[Qemu-devel] [PATCH 2/2] Add PIIX4 properties to control PM system states.

[Gleb Natapov <gleb@redhat.com>]

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>
---
 hw/acpi.c       |    5 ++++-
 hw/acpi.h       |    2 +-
 hw/acpi_piix4.c |   16 +++++++++++++++-
 hw/vt82c686.c   |    2 +-
 4 files changed, 21 insertions(+), 4 deletions(-)

diff --git a/hw/acpi.c b/hw/acpi.c
index 5d521e5..effc7ec 100644
--- a/hw/acpi.c
+++ b/hw/acpi.c
@@ -370,7 +370,7 @@ void acpi_pm1_cnt_init(ACPIREGS *ar)
     qemu_register_wakeup_notifier(&ar->wakeup);
 }
 
-void acpi_pm1_cnt_write(ACPIREGS *ar, uint16_t val)
+void acpi_pm1_cnt_write(ACPIREGS *ar, uint16_t val, char s4)
 {
     ar->pm1.cnt.cnt = val & ~(ACPI_BITMASK_SLEEP_ENABLE);
 
@@ -385,6 +385,9 @@ void acpi_pm1_cnt_write(ACPIREGS *ar, uint16_t val)
             qemu_system_suspend_request();
             break;
         default:
+            if (sus_typ == s4) { /* S4 request */
+                qemu_system_shutdown_request();
+            }
             break;
         }
     }
diff --git a/hw/acpi.h b/hw/acpi.h
index fe8cdb4..7337f41 100644
--- a/hw/acpi.h
+++ b/hw/acpi.h
@@ -139,7 +139,7 @@ void acpi_pm1_evt_reset(ACPIREGS *ar);
 
 /* PM1a_CNT: piix and ich9 don't implement PM1b CNT. */
 void acpi_pm1_cnt_init(ACPIREGS *ar);
-void acpi_pm1_cnt_write(ACPIREGS *ar, uint16_t val);
+void acpi_pm1_cnt_write(ACPIREGS *ar, uint16_t val, char s4);
 void acpi_pm1_cnt_update(ACPIREGS *ar,
                          bool sci_enable, bool sci_disable);
 void acpi_pm1_cnt_reset(ACPIREGS *ar);
diff --git a/hw/acpi_piix4.c b/hw/acpi_piix4.c
index 585da4e..883314d 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;
@@ -425,6 +430,7 @@ i2c_bus *piix4_pm_init(PCIBus *bus, int devfn, uint32_t smb_io_base,
 {
     PCIDevice *dev;
     PIIX4PMState *s;
+    uint8_t suspend[6] = {128, 0, 0, 129, 128, 128};
 
     dev = pci_create(bus, devfn, "PIIX4_PM");
     qdev_prop_set_uint32(&dev->qdev, "smb_io_base", smb_io_base);
@@ -437,11 +443,19 @@ i2c_bus *piix4_pm_init(PCIBus *bus, int devfn, uint32_t smb_io_base,
 
     qdev_init_nofail(&dev->qdev);
 
+    suspend[3] = 1 | ((!s->disable_s3) << 7);
+    suspend[4] = s->s4_val | ((!s->disable_s4) << 7);
+
+    fw_cfg_add_file("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(),
 };
 
diff --git a/hw/vt82c686.c b/hw/vt82c686.c
index 6fb7950..5d7c00c 100644
--- a/hw/vt82c686.c
+++ b/hw/vt82c686.c
@@ -210,7 +210,7 @@ static void pm_ioport_writew(void *opaque, uint32_t addr, uint32_t val)
         pm_update_sci(s);
         break;
     case 0x04:
-        acpi_pm1_cnt_write(&s->ar, val);
+        acpi_pm1_cnt_write(&s->ar, val, 0);
         break;
     default:
         break;
-- 
1.7.7.3