Re: [PATCH v5 2/5] i386/pc: create pci-host qdev prior to pc_memory_init()

[Joao Martins]

On 6/16/22 14:21, Reviewed-by: Igor Mammedov wrote:
> On Fri, 20 May 2022 11:45:29 +0100
> Joao Martins <joao.m.martins@oracle.com> wrote:
> 
>> At the start of pc_memory_init() we usually pass a range of
>> 0..UINT64_MAX as pci_memory, when really its 2G (i440fx) or
>> 32G (q35). To get the real user value, we need to get pci-host
>> passed property for default pci_hole64_size. Thus to get that,
>> create the qdev prior to memory init to better make estimations
>> on max used/phys addr.
>>
>> This is in preparation to determine that host-phys-bits are
>> enough and also for pci-hole64-size to be considered to relocate
>> ram-above-4g to be at 1T (on AMD platforms).
> 
> with comments below fixed
> Reviewed-by: Igor Mammedov <imammedo@redhat.com>
>  
Having fixed your comments, I added this thanks!

>> Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
>> ---
>>  hw/i386/pc_piix.c            | 5 ++++-
>>  hw/i386/pc_q35.c             | 6 +++---
>>  hw/pci-host/i440fx.c         | 3 +--
>>  include/hw/pci-host/i440fx.h | 2 +-
>>  4 files changed, 9 insertions(+), 7 deletions(-)
>>
>> diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
>> index 578e537b3525..12d4a279c793 100644
>> --- a/hw/i386/pc_piix.c
>> +++ b/hw/i386/pc_piix.c
>> @@ -91,6 +91,7 @@ static void pc_init1(MachineState *machine,
>>      MemoryRegion *pci_memory;
>>      MemoryRegion *rom_memory;
>>      ram_addr_t lowmem;
>> +    DeviceState *i440fx_dev;
>>  
>>      /*
>>       * Calculate ram split, for memory below and above 4G.  It's a bit
>> @@ -164,9 +165,11 @@ static void pc_init1(MachineState *machine,
>>          pci_memory = g_new(MemoryRegion, 1);
>>          memory_region_init(pci_memory, NULL, "pci", UINT64_MAX);
>>          rom_memory = pci_memory;
>> +        i440fx_dev = qdev_new(host_type);
>>      } else {
>>          pci_memory = NULL;
>>          rom_memory = system_memory;
>> +        i440fx_dev = NULL;
>>      }
>>  
>>      pc_guest_info_init(pcms);
>> @@ -199,7 +202,7 @@ static void pc_init1(MachineState *machine,
>>  
>>          pci_bus = i440fx_init(host_type,
>>                                pci_type,
>> -                              &i440fx_state,
>> +                              i440fx_dev, &i440fx_state,
> confusing names, suggest to rename i440fx_state -> pci_i440fx and i440fx_dev 
> -> i440fx_host
> or something like this
> 
I've changed i440fx_dev as that's what I add in this patch.

>>                                system_memory, system_io, machine->ram_size,
>>                                x86ms->below_4g_mem_size,
>>                                x86ms->above_4g_mem_size,
>> diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
>> index 42eb8b97079a..8d867bdb274a 100644
>> --- a/hw/i386/pc_q35.c
>> +++ b/hw/i386/pc_q35.c
>> @@ -203,12 +203,12 @@ static void pc_q35_init(MachineState *machine)
>>                              pcms->smbios_entry_point_type);
>>      }
>>  
>> -    /* allocate ram and load rom/bios */
>> -    pc_memory_init(pcms, get_system_memory(), rom_memory, &ram_memory);
>> -
>>      /* create pci host bus */
>>      q35_host = Q35_HOST_DEVICE(qdev_new(TYPE_Q35_HOST_DEVICE));
>>  
>> +    /* allocate ram and load rom/bios */
>> +    pc_memory_init(pcms, get_system_memory(), rom_memory, &ram_memory);
>> +
>>      object_property_add_child(qdev_get_machine(), "q35", OBJECT(q35_host));
>>      object_property_set_link(OBJECT(q35_host), MCH_HOST_PROP_RAM_MEM,
>>                               OBJECT(ram_memory), NULL);
>> diff --git a/hw/pci-host/i440fx.c b/hw/pci-host/i440fx.c
>> index e08716142b6e..5c1bab5c58ed 100644
>> --- a/hw/pci-host/i440fx.c
>> +++ b/hw/pci-host/i440fx.c
>> @@ -238,6 +238,7 @@ static void i440fx_realize(PCIDevice *dev, Error **errp)
>>  }
>>  
>>  PCIBus *i440fx_init(const char *host_type, const char *pci_type,
> 
> does it still need 'host_type'?
> 
I've removed it.

>> +                    DeviceState *dev,
>>                      PCII440FXState **pi440fx_state,
>>                      MemoryRegion *address_space_mem,
>>                      MemoryRegion *address_space_io,
>> @@ -247,7 +248,6 @@ PCIBus *i440fx_init(const char *host_type, const char 
>> *pci_type,
>>                      MemoryRegion *pci_address_space,
>>                      MemoryRegion *ram_memory)
>>  {
>> -    DeviceState *dev;
>>      PCIBus *b;
>>      PCIDevice *d;
>>      PCIHostState *s;
>> @@ -255,7 +255,6 @@ PCIBus *i440fx_init(const char *host_type, const char 
>> *pci_type,
>>      unsigned i;
>>      I440FXState *i440fx;
>>  
>> -    dev = qdev_new(host_type);
>>      s = PCI_HOST_BRIDGE(dev);
>>      b = pci_root_bus_new(dev, NULL, pci_address_space,
>>                           address_space_io, 0, TYPE_PCI_BUS);
>> diff --git a/include/hw/pci-host/i440fx.h b/include/hw/pci-host/i440fx.h
>> index f068aaba8fda..c4710445e30a 100644
>> --- a/include/hw/pci-host/i440fx.h
>> +++ b/include/hw/pci-host/i440fx.h
>> @@ -36,7 +36,7 @@ struct PCII440FXState {
>>  #define TYPE_IGD_PASSTHROUGH_I440FX_PCI_DEVICE "igd-passthrough-i440FX"
>>  
>>  PCIBus *i440fx_init(const char *host_type, const char *pci_type,
>> -                    PCII440FXState **pi440fx_state,
>> +                    DeviceState *dev, PCII440FXState **pi440fx_state,
>>                      MemoryRegion *address_space_mem,
>>                      MemoryRegion *address_space_io,
>>                      ram_addr_t ram_size,
>