On Sat, 23 Jul 2016 00:45:50 -0700 Stefan Agner <stefan@xxxxxxxx> wrote: > On 2016-07-22 11:11, Marc Zyngier wrote: > > On 22/07/16 18:56, Stefan Agner wrote: > >> On 2016-07-22 10:49, Marc Zyngier wrote: > >>> 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 > >> > >> Hehe, was just plowing through code and came to that conclusion, glad I > >> got that right :-) > >> > >> What defconfig do you use? I could reproduce the issue also with > >> multi_v7_defconfig + ARM_LPAE + KVM. > > > > I have my own config file with the crap I need to make things work on > > the various platforms I have around. If multi_v7_defconfig works on the > > cubietruck, I'll give it a spin tomorrow. I need a beer now. > > > >> Btw, I am not exactly on vanilla 4.7-rc7, I merged Shawns for-next + > >> clock next to get to the bits and pieces required for my board... > >> > >> That said, it works fine otherwise, and the stacktrace looks rather > >> platform independent... > > > > Yeah, and that's the worrying part. > > > FWIW, I tried here with Qemu 2.6.0, same stack trace... I don't think this is userspace related, specially given that Andrew managed to trigger it on arm64 as well. I guess we're looking at something that changes the layout of memory (page size in Drew's case), and exposes another latent bug. I'll try to get multi_v7_defconfig running on my CT later today, and hopefully the thing will explode. Fingers crossed. M. -- Jazz is not dead. It just smells funny. _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
