On Mon, Feb 25, 2019 at 09:15:34AM +0800, Wei Yang wrote:
>On Mon, Feb 25, 2019 at 09:07:08AM +0800, Wei Yang wrote:
>>Currently we do device realization like below:
>>
>> hotplug_handler_pre_plug()
>> dc->realize()
>> hotplug_handler_plug()
>>
>>Before we do device realization and plug, we should allocate necessary
>>resources and check if memory-hotplug-support property is enabled.
>>
>>At the piix4 and ich9, the memory-hotplug-support property is checked at
>>plug stage. This means that device has been realized and mapped into guest
>>address space 'pc_dimm_plug()' by the time acpi plug handler is called,
>>where it might fail and crash QEMU due to reaching g_assert_not_reached()
>>(piix4) or error_abort (ich9).
>>
>>Fix it by checking if memory hotplug is enabled at pre_plug stage
>>where we can gracefully abort hotplug request.
>>
>>Signed-off-by: Wei Yang <richardw.y...@linux.intel.com>
>>CC: Igor Mammedov <imamm...@redhat.com>
>>CC: Eric Blake <ebl...@redhat.com>
>>Signed-off-by: Wei Yang <richardw.y...@linux.intel.com>
>>
>>---
>>v5:
>> * rebase on latest upstream
>> * remove a comment before hotplug_handler_pre_plug
>> * fix alignment for ich9_pm_device_pre_plug_cb
>>v4:
>> * fix code alignment of piix4_device_pre_plug_cb
>>v3:
>> * replace acpi_memory_hotplug with memory-hotplug-support in changelog
>> * fix code alignment of ich9_pm_device_pre_plug_cb
>> * print which device type memory-hotplug-support is disabled in
>> ich9_pm_device_pre_plug_cb and piix4_device_pre_plug_cb
>>v2:
>> * (imamm...@redhat.com)
>> - Almost the whole third paragraph
>> * apply this change to ich9
>> * use hotplug_handler_pre_plug() instead of open-coding check
>>---
>> hw/acpi/ich9.c | 15 +++++++++++++--
>> hw/acpi/piix4.c | 13 ++++++++++---
>> hw/i386/pc.c | 2 ++
>> hw/isa/lpc_ich9.c | 1 +
>> include/hw/acpi/ich9.h | 2 ++
>> 5 files changed, 28 insertions(+), 5 deletions(-)
>>
>>diff --git a/hw/acpi/ich9.c b/hw/acpi/ich9.c
>>index c5d8646abc..e53dfe1ee3 100644
>>--- a/hw/acpi/ich9.c
>>+++ b/hw/acpi/ich9.c
>>@@ -483,13 +483,24 @@ void ich9_pm_add_properties(Object *obj, ICH9LPCPMRegs
>>*pm, Error **errp)
>> NULL);
>> }
>>
>>+void ich9_pm_device_pre_plug_cb(HotplugHandler *hotplug_dev, DeviceState
>>*dev,
>>+ Error **errp)
>>+{
>>+ ICH9LPCState *lpc = ICH9_LPC_DEVICE(hotplug_dev);
>>+
>>+ if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM) &&
>>+ !lpc->pm.acpi_memory_hotplug.is_enabled)
>>+ error_setg(errp,
>>+ "memory hotplug is not enabled: %s.memory-hotplug-support
>>"
>>+ "is not set", object_get_typename(OBJECT(lpc)));
>>+}
>>+
>> void ich9_pm_device_plug_cb(HotplugHandler *hotplug_dev, DeviceState *dev,
>> Error **errp)
>> {
>> ICH9LPCState *lpc = ICH9_LPC_DEVICE(hotplug_dev);
>>
>>- if (lpc->pm.acpi_memory_hotplug.is_enabled &&
>>- object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
>>+ if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
>> if (object_dynamic_cast(OBJECT(dev), TYPE_NVDIMM)) {
>> nvdimm_acpi_plug_cb(hotplug_dev, dev);
>> } else {
>>diff --git a/hw/acpi/piix4.c b/hw/acpi/piix4.c
>>index df8c0db909..8b9654e437 100644
>>--- a/hw/acpi/piix4.c
>>+++ b/hw/acpi/piix4.c
>>@@ -374,9 +374,16 @@ static void piix4_pm_powerdown_req(Notifier *n, void
>>*opaque)
>> static void piix4_device_pre_plug_cb(HotplugHandler *hotplug_dev,
>> DeviceState *dev, Error **errp)
>
Where will we invoke this check for pci devices?
pc_machine_device_pre_plug_cb() seems has no connection with this function. So
how this pre_plug handler takes effect?
Do I miss something?
--
Wei Yang
Help you, Help me
