From c5be7517d658ae787de6d0ccc8e93db01fdf60a1 Mon Sep 17 00:00:00 2001 From: Igor Mammedov Date: Wed, 23 Sep 2020 05:46:41 -0400 Subject: [PATCH] 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 Reviewed-by: Laszlo Ersek Tested-by: Laszlo Ersek Message-Id: <20200923094650.1301166-3-imammedo@redhat.com> Tested-by: Laszlo Ersek Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- hw/acpi/ich9.c | 12 +++++++++++- hw/i386/x86.c | 11 +++++++++++ 2 files changed, 22 insertions(+), 1 deletion(-) diff --git a/hw/acpi/ich9.c b/hw/acpi/ich9.c index 6a19070cec..0acc9a3107 100644 --- a/hw/acpi/ich9.c +++ b/hw/acpi/ich9.c @@ -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, diff --git a/hw/i386/x86.c b/hw/i386/x86.c index c2ea989579..403c2b1dad 100644 --- a/hw/i386/x86.c +++ b/hw/i386/x86.c @@ -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;