On 22/07/16 18:38, Andrew Jones wrote:
> On Fri, Jul 22, 2016 at 04:40:15PM +0100, Marc Zyngier wrote:
>> On 22/07/16 15:35, Andrew Jones wrote:
>>> On Fri, Jul 22, 2016 at 11:42:02AM +0100, Andre Przywara wrote:
>>>> Hi Stefan,
>>>>
>>>> On 22/07/16 06:57, Stefan Agner wrote:
>>>>> Hi,
>>>>>
>>>>> I tried KVM on a Cortex-A7 platform (i.MX 7Dual SoC) and encountered
>>>>> this stack trace immediately after invoking qemu-system-arm:
>>>>>
>>>>> Unable to handle kernel paging request at virtual address ffffffe4
>>>>> pgd = 8ca52740
>>>>> [ffffffe4] *pgd=80000080007003, *pmd=8ff7e003, *pte=00000000
>>>>> Internal error: Oops: 207 [#1] SMP ARM
>>>>> Modules linked in:
>>>>> CPU: 0 PID: 329 Comm: qemu-system-arm Tainted: G W
>>>>> 4.7.0-rc7-00094-gea3ed2c #109
>>>>> Hardware name: Freescale i.MX7 Dual (Device Tree)
>>>>> task: 8ca3ee40 ti: 8d2b0000 task.ti: 8d2b0000
>>>>> PC is at do_raw_spin_lock+0x8/0x1dc
>>>>> LR is at kvm_vgic_flush_hwstate+0x8c/0x224
>>>>> pc : [<8027c87c>] lr : [<802172d4>] psr: 60070013
>>>>> sp : 8d2b1e38 ip : 8d2b0000 fp : 00000001
>>>>> r10: 8d2b0000 r9 : 00010000 r8 : 8d2b8e54
>>>>> fec 30be0000.ethernet eth0: MDIO read timeout
>>>>> r7 : 8d2b8000 r6 : 8d2b8e74 r5 : 00000000 r4 : ffffffe0
>>>>> r3 : 00004ead r2 : 00000000 r1 : 00000000 r0 : ffffffe0
>>>>> Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user
>>>>> Control: 30c5387d Table: 8ca52740 DAC: fffffffd
>>>>> Process qemu-system-arm (pid: 329, stack limit = 0x8d2b0210)
>>>>> Stack: (0x8d2b1e38 to 0x8d2b2000)
>>>>> 1e20: ffffffe0
>>>>> 00000000
>>>>> 1e40: 8d2b8e74 8d2b8000 8d2b8e54 00010000 8d2b0000 802172d4 8d2b8000
>>>>> 810074f8
>>>>> 1e60: 81007508 8ca5f800 8d284000 00010000 8d2b0000 8020fbd4 8ce9a000
>>>>> 8ca5f800
>>>>> 1e80: 00000000 00010000 00000000 00ff0000 8d284000 00000000 00000000
>>>>> 7ffbfeff
>>>>> 1ea0: fffffffe 00000000 8d28b780 00000000 755fec6c 00000000 00000000
>>>>> ffffe000
>>>>> 1ec0: 8d2b8000 00000000 8d28b780 00000000 755fec6c 8020af90 00000000
>>>>> 8023f248
>>>>> 1ee0: 0000000a 755fe98c 8d2b1f08 00000008 8021aa84 ffffe000 00000000
>>>>> 00000000
>>>>> 1f00: 8a00d860 8d28b780 80334f94 00000000 8d2b0000 80334748 00000000
>>>>> 00000000
>>>>> 1f20: 00000000 8d28b780 00004000 00000009 8d28b500 00000024 8104ebee
>>>>> 80bc2ec4
>>>>> 1f40: 80bafa24 8034138c 00000000 00000000 80341248 00000000 755fec6c
>>>>> 007c1e70
>>>>> 1f60: 00000009 00004258 0000ae80 8d28b781 00000009 8d28b780 0000ae80
>>>>> 00000000
>>>>> 1f80: 8d2b0000 00000000 755fec6c 80334f94 007c1e70 322a7400 00004258
>>>>> 00000036
>>>>> 1fa0: 8021aa84 8021a900 007c1e70 322a7400 00000009 0000ae80 00000000
>>>>> 755feac0
>>>>> 1fc0: 007c1e70 322a7400 00004258 00000036 7e9aff58 01151da4 76f8b4c0
>>>>> 755fec6c
>>>>> 1fe0: 0038192c 755fea9c 00048ae7 7697d66c 60070010 00000009 00000000
>>>>> 00000000
>>>>> [<8027c87c>] (do_raw_spin_lock) from [<802172d4>]
>>>>> (kvm_vgic_flush_hwstate+0x8c/0x224)
>>>>> [<802172d4>] (kvm_vgic_flush_hwstate) from [<8020fbd4>]
>>>>> (kvm_arch_vcpu_ioctl_run+0x110/0x478)
>>>>> [<8020fbd4>] (kvm_arch_vcpu_ioctl_run) from [<8020af90>]
>>>>> (kvm_vcpu_ioctl+0x2e0/0x6d4)
>>>>> [<8020af90>] (kvm_vcpu_ioctl) from [<80334748>]
>>>>> (do_vfs_ioctl+0xa0/0x8b8)
>>>>> [<80334748>] (do_vfs_ioctl) from [<80334f94>] (SyS_ioctl+0x34/0x5c)
>>>>> [<80334f94>] (SyS_ioctl) from [<8021a900>] (ret_fast_syscall+0x0/0x1c)
>>>>> Code: e49de004 ea09ea24 e92d47f0 e3043ead (e5902004)
>>>>> ---[ end trace cb88537fdc8fa206 ]---
>>>>>
>>>>> I use CONFIG_KVM_NEW_VGIC=y. This happens to me with a rather minimal
>>>>> qemu invocation (qemu-system-arm -enable-kvm -M virt -cpu host
>>>>> -nographic -serial stdio -kernel zImage).
>>>>>
>>>>> Using a bit older Qemu version 2.4.0.
>>>>
>>>> I just tried with a self compiled QEMU 2.4.0 and the Ubuntu 14.04
>>>> provided 2.0.0, it worked fine with Linus' current HEAD as a host kernel
>>>> on a Midway (Cortex-A15).
>>>
>>> I can reproduce the issue with a latest QEMU build on AMD Seattle
>>> (I haven't tried anywhere else yet)
>>>
>>>>
>>>> Can you try to disable the new VGIC, just to see if that's a regression?
>>>
>>> Disabling NEW_VGIC "fixes" guest boots.
>>>
>>> I'm not using defconfig for my host kernel. I'll do a couple more
>>> tests and provide a comparison of my config vs. a defconfig in
>>> a few minutes.
>>
>> Damn. It is not failing for me, so it has to be a kernel config thing...
>> If you can narrow it down to the difference with defconfig, that'd be
>> tremendously helpful.
>
> It's PAGE_SIZE; 64K doesn't work, 4K does, regardless of VA_BITS
> selection.
That definitely doesn't match Stefan's report (32bit only has 4k). I'll
give 64k a go in a minute (but I remember doing some 64k stuff a couple
of weeks ago and everything was OK).
Thanks,
M.
--
Jazz is not dead. It just smells funny...
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