Re: [PATCH-for-11.0 v6 05/13] hw/nvram/fw_cfg: Propagate I/O MemoryRegion to fw_cfg_init_io_dma()

["Philippe Mathieu-Daudé" <philmd@linaro.org>]

On 3/12/25 16:39, Zhao Liu wrote:
> On Wed, Dec 03, 2025 at 07:09:33AM +0100, Philippe Mathieu-Daudé wrote:
>> Date: Wed,  3 Dec 2025 07:09:33 +0100
>> From: Philippe Mathieu-Daudé <philmd@linaro.org>
>> Subject: [PATCH-for-11.0 v6 05/13] hw/nvram/fw_cfg: Propagate I/O
>>   MemoryRegion to fw_cfg_init_io_dma()
>> X-Mailer: git-send-email 2.51.0
>>
>> To allow callers to use I/O MemoryRegion different than the
>> global get_system_io(), pass it as argument.
>>
>> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
>> ---
>>   include/hw/nvram/fw_cfg.h | 4 ++--
>>   hw/i386/fw_cfg.c          | 3 ++-
>>   hw/i386/microvm.c         | 3 ++-
>>   hw/i386/pc.c              | 3 ++-
>>   hw/nvram/fw_cfg.c         | 5 ++---
>>   5 files changed, 10 insertions(+), 8 deletions(-)
> 
> ...
> 
>> diff --git a/hw/i386/microvm.c b/hw/i386/microvm.c
>> index 94d22a232ac..69f04d74a15 100644
>> --- a/hw/i386/microvm.c
>> +++ b/hw/i386/microvm.c
>> @@ -289,6 +289,7 @@ static void microvm_memory_init(MicrovmMachineState *mms)
>>       X86MachineState *x86ms = X86_MACHINE(mms);
>>       MemoryRegion *ram_below_4g, *ram_above_4g;
>>       MemoryRegion *system_memory = get_system_memory();
>> +    MemoryRegion *io_memory = get_system_io();
>>       FWCfgState *fw_cfg;
>>       ram_addr_t lowmem = 0xc0000000; /* 3G */
>>       int i;
>> @@ -319,7 +320,7 @@ static void microvm_memory_init(MicrovmMachineState *mms)
>>           e820_add_entry(0x100000000ULL, x86ms->above_4g_mem_size, E820_RAM);
>>       }
>>   
>> -    fw_cfg = fw_cfg_init_io_dma(FW_CFG_IO_BASE, FW_CFG_IO_BASE + 4,
>> +    fw_cfg = fw_cfg_init_io_dma(io_memory, FW_CFG_IO_BASE, FW_CFG_IO_BASE + 4,
> 
> It seems here we can use get_system_io() directly :).

I tried to follow the function style (see local system_memory
declaration); I don't mind ;)

> 
> Otherwise,
> 
> Reviewed-by: Zhao Liu <zhao1.liu@intel.com>

Thanks!

> 
>>                                   &address_space_memory);
>>   
>>       fw_cfg_add_i16(fw_cfg, FW_CFG_NB_CPUS, machine->smp.cpus);