Re: [Qemu-devel] [PATCH v4 05/11] qemu-log: Improve the "exec" TB execution logging

[Christopher Covington <cov@codeaurora.org>]

Hi Peter, Alex,

On 08/03/2015 05:14 AM, Alex Bennée wrote:
> From: Peter Maydell <peter.maydell@linaro.org>
> 
> Improve the TB execution logging so that it is easier to identify
> what is happening from trace logs:
>  * move the "Trace" logging of executed TBs into cpu_tb_exec()
>    so that it is emitted if and only if we actually execute a TB,
>    and for consistency for the CPU state logging
>  * log when we link two TBs together via tb_add_jump()
>  * log when cpu_tb_exec() returns early from a chain of TBs
> 
> The new style logging looks like this:
> 
> Trace 0x7fb7cc822ca0 [ffffffc0000dce00]
> Linking TBs 0x7fb7cc822ca0 [ffffffc0000dce00] index 0 -> 0x7fb7cc823110 [ffffffc0000dce10]
> Trace 0x7fb7cc823110 [ffffffc0000dce10]
> Trace 0x7fb7cc823420 [ffffffc000302688]
> Trace 0x7fb7cc8234a0 [ffffffc000302698]
> Trace 0x7fb7cc823520 [ffffffc0003026a4]
> Trace 0x7fb7cc823560 [ffffffc0000dce44]
> Linking TBs 0x7fb7cc823560 [ffffffc0000dce44] index 1 -> 0x7fb7cc8235d0 [ffffffc0000dce70]
> Trace 0x7fb7cc8235d0 [ffffffc0000dce70]
> Abandoned execution of TB chain before 0x7fb7cc8235d0 [ffffffc0000dce70]
> Trace 0x7fb7cc8235d0 [ffffffc0000dce70]
> Trace 0x7fb7cc822fd0 [ffffffc0000dd52c]

Do you think there's some way to log the loop count when a circular chain is
executed?

System Emulation started at Mon Aug 10 15:30:49 2015
Invocation:aarch64-softmmu/qemu-system-aarch64 -M virt -cpu cortex-a57 -m 2G
-kernel psci-exit -d exec,int,in_asm -nodefaults -nographic -monitor none
-icount shift=0
----------------
IN:
0x0000000080000000:  d2800140      mov x0, #0xa
0x0000000080000004:  f1000400      subs x0, x0, #0x1 (1)
0x0000000080000008:  54ffffe1      b.ne #-0x4 (addr 0x80000004)

Trace 0x7f38787cb000 [0000000080000000]
----------------
IN:
0x0000000080000004:  f1000400      subs x0, x0, #0x1 (1)
0x0000000080000008:  54ffffe1      b.ne #-0x4 (addr 0x80000004)

Linking TBs 0x7f38787cb000 [0000000080000000] index 1 -> 0x7f38787cb0d0
[0000000080000004]
Trace 0x7f38787cb0d0 [0000000080000004]
Linking TBs 0x7f38787cb0d0 [0000000080000004] index 1 -> 0x7f38787cb0d0
[0000000080000004]
Trace 0x7f38787cb0d0 [0000000080000004]
----------------
IN:
0x000000008000000c:  d2800100      mov x0, #0x8
0x0000000080000010:  f2b08000      movk x0, #0x8400, lsl #16
0x0000000080000014:  d4000002      hvc #0x0

Linking TBs 0x7f38787cb0d0 [0000000080000004] index 0 -> 0x7f38787cb1c0
[000000008000000c]
Trace 0x7f38787cb1c0 [000000008000000c]
Taking exception 11 [Hypervisor Call]
...from EL1
...with ESR 0x5a000000

Thanks,
Christopher Covington

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