On Fri, Feb 15, 2019 at 12:14:32PM +0100, Igor Mammedov wrote: >On Thu, 14 Feb 2019 20:53:31 +0000 >Wei Yang <richard.weiy...@gmail.com> wrote: > >> On Thu, Feb 14, 2019 at 12:25:27PM +0100, Igor Mammedov wrote: >> >On Thu, 14 Feb 2019 08:52:25 +0800 >> >Wei Yang <richardw.y...@linux.intel.com> 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 would allocate necessary >> >> resources and check the capacity. >> >'capacity' probably is not right word to use here >> >maybe s/the capacity/if 'memory-hotplug-support' property is enabled/ >> > >> >> >> >> While we leave acpi_memory_hotplug capacity check in the last step. This >> >wouldn't use 'leave' and 'capacity' here either, pls rephrase. >> > >> >> looks not comply with current architecture and does some unnecessary >> >s/looks not/doesn't/ >> >> work. >> >add more explanation about 'unnecessary work'. >> >problem as I see it, is that after successful pc_dimm_plug() >> >we get into piix4_device_plug_cb() and since >> > s->acpi_memory_hotplug.is_enabled == false >> >and all other 'if' conditions also false we would endup >> >at g_assert_not_reached() causing QEMU crash in piix4 case >> >and with error_abort up the call chain in case of ich9. >> > >> >> Thanks Igor, I rephrase above change log like this. Does this look >> better to you now? >> >> Before we do device realization and plug, we would allocate >s/would/should/ > >> necessary resources and check if memory-hotplug-support property is >> enabled. >> >> In piix4 and ich9, the acpi_memory_hotplug property is checked in >s/in/at the/ >> plug stage, this doesn't comply with current architecture. This >drop ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ >> means we have prepared everything and even do pc_dimm_plug() > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ >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). > >or something like this, I'm not native speaker either so CC Eric Blake >on next respin so he could check commit message. >
Thanks for your patience and detailed suggestion :-) >> successfuly, but failed at last because >> acpi_memory_hotplug.is_enabled == false. Which is worse is in piix4, >> this endup at g_assert_not_reached() and cause QEMU crash. >> >> >> >> This patch abstract the check on acpi_memory_hotplug capacity in >> >> pre_plug stage. >> >> >> >> Signed-off-by: Wei Yang <richardw.y...@linux.intel.com> >> >> --- >> >> hw/acpi/piix4.c | 14 ++++++++++++-- >> >> hw/i386/pc.c | 8 ++++++++ >> >doesn't look complete, why did you skip on similar code in ich9 >> >(Q35 machine)? >> > >> >> You are right, I missed this part. >> >> >> 2 files changed, 20 insertions(+), 2 deletions(-) >> >> >> >> diff --git a/hw/acpi/piix4.c b/hw/acpi/piix4.c >> >> index e330f24c71..c97b747496 100644 >> >> --- a/hw/acpi/piix4.c >> >> +++ b/hw/acpi/piix4.c >> >> @@ -370,13 +370,22 @@ static void piix4_pm_powerdown_req(Notifier *n, >> >> void *opaque) >> >> acpi_pm1_evt_power_down(&s->ar); >> >> } >> >> >> >> +static void piix4_device_pre_plug_cb(HotplugHandler *hotplug_dev, >> >> + DeviceState *dev, Error **errp) >> >> +{ >> >> + PIIX4PMState *s = PIIX4_PM(hotplug_dev); >> >> + >> >> + if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM) && >> >> + !s->acpi_memory_hotplug.is_enabled) >> >> + error_setg(errp, >> >> + "memory hotplug is not enabled: PIIX4 memory hotplug >> >> disabled"); >> >> +} >> >> static void piix4_device_plug_cb(HotplugHandler *hotplug_dev, >> >> DeviceState *dev, Error **errp) >> >> { >> >> PIIX4PMState *s = PIIX4_PM(hotplug_dev); >> >> >> >> - if (s->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 { >> >> @@ -702,6 +711,7 @@ static void piix4_pm_class_init(ObjectClass *klass, >> >> void *data) >> >> */ >> >> dc->user_creatable = false; >> >> dc->hotpluggable = false; >> >> + hc->pre_plug = piix4_device_pre_plug_cb; >> >> hc->plug = piix4_device_plug_cb; >> >> hc->unplug_request = piix4_device_unplug_request_cb; >> >> hc->unplug = piix4_device_unplug_cb; >> >> diff --git a/hw/i386/pc.c b/hw/i386/pc.c >> >> index 734d3268fa..3c6eed0cd3 100644 >> >> --- a/hw/i386/pc.c >> >> +++ b/hw/i386/pc.c >> >> @@ -1662,6 +1662,7 @@ static void pc_memory_pre_plug(HotplugHandler >> >> *hotplug_dev, DeviceState *dev, >> >> const PCMachineClass *pcmc = PC_MACHINE_GET_CLASS(pcms); >> >> const bool is_nvdimm = object_dynamic_cast(OBJECT(dev), TYPE_NVDIMM); >> >> const uint64_t legacy_align = TARGET_PAGE_SIZE; >> >> + HotplugHandlerClass *hhc; >> >> >> >> /* >> >> * When -no-acpi is used with Q35 machine type, no ACPI is built, >> >> @@ -1674,6 +1675,13 @@ static void pc_memory_pre_plug(HotplugHandler >> >> *hotplug_dev, DeviceState *dev, >> >> return; >> >> } >> >> >> >> + /* >> >> + * Check acpi_dev memory hotplug capacity >> >> + */ >> >> + hhc = HOTPLUG_HANDLER_GET_CLASS(pcms->acpi_dev); >> >> + if (hcc->pre_plug) >> >> + hhc->pre_plug(HOTPLUG_HANDLER(pcms->acpi_dev), dev, errp); >> >use hotplug_handler_pre_plug() instead of open-coding check >> > >> >> Thanks, will fix this. >> >> >> if (is_nvdimm && !pcms->acpi_nvdimm_state.is_enabled) { >> >> error_setg(errp, "nvdimm is not enabled: missing 'nvdimm' in >> >> '-M'"); >> >> return; >> > >> -- Wei Yang Help you, Help me