Re: [PATCH] hw/pci: Display correct size for unmapped BARs in HMP 'info pci'

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

On 3/1/23 18:39, BALATON Zoltan wrote:
> On Tue, 3 Jan 2023, Philippe Mathieu-Daudé wrote:
>> When a BAR is not mapped, the displayed size is shifted by 1 byte:
>>
>>  (qemu) info pci
>>    ...
>>    Bus  0, device  11, function 0:
>>      Ethernet controller: PCI device 1022:2000
>>        PCI subsystem 0000:0000
>>        IRQ 10, pin A
>>        BAR0: I/O at 0xffffffffffffffff [0x001e].
>>        BAR1: 32 bit memory at 0xffffffffffffffff [0x0000001e].   <===
>>        BAR6: 32 bit memory at 0xffffffffffffffff [0x0003fffe].   <===
>>        id ""
>>    Bus  0, device  18, function 0:
>>      VGA controller: PCI device 1013:00b8
>>        PCI subsystem 1af4:1100
>>        BAR0: 32 bit prefetchable memory at 0x10000000 [0x11ffffff].
>>        BAR1: 32 bit memory at 0x12050000 [0x12050fff].
>>        BAR6: 32 bit memory at 0xffffffffffffffff [0x0000fffe].   <===
>>        id ""
>>
>> Only substract this byte when the BAR is mapped to display
>> the correct size:
>>
>>  (qemu) info pci
>>    ...
>>    Bus  0, device  11, function 0:
>>      Ethernet controller: PCI device 1022:2000
>>        PCI subsystem 0000:0000
>>        IRQ 10, pin A
>>        BAR0: I/O at 0xffffffffffffffff [0x001f].
>>        BAR1: 32 bit memory at 0xffffffffffffffff [0x0000001f].   <===
>>        BAR6: 32 bit memory at 0xffffffffffffffff [0x0003ffff].   <===
>>        id ""
>>    Bus  0, device  18, function 0:
>>      VGA controller: PCI device 1013:00b8
>>        PCI subsystem 1af4:1100
>>        BAR0: 32 bit prefetchable memory at 0x10000000 [0x11ffffff].
>>        BAR1: 32 bit memory at 0x12050000 [0x12050fff].
>>        BAR6: 32 bit memory at 0xffffffffffffffff [0x0000ffff].   <===
>>        id ""
>>
>> Fixes: 0ac32c8375 ("PCI interrupt support - 'info pci' monitor command")
>> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
>> ---
>> hw/pci/pci-hmp-cmds.c | 6 ++++--
>> 1 file changed, 4 insertions(+), 2 deletions(-)
>>
>> diff --git a/hw/pci/pci-hmp-cmds.c b/hw/pci/pci-hmp-cmds.c
>> index fb7591d6ab..8cfa5f9cd1 100644
>> --- a/hw/pci/pci-hmp-cmds.c
>> +++ b/hw/pci/pci-hmp-cmds.c
>> @@ -75,22 +75,24 @@ static void hmp_info_pci_device(Monitor *mon, 
>> const PciDeviceInfo *dev)
>>
>>     for (region = dev->regions; region; region = region->next) {
>>         uint64_t addr, size;
>> +        bool mapped;
>>
>>         addr = region->value->address;
>>         size = region->value->size;
> 
> As size is not used for anything else, you could adjust the value here 
> once either as
> 
> size = region->value->size - (addr != -1 ? 1 : 0);
> 
> or in an if then you don't need the bool and tweak the value when 
> printing. This looks simpler to me.

Good idea, thanks!