[Qemu-devel] [PATCH] i2c: fix migration regression introduced by broadcast support

[Igor Mammedov]

QEMU fails migration with following error:

qemu-system-x86_64: Missing section footer for i2c_bus
qemu-system-x86_64: load of migration failed: Invalid argument

when migrating from:
  qemu-system-x86_64-v2.6.0 -m 256M rhel72.img -M pc-i440fx-2.6
to
  qemu-system-x86_64-v2.7.0-rc0 -m 256M rhel72.img -M pc-i440fx-2.6

Regression is added by commit 2293c27f (i2c: implement broadcast write)

Fix it by moving 'broadcast' VMState to an optional subsection
enabled by default and disabled via compat properties
for pc/q35-2.6 and older machine types.

Signed-off-by: Igor Mammedov <address@hidden>
---
CC: address@hidden
CC: address@hidden
CC: address@hidden
CC: address@hidden
CC: address@hidden
---
 include/hw/i2c/i2c.h      |  2 +-
 include/hw/i2c/pm_smbus.h |  1 +
 include/hw/i386/pc.h      | 10 ++++++++++
 hw/acpi/piix4.c           |  2 ++
 hw/arm/pxa2xx.c           |  4 ++--
 hw/arm/stellaris.c        |  2 +-
 hw/i2c/aspeed_i2c.c       |  2 +-
 hw/i2c/bitbang_i2c.c      |  2 +-
 hw/i2c/core.c             | 32 +++++++++++++++++++++++++++++---
 hw/i2c/exynos4210_i2c.c   |  2 +-
 hw/i2c/imx_i2c.c          |  2 +-
 hw/i2c/omap_i2c.c         |  2 +-
 hw/i2c/pm_smbus.c         |  2 +-
 hw/i2c/smbus_ich9.c       |  7 +++++++
 hw/i2c/versatile_i2c.c    |  2 +-
 hw/misc/auxbus.c          |  2 +-
 16 files changed, 61 insertions(+), 15 deletions(-)

diff --git a/include/hw/i2c/i2c.h b/include/hw/i2c/i2c.h
index c4085aa..488a0fa 100644
--- a/include/hw/i2c/i2c.h
+++ b/include/hw/i2c/i2c.h
@@ -50,7 +50,7 @@ struct I2CSlave
     uint8_t address;
 };
 
-I2CBus *i2c_init_bus(DeviceState *parent, const char *name);
+I2CBus *i2c_init_bus(DeviceState *parent, const char *name, bool broadcast);
 void i2c_set_slave_address(I2CSlave *dev, uint8_t address);
 int i2c_bus_busy(I2CBus *bus);
 int i2c_start_transfer(I2CBus *bus, uint8_t address, int recv);
diff --git a/include/hw/i2c/pm_smbus.h b/include/hw/i2c/pm_smbus.h
index 2a837af..b17c052 100644
--- a/include/hw/i2c/pm_smbus.h
+++ b/include/hw/i2c/pm_smbus.h
@@ -3,6 +3,7 @@
 
 typedef struct PMSMBus {
     I2CBus *smbus;
+    bool smb_broadcast_enabled;
     MemoryRegion io;
 
     uint8_t smb_stat;
diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
index c87c5c1..738b8a5 100644
--- a/include/hw/i386/pc.h
+++ b/include/hw/i386/pc.h
@@ -391,6 +391,16 @@ bool e820_get_entry(int, uint32_t, uint64_t *, uint64_t *);
         .driver   = "apic",\
         .property = "legacy-instance-id",\
         .value    = "on",\
+    },\
+    {\
+        .driver   = "ICH9 SMB",\
+        .property = "smbus-broadcast-enabled",\
+        .value    = "off",\
+    },\
+    {\
+        .driver   = "PIIX4_PM",\
+        .property = "smbus-broadcast-enabled",\
+        .value    = "off",\
     },
 
