diff mbox

[RFC,5/9] ich9: Document why cannot_instantiate_with_device_add_yet

Message ID 1381416174-5110-6-git-send-email-armbru@redhat.com
State New
Headers show

Commit Message

Markus Armbruster Oct. 10, 2013, 2:42 p.m. UTC 
From: Markus Armbruster <armbru@redhat.com>

An ICH9 southbridge contains several PCI devices, some of them with
multiple functions.  We model each function as a separate qdev.  Two
of them need some special wiring set up in pc_q35_init() to work: the
LPC controller at 00:1f.0, and the SMBus controller at 00:1f.3.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
---
 hw/i2c/smbus_ich9.c | 6 +++++-
 hw/isa/lpc_ich9.c   | 7 +++++--
 2 files changed, 10 insertions(+), 3 deletions(-)

Comments

Paolo Bonzini Oct. 10, 2013, 4:01 p.m. UTC | #1 
Il 10/10/2013 16:42, armbru@redhat.com ha scritto:
> From: Markus Armbruster <armbru@redhat.com>
> 
> An ICH9 southbridge contains several PCI devices, some of them with
> multiple functions.  We model each function as a separate qdev.  Two
> of them need some special wiring set up in pc_q35_init() to work: the
> LPC controller at 00:1f.0, and the SMBus controller at 00:1f.3.
> 
> Signed-off-by: Markus Armbruster <armbru@redhat.com>
> ---
>  hw/i2c/smbus_ich9.c | 6 +++++-
>  hw/isa/lpc_ich9.c   | 7 +++++--
>  2 files changed, 10 insertions(+), 3 deletions(-)
> 
> diff --git a/hw/i2c/smbus_ich9.c b/hw/i2c/smbus_ich9.c
> index c1ffa34..8d47eaf 100644
> --- a/hw/i2c/smbus_ich9.c
> +++ b/hw/i2c/smbus_ich9.c
> @@ -97,11 +97,15 @@ static void ich9_smb_class_init(ObjectClass *klass, void *data)
>      k->device_id = PCI_DEVICE_ID_INTEL_ICH9_6;
>      k->revision = ICH9_A2_SMB_REVISION;
>      k->class_id = PCI_CLASS_SERIAL_SMBUS;
> -    dc->cannot_instantiate_with_device_add_yet = true; /* FIXME explain why */
>      dc->vmsd = &vmstate_ich9_smbus;
>      dc->desc = "ICH9 SMBUS Bridge";
>      k->init = ich9_smbus_initfn;
>      k->config_write = ich9_smbus_write_config;
> +    /*
> +     * Reason: part of ICH9 southbridge, needs to be wired up by
> +     * pc_q35_init()
> +     */
> +    dc->cannot_instantiate_with_device_add_yet = true;
>  }
>  
>  i2c_bus *ich9_smb_init(PCIBus *bus, int devfn, uint32_t smb_io_base)
> diff --git a/hw/isa/lpc_ich9.c b/hw/isa/lpc_ich9.c
> index ad841b5..d00d698 100644
> --- a/hw/isa/lpc_ich9.c
> +++ b/hw/isa/lpc_ich9.c
> @@ -604,14 +604,17 @@ static void ich9_lpc_class_init(ObjectClass *klass, void *data)
>      dc->reset = ich9_lpc_reset;
>      k->init = ich9_lpc_initfn;
>      dc->vmsd = &vmstate_ich9_lpc;
> -    dc->cannot_instantiate_with_device_add_yet = true; /* FIXME explain why */
>      k->config_write = ich9_lpc_config_write;
>      dc->desc = "ICH9 LPC bridge";
>      k->vendor_id = PCI_VENDOR_ID_INTEL;
>      k->device_id = PCI_DEVICE_ID_INTEL_ICH9_8;
>      k->revision = ICH9_A2_LPC_REVISION;
>      k->class_id = PCI_CLASS_BRIDGE_ISA;
> -
> +    /*
> +     * Reason: part of ICH9 southbridge, needs to be wired up by
> +     * pc_q35_init()
> +     */
> +    dc->cannot_instantiate_with_device_add_yet = true;
>  }
>  
>  static const TypeInfo ich9_lpc_info = {
> 

I think SMBus is fine.  Even though the standard configuration of the
Q35 SMBus cannot be reproduced with -device, that's a problem of
hw/i2c/smbus_eeprom.c, not of the smbus bridge itself.  I think
hw/i2c/smbus_eeprom.c should rather be marked as
cannot_instantiate_with_device_add_yet (which makes sense, because it
has a PROP_PTR).

