Re: [Qemu-devel] [PATCH V9 0/8] memory: unify ioport registration

[Jan Kiszka]

On 2012-09-11 13:27, Julien Grall wrote:
> On 09/11/2012 10:25 AM, Avi Kivity wrote:
>> On 09/11/2012 12:15 PM, Avi Kivity wrote:
>>    
>>> On 09/04/2012 06:13 PM, Julien Grall wrote:
>>>      
>>>> This is the nineth version of patch series about ioport registration.
>>>>
>>>> Some part of QEMU still use register_ioport* functions to register ioport.
>>>> These functions doesn't allow to use Memory Listener on it.
>>>>        
>>> Thanks, applied all (w/ updated patch 4), will push shortly.
>>>
>>>
>>>      
>> Aborts with the command line
>>
>>    qemu-system-x86_64 -device isa-debugcon,iobase=0x402,chardev=stdio 
>> -chardev stdio,id=stdio
>>
>>
>>    
> 
> I have bisected and found the problem with bochs_bios_init in hw/pc.c.
> Bosch already register the iport 0x402. I'm not sure that it's a bug.
> In fact register_ioport_read/write check if the current ioport is used
> with the opaque variable.
> Before my patch, bochs_bios_init registered it's ioport with opaque
> NULL, so if someone (like debugcon) wants to use the ioport there is
> no problem. But now, I used portio_list_init to register bochs ioport,
> so the opaque is not NULL.
> I don't really know how to resolve this problem. Perhaps we could
> just improve the debug message.

My suggestion:

pc: Don't listen on debug ports by default

Only listen on debug ports when we also handle them. They are better
handled by debugcon these days which is runtime configurable.

Signed-off-by: Jan Kiszka <address@hidden>

diff --git a/hw/pc.c b/hw/pc.c
index 112739a..70abf0e 100644
--- a/hw/pc.c
+++ b/hw/pc.c
@@ -539,9 +539,9 @@ static void bochs_bios_write(void *opaque, uint32_t addr, 
uint32_t val)
     case 0x401:
         /* used to be panic, now unused */
         break;
+#ifdef DEBUG_BIOS
     case 0x402:
     case 0x403:
-#ifdef DEBUG_BIOS
         fprintf(stderr, "%c", val);
 #endif
         break;

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