x86: lpc9: let firmware negotiate 'CPU hotplug with SMI' features

It will allow firmware to notify QEMU that firmware requires SMI
being triggered on CPU hot[un]plug, so that it would be able to account
for hotplugged CPU and relocate it to new SMM base and/or safely remove
CPU on unplug.

Using negotiated features, follow up patches will insert SMI upcall
into AML code, to make sure that firmware processes hotplug before
guest OS would attempt to use new CPU.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20200923094650.1301166-2-imammedo@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 05:46:40 -04:00 committed by Michael S. Tsirkin
parent 2d69eba5fe
commit 00dc02d284
3 changed files with 18 additions and 1 deletions

View File

@ -97,7 +97,9 @@
#include "trace.h"
#include CONFIG_DEVICES
GlobalProperty pc_compat_5_1[] = {};
GlobalProperty pc_compat_5_1[] = {
{ "ICH9-LPC", "x-smi-cpu-hotplug", "off" },
};
const size_t pc_compat_5_1_len = G_N_ELEMENTS(pc_compat_5_1);
GlobalProperty pc_compat_5_0[] = {

View File

@ -373,6 +373,15 @@ static void smi_features_ok_callback(void *opaque)
/* guest requests invalid features, leave @features_ok at zero */
return;
}
if (!(guest_features & BIT_ULL(ICH9_LPC_SMI_F_BROADCAST_BIT)) &&
guest_features & (BIT_ULL(ICH9_LPC_SMI_F_CPU_HOTPLUG_BIT) |
BIT_ULL(ICH9_LPC_SMI_F_CPU_HOT_UNPLUG_BIT))) {
/*
* cpu hot-[un]plug with SMI requires SMI broadcast,
* leave @features_ok at zero
*/
return;
}
/* valid feature subset requested, lock it down, report success */
lpc->smi_negotiated_features = guest_features;
@ -747,6 +756,10 @@ static Property ich9_lpc_properties[] = {
DEFINE_PROP_BOOL("noreboot", ICH9LPCState, pin_strap.spkr_hi, true),
DEFINE_PROP_BIT64("x-smi-broadcast", ICH9LPCState, smi_host_features,
ICH9_LPC_SMI_F_BROADCAST_BIT, true),
DEFINE_PROP_BIT64("x-smi-cpu-hotplug", ICH9LPCState, smi_host_features,
ICH9_LPC_SMI_F_CPU_HOTPLUG_BIT, true),
DEFINE_PROP_BIT64("x-smi-cpu-hotunplug", ICH9LPCState, smi_host_features,
ICH9_LPC_SMI_F_CPU_HOT_UNPLUG_BIT, false),
DEFINE_PROP_END_OF_LIST(),
};

View File

@ -247,5 +247,7 @@ struct ICH9LPCState {
/* bit positions used in fw_cfg SMI feature negotiation */
#define ICH9_LPC_SMI_F_BROADCAST_BIT 0
#define ICH9_LPC_SMI_F_CPU_HOTPLUG_BIT 1
#define ICH9_LPC_SMI_F_CPU_HOT_UNPLUG_BIT 2
#endif /* HW_ICH9_H */