On Thu, 01 Feb 2024 15:17:53 +0000 Alex Bennée <alex.ben...@linaro.org> wrote:
> Peter Maydell <peter.mayd...@linaro.org> writes: > > > On Thu, 1 Feb 2024 at 14:01, Jonathan Cameron > > <jonathan.came...@huawei.com> wrote: > >> > Can you run QEMU under gdb and give the backtrace when it stops > >> > on the abort() ? That will probably have a helpful clue. I > >> > suspect something is failing to pass a valid retaddr in > >> > when it calls a load/store function. > > > >> [Switching to Thread 0x7ffff56ff6c0 (LWP 21916)] > >> __pthread_kill_implementation (no_tid=0, signo=6, threadid=<optimized > >> out>) at ./nptl/pthread_kill.c:44 > >> 44 ./nptl/pthread_kill.c: No such file or directory. > >> (gdb) bt > >> #0 __pthread_kill_implementation (no_tid=0, signo=6, threadid=<optimized > >> out>) at ./nptl/pthread_kill.c:44 > >> #1 __pthread_kill_internal (signo=6, threadid=<optimized out>) at > >> ./nptl/pthread_kill.c:78 > >> #2 __GI___pthread_kill (threadid=<optimized out>, signo=signo@entry=6) at > >> ./nptl/pthread_kill.c:89 > >> #3 0x00007ffff77c43b6 in __GI_raise (sig=sig@entry=6) at > >> ../sysdeps/posix/raise.c:26 > >> #4 0x00007ffff77aa87c in __GI_abort () at ./stdlib/abort.c:79 > >> #5 0x0000555555c0d4ce in cpu_abort > >> (cpu=cpu@entry=0x555556fd9000, fmt=fmt@entry=0x555555fe3378 > >> "cpu_io_recompile: could not find TB for pc=%p") > >> at ../../cpu-target.c:359 > >> #6 0x0000555555c59435 in cpu_io_recompile (cpu=cpu@entry=0x555556fd9000, > >> retaddr=retaddr@entry=0) at ../../accel/tcg/translate-all.c:611 > >> #7 0x0000555555c5c956 in io_prepare > >> (retaddr=0, addr=19595792376, attrs=..., xlat=<optimized out>, > >> cpu=0x555556fd9000, out_offset=<synthetic pointer>) > >> at ../../accel/tcg/cputlb.c:1339 > <snip> > >> #21 tb_htable_lookup (cpu=<optimized out>, > >> pc=pc@entry=18446744072116178925, cs_base=0, flags=415285936, > >> cflags=4278353920) > >> at ../../accel/tcg/cpu-exec.c:231 > >> #22 0x0000555555c50c08 in tb_lookup > >> (cpu=cpu@entry=0x555556fd9000, pc=pc@entry=18446744072116178925, > >> cs_base=cs_base@entry=0, flags=<optimized out>, cflags=<optimized out>) at > >> ../../accel/tcg/cpu-exec.c:267 > >> #23 0x0000555555c51e23 in helper_lookup_tb_ptr (env=0x555556fdb7c0) at > >> ../../accel/tcg/cpu-exec.c:423 > >> #24 0x00007fffa9076ead in code_gen_buffer () > >> #25 0x0000555555c50fab in cpu_tb_exec (cpu=cpu@entry=0x555556fd9000, > >> itb=<optimized out>, tb_exit=tb_exit@entry=0x7ffff56fe708) > >> at ../../accel/tcg/cpu-exec.c:458 > >> #26 0x0000555555c51492 in cpu_loop_exec_tb > >> (tb_exit=0x7ffff56fe708, last_tb=<synthetic pointer>, > >> pc=18446744072116179169, tb=<optimized out>, cpu=0x555556fd9000) > >> at ../../accel/tcg/cpu-exec.c:920 > >> #27 cpu_exec_loop (cpu=cpu@entry=0x555556fd9000, > >> sc=sc@entry=0x7ffff56fe7a0) at ../../accel/tcg/cpu-exec.c:1041 > >> #28 0x0000555555c51d11 in cpu_exec_setjmp (cpu=cpu@entry=0x555556fd9000, > >> sc=sc@entry=0x7ffff56fe7a0) at ../../accel/tcg/cpu-exec.c:1058 > >> #29 0x0000555555c523b4 in cpu_exec (cpu=cpu@entry=0x555556fd9000) at > >> ../../accel/tcg/cpu-exec.c:1084 > >> #30 0x0000555555c74053 in tcg_cpus_exec (cpu=cpu@entry=0x555556fd9000) at > >> ../../accel/tcg/tcg-accel-ops.c:76 > >> #31 0x0000555555c741a0 in mttcg_cpu_thread_fn > >> (arg=arg@entry=0x555556fd9000) at ../../accel/tcg/tcg-accel-ops-mttcg.c:95 > >> #32 0x0000555555dfb580 in qemu_thread_start (args=0x55555703c3e0) at > >> ../../util/qemu-thread-posix.c:541 > >> #33 0x00007ffff78176ba in start_thread (arg=<optimized out>) at > >> ./nptl/pthread_create.c:444 > >> #34 0x00007ffff78a60d0 in clone3 () at > >> ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81 > > > > So, that looks like: > > * we call cpu_tb_exec(), which executes some generated code > > * that generated code calls the lookup_tb_ptr helper to see > > if we have a generated TB already for the address we're going > > to execute next > > * lookup_tb_ptr probes the TLB to see if we know the host RAM > > address for the guest address > > * this results in a TLB walk for an instruction fetch > > * the page table descriptor load is to IO memory > > * io_prepare assumes it needs to do a TLB recompile, because > > can_do_io is clear > > > > I am not surprised that the corner case of "the guest put its > > page tables in an MMIO device" has not yet come up :-) > > > > I'm really not sure how the icount handling should interact > > with that... > > Its not just icount - we need to handle it for all modes now. That said > seeing as we are at the end of a block shouldn't can_do_io be set? > > Does: > > modified accel/tcg/translator.c > @@ -201,6 +201,8 @@ void translator_loop(CPUState *cpu, TranslationBlock *tb, > int *max_insns, > } > } > > + set_can_do_io(db, true); > + > /* Emit code to exit the TB, as indicated by db->is_jmp. */ > ops->tb_stop(db, cpu); > gen_tb_end(tb, cflags, icount_start_insn, db->num_insns); > > do the trick? no :( > > > > > -- PMM >
