Re: [Qemu-devel] Could not boot a guest vm from kvm mode based on APM X-Gene Host and latest qemu

["Alex Bennée" <alex.bennee@linaro.org>]

liang yan <liangy@hpe.com> writes:

> On 09/16/2015 08:34 AM, Alex Bennée wrote:
>> liang yan <liangy@hpe.com> writes:
>>
>>> Hello, All,
>>>
>>> I am trying to enable kvm for a guest vm on an APM X-Gene Host with
>>> latest qemu, but could not make it work.
>>>
>>> The host is APM X-Gene 8-core, Linux kernel is 4.1.0-rc7-1-arm64,
>>>
>>> Guest kernel is linux-3.16rc3
>>>
>>> QEMU is latest version
>>>
>>> Host has these dmesg info
>>> [    2.708259] kvm [1]: GICH base=0x780c0000, GICV base=0x780e0000, IRQ=25
>>> [    2.708327] kvm [1]: timer IRQ30
>>> [    2.708335] kvm [1]: Hyp mode initialized successfully
>>>
>>> Host has dev/kvm.
>>>
>>> command-line is
>>> aarch64-softmmu/qemu-system-aarch64 -machine virt,kernel_irqchip=off
>>> -cpu cortex-a57 -machine accel=kvm -nographic -smp 1 -m 2048 -kernel
>>> aarch64-linux-3.16rc3-buildroot.img  --append "console=ttyAMA0"
>> I thought I recognised one of my images ;-)
>>
>> Why are you running with kernel_irqchip=off?
>
>
> Hello, Alex,
>
> Thanks for your reply and your pre-boot image. Very helpful.
>
> The reason I ran with "kernel_irqchip=off" is because it showed the 
> error "Create kernel irqchip failed: No such device"
> are you familiar with it?

No but I suspect it is a kernel configuration issue. Are you running a
defconfig?

>
> I did not try kernel 4.3.x yet, have you released on your linaro website 
> now?

That's running directly from Linus' tree so it's pure mainline.

> Thanks for your log file, it shows something wrong with the vcpu, I am 
> gonna check the kvm code from host kernel now.
> Will let you know the update.

Mark Zyngier pointed out that's a know bug that there are patches
in-flight for.

>
>
> Best,
> Liang
>
>> Without it I can boot the image fine on my APM running 4.3.0-rc1-ajb but
>> with it I helpfully seg the kernel:
> =============================================
>>
>> [16035.990518] Bad mode in Synchronous Abort handler detected, code 0x86000006 -- IABT (current EL)
> =============================================
>> [16035.997970] CPU: 1 PID: 21328 Comm: qemu-system-aar Not tainted 4.3.0-rc1-ajb #446
>> [16036.004203] Hardware name: APM X-Gene Mustang board (DT)
>> [16036.008191] task: ffffffc3ecea8000 ti: ffffffc3d8078000 task.ti: ffffffc3d8078000
>> [16036.014338] PC is at 0x0
>> [16036.015564] LR is at kvm_vgic_map_resources+0x30/0x3c
>> [16036.019291] pc : [<0000000000000000>] lr : [<ffffffc0000ae900>] pstate: 00000145
>> [16036.025350] sp : ffffffc3d807bb20
>> [16036.027348] x29: ffffffc3d807bb20 x28: ffffffc3d8078000
>> [16036.031355] x27: ffffffc000642000 x26: 000000000000001d
>> [16036.035361] x25: 000000000000011b x24: ffffffc3d80c1000
>> [16036.039368] x23: 0000000000000000 x22: 0000000000000000
>> [16036.043374] x21: ffffffc0fa240000 x20: ffffffc0fa807800
>> [16036.047380] x19: ffffffc0fa807800 x18: 0000007f97af20e0
>> [16036.051387] x17: 0000007f99c44810 x16: ffffffc0001fb030
>> [16036.055394] x15: 0000007f99cc9588 x14: 0000000000922000
>> [16036.059401] x13: 000000000097eb80 x12: 00000000004de0f0
>> [16036.063406] x11: 0000000000000038 x10: 00000000ffffffff
>> [16036.067413] x9 : 0000007f97af2480 x8 : 0000000000000050
>> [16036.071419] x7 : ffffffc3ec24c840 x6 : 0000000000000000
>> [16036.075424] x5 : 0000000000000003 x4 : ffffffc3ece72080
>> [16036.079430] x3 : ffffffc3ece72080 x2 : 0000000000000000
>> [16036.083436] x1 : ffffffc000a26260 x0 : ffffffc0fa807800
> ====================================
>> [16036.087628] Internal error: Oops - bad mode: 0 [#1] SMP
> ====================================
>
>> [16036.091528] Modules linked in:
>> [16036.093278] CPU: 1 PID: 21328 Comm: qemu-system-aar Not tainted 4.3.0-rc1-ajb #446
>> [16036.099510] Hardware name: APM X-Gene Mustang board (DT)
>> [16036.103497] task: ffffffc3ecea8000 ti: ffffffc3d8078000 task.ti: ffffffc3d8078000
>> [16036.109642] PC is at 0x0
>> [16036.110864] LR is at kvm_vgic_map_resources+0x30/0x3c
>> [16036.114590] pc : [<0000000000000000>] lr : [<ffffffc0000ae900>] pstate: 00000145
>> [16036.120649] sp : ffffffc3d807bb20
>> [16036.122648] x29: ffffffc3d807bb20 x28: ffffffc3d8078000
>> [16036.126654] x27: ffffffc000642000 x26: 000000000000001d
>> [16036.130659] x25: 000000000000011b x24: ffffffc3d80c1000
>> [16036.134666] x23: 0000000000000000 x22: 0000000000000000
>> [16036.138671] x21: ffffffc0fa240000 x20: ffffffc0fa807800
>> [16036.142678] x19: ffffffc0fa807800 x18: 0000007f97af20e0
>> [16036.146685] x17: 0000007f99c44810 x16: ffffffc0001fb030
>> [16036.150690] x15: 0000007f99cc9588 x14: 0000000000922000
>> [16036.154696] x13: 000000000097eb80 x12: 00000000004de0f0
>> [16036.158701] x11: 0000000000000038 x10: 00000000ffffffff
>> [16036.162706] x9 : 0000007f97af2480 x8 : 0000000000000050
>> [16036.166712] x7 : ffffffc3ec24c840 x6 : 0000000000000000
>> [16036.170719] x5 : 0000000000000003 x4 : ffffffc3ece72080
>> [16036.174725] x3 : ffffffc3ece72080 x2 : 0000000000000000
>> [16036.178731] x1 : ffffffc000a26260 x0 : ffffffc0fa807800
>>
>>>
>>> when using cpu "cortex-a57", got the error "kvm_init_vcpu failed:
>>> Invalid argument"
>>> when using cpu "host", got the error "Failed to retrieve host CPU features!"
>>>
>>> By the way, all the command line works well under "tcg" mode.
>>> Anyone has a quick idea? Thanks in advance.
>>>
>>> Best,
>>> Liang

-- 
Alex Bennée