Alternatively, you can resuscitate the first two patches of
http://lists.gnu.org/archive/html/qemu-devel/2012-02/msg00449.html

Paolo
Paolo Bonzini Oct. 10, 2013, 4:03 p.m. UTC | #2 
Il 10/10/2013 18:01, Paolo Bonzini ha scritto:
> Il 10/10/2013 16:42, armbru@redhat.com ha scritto:
>> From: Markus Armbruster <armbru@redhat.com>
>>
>> An ICH9 southbridge contains several PCI devices, some of them with
>> multiple functions.  We model each function as a separate qdev.  Two
>> of them need some special wiring set up in pc_q35_init() to work: the
>> LPC controller at 00:1f.0, and the SMBus controller at 00:1f.3.
>>
>> Signed-off-by: Markus Armbruster <armbru@redhat.com>
>> ---
>>  hw/i2c/smbus_ich9.c | 6 +++++-
>>  hw/isa/lpc_ich9.c   | 7 +++++--
>>  2 files changed, 10 insertions(+), 3 deletions(-)
>>
>> diff --git a/hw/i2c/smbus_ich9.c b/hw/i2c/smbus_ich9.c
>> index c1ffa34..8d47eaf 100644
>> --- a/hw/i2c/smbus_ich9.c
>> +++ b/hw/i2c/smbus_ich9.c
>> @@ -97,11 +97,15 @@ static void ich9_smb_class_init(ObjectClass *klass, void *data)
>>      k->device_id = PCI_DEVICE_ID_INTEL_ICH9_6;
>>      k->revision = ICH9_A2_SMB_REVISION;
>>      k->class_id = PCI_CLASS_SERIAL_SMBUS;
>> -    dc->cannot_instantiate_with_device_add_yet = true; /* FIXME explain why */
>>      dc->vmsd = &vmstate_ich9_smbus;
>>      dc->desc = "ICH9 SMBUS Bridge";
>>      k->init = ich9_smbus_initfn;
>>      k->config_write = ich9_smbus_write_config;
>> +    /*
>> +     * Reason: part of ICH9 southbridge, needs to be wired up by
>> +     * pc_q35_init()
>> +     */
>> +    dc->cannot_instantiate_with_device_add_yet = true;
>>  }
>>  
>>  i2c_bus *ich9_smb_init(PCIBus *bus, int devfn, uint32_t smb_io_base)
>> diff --git a/hw/isa/lpc_ich9.c b/hw/isa/lpc_ich9.c
>> index ad841b5..d00d698 100644
>> --- a/hw/isa/lpc_ich9.c
>> +++ b/hw/isa/lpc_ich9.c
>> @@ -604,14 +604,17 @@ static void ich9_lpc_class_init(ObjectClass *klass, void *data)
>>      dc->reset = ich9_lpc_reset;
>>      k->init = ich9_lpc_initfn;
>>      dc->vmsd = &vmstate_ich9_lpc;
>> -    dc->cannot_instantiate_with_device_add_yet = true; /* FIXME explain why */
>>      k->config_write = ich9_lpc_config_write;
>>      dc->desc = "ICH9 LPC bridge";
>>      k->vendor_id = PCI_VENDOR_ID_INTEL;
>>      k->device_id = PCI_DEVICE_ID_INTEL_ICH9_8;
>>      k->revision = ICH9_A2_LPC_REVISION;
>>      k->class_id = PCI_CLASS_BRIDGE_ISA;
>> -
>> +    /*
>> +     * Reason: part of ICH9 southbridge, needs to be wired up by
>> +     * pc_q35_init()
>> +     */
>> +    dc->cannot_instantiate_with_device_add_yet = true;
>>  }
>>  
>>  static const TypeInfo ich9_lpc_info = {
>>
> 
> I think SMBus is fine.  Even though the standard configuration of the
> Q35 SMBus cannot be reproduced with -device, that's a problem of
> hw/i2c/smbus_eeprom.c, not of the smbus bridge itself.  I think
> hw/i2c/smbus_eeprom.c should rather be marked as
> cannot_instantiate_with_device_add_yet (which makes sense, because it
> has a PROP_PTR).
> 
> Alternatively, you can resuscitate the first two patches of
> http://lists.gnu.org/archive/html/qemu-devel/2012-02/msg00449.html

