Re: [PATCH 4/7] hw/i386/pc_q35: Resolve redundant q35_host variable

[Bernhard Beschow <shentey@gmail.com>]

Am 27. Januar 2023 19:22:49 UTC schrieb BALATON Zoltan <balaton@eik.bme.hu>:
>On Fri, 27 Jan 2023, Bernhard Beschow wrote:
>> The variable is redundant to "phb" and is never used by its real type.
>
>Also replace qdev_get_machine() with reference already passed to init function. (Maybe worth mentioning in commit message even if too small change for a separate patch.)

Indeed, this can easily be missed. A separate patch allows for clean justification.

>
>> Signed-off-by: Bernhard Beschow <shentey@gmail.com>
>> ---
>> hw/i386/pc_q35.c | 22 ++++++++++------------
>> 1 file changed, 10 insertions(+), 12 deletions(-)
>> 
>> diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
>> index 83c57c6eb1..dc94ce1081 100644
>> --- a/hw/i386/pc_q35.c
>> +++ b/hw/i386/pc_q35.c
>> @@ -118,7 +118,6 @@ static void pc_q35_init(MachineState *machine)
>>     PCMachineState *pcms = PC_MACHINE(machine);
>>     PCMachineClass *pcmc = PC_MACHINE_GET_CLASS(pcms);
>>     X86MachineState *x86ms = X86_MACHINE(machine);
>> -    Q35PCIHost *q35_host;
>>     PCIHostState *phb;
>
>The phb variable itself is only used once to get the bus from it and it's mostly cast to Object * so maybe store it in a variable of that type to remove most of the casts and IMO you can also remove PCIHostState *phb and just use:
>
>host_bus = PCI_HOST_BRIDGE(phost)->bus;

Maybe one could also fish out the PCI bus using qdev_get_child_bus() like we do in pc_piix for the ISA bus already. Hm...

Best regards,
Bernhard
>
>Regards,
>BALATON Zoltan
>
>>     PCIBus *host_bus;
>>     PCIDevice *lpc;
>> @@ -206,10 +205,10 @@ static void pc_q35_init(MachineState *machine)
>>     }
>> 
>>     /* create pci host bus */
>> -    q35_host = Q35_HOST_DEVICE(qdev_new(TYPE_Q35_HOST_DEVICE));
>> +    phb = PCI_HOST_BRIDGE(qdev_new(TYPE_Q35_HOST_DEVICE));
>> 
>>     if (pcmc->pci_enabled) {
>> -        pci_hole64_size = object_property_get_uint(OBJECT(q35_host),
>> +        pci_hole64_size = object_property_get_uint(OBJECT(phb),
>>                                                    PCI_HOST_PROP_PCI_HOLE64_SIZE,
>>                                                    &error_abort);
>>     }
>> @@ -218,22 +217,21 @@ static void pc_q35_init(MachineState *machine)
>>     pc_memory_init(pcms, get_system_memory(), rom_memory, &ram_memory,
>>                    pci_hole64_size);
>> 
>> -    object_property_add_child(qdev_get_machine(), "q35", OBJECT(q35_host));
>> -    object_property_set_link(OBJECT(q35_host), MCH_HOST_PROP_RAM_MEM,
>> +    object_property_add_child(OBJECT(machine), "q35", OBJECT(phb));
>> +    object_property_set_link(OBJECT(phb), MCH_HOST_PROP_RAM_MEM,
>>                              OBJECT(ram_memory), NULL);
>> -    object_property_set_link(OBJECT(q35_host), MCH_HOST_PROP_PCI_MEM,
>> +    object_property_set_link(OBJECT(phb), MCH_HOST_PROP_PCI_MEM,
>>                              OBJECT(pci_memory), NULL);
>> -    object_property_set_link(OBJECT(q35_host), MCH_HOST_PROP_SYSTEM_MEM,
>> +    object_property_set_link(OBJECT(phb), MCH_HOST_PROP_SYSTEM_MEM,
>>                              OBJECT(get_system_memory()), NULL);
>> -    object_property_set_link(OBJECT(q35_host), MCH_HOST_PROP_IO_MEM,
>> +    object_property_set_link(OBJECT(phb), MCH_HOST_PROP_IO_MEM,
>>                              OBJECT(system_io), NULL);
>> -    object_property_set_int(OBJECT(q35_host), PCI_HOST_BELOW_4G_MEM_SIZE,
>> +    object_property_set_int(OBJECT(phb), PCI_HOST_BELOW_4G_MEM_SIZE,
>>                             x86ms->below_4g_mem_size, NULL);
>> -    object_property_set_int(OBJECT(q35_host), PCI_HOST_ABOVE_4G_MEM_SIZE,
>> +    object_property_set_int(OBJECT(phb), PCI_HOST_ABOVE_4G_MEM_SIZE,
>>                             x86ms->above_4g_mem_size, NULL);
>>     /* pci */
>> -    sysbus_realize_and_unref(SYS_BUS_DEVICE(q35_host), &error_fatal);
>> -    phb = PCI_HOST_BRIDGE(q35_host);
>> +    sysbus_realize_and_unref(SYS_BUS_DEVICE(phb), &error_fatal);
>>     host_bus = phb->bus;
>>     /* create ISA bus */
>>     lpc = pci_create_simple_multifunction(host_bus, PCI_DEVFN(ICH9_LPC_DEV,
>>