On Thu, 18 Mar 2021 16:59:47 +0000, Will Deacon <will@xxxxxxxxxx> wrote: > > On Thu, Mar 18, 2021 at 02:33:11PM +0000, Andrew Scull wrote: > > To aid with debugging, add details of the source of a panic from nVHE > > hyp. This is done by having nVHE hyp exit to nvhe_hyp_panic_handler() > > rather than directly to panic(). The handler will then add the extra > > details for debugging before panicking the kernel. > > > > If the panic was due to a BUG(), look up the metadata to log the file > > and line, if available, otherwise log an address that can be looked up > > in vmlinux. The hyp offset is also logged to allow other hyp VAs to be > > converted, similar to how the kernel offset is logged during a panic. > > > > __hyp_panic_string is now inlined since it no longer needs to be > > referenced as a symbol and the message is free to diverge between VHE > > and nVHE. > > > > The following is an example of the logs generated by a BUG in nVHE hyp. > > > > [ 46.754840] kvm [307]: nVHE hyp BUG at: arch/arm64/kvm/hyp/nvhe/switch.c:242! > > [ 46.755357] kvm [307]: Hyp Offset: 0xfffea6c58e1e0000 > > [ 46.755824] Kernel panic - not syncing: HYP panic: > > [ 46.755824] PS:400003c9 PC:0000d93a82c705ac ESR:f2000800 > > [ 46.755824] FAR:0000000080080000 HPFAR:0000000000800800 PAR:0000000000000000 > > [ 46.755824] VCPU:0000d93a880d0000 > > [ 46.756960] CPU: 3 PID: 307 Comm: kvm-vcpu-0 Not tainted 5.12.0-rc3-00005-gc572b99cf65b-dirty #133 > > [ 46.757459] Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015 > > [ 46.758366] Call trace: > > [ 46.758601] dump_backtrace+0x0/0x1b0 > > [ 46.758856] show_stack+0x18/0x70 > > [ 46.759057] dump_stack+0xd0/0x12c > > [ 46.759236] panic+0x16c/0x334 > > [ 46.759426] arm64_kernel_unmapped_at_el0+0x0/0x30 > > [ 46.759661] kvm_arch_vcpu_ioctl_run+0x134/0x750 > > [ 46.759936] kvm_vcpu_ioctl+0x2f0/0x970 > > [ 46.760156] __arm64_sys_ioctl+0xa8/0xec > > [ 46.760379] el0_svc_common.constprop.0+0x60/0x120 > > [ 46.760627] do_el0_svc+0x24/0x90 > > [ 46.760766] el0_svc+0x2c/0x54 > > [ 46.760915] el0_sync_handler+0x1a4/0x1b0 > > [ 46.761146] el0_sync+0x170/0x180 > > [ 46.761889] SMP: stopping secondary CPUs > > [ 46.762786] Kernel Offset: 0x3e1cd2820000 from 0xffff800010000000 > > [ 46.763142] PHYS_OFFSET: 0xffffa9f680000000 > > [ 46.763359] CPU features: 0x00240022,61806008 > > [ 46.763651] Memory Limit: none > > Nice! > > > [ 46.813867] ---[ end Kernel panic - not syncing: HYP panic: > > [ 46.813867] PS:400003c9 PC:0000d93a82c705ac ESR:f2000800 > > [ 46.813867] FAR:0000000080080000 HPFAR:0000000000800800 PAR:0000000000000000 > > [ 46.813867] VCPU:0000d93a880d0000 ]--- > > Why did these last three lines get printed twice? That's the panic string that gets repeated, a standard "feature" of the panic code: root@tiger-roach:~# echo -n 'c' > /proc/sysrq-trigger [250622.941867] sysrq: Trigger a crash [250622.941903] Kernel panic - not syncing: sysrq triggered crash [250622.945515] CPU: 0 PID: 4890 Comm: bash Tainted: G E 5.11.0 #3124 [250622.952930] Hardware name: , BIOS 2021.01-rc2-00012-gde865f7ee1 11/16/2020 [250622.959917] Call trace: [250622.962417] dump_backtrace+0x0/0x1e4 [250622.966126] show_stack+0x24/0x80 [250622.969490] dump_stack+0xc8/0x120 [250622.972940] panic+0x178/0x38c [250622.976045] sysrq_handle_crash+0x28/0x30 [250622.980098] __handle_sysrq+0x98/0x1a4 [250622.983893] write_sysrq_trigger+0x94/0x12c [250622.988120] proc_reg_write+0xb4/0xf0 [250622.991828] vfs_write+0xfc/0x29c [250622.995192] ksys_write+0x74/0x100 [250622.998642] __arm64_sys_write+0x28/0x3c [250623.002610] el0_svc_common.constprop.0+0x80/0x1c0 [250623.007440] do_el0_svc+0x30/0xa0 [250623.010803] el0_svc+0x28/0x70 [250623.013908] el0_sync_handler+0x1a8/0x1ac [250623.017962] el0_sync+0x174/0x180 [250623.021331] SMP: stopping secondary CPUs [250623.025301] Kernel Offset: 0x435917bf0000 from 0xffff800010000000 [250623.031417] PHYS_OFFSET: 0xffff9bc5c0000000 [250623.035643] CPU features: 0x08240022,2aa0a830 [250623.040042] Memory Limit: none [250623.043153] ---[ end Kernel panic - not syncing: sysrq triggered crash ]--- KVM just happens to have a fairly large, multi line panic string. M. -- Without deviation from the norm, progress is not possible. _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
