| Message ID | e46c5ecd19c78b2f0ecd5dbf9cb10c0b476c3812.1441008774.git.zhugh.fnst@cn.fujitsu.com |
|---|---|
| State | New |
| Headers | show |
On Mon, 31 Aug 2015 17:47:45 +0800 Zhu Guihua <zhugh.fnst@cn.fujitsu.com> wrote: > 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. > May be: During reset some devices (such as hpet, rtc) might send IRQ to APIC which changes APIC's state from default one it's supposed to have at machine startup time. Fix this by resetting APIC after devices have been reset to cancel any changes that qemu_devices_reset() might have done to its state. > 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 <zhugh.fnst@cn.fujitsu.com> > --- > 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. > + */ S/^^^/ Reset APIC after devices have been reset to cancel any changes that qemu_devices_reset() might have done. > + 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;
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;
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 <zhugh.fnst@cn.fujitsu.com> --- hw/i386/pc.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+)