[Qemu-devel] Re: [Bug 657329] [NEW] APIC unusable on QEMU

[Jan Kiszka]

Am 09.10.2010 15:51, Geoffrey Lee wrote:
> Public bug reported:
> 
> The APIC is unusable with QEMU using x86-64 system emulation.  Problem
> exists in the latest stable QEMU 0.12.5 as well as the latest git head.
> I am using Mac OS X 10.6, 64-bit version of QEMU.
> 
> The QEMU binary was configured with:
> 
>  ./configure --target-list=i386-softmmu,x86_64-softmmubck-i-search:
> conf_
> 
> Problem is that the hw/apic.c file (as well as a few other naughty
> files) rely on the cpu_single_env global - which is set to NULL in cpu-
> exec.c.
> 
> Below is a test reading the local APIC version register:
> 
> Before taking it out:
> 
> (qemu) xp 0xfee00030
> 00000000fee00030: 0x00000000
> (qemu)
> 
> After:
> 
> (qemu) xp 0xfee00030
> 00000000fee00030: 0x00050011
> (qemu)

Well, the APIC is very well usable for the VCPUs (which run with proper
cpu_single_env set. It is just out of reach for your debugging attempt.
We are working (granted: not actively ATM) on a proper device dump
interface that will allow to inspect the current APIC state as well.

BTW, your "fix" won't work if you enable io-thread support.

Jan

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