Hyper-V framebuffer driver

[yuripv]

Summary

WIP for Hyper-V framebuffer driver.

This allows to use more comfortable resolution than the one that comes by default in Gen2 UEFI VMs (1024x768).

Currently the resolution used is the one that is explicitly specified on the host (note the -single, otherwise the one reported to VM is not it):
Set-VMVideo -vmname <name> -ResolutionType single -HorizontalResolution 1920 -VerticalResolution 1080

What is missing is the sane way to send updates to the host, vt drivers do not seem to have any kind of "dirt" callback.

[yuripv]

Add naive implementation of scheduled updates.

[yuripv]

• add sysctl to control the "fps"
• add pnp entries
• add to build

[lwhsu]

sys/dev/hyperv/hvfb/hv_fb.c

2

Just being curious, is this code copied and modified from the existing one? If you modified enough, maybe you also want to add your copyright along with this?

[schakrabarti_microsoft.com]

Has this change been tested?

[yuripv]

In D39395#899221, @schakrabarti_microsoft.com wrote:

Has this change been tested?

Of course, I used it as I was working on it :)

I didn't add anyone to reviewers though just yet as I am still thinking about the options here:

1. have this in base for a (bit better) resolution with console and scfb
2. have this entirely in drm-kmod (that will be completely separate change) for things like wayland compositors to work
3. have this in base and provide interfaces for drm module to re-use

[arrowd]

It'd be great to get this in.

[schakrabarti_microsoft.com]

In D39395#899654, @yuripv wrote:

In D39395#899221, @schakrabarti_microsoft.com wrote:

Has this change been tested?

Of course, I used it as I was working on it :)

I didn't add anyone to reviewers though just yet as I am still thinking about the options here:

1. have this in base for a (bit better) resolution with console and scfb
2. have this entirely in drm-kmod (that will be completely separate change) for things like wayland compositors to work
3. have this in base and provide interfaces for drm module to re-use

Please add me and Wei Hu as reviewer .