[Qemu-devel] Some issues of hotpluging memory and cpus

[Qemu-devel] Some issues of hotpluging memory and cpus

[linzhecheng]

Hi, all,
I had some problems when doing memory hot plugging. After a lot of tests, I was able to stably reproduce the following issues with Windows 2012 R2:

1. If I hot-plug the memory immediately after hot-plugging the CPUs, these memory devices will not be detected by windows OS because I cannot see them in the device manager.
2. If I add a certain delay (for example, 2s or more) between the hot-plugging memory and the CPU, the memory devices will be detected but some of them may not be online.
And Memory Module Properties displaying the following contents:

This device cannot start. (Code 10)
{Conflicting Address Range}
The specified address range conflicts with the address space.

3. usb tablet mouse would not work probability after hot adding memory.

Due to the closed nature of windows OS, I can't know what's going on inside.
Is it related to acpi tables exposure?
I hope you can give me some advice, thank you.

Re: [Qemu-devel] Some issues of hotpluging memory and cpus

[Igor Mammedov]

On Mon, 25 Jun 2018 13:30:10 +0000
linzhecheng <linzhecheng@huawei.com> wrote:

> Hi, all,
> I had some problems when doing memory hot plugging. After a lot of tests, I was able to stably reproduce the following issues with Windows 2012 R2:
> 
> 1. If I hot-plug the memory immediately after hot-plugging the CPUs, these memory devices will not be detected by windows OS because I cannot see them in the device manager.
> 2. If I add a certain delay (for example, 2s or more) between the hot-plugging memory and the CPU, the memory devices will be detected but some of them may not be online.
> And Memory Module Properties displaying the following contents:
> 
> This device cannot start. (Code 10)
> {Conflicting Address Range}
> The specified address range conflicts with the address space.
it could help if you can find in device manger what it conflicts with


> 3. usb tablet mouse would not work probability after hot adding memory.
> 
> Due to the closed nature of windows OS, I can't know what's going on inside.
> Is it related to acpi tables exposure?
> I hope you can give me some advice, thank you.

you also can try running QEMU with cphp_* and mhp_* trace events enabled [*],
it should show ACPI interaction os Windows with QEMU including address assignment.


*) docs/devel/tracing.txt