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) Eric > > I'll try and dig a QEMU of that particular vintage to reproduce it. > > Thanks for the heads up! > > M. > _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
