ich9: add TCO interface emulation

This interface provides some registers within a 32-byte range and can be
acessed through PCI-to-LPC bridge interface (PMBASE + 0x60).

It's commonly used as a watchdog timer to detect system lockups through
SMIs that are generated -- if TCO_EN bit is set -- on every timeout. If
NO_REBOOT bit is not set in GCS (General Control and Status register),
the system will be resetted upon second timeout if TCO_RLD register
wasn't previously written to prevent timeout.

This patch adds support to TCO watchdog logic and few other features
like mapping NMIs to SMIs (NMI2SMI_EN bit), system intruder detection,
etc. are not implemented yet.

Signed-off-by: Paulo Alcantara <pcacjr@zytor.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
index 8aa3a67..24ee086 100644
--- a/hw/i386/pc_q35.c
+++ b/hw/i386/pc_q35.c
@@ -253,7 +253,7 @@ static void pc_q35_init(MachineState *machine)
                          (pc_machine->vmport != ON_OFF_AUTO_ON), 0xff0104);
 
     /* connect pm stuff to lpc */
-    ich9_lpc_pm_init(lpc, pc_machine_is_smm_enabled(pc_machine));
+    ich9_lpc_pm_init(lpc, pc_machine_is_smm_enabled(pc_machine), !mc->no_tco);
 
     /* ahci and SATA device, for q35 1 ahci controller is built-in */
     ahci = pci_create_simple_multifunction(host_bus,
@@ -397,6 +397,7 @@ static void pc_q35_2_4_machine_options(MachineClass *m)
     m->default_machine_opts = "firmware=bios-256k.bin";
     m->default_display = "std";
     m->no_floppy = 1;
+    m->no_tco = 0;
     m->alias = "q35";
 }
 
@@ -408,6 +409,7 @@ static void pc_q35_2_3_machine_options(MachineClass *m)
 {
     pc_q35_2_4_machine_options(m);
     m->no_floppy = 0;
+    m->no_tco = 1;
     m->alias = NULL;
     SET_MACHINE_COMPAT(m, PC_COMPAT_2_3);
 }