 #define PC_COMPAT_2_5 \
diff --git a/hw/acpi/piix4.c b/hw/acpi/piix4.c
index 2adc246..8a29179 100644
--- a/hw/acpi/piix4.c
+++ b/hw/acpi/piix4.c
@@ -669,6 +669,8 @@ static Property piix4_pm_properties[] = {
                      use_acpi_pci_hotplug, true),
     DEFINE_PROP_BOOL("memory-hotplug-support", PIIX4PMState,
                      acpi_memory_hotplug.is_enabled, true),
+    DEFINE_PROP_BOOL("smbus-broadcast-enabled", PIIX4PMState,
+                     smb.smb_broadcast_enabled, true),
     DEFINE_PROP_END_OF_LIST(),
 };
 
diff --git a/hw/arm/pxa2xx.c b/hw/arm/pxa2xx.c
index cb55704..045ab20 100644
--- a/hw/arm/pxa2xx.c
+++ b/hw/arm/pxa2xx.c
@@ -1491,7 +1491,7 @@ PXA2xxI2CState *pxa2xx_i2c_init(hwaddr base,
 
     s = PXA2XX_I2C(i2c_dev);
     /* FIXME: Should the slave device really be on a separate bus?  */
-    i2cbus = i2c_init_bus(dev, "dummy");
+    i2cbus = i2c_init_bus(dev, "dummy", true);
     dev = i2c_create_slave(i2cbus, TYPE_PXA2XX_I2C_SLAVE, 0);
     s->slave = PXA2XX_I2C_SLAVE(dev);
     s->slave->host = s;
@@ -1505,7 +1505,7 @@ static void pxa2xx_i2c_initfn(Object *obj)
     PXA2xxI2CState *s = PXA2XX_I2C(obj);
     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
 
-    s->bus = i2c_init_bus(dev, "i2c");
+    s->bus = i2c_init_bus(dev, "i2c", true);
 
     memory_region_init_io(&s->iomem, obj, &pxa2xx_i2c_ops, s,
                           "pxa2xx-i2c", s->region_size);
diff --git a/hw/arm/stellaris.c b/hw/arm/stellaris.c
index 794a3ad..ac38e4d 100644
--- a/hw/arm/stellaris.c
+++ b/hw/arm/stellaris.c
@@ -882,7 +882,7 @@ static void stellaris_i2c_init(Object *obj)
     I2CBus *bus;
 
     sysbus_init_irq(sbd, &s->irq);
-    bus = i2c_init_bus(dev, "i2c");
+    bus = i2c_init_bus(dev, "i2c", true);
     s->bus = bus;
 
     memory_region_init_io(&s->iomem, obj, &stellaris_i2c_ops, s,
diff --git a/hw/i2c/aspeed_i2c.c b/hw/i2c/aspeed_i2c.c
index ce5b1f0..af62636 100644
--- a/hw/i2c/aspeed_i2c.c
+++ b/hw/i2c/aspeed_i2c.c
@@ -394,7 +394,7 @@ static void aspeed_i2c_realize(DeviceState *dev, Error 
**errp)
         snprintf(name, sizeof(name), "aspeed.i2c.%d", i);
         s->busses[i].controller = s;
         s->busses[i].id = i;
-        s->busses[i].bus = i2c_init_bus(dev, name);
+        s->busses[i].bus = i2c_init_bus(dev, name, true);
         memory_region_init_io(&s->busses[i].mr, OBJECT(dev),
                               &aspeed_i2c_bus_ops, &s->busses[i], name, 0x40);
         memory_region_add_subregion(&s->iomem, 0x40 * (i + offset),
diff --git a/hw/i2c/bitbang_i2c.c b/hw/i2c/bitbang_i2c.c
index d3a2989..63f922b 100644
--- a/hw/i2c/bitbang_i2c.c
+++ b/hw/i2c/bitbang_i2c.c
@@ -220,7 +220,7 @@ static void gpio_i2c_init(Object *obj)
     memory_region_init(&s->dummy_iomem, obj, "gpio_i2c", 0);
     sysbus_init_mmio(sbd, &s->dummy_iomem);
 
-    bus = i2c_init_bus(dev, "i2c");
+    bus = i2c_init_bus(dev, "i2c", true);
     s->bitbang = bitbang_i2c_init(bus);
 
     qdev_init_gpio_in(dev, bitbang_i2c_gpio_set, 2);
diff --git a/hw/i2c/core.c b/hw/i2c/core.c
index abb3efb..3ab1ed5 100644
--- a/hw/i2c/core.c
+++ b/hw/i2c/core.c
@@ -9,6 +9,7 @@
 
