| Message ID | 20200720141610.574308-4-imammedo@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | x86: fix cpu hotplug with secure boot | expand |
On 07/20/20 16:16, Igor Mammedov wrote: > CPU hot-unplug with SMM requires firmware participation to prevent > guest crash (i.e. CPU can be removed only after OS _and_ firmware > were prepared for th action). (1) s/th action/the action/ > Previous patches introduced ICH9_LPC_SMI_F_CPU_HOT_UNPLUG_BIT > feature bit, which is advertised by firmware when it has support > for CPU hot-unplug. Use it to check if guest is able to handle > unplug and make device_del fail gracefully if hot-unplug feature > hasn't been negotiated. > > Signed-off-by: Igor Mammedov <imammedo@redhat.com> > --- > hw/acpi/ich9.c | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > diff --git a/hw/acpi/ich9.c b/hw/acpi/ich9.c > index 0acc9a3107..98fc363186 100644 > --- a/hw/acpi/ich9.c > +++ b/hw/acpi/ich9.c > @@ -460,6 +460,17 @@ void ich9_pm_device_unplug_request_cb(HotplugHandler *hotplug_dev, > errp); > } else if (object_dynamic_cast(OBJECT(dev), TYPE_CPU) && > !lpc->pm.cpu_hotplug_legacy) { > + 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_HOT_UNPLUG_BIT))) { > + error_setg(errp, "cpu hot-unplug with SMI wasn't enabled " > + "by firmware"); > + error_append_hint(errp, "update machine type to newer than 5.1 " > + "and firmware that suppors CPU hot-unplug with SMM"); (2) I think the "machine type to newer than 5.1" reference should be removed at this point. (Similarly to how "x-smi-cpu-hotunplug" should default to "false" at this point in time, in patch#1.) We don't know when hot-unplug will work; we only know that it doesn't work now. We could say something like error_append_hint(errp, "update machine type to a version having " "x-smi-cpu-hotunplug=on and firmware that " "suppors CPU hot-unplug with SMM"); > + return; > + } > + > acpi_cpu_unplug_request_cb(hotplug_dev, &lpc->pm.cpuhp_state, > dev, errp); > } else { > These superficial comments aside, the patch works for me: Tested-by: Laszlo Ersek <lersek@redhat.com> and with (1) and (2) fixed: Reviewed-by: Laszlo Ersek <lersek@redhat.com> Thanks Laszlo
diff --git a/hw/acpi/ich9.c b/hw/acpi/ich9.c index 0acc9a3107..98fc363186 100644 --- a/hw/acpi/ich9.c +++ b/hw/acpi/ich9.c @@ -460,6 +460,17 @@ void ich9_pm_device_unplug_request_cb(HotplugHandler *hotplug_dev, errp); } else if (object_dynamic_cast(OBJECT(dev), TYPE_CPU) && !lpc->pm.cpu_hotplug_legacy) { + 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_HOT_UNPLUG_BIT))) { + error_setg(errp, "cpu hot-unplug with SMI wasn't enabled " + "by firmware"); + error_append_hint(errp, "update machine type to newer than 5.1 " + "and firmware that suppors CPU hot-unplug with SMM"); + return; + } + acpi_cpu_unplug_request_cb(hotplug_dev, &lpc->pm.cpuhp_state, dev, errp); } else {
CPU hot-unplug with SMM requires firmware participation to prevent guest crash (i.e. CPU can be removed only after OS _and_ firmware were prepared for th action). Previous patches introduced ICH9_LPC_SMI_F_CPU_HOT_UNPLUG_BIT feature bit, which is advertised by firmware when it has support for CPU hot-unplug. Use it to check if guest is able to handle unplug and make device_del fail gracefully if hot-unplug feature hasn't been negotiated. Signed-off-by: Igor Mammedov <imammedo@redhat.com> --- hw/acpi/ich9.c | 11 +++++++++++ 1 file changed, 11 insertions(+)