pc: Add an SMB0 ACPI device to q35

This is so I2C devices can be found in the ACPI namespace.  Currently
that's only IPMI, but devices can be easily added now.

Adding the devices required some PCI information, and the bus itself
to be added to the PCMachineState structure.

Note that this only works on Q35, the ACPI for PIIX4 is not capable
of handling an SMBus device.

Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>

hw/i386/acpi-build.c

@@ -1809,6 +1809,18 @@ static Aml *build_q35_osc_method(void)
     return method;
 }
 
+static void build_smb0(Aml *table, I2CBus *smbus, int devnr, int func)
+{
+    Aml *scope = aml_scope("_SB.PCI0");
+    Aml *dev = aml_device("SMB0");
+
+    aml_append(dev, aml_name_decl("_HID", aml_eisaid("APP0005")));
+    aml_append(dev, aml_name_decl("_ADR", aml_int(devnr << 16 | func)));
+    build_acpi_ipmi_devices(dev, BUS(smbus), "\\_SB.PCI0.SMB0");
+    aml_append(scope, dev);
+    aml_append(table, scope);
+}
+
 static void
 build_dsdt(GArray *table_data, BIOSLinker *linker,
            AcpiPmInfo *pm, AcpiMiscInfo *misc,
@@ -1862,6 +1874,9 @@ build_dsdt(GArray *table_data, BIOSLinker *linker,
         build_q35_isa_bridge(dsdt);
         build_isa_devices_aml(dsdt);
         build_q35_pci0_int(dsdt);
+        if (pcms->smbus && !pcmc->do_not_add_smb_acpi) {
+            build_smb0(dsdt, pcms->smbus, ICH9_SMB_DEV, ICH9_SMB_FUNC);
+        }
     }
 
     if (pcmc->legacy_cpu_hotplug) {

hw/i386/pc_piix.c

@@ -283,15 +283,14 @@ else {
 
     if (pcmc->pci_enabled && acpi_enabled) {
         DeviceState *piix4_pm;
-        I2CBus *smbus;
 
         smi_irq = qemu_allocate_irq(pc_acpi_smi_interrupt, first_cpu, 0);
         /* TODO: Populate SPD eeprom data.  */
-        smbus = piix4_pm_init(pci_bus, piix3_devfn + 3, 0xb100,
+        pcms->smbus = piix4_pm_init(pci_bus, piix3_devfn + 3, 0xb100,
                                     pcms->gsi[9], smi_irq,
                                     pc_machine_is_smm_enabled(pcms),
                                     &piix4_pm);
-        smbus_eeprom_init(smbus, 8, NULL, 0);
+        smbus_eeprom_init(pcms->smbus, 8, NULL, 0);
 
         object_property_add_link(OBJECT(machine), PC_MACHINE_ACPI_DEVICE_PROP,
                                  TYPE_HOTPLUG_HANDLER,
@@ -476,6 +475,7 @@ static void pc_i440fx_3_1_machine_options(MachineClass *m)
 
     pc_i440fx_4_0_machine_options(m);
     m->is_default = 0;
+    pcmc->do_not_add_smb_acpi = true;
     m->smbus_no_migration_support = true;
     m->alias = NULL;
     pcmc->pvh_enabled = false;

hw/i386/pc_q35.c

@@ -316,10 +316,10 @@ static void pc_q35_init(MachineState *machine)
 
     if (pcms->smbus_enabled) {
         /* TODO: Populate SPD eeprom data.  */
-        smbus_eeprom_init(ich9_smb_init(host_bus,
+        pcms->smbus = ich9_smb_init(host_bus,
                                     PCI_DEVFN(ICH9_SMB_DEV, ICH9_SMB_FUNC),
-                                        0xb100),
-                          8, NULL, 0);
+                                    0xb100);
+        smbus_eeprom_init(pcms->smbus, 8, NULL, 0);
     }
 
     pc_cmos_init(pcms, idebus[0], idebus[1], rtc_state);
@@ -421,6 +421,7 @@ static void pc_q35_3_1_machine_options(MachineClass *m)
 
     pc_q35_4_0_machine_options(m);
     m->default_kernel_irqchip_split = false;
+    pcmc->do_not_add_smb_acpi = true;
     m->smbus_no_migration_support = true;
     m->alias = NULL;
     pcmc->pvh_enabled = false;

include/hw/i386/pc.h

@@ -38,6 +38,7 @@ struct PCMachineState {
     HotplugHandler *acpi_dev;
     ISADevice *rtc;
     PCIBus *bus;
+    I2CBus *smbus;
     FWCfgState *fw_cfg;
     qemu_irq *gsi;
     PFlashCFI01 *flash[2];
@@ -117,6 +118,7 @@ typedef struct PCMachineClass {
     bool rsdp_in_ram;
     int legacy_acpi_table_size;
     unsigned acpi_data_size;
+    bool do_not_add_smb_acpi;
 
     /* SMBIOS compat: */
     bool smbios_defaults;