[Qemu-devel] Re: [PATCH 2/2] Don't register cpu reset handler for cpu with APIC.

[Jan Kiszka <jan.kiszka@web.de>]

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Gleb Natapov wrote:
> On Tue, Jun 09, 2009 at 12:21:09PM +0200, Jan Kiszka wrote:
>> Gleb Natapov wrote:
>>> APIC reset handler already resets cpu. Also register cpu_reset handler
>>> directly to make it impossible to add additional code to main_cpu_reset()
>>> by mistake.
>>>
>>> Signed-off-by: Gleb Natapov <gleb@redhat.com>
>>> ---
>>>  hw/pc.c |   10 +++-------
>>>  1 files changed, 3 insertions(+), 7 deletions(-)
>>>
>>> diff --git a/hw/pc.c b/hw/pc.c
>>> index d5b4112..5e7b115 100644
>>> --- a/hw/pc.c
>>> +++ b/hw/pc.c
>>> @@ -751,12 +751,6 @@ static void load_linux(target_phys_addr_t option_rom,
>>>      generate_bootsect(option_rom, gpr, seg, 0);
>>>  }
>>>  
>>> -static void main_cpu_reset(void *opaque)
>>> -{
>>> -    CPUState *env = opaque;
>>> -    cpu_reset(env);
>>> -}
>>> -
>>>  static const int ide_iobase[2] = { 0x1f0, 0x170 };
>>>  static const int ide_iobase2[2] = { 0x3f6, 0x376 };
>>>  static const int ide_irq[2] = { 14, 15 };
>>> @@ -878,9 +872,11 @@ static void pc_init1(ram_addr_t ram_size,
>>>          }
>>>          if (i != 0)
>>>              env->halted = 1;
>>> -        qemu_register_reset(main_cpu_reset, 0, env);
>>>          if ((env->cpuid_features & CPUID_APIC) || smp_cpus > 1) {
>>>              apic_init(env);
>>> +        } else {
>>> +	    /* APIC reset callback resets cpu */
>> That comment should rather go into the previous block (and please remove
>> the tab).
>>
>>> +            qemu_register_reset((QEMUResetHandler*)cpu_reset, 0, env);
>>>          }
>>>      }
>>>  
>> Looks fine to me otherwise. Will give these patches a try later today.
>>
> Let me know when you tested it and if no additional fixes needed I'll resend
> fixed version.

No regressions found with both patches applied.

I was not able to convince a 586 Linux kernel to boot more than one CPU
in the absence of LAPICs. But that was independent of the patches and is
likely a BIOS issue ("BIOS bug, local APIC #0 not detected!...").

Jan


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