Ah, got it---the SMBus and LPC need to be connected to each other.
Still, the SMBus EEPROM is a candidate for
cannot_instantiate_with_device_add_yet.

Paolo
Markus Armbruster Oct. 11, 2013, 6:13 a.m. UTC | #3 
Paolo Bonzini <pbonzini@redhat.com> writes:

> Il 10/10/2013 18:01, Paolo Bonzini ha scritto:
>> Il 10/10/2013 16:42, armbru@redhat.com ha scritto:
>>> From: Markus Armbruster <armbru@redhat.com>
>>>
>>> An ICH9 southbridge contains several PCI devices, some of them with
>>> multiple functions.  We model each function as a separate qdev.  Two
>>> of them need some special wiring set up in pc_q35_init() to work: the
>>> LPC controller at 00:1f.0, and the SMBus controller at 00:1f.3.
>>>
>>> Signed-off-by: Markus Armbruster <armbru@redhat.com>
>>> ---
>>>  hw/i2c/smbus_ich9.c | 6 +++++-
>>>  hw/isa/lpc_ich9.c   | 7 +++++--
>>>  2 files changed, 10 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/hw/i2c/smbus_ich9.c b/hw/i2c/smbus_ich9.c
>>> index c1ffa34..8d47eaf 100644
>>> --- a/hw/i2c/smbus_ich9.c
>>> +++ b/hw/i2c/smbus_ich9.c
>>> @@ -97,11 +97,15 @@ static void ich9_smb_class_init(ObjectClass *klass, void *data)
>>>      k->device_id = PCI_DEVICE_ID_INTEL_ICH9_6;
>>>      k->revision = ICH9_A2_SMB_REVISION;
>>>      k->class_id = PCI_CLASS_SERIAL_SMBUS;
>>> -    dc->cannot_instantiate_with_device_add_yet = true; /* FIXME explain why */
>>>      dc->vmsd = &vmstate_ich9_smbus;
>>>      dc->desc = "ICH9 SMBUS Bridge";
>>>      k->init = ich9_smbus_initfn;
>>>      k->config_write = ich9_smbus_write_config;
>>> +    /*
>>> +     * Reason: part of ICH9 southbridge, needs to be wired up by
>>> +     * pc_q35_init()
>>> +     */
>>> +    dc->cannot_instantiate_with_device_add_yet = true;
>>>  }
>>>  
>>>  i2c_bus *ich9_smb_init(PCIBus *bus, int devfn, uint32_t smb_io_base)
>>> diff --git a/hw/isa/lpc_ich9.c b/hw/isa/lpc_ich9.c
>>> index ad841b5..d00d698 100644
>>> --- a/hw/isa/lpc_ich9.c
>>> +++ b/hw/isa/lpc_ich9.c
>>> @@ -604,14 +604,17 @@ static void ich9_lpc_class_init(ObjectClass *klass, void *data)
>>>      dc->reset = ich9_lpc_reset;
>>>      k->init = ich9_lpc_initfn;
>>>      dc->vmsd = &vmstate_ich9_lpc;
>>> -    dc->cannot_instantiate_with_device_add_yet = true; /* FIXME explain why */
>>>      k->config_write = ich9_lpc_config_write;
>>>      dc->desc = "ICH9 LPC bridge";
>>>      k->vendor_id = PCI_VENDOR_ID_INTEL;
>>>      k->device_id = PCI_DEVICE_ID_INTEL_ICH9_8;
>>>      k->revision = ICH9_A2_LPC_REVISION;
>>>      k->class_id = PCI_CLASS_BRIDGE_ISA;
>>> -
>>> +    /*
>>> +     * Reason: part of ICH9 southbridge, needs to be wired up by
>>> +     * pc_q35_init()
>>> +     */
>>> +    dc->cannot_instantiate_with_device_add_yet = true;
>>>  }
>>>  
>>>  static const TypeInfo ich9_lpc_info = {
>>>
>> 
>> I think SMBus is fine.  Even though the standard configuration of the
>> Q35 SMBus cannot be reproduced with -device, that's a problem of
>> hw/i2c/smbus_eeprom.c, not of the smbus bridge itself.  I think
>> hw/i2c/smbus_eeprom.c should rather be marked as
>> cannot_instantiate_with_device_add_yet (which makes sense, because it
>> has a PROP_PTR).
>> 
>> Alternatively, you can resuscitate the first two patches of
>> http://lists.gnu.org/archive/html/qemu-devel/2012-02/msg00449.html

