Opened 16 months ago
Closed 3 months ago
#18520 closed bug (fixed)
Undefined instruction exception on arch_cpu_idle() call in QEMU with KVM (ARM image)
Reported by: | Illen | Owned by: | davidkaroly |
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Priority: | normal | Milestone: | Unscheduled |
Component: | System/Kernel | Version: | R1/Development |
Keywords: | Cc: | ||
Blocked By: | Blocking: | ||
Platform: | arm |
Description
This happens only with qemu-system-aarch64 running with KVM accelerator (not qemu-system-arm with emulated cortex-a15 core).
Host: Lenovo Vibe K5 running postmarketOS with Linux 6.3.0
Host CPU: Qualcomm Snapdragon 415 (MSM8929)
QEMU command:
qemu-system-aarch64 -bios AAVMF32_CODE.fd -enable-kvm -M virt -cpu host,aarch64=off -m 1024 -device virtio-blk-device,drive=x0,bus=virtio-mmio-bus.0 -drive file="haiku-mmc.image",if=none,format=raw,id=x0 -device ramfb -usb -device qemu-xhci,id=xhci -device usb-mouse -device usb-kbd -serial stdio -vnc :0
EDK2 firmware taken from qemu-efi-arm package from Debian Buster.
Stack trace:
usb xhci -1: starting XHCI host controller Exception: Undefined Instruction R00=00000001 R01=600000d3 R02=00000001 R03=00000000 R04=801efc40 R05=00000000 R06=801cc104 R07=801f0b24 R08=801f0b20 R09=30c5183d R10=7fa88c9c R11=82684fdc R12=801cd8ac SPs=82684fd8 LRs=80065228 PC =80065268 SPu=00000000 LRu=00000000 CPSR=60000053 PANIC: not handled! Welcome to Kernel Debugging Land... Thread 1 "idle thread 1" running on CPU 0 iframe 0x82684f8c (end = 0x82684fd8) stack trace for thread 0x1 "idle thread 1" kernel stack: 0x82681000 to 0x82685000 frame caller <image>:function + offset 0 82684e7c (+ 52) 80164898 <kernel_arm> arch_debug_call_with_fault_handler() + 0x1c 1 82684eb0 (+ 56) 800c1d1c <kernel_arm> _ZL20kernel_debugger_loopPKcS0_St9__va_listi() + 0x140 2 82684ee8 (+ 80) 800c2240 <kernel_arm> _ZL24kernel_debugger_internalPKcS0_St9__va_listi() + 0x1bc 3 82684f38 (+ 24) 800c25a0 <kernel_arm> panic() + 0x48 4 82684f50 (+ 56) 80163350 <kernel_arm> arch_arm_undefined() + 0xec 5 82684f88 (+ 4) 80162808 <kernel_arm> arm_undefined() + 0x60 iframe at 0x82684f8c R00 0x00000001 R01 0x600000d3 R02 0x00000001 R03 0x00000000 R04 0x801efc40 R05 0x00000000 R06 0x801cc104 R07 0x801f0b24 R08 0x801f0b20 R09 0x30c5183d R10 0x7fa88c9c R11 0x82684fdc R12 0x801cd8ac SPs 0x82684fd8 LRs 0x80065228 PC 0x80065268 SPu 0x00000000 LRu 0x00000000 SPSR 0x60000053 6 82684f8c (+ 80) 80065268 <kernel_arm> cpu_idle() + 0x4c 7 82684fdc (+ 32) 80071f98 <kernel_arm> _start() + 0x274 8 82684ffc (+ 0) 7c15c048
Haiku hrev57156 ARM
According to ARMv7 Reference Manual, on ARMv7 and later "Wait for Interrupt" is supported through WFI
instruction (not a CP15 c7 function like done here, probably for older ARM CPUs).
Since from what I see Haiku ARM port targets ARMv7 CPU anyway, it probably makes more sense to just use WFI
.
This seems to fix the problem:
diff --git a/headers/private/kernel/arch/arm/arch_cpu.h b/headers/private/kernel/arch/arm/arch_cpu.h index a165f1ca09..b80e650425 100644 --- a/headers/private/kernel/arch/arm/arch_cpu.h +++ b/headers/private/kernel/arch/arm/arch_cpu.h @@ -122,9 +122,7 @@ arch_cpu_pause(void) static inline void arch_cpu_idle(void) { - uint32 Rd = 0; - asm volatile("mcr p15, 0, %[c7format], c7, c0, 4" - : : [c7format] "r" (Rd) ); + asm volatile("wfi"); }
Change History (4)
comment:1 by , 16 months ago
Owner: | changed from | to
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Status: | new → assigned |
comment:2 by , 16 months ago
Summary: | Undefined instruction exception on arch_cpu_idle() call in QEMU with KVM → Undefined instruction exception on arch_cpu_idle() call in QEMU with KVM (ARM image) |
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comment:3 by , 16 months ago
Yes, wfi
sounds like a good idea. We're already using ARMv7 memory barrier instructions isb
and dsb
instead of the respective ARMv6 cp15 instructions.
Just adding a mention that it is related to the arm image. Thanks for reporting!