QEMU简单后端跟踪不会打印任何内容 [英] QEMU simple backend tracing dosen't print anything

问题描述

我正在从QEMU获取简单的跟踪文件. 我遵循了docs/tracing.txt

I'm doing get simple trace file from QEMU. I followed instructions docs/tracing.txt

使用此命令"qemu-system-x86_64 -m 2G -trace events =/tmp/events ../qemu/test.img"

with this command "qemu-system-x86_64 -m 2G -trace events=/tmp/events ../qemu/test.img"

我只想获取简单的跟踪文件. 我有trace-pid文件，但是里面没有任何东西.

i'd like to get just simple trace file. i've got trace-pid file, however, it dosen't have anything in it.

1. 使用简单"跟踪后端进行构建:

1. Build with the 'simple' trace backend:

./configure --enable-trace-backends =简单 制作

./configure --enable-trace-backends=simple make

使用您要跟踪的事件创建文件:

Create a file with the events you want to trace:

echo bdrv_aio_readv>/tmp/events 回声bdrv_aio_writev >>/tmp/events

echo bdrv_aio_readv > /tmp/events echo bdrv_aio_writev >> /tmp/events

运行虚拟机以生成跟踪文件:

Run the virtual machine to produce a trace file:

qemu -trace events =/tmp/events ...#您正常的QEMU调用

qemu -trace events=/tmp/events ... # your normal QEMU invocation

漂亮地打印二进制跟踪文件:

Pretty-print the binary trace file:

./scripts/simpletrace.py trace-events trace- *#使用QEMU覆盖*

./scripts/simpletrace.py trace-events trace-* # Override * with QEMU

我遵循了此说明. 请有人给我一些有关这种情况的建议.

i followd this instructions. please somebody give me some advise for this situation.

谢谢！

推荐答案

通过遵循相同的文档，我遇到了相同的问题. https://fossies.org/linux/qemu/docs/tracing.txt 一无所有，因为 默认情况下，未启用bdrv_aio_readv和bdrv_aio_writev，至少未启用我编译的版本.您需要在源目录下打开trace-events，寻找一些未禁用的行，例如我使用: 回声"load_file">/tmp/events 然后开始qemu， 来宾开始后，我跑步 ./scripts/simpletrace.py跟踪事件trace-Pid 我有

I got same problem by following the same document. https://fossies.org/linux/qemu/docs/tracing.txt got nothing because bdrv_aio_readv and bdrv_aio_writev was not enabled by default, at least the version I complied, was not enabled. you need to open trace-events under source directory, looking for some line without disabled, e.g. I using: echo "load_file" > /tmp/events Then start qemu, after a guest started, I run ./scripts/simpletrace.py trace-events trace-Pid I got

load_file 1474.156 pid=5249 name=kvmvapic.bin path=qemu-2.8.0-rc0/pc-bios/kvmvapic.bin
load_file 22437.571 pid=5249 name=vgabios-stdvga.bin path=qemu-2.8.0-rc0/pc-bios/vgabios-stdvga.bin
load_file 10034.465 pid=5249 name=efi-e1000.rom 

您还可以在qemu命令行中添加-monitor stdio，启动后，您可以在qemu CLI中执行以下命令:

you can also add -monitor stdio to qemu command line, after it started, you can the following command in qemu CLI:

(qemu)信息跟踪事件

(qemu) info trace-events

load_file : state 1
vm_state_notify : state 1
balloon_event : state 0
cpu_out : state 0
cpu_in : state 0

1表示已启用的事件.

1 means enabled events.

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