Add PIIX4 properties to control PM system states.

This patch adds two things. First it allows QEMU to distinguish between
regular powerdown and S4 powerdown. Later separate QMP notification will
be added for S4 powerdown. Second it allows S3/S4 states to be disabled
from QEMU command line. Some guests known to be broken with regards to
power management, but allow to use it anyway. Using new properties
management will be able to disable S3/S4 for such guests.

Supported system state are passed to a firmware using new fw_cfg file.
The file contains  6 byte array. Each byte represents one system
state. If byte at offset X has its MSB set it means that system state
X is supported and to enter it guest should use the value from lowest 3
bits.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 18 insertions, 2 deletions

diff --git a/hw/acpi_piix4.c b/hw/acpi_piix4.c
index a11c8e7ae0..0aace60f24 100644
--- a/hw/acpi_piix4.c
+++ b/hw/acpi_piix4.c
@@ -27,6 +27,7 @@
 #include "sysemu.h"
 #include "range.h"
 #include "ioport.h"
+#include "fw_cfg.h"
 
 //#define DEBUG
 
@@ -71,6 +72,10 @@ typedef struct PIIX4PMState {
     struct pci_status pci0_status;
     uint32_t pci0_hotplug_enable;
     uint32_t pci0_slot_device_present;
+
+    uint8_t disable_s3;
+    uint8_t disable_s4;
+    uint8_t s4_val;
 } PIIX4PMState;
 
 static void piix4_acpi_system_hot_add_init(PCIBus *bus, PIIX4PMState *s);
@@ -123,7 +128,7 @@ static void pm_ioport_write(IORange *ioport, uint64_t addr, unsigned width,
         pm_update_sci(s);
         break;
     case 0x04:
-        acpi_pm1_cnt_write(&s->ar, val);
+        acpi_pm1_cnt_write(&s->ar, val, s->s4_val);
         break;
     default:
         break;
@@ -424,7 +429,7 @@ static int piix4_pm_initfn(PCIDevice *dev)
 
 i2c_bus *piix4_pm_init(PCIBus *bus, int devfn, uint32_t smb_io_base,
                        qemu_irq sci_irq, qemu_irq smi_irq,
-                       int kvm_enabled)
+                       int kvm_enabled, void *fw_cfg)
 {
     PCIDevice *dev;
     PIIX4PMState *s;
@@ -440,11 +445,22 @@ i2c_bus *piix4_pm_init(PCIBus *bus, int devfn, uint32_t smb_io_base,
 
     qdev_init_nofail(&dev->qdev);
 
+    if (fw_cfg) {
+        uint8_t suspend[6] = {128, 0, 0, 129, 128, 128};
+        suspend[3] = 1 | ((!s->disable_s3) << 7);
+        suspend[4] = s->s4_val | ((!s->disable_s4) << 7);
+
+        fw_cfg_add_file(fw_cfg, "etc/system-states", g_memdup(suspend, 6), 6);
+    }
+
     return s->smb.smbus;
 }
 
 static Property piix4_pm_properties[] = {
     DEFINE_PROP_UINT32("smb_io_base", PIIX4PMState, smb_io_base, 0),
+    DEFINE_PROP_UINT8("disable_s3", PIIX4PMState, disable_s3, 0),
+    DEFINE_PROP_UINT8("disable_s4", PIIX4PMState, disable_s4, 0),
+    DEFINE_PROP_UINT8("s4_val", PIIX4PMState, s4_val, 2),
     DEFINE_PROP_END_OF_LIST(),
 };