Re: [Qemu-devel] ppc vga output breakage since commit c3c1bb99

[Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>]

On 30/03/15 12:47, Paolo Bonzini wrote:

> On 30/03/2015 13:45, Peter Crosthwaite wrote:
>> Can the address_space_translate_address() length clamp be made
>> conditional on non-MMIO access as the RC fix? I submitted
>> c3c1bb99d1c11978d9ce94d1bdcf0705378c1459 as I think its the right
>> thing to do regardless of memory type, but in reality it only fixes a
>> bug I encountered with RAM memory regions. The original code ignores
>> address_space_translate_internal() return-by-pointer length value
>> absolutely and the new code uses it absolutely. Should we just if the
>> whole thing, old vs new behaviour on MMIO vs non-MMIO?
>>
>> Happy to submit that fixup if that's the accepted plan.
> 
> I submitted what I think is the right fix (sorry Mark for misspelling
> your email address).  I think you're patch is correct, so I'd rather not
> introduce hacks for the release; we can either revert it, or fix ioport.c.

Ah wait a second - the same patch c3c1bb99 also breaks reset on SPARC32:

$ ./qemu-system-sparc -prom-env 'auto-boot?=false' -nographic
Configuration device id QEMU version 1 machine id 32
Probing SBus slot 0 offset 0
Probing SBus slot 1 offset 0
Probing SBus slot 2 offset 0
Probing SBus slot 3 offset 0
Probing SBus slot 4 offset 0
Probing SBus slot 5 offset 0
Invalid FCode start byte
CPUs: 1 x FMI,MB86904
UUID: 00000000-0000-0000-0000-000000000000
Welcome to OpenBIOS v1.1 built on Mar 12 2015 08:08
  Type 'help' for detailed information

0 > reset-all Unhandled Exception 0x00000029
PC = 0xffd10c08 NPC = 0xffd10c0c
Stopping execution

The reset is controlled by writing a 1 to the hardware reset register at
physical address 0x71f00000 (system-control according to "info mtree")
which is handled in hw/misc/slavio_misc.c.

Given that SYSCTRL_SIZE isn't used at all (and the access size for
slavio_led_mem_ops also looks wrong), the following seems to be the
correct fix for the reset and LED access:


--- a/hw/misc/slavio_misc.c
+++ b/hw/misc/slavio_misc.c
@@ -68,6 +68,7 @@ typedef struct APCState {
 } APCState;

 #define MISC_SIZE 1
+#define LED_SIZE 2
 #define SYSCTRL_SIZE 4

 #define AUX1_TC        0x02
@@ -452,13 +453,13 @@ static int slavio_misc_init1(SysBusDevice *sbd)
     /* 16 bit registers */
     /* ss600mp diag LEDs */
     memory_region_init_io(&s->led_iomem, OBJECT(s), &slavio_led_mem_ops, s,
-                          "leds", MISC_SIZE);
+                          "leds", LED_SIZE);
     sysbus_init_mmio(sbd, &s->led_iomem);

     /* 32 bit registers */
     /* System control */
     memory_region_init_io(&s->sysctrl_iomem, OBJECT(s),
&slavio_sysctrl_mem_ops, s,
-                          "system-control", MISC_SIZE);
+                          "system-control", SYSCTRL_SIZE);
     sysbus_init_mmio(sbd, &s->sysctrl_iomem);

     /* AUX 1 (Misc System Functions) */


Then again it is getting quite late in the release cycle...


ATB,

Mark.