Re: [PATCH v4] hw/nvme: Use ioeventfd to handle doorbell updates

[Jinhao Fan]

at 3:41 PM, Klaus Jensen <its@irrelevant.dk> wrote:

> On Jul 26 15:35, Jinhao Fan wrote:
>> at 4:55 AM, Klaus Jensen <its@irrelevant.dk> wrote:
>> 
>>> We have a regression following this patch that we need to address.
>>> 
>>> With this patch, issuing a reset on the device (`nvme reset /dev/nvme0`
>>> will do the trick) causes QEMU to hog my host cpu at 100%.
>>> 
>>> I'm still not sure what causes this. The trace output is a bit
>>> inconclusive still.
>>> 
>>> I'll keep looking into it.
>> 
>> I cannot reproduce this bug. I just start the VM and used `nvme reset
>> /dev/nvme0`. Did you do anything before the reset?
> 
> Interesting and thanks for checking! Looks like a kernel issue then!
> 
> I remember that I'm using a dev branch (nvme-v5.20) of the kernel and
> reverting to a stock OS kernel did not produce the bug.

I’m using 5.19-rc4 which I pulled from linux-next on Jul 1. It works ok on
my machine.