 #include "qemu/osdep.h"
 #include "hw/i2c/i2c.h"
+#include "qapi/error.h"
 
 typedef struct I2CNode I2CNode;
 
@@ -22,6 +23,7 @@ struct I2CBus
     BusState qbus;
     QLIST_HEAD(, I2CNode) current_devs;
     uint8_t saved_address;
+    bool broadcast_enabled;
     bool broadcast;
 };
 
@@ -45,12 +47,32 @@ static void i2c_bus_pre_save(void *opaque)
 
     bus->saved_address = -1;
     if (!QLIST_EMPTY(&bus->current_devs)) {
-        if (!bus->broadcast) {
+        if (!bus->broadcast_enabled && !bus->broadcast) {
             bus->saved_address = QLIST_FIRST(&bus->current_devs)->elt->address;
         }
     }
 }
 
+static bool vmstate_test_use_broadcast(void *opaque)
+{
+    I2CBus *bus = opaque;
+
+    return bus->broadcast_enabled;
+}
+
+static const VMStateDescription vmstate_broadcast_state = {
+    .name = "i2c_bus/broadcast",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .minimum_version_id_old = 1,
+    .needed = vmstate_test_use_broadcast,
+    .fields      = (VMStateField[]) {
+        VMSTATE_BOOL(broadcast, I2CBus),
+        VMSTATE_END_OF_LIST()
+    }
+
+};
+
 static const VMStateDescription vmstate_i2c_bus = {
     .name = "i2c_bus",
     .version_id = 1,
@@ -58,17 +80,21 @@ static const VMStateDescription vmstate_i2c_bus = {
     .pre_save = i2c_bus_pre_save,
     .fields = (VMStateField[]) {
         VMSTATE_UINT8(saved_address, I2CBus),
-        VMSTATE_BOOL(broadcast, I2CBus),
         VMSTATE_END_OF_LIST()
+    },
+    .subsections = (const VMStateDescription * []) {
+        &vmstate_broadcast_state,
+        NULL
     }
 };
 
 /* Create a new I2C bus.  */
-I2CBus *i2c_init_bus(DeviceState *parent, const char *name)
+I2CBus *i2c_init_bus(DeviceState *parent, const char *name, bool broadcast)
 {
     I2CBus *bus;
 
     bus = I2C_BUS(qbus_create(TYPE_I2C_BUS, parent, name));
+    bus->broadcast_enabled = broadcast;
     QLIST_INIT(&bus->current_devs);
     vmstate_register(NULL, -1, &vmstate_i2c_bus, bus);
     return bus;
diff --git a/hw/i2c/exynos4210_i2c.c b/hw/i2c/exynos4210_i2c.c
index c96fa7d..1f78399 100644
--- a/hw/i2c/exynos4210_i2c.c
+++ b/hw/i2c/exynos4210_i2c.c
@@ -309,7 +309,7 @@ static void exynos4210_i2c_init(Object *obj)
                           TYPE_EXYNOS4_I2C, EXYNOS4_I2C_MEM_SIZE);
     sysbus_init_mmio(sbd, &s->iomem);
     sysbus_init_irq(sbd, &s->irq);
-    s->bus = i2c_init_bus(dev, "i2c");
+    s->bus = i2c_init_bus(dev, "i2c", true);
 }
 
 static void exynos4210_i2c_class_init(ObjectClass *klass, void *data)
diff --git a/hw/i2c/imx_i2c.c b/hw/i2c/imx_i2c.c
index 37e5a62..aa8fb9f 100644
--- a/hw/i2c/imx_i2c.c
+++ b/hw/i2c/imx_i2c.c
@@ -310,7 +310,7 @@ static void imx_i2c_realize(DeviceState *dev, Error **errp)
                           IMX_I2C_MEM_SIZE);
     sysbus_init_mmio(SYS_BUS_DEVICE(dev), &s->iomem);
     sysbus_init_irq(SYS_BUS_DEVICE(dev), &s->irq);
-    s->bus = i2c_init_bus(DEVICE(dev), "i2c");
+    s->bus = i2c_init_bus(DEVICE(dev), "i2c", true);
 }
 
