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[Qemu-devel] [PATCH v10 2/4] x86: use new method to correct reset sequen


From: Zhu Guihua
Subject: [Qemu-devel] [PATCH v10 2/4] x86: use new method to correct reset sequence
Date: Mon, 31 Aug 2015 17:47:45 +0800

Something must be occur during reset of the X86 platform in a specific
order. For example, some devices (such as hpet, rtc) reset will send
irq to apic, this will update the apic register. In order to ensure
the apic register could be set to default values, apic reset must be
after those devices reset.

This patch uses the new QEMUMachine reset method to solve the above
problem, ensuring the various reset happen in the correct order.

Signed-off-by: Zhu Guihua <address@hidden>
---
 hw/i386/pc.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index e15971c..875ada8 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -1928,6 +1928,27 @@ static void pc_machine_initfn(Object *obj)
                              NULL, &error_abort);
 }
 
+static void pc_machine_reset(void)
+{
+    CPUState *cs;
+    X86CPU *cpu;
+
+    qemu_devices_reset();
+
+    /* When some devices (such as hpet, rtc) do their reset, they will
+     * send irq to APIC. This will modify the value of the APIC register.
+     * In order to ensure the APIC register can be set to default value,
+     * APIC reset must be after those devices reset.
+     */
+    CPU_FOREACH(cs) {
+        cpu = X86_CPU(cs);
+
+        if (cpu->apic_state) {
+            device_reset(cpu->apic_state);
+        }
+    }
+}
+
 static unsigned pc_cpu_index_to_socket_id(unsigned cpu_index)
 {
     unsigned pkg_id, core_id, smt_id;
@@ -1948,6 +1969,7 @@ static void pc_machine_class_init(ObjectClass *oc, void 
*data)
     mc->default_boot_order = "cad";
     mc->hot_add_cpu = pc_hot_add_cpu;
     mc->max_cpus = 255;
+    mc->reset = pc_machine_reset;
     hc->plug = pc_machine_device_plug_cb;
     hc->unplug_request = pc_machine_device_unplug_request_cb;
     hc->unplug = pc_machine_device_unplug_cb;
-- 
1.9.3




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