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| author | Igor Mammedov <imammedo@redhat.com> | 2020-09-23 05:46:42 -0400 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2020-09-29 02:15:24 -0400 |
| commit | b48ad7c02ba77c151bb8b10db6418615fa4ff458 (patch) | |
| tree | 5584208ca749f4acef97ac59e89db1e20db3e95b /hw/acpi/ich9.c | |
| parent | c5be7517d658ae787de6d0ccc8e93db01fdf60a1 (diff) | |
| download | focaccia-qemu-b48ad7c02ba77c151bb8b10db6418615fa4ff458.tar.gz focaccia-qemu-b48ad7c02ba77c151bb8b10db6418615fa4ff458.zip | |
x86: cpuhp: refuse cpu hot-unplug request earlier if not supported
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 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> Tested-by: Laszlo Ersek <lersek@redhat.com> Reviewed-by: Laszlo Ersek <lersek@redhat.com> Message-Id: <20200923094650.1301166-4-imammedo@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'hw/acpi/ich9.c')
| -rw-r--r-- | hw/acpi/ich9.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/hw/acpi/ich9.c b/hw/acpi/ich9.c index 0acc9a3107..95cb0f935b 100644 --- a/hw/acpi/ich9.c +++ b/hw/acpi/ich9.c @@ -460,6 +460,18 @@ 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 a version having " + "x-smi-cpu-hotunplug=on and firmware that " + "supports CPU hot-unplug with SMM"); + return; + } + acpi_cpu_unplug_request_cb(hotplug_dev, &lpc->pm.cpuhp_state, dev, errp); } else { |