 static void imx_i2c_class_init(ObjectClass *klass, void *data)
diff --git a/hw/i2c/omap_i2c.c b/hw/i2c/omap_i2c.c
index f7c92ea..852a61d 100644
--- a/hw/i2c/omap_i2c.c
+++ b/hw/i2c/omap_i2c.c
@@ -456,7 +456,7 @@ static void omap_i2c_init(Object *obj)
     sysbus_init_irq(sbd, &s->drq[0]);
     sysbus_init_irq(sbd, &s->drq[1]);
     sysbus_init_mmio(sbd, &s->iomem);
-    s->bus = i2c_init_bus(dev, NULL);
+    s->bus = i2c_init_bus(dev, NULL, true);
 }
 
 static void omap_i2c_realize(DeviceState *dev, Error **errp)
diff --git a/hw/i2c/pm_smbus.c b/hw/i2c/pm_smbus.c
index 6fc3923..4e91cc1 100644
--- a/hw/i2c/pm_smbus.c
+++ b/hw/i2c/pm_smbus.c
@@ -222,7 +222,7 @@ static const MemoryRegionOps pm_smbus_ops = {
 
 void pm_smbus_init(DeviceState *parent, PMSMBus *smb)
 {
-    smb->smbus = i2c_init_bus(parent, "i2c");
+    smb->smbus = i2c_init_bus(parent, "i2c", smb->smb_broadcast_enabled);
     memory_region_init_io(&smb->io, OBJECT(parent), &pm_smbus_ops, smb,
                           "pm-smbus", 64);
 }
diff --git a/hw/i2c/smbus_ich9.c b/hw/i2c/smbus_ich9.c
index 48fab22..6e739e3 100644
--- a/hw/i2c/smbus_ich9.c
+++ b/hw/i2c/smbus_ich9.c
@@ -86,6 +86,12 @@ static void ich9_smbus_realize(PCIDevice *d, Error **errp)
                      &s->smb.io);
 }
 
+static Property ich9_smbus_properties[] = {
+    DEFINE_PROP_BOOL("smbus-broadcast-enabled", ICH9SMBState,
+                     smb.smb_broadcast_enabled, true),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
 static void ich9_smb_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
@@ -97,6 +103,7 @@ static void ich9_smb_class_init(ObjectClass *klass, void 
*data)
     k->class_id = PCI_CLASS_SERIAL_SMBUS;
     dc->vmsd = &vmstate_ich9_smbus;
     dc->desc = "ICH9 SMBUS Bridge";
+    dc->props = ich9_smbus_properties;
     k->realize = ich9_smbus_realize;
     k->config_write = ich9_smbus_write_config;
     /*
diff --git a/hw/i2c/versatile_i2c.c b/hw/i2c/versatile_i2c.c
index da9f298..490c93a 100644
--- a/hw/i2c/versatile_i2c.c
+++ b/hw/i2c/versatile_i2c.c
@@ -86,7 +86,7 @@ static void versatile_i2c_init(Object *obj)
     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
     I2CBus *bus;
 
-    bus = i2c_init_bus(dev, "i2c");
+    bus = i2c_init_bus(dev, "i2c", true);
     s->bitbang = bitbang_i2c_init(bus);
     memory_region_init_io(&s->iomem, obj, &versatile_i2c_ops, s,
                           "versatile_i2c", 0x1000);
diff --git a/hw/misc/auxbus.c b/hw/misc/auxbus.c
index e4a7ba4..47ee115 100644
--- a/hw/misc/auxbus.c
+++ b/hw/misc/auxbus.c
@@ -214,7 +214,7 @@ static void aux_bridge_init(Object *obj)
 {
     AUXTOI2CState *s = AUXTOI2C(obj);
 
-    s->i2c_bus = i2c_init_bus(DEVICE(obj), "aux-i2c");
+    s->i2c_bus = i2c_init_bus(DEVICE(obj), "aux-i2c", true);
 }
 
 static inline I2CBus *aux_bridge_get_i2c_bus(AUXTOI2CState *bridge)
-- 
2.7.4