RE: [PATCH 07/13] x86/kconfig/64: Enable more virtualization guest options in the defconfig: enable Xen, Xen_PVH, Jailhouse, ACRN, Intel TDX and Hyper-V

[Michael Kelley]

From: Ingo Molnar <mingo@xxxxxxxxxx> Sent: Friday, May 16, 2025 12:49 AM
> 
> * Michael Kelley <mhklinux@xxxxxxxxxxx> wrote:
> 
> > From: Ingo Molnar <mingo@xxxxxxxxxx> Sent: Thursday, May 15, 2025 6:27 AM
> > >
> > > Since the x86 defconfig aims to be a distro kernel work-alike with
> > > fewer drivers and a shorter build time, refresh all the virtualization
> > > guest Kconfig features, enabling paravirt spinlocks, and
> > > enabling the guest support code for the following guests:
> > >
> > >  - Xen
> > >  - Xen_PVH
> > >  - Jailhouse
> > >  - ACRN
> > >  - Intel TDX
> > >  - Hyper-V
> >
> > I built and tested a Hyper-V guest with defconfig.
> 
> Thank you!
> 
> > The Hyper-V storage and keyboard drivers are pulled in automatically,
> > so my previous comment about them being "missing" is moot.
> 
> Yeah. "defconfig compression" is a bit non-obvious, as the file doesn't
> carry indirect select and default-y-enabled options.
> 
> > But the Linux console for each Hyper-V guest is a synthetic graphics
> > console, and that didn't work with the DRM_HYPERV driver. Missing
> > the console pretty much kills any usefulness. DRM doesn't have
> > Linux console support, so it needs CONFIG_DRM_FBDEV_EMULATION
> > to be set, and defconfig doesn't have it.
> >
> > So either CONFIG_DRM_FBDEV_EMULATION needs to be added, or
> > defconfig should switch to the older HYPERV_FB driver. I think we'd
> > rather do the former. Vitaly -- any thoughts?
> 
> We can certainly enable that option, and it's likely useful for other
> guests as well - see the delta patch below I applied.
> 
> Based on your description I also added your Tested-by tag:
> 
>     Tested-by: Michael Kelley <mhklinux@xxxxxxxxxxx> # On Hyper-V
> 

Sounds good!  Thank you.

Michael

> And pushed it all out to:
> 
>   git://git.kernel.org/pub/scm/linux/kernel/git/mingo/tip.git WIP.x86/kconfig
> 
> Thanks,
> 
> 	Ingo
> 
> =================================>
>  arch/x86/configs/x86_64_defconfig | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/arch/x86/configs/x86_64_defconfig b/arch/x86/configs/x86_64_defconfig
> index df786b8b4e85..15c6b5f3b2fc 100644
> --- a/arch/x86/configs/x86_64_defconfig
> +++ b/arch/x86/configs/x86_64_defconfig
> @@ -203,6 +203,7 @@ CONFIG_AGP=y
>  CONFIG_AGP_AMD64=y
>  CONFIG_AGP_INTEL=y
>  CONFIG_DRM=y
> +CONFIG_DRM_FBDEV_EMULATION=y
>  CONFIG_DRM_I915=y
>  CONFIG_DRM_VIRTIO_GPU=y
>  CONFIG_DRM_HYPERV=y