id = 1200
title = "always zero when query-dirty-rate"
state = "opened"
created_at = "2022-09-08T08:31:08.604Z"
closed_at = "n/a"
labels = ["Migration"]
url = "https://gitlab.com/qemu-project/qemu/-/issues/1200"
host-os = "n/a"
host-arch = "n/a"
qemu-version = "n/a"
guest-os = "n/a"
guest-arch = "n/a"
description = """The creation of VM works well(by virt-install), and I can enter it by 'virsh console or ssh'.

Now, I try to use qemu's feature: calc-dirty-rate.

But, always get '"dirty-rate":0' when 'query-dirty-rate', occasionally '"dirty-rate":2'.

At the same time, I run 'mbw'(mbw -t0 -n 1000000 1024 -q) in vm, a memcpy-intensive benchmark.


I'm not sure if some configurations of QEMU/KVM are not enabled.

looking forward to your reply!"""
reproduce = """```
1. virsh qemu-monitor-command centos-huazhang '{"execute":"calc-dirty-rate", "arguments": {"calc-time": 1}}'

   {"return":{},"id":"libvirt-16"}

2. virsh qemu-monitor-command centos-huazhang1 '{"execute":"query-dirty-rate"}'
   
   {"return":{"status":"measured","sample-pages":512,"dirty-rate":0,"mode":"page-sampling","start-time":607266,"calc-time":1},"id":"libvirt-17"}

```"""
additional = "n/a"