppc64/opal-calls.S
@@ -79,3 +79,7 @@ opal_return_mmu:
 OPAL_CALL(opal_console_write, OPAL_CONSOLE_WRITE)
 OPAL_CALL(opal_console_flush, OPAL_CONSOLE_FLUSH)
 OPAL_CALL(opal_reinit_cpus, OPAL_REINIT_CPUS)
+
+OPAL_CALL(opal_cec_power_down, OPAL_CEC_POWER_DOWN)
+OPAL_CALL(opal_cec_reboot, OPAL_CEC_REBOOT)
+OPAL_CALL(opal_poll_events, OPAL_POLL_EVENTS)
diff --git a/xen/arch/ppc/setup.c b/xen/arch/ppc/setup.c
index 7fe06aa4bf..5fb5ab64e3 100644
--- a/xen/arch/ppc/setup.c
+++ b/xen/arch/ppc/setup.c
@@ -2,6 +2,8 @@
 #include <xen/init.h>
 #include <xen/lib.h>
 #include <xen/mm.h>
+#include <xen/shutdown.h>
+
 #include <public/version.h>
 #include <asm/boot.h>
 #include <asm/early_printk.h>
@@ -43,11 +45,7 @@ void __init noreturn start_xen(unsigned long r3, unsigned long r4,
 
     early_printk("Hello, ppc64le!\n");
 
-    for ( ; ; )
-        /* Set current hardware thread to very low priority */
-        HMT_very_low();
-
-    unreachable();
+    machine_halt();
 }
 
 void arch_get_xen_caps(xen_capabilities_info_t *info)
diff --git a/xen/arch/ppc/shutdown.c b/xen/arch/ppc/shutdown.c
new file mode 100644
index 0000000000..6e49a095d8
--- /dev/null
+++ b/xen/arch/ppc/shutdown.c
@@ -0,0 +1,48 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#include <xen/shutdown.h>
+
+#include <asm/opal-api.h>
+
+int64_t opal_cec_power_down(uint64_t request);
+int64_t opal_cec_reboot(void);
+int64_t opal_poll_events(uint64_t *outstanding_event_mask);
+
+void machine_halt(void)
+{
+    int rc;
+
+    /* TODO: mask any OPAL IRQs before shutting down */
+
+    do {
+        rc = opal_cec_power_down(0);
+
+        if ( rc == OPAL_BUSY_EVENT )
+            opal_poll_events(NULL);
+
+    } while ( rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT );
+
+    for ( ;; )
+        opal_poll_events(NULL);
+}
+
+void machine_restart(unsigned int delay_millisecs)
+{
+    int rc;
+
+    /*
+     * TODO: mask any OPAL IRQs before shutting down
+     * TODO: mdelay(delay_millisecs);
+     */
+
+    do {
+        rc = opal_cec_reboot();
+
+        if ( rc == OPAL_BUSY_EVENT )
+            opal_poll_events(NULL);
+
+    } while ( rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT );
+
+    for ( ;; )
+        opal_poll_events(NULL);
+}
+
diff --git a/xen/arch/ppc/stubs.c b/xen/arch/ppc/stubs.c
index e743a86710..50e54d61c0 100644
--- a/xen/arch/ppc/stubs.c
+++ b/xen/arch/ppc/stubs.c
@@ -60,18 +60,6 @@ void vcpu_show_execution_state(struct vcpu *v)
     BUG_ON("unimplemented");
 }
 
-/* shutdown.c */
-
-void machine_restart(unsigned int delay_millisecs)
-{
-    BUG_ON("unimplemented");
-}
-
-void machine_halt(void)
-{
-    BUG_ON("unimplemented");
-}
-
 /* vm_event.c */
 
 void vm_event_fill_regs(vm_event_request_t *req)