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| author | Christian Krinitsin <mail@krinitsin.com> | 2025-07-03 19:39:53 +0200 |
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| committer | Christian Krinitsin <mail@krinitsin.com> | 2025-07-03 19:39:53 +0200 |
| commit | dee4dcba78baf712cab403d47d9db319ab7f95d6 (patch) | |
| tree | 418478faf06786701a56268672f73d6b0b4eb239 /results/classifier/deepseek-r1:14b/output/hypervisor/2791 | |
| parent | 4d9e26c0333abd39bdbd039dcdb30ed429c475ba (diff) | |
| download | emulator-bug-study-dee4dcba78baf712cab403d47d9db319ab7f95d6.tar.gz emulator-bug-study-dee4dcba78baf712cab403d47d9db319ab7f95d6.zip | |
restructure results
Diffstat (limited to 'results/classifier/deepseek-r1:14b/output/hypervisor/2791')
| -rw-r--r-- | results/classifier/deepseek-r1:14b/output/hypervisor/2791 | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/results/classifier/deepseek-r1:14b/output/hypervisor/2791 b/results/classifier/deepseek-r1:14b/output/hypervisor/2791 new file mode 100644 index 00000000..b01153c9 --- /dev/null +++ b/results/classifier/deepseek-r1:14b/output/hypervisor/2791 @@ -0,0 +1,64 @@ + +"Missing character write event in the replay log" when trying rr=replay with snapshot +Description of problem: +Probably best to just illustrate with commands. Happy path: + +```sh +rm replay.bin snapshots.qcow2; qemu-img create -f qcow2 snapshots.qcow2 256M + +~/src/qemu/build/qemu-system-x86_64 -nodefaults -nographic -serial stdio \ + -icount shift=auto,rr=record,rrfile=replay.bin,rrsnapshot=init \ + -drive file=snapshots.qcow2,if=none,id=rr \ + -kernel ./.kunit/arch/x86/boot/bzImage -append "nokaslr console=ttyS0" + +# It runs, guest kernel crashes when realising it has no rootfs, all good +du -sh snapshots.qcow2 # 976K + +# Repeat same command just switched to rr=replay +~/src/qemu/build/qemu-system-x86_64 -nodefaults -nographic -serial stdio \ + -icount shift=auto,rr=replay,rrfile=replay.bin,rrsnapshot=init \ + -drive file=snapshots.qcow2,if=none,id=rr \ + -kernel ./.kunit/arch/x86/boot/bzImage -append "nokaslr console=ttyS0" +# Much slower, but same result. All good +``` + +But, I want to take a snapshot later in boot. + +```sh +rm replay.bin snapshots.qcow2; qemu-img create -f qcow2 snapshots.qcow2 256M + +# This time, running with debug. Also have to switch to -monitor stdio because of +# https://gitlab.com/qemu-project/qemu/-/issues/2790 +~/src/qemu/build/qemu-system-x86_64 -nodefaults -nographic -monitor stdio \ + -icount shift=auto,rr=record,rrfile=replay.bin,rrsnapshot=init \ + -drive file=snapshots.qcow2,if=none,id=rr \ + -kernel ./.kunit/arch/x86/boot/bzImage -append "nokaslr console=ttyS0" \ + -s -S + +# In another terminal, attach a debugger, set a breakpoint, continue to the breakpoint +gdb -ex "target remote localhost:1234" .kunit/vmlinux +(gdb) hb start_kernel +(gdb) continue + +# When the breakpoint is hit, back in the first terminal: +(qemu) savevm test +(qemu) quit + +du -sh snapshots.qcow2 # 21M + +# Now try to replay again +~/src/qemu/build/qemu-system-x86_64 -nodefaults -nographic -serial stdio \ + -icount shift=auto,rr=replay,rrfile=replay.bin,rrsnapshot=init \ + -drive file=snapshots.qcow2,if=none,id=rr \ + -kernel ./.kunit/arch/x86/boot/bzImage -append "nokaslr console=ttyS0" +``` + +Result: + +``` +qemu-system-x86_64: Missing character write event in the replay log (insn total 1598039/586 left, event 886 is EVENT_INSTRUCTION) +fish: Job 1, '~/src/qemu/build/qemu-system-x8…' terminated by signal -icount shift=auto,rr=repla… ( -drive file=snapshots.qcow2…) +fish: Job -kernel ./.kunit/arch/x86/b…, 'SIGABRT' terminated by signal Abort () +``` + +Exit code is 134. |