x86: cpuhp: prevent guest crash on CPU hotplug when broadcast SMI is in use

There were reports of guest crash on CPU hotplug, when using q35 machine
type and OVMF with SMM, due to hotplugged CPU trying to process SMI at
default SMI handler location without it being relocated by firmware first.

Fix it by refusing hotplug if firmware hasn't negotiated CPU hotplug with
SMI support while SMI broadcast is in use.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20200923094650.1301166-3-imammedo@redhat.com>
Tested-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Igor Mammedov 2020-09-23 05:46:41 -04:00 committed by Michael S. Tsirkin
parent 00dc02d284
commit c5be7517d6
2 changed files with 22 additions and 1 deletions

View File

@ -408,10 +408,20 @@ void ich9_pm_device_pre_plug_cb(HotplugHandler *hotplug_dev, DeviceState *dev,
ICH9LPCState *lpc = ICH9_LPC_DEVICE(hotplug_dev);
if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM) &&
!lpc->pm.acpi_memory_hotplug.is_enabled)
!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)));
} else if (object_dynamic_cast(OBJECT(dev), TYPE_CPU)) {
uint64_t negotiated = lpc->smi_negotiated_features;
if (negotiated & BIT_ULL(ICH9_LPC_SMI_F_BROADCAST_BIT) &&
!(negotiated & BIT_ULL(ICH9_LPC_SMI_F_CPU_HOTPLUG_BIT))) {
error_setg(errp, "cpu hotplug with SMI wasn't enabled by firmware");
error_append_hint(errp, "update machine type to newer than 5.1 "
"and firmware that suppors CPU hotplug with SMM");
}
}
}
void ich9_pm_device_plug_cb(HotplugHandler *hotplug_dev, DeviceState *dev,

View File

@ -279,6 +279,17 @@ void x86_cpu_pre_plug(HotplugHandler *hotplug_dev,
return;
}
if (x86ms->acpi_dev) {
Error *local_err = NULL;
hotplug_handler_pre_plug(HOTPLUG_HANDLER(x86ms->acpi_dev), dev,
&local_err);
if (local_err) {
error_propagate(errp, local_err);
return;
}
}
init_topo_info(&topo_info, x86ms);
env->nr_dies = x86ms->smp_dies;