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. root@flakes:~# zgrep 64K /proc/config.gz CONFIG_ARM64_64K_PAGES=y VMs up and running. It is definitely something else, potentially affected by the page size. This is going to be a fun weekend. Thanks for having had a look! M. -- Jazz is not dead. It just smells funny... _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
