Re: heads-up: planned changes in nvmm

[Maxime Villard <max%m00nbsd.net@localhost>]

Le 22/10/2019 à 22:34, Maxime Villard a écrit :
> [I am not subscribed to this list, so if you want to answer, make sure to
> CC me.]
>
> I will soon commit a set of changes in NVMM, which will require a full
> rebuild and reinstallation of: the kernel NVMM driver, the libnvmm API,
> the libnvmm ATF tests, and the qemu-nvmm package if you're using it.
>
> You can cherry-pick each change, but it will be easier to just do a full
> distribution rebuild and reinstall.
>
> Overall it is no different than what I've been doing over the last six
> months. This time, however, the changes will also be pulled up to 9beta
> afterwards.
>
> I will push my changes in -current and update the qemu-nvmm package in
> several rounds probably over several days, and then will pull up to 9beta.
>
> In the meantime, do not upgrade your qemu-nvmm package if you're on 9beta.

So I think I'm done, I'll let the dust settle for a few days, and then will
request pullup9.

To summarize, most of the changes were internal cleanup and API renaming.
There are three user-visible changes however:

(1) PCID support for 64bit guests. This increases performance of many such
guests, because since Meltdown, almost every OS uses PCID, including NetBSD.

(2) New nvmmctl tool, to query the registered VMs in the system. Not
totally useful in its current form, but still good.

(3) Support for Windows 64bit guests. I tested Win8-64bit and Win10-64bit.
This is supported only on Intel CPUs for now, because I don't have a recent
AMD CPU on which to test. Basically, for Win 64bit to work, you must have
the "TPR VCPU conf" capability, ie:
	$ nvmmctl identify
	...
	nvmm: Arch VCPU conf 0x3<CPUID,TPR>
	...
For now on AMD CPUs you will see it's not there. If someone has a recent
AMD CPU on which to test, I can add support.

Also, I've updated the instructions on this page [1], qemu-nvmm must now
be part of the "nvmm" group or launched from a user part of that group.

[1] https://m00nbsd.net/4e0798b7f2620c965d0dd9d6a7a2f296.html