Getting rid of pointer properties is useful work, but outside the scope
of this series.

> Ah, got it---the SMBus and LPC need to be connected to each other.

Yup, that's the reason.

> Still, the SMBus EEPROM is a candidate for
> cannot_instantiate_with_device_add_yet.

I'll add it in the next version, along with all other devices with
pointer properties.  Thanks!
diff mbox

Patch

diff --git a/hw/i2c/smbus_ich9.c b/hw/i2c/smbus_ich9.c
index c1ffa34..8d47eaf 100644
--- a/hw/i2c/smbus_ich9.c
+++ b/hw/i2c/smbus_ich9.c
@@ -97,11 +97,15 @@  static void ich9_smb_class_init(ObjectClass *klass, void *data)
     k->device_id = PCI_DEVICE_ID_INTEL_ICH9_6;
     k->revision = ICH9_A2_SMB_REVISION;
     k->class_id = PCI_CLASS_SERIAL_SMBUS;
-    dc->cannot_instantiate_with_device_add_yet = true; /* FIXME explain why */
     dc->vmsd = &vmstate_ich9_smbus;
     dc->desc = "ICH9 SMBUS Bridge";
     k->init = ich9_smbus_initfn;
     k->config_write = ich9_smbus_write_config;
+    /*
+     * Reason: part of ICH9 southbridge, needs to be wired up by
+     * pc_q35_init()
+     */
+    dc->cannot_instantiate_with_device_add_yet = true;
 }
 
 i2c_bus *ich9_smb_init(PCIBus *bus, int devfn, uint32_t smb_io_base)
diff --git a/hw/isa/lpc_ich9.c b/hw/isa/lpc_ich9.c
index ad841b5..d00d698 100644
--- a/hw/isa/lpc_ich9.c
+++ b/hw/isa/lpc_ich9.c
@@ -604,14 +604,17 @@  static void ich9_lpc_class_init(ObjectClass *klass, void *data)
     dc->reset = ich9_lpc_reset;
     k->init = ich9_lpc_initfn;
     dc->vmsd = &vmstate_ich9_lpc;
-    dc->cannot_instantiate_with_device_add_yet = true; /* FIXME explain why */
     k->config_write = ich9_lpc_config_write;
     dc->desc = "ICH9 LPC bridge";
     k->vendor_id = PCI_VENDOR_ID_INTEL;
     k->device_id = PCI_DEVICE_ID_INTEL_ICH9_8;
     k->revision = ICH9_A2_LPC_REVISION;
     k->class_id = PCI_CLASS_BRIDGE_ISA;
-
+    /*
+     * Reason: part of ICH9 southbridge, needs to be wired up by
+     * pc_q35_init()
+     */
+    dc->cannot_instantiate_with_device_add_yet = true;
 }
 
 static const TypeInfo ich9_lpc_info = {