On 22/07/16 08:52, Auger Eric wrote: > Hi Marc, > > On 22/07/2016 09:47, Marc Zyngier 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. >>> >>> Is there something missing on my platform or is this a general KVM ARM >>> issue? >> >> This looks like a genuine bug, and I suspect this is triggered by having >> an older QEMU that predates the explicit vgic init, hence relying on the >> "init at first run". But in the meantime, could you dump me the bit of >> kernel log that shows the KVM initialization, just in case I spot >> something odd there? > Had the same idea but QEMU v2.4.0 has the commit: > > hw/intc/arm_gic: Initialize the vgic in the realize function > (f0bb55890a173cb1e9e87d608647cac70f8f9dd4) Fair enough. I'm (slowly) rebuilding a v2.4.0 QEMU on my A7 board, and hopefully I'll be able to reproduce this sucker. Thanks, M. -- Jazz is not dead. It just smells funny... _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
