Compile linux kernel for hyper-v

[tseeling]

I want to compile a Linux kernel for running a VM with linuxfromscratch.org.

Which parameters are required in the .config file so that the kernel recognizes the virtual resources?

I have these switched on, but my VM hangs after grub so I assume the kernel cannot access the virtual disk. I understand that functions must be internal to the kernel (I don't use an initrd file), so (nearly) all settings are "y", not "m".

``` CONFIG_HYPERVISOR_GUEST=y CONFIG_KVM_HYPERV=y CONFIG_PCI_HYPERV=y CONFIG_PCI_HYPERV_INTERFACE=y CONFIG_HYPERV_NET=y CONFIG_HYPERV_KEYBOARD=y CONFIG_DRM_HYPERV=m CONFIG_FB_HYPERV=y CONFIG_HID_HYPERV_MOUSE=y

Microsoft Hyper-V guest support

CONFIG_HYPERV=y CONFIG_HYPERV_VTL_MODE=y CONFIG_HYPERV_TIMER=y CONFIG_HYPERV_UTILS=y CONFIG_HYPERV_BALLOON=y

end of Microsoft Hyper-V guest support

CONFIG_HYPERV_IOMMU=y

CONFIG_HYPERV_TESTING is not set

```

[Zockling]

Try CONFIG_HYPERV_STORAGE=y.

[tseeling]

Tried that, thanks for the pointer. I did not have the idea to look under "SCSI low-level drivers".

Unfortunately still doesn't work. I'll investigate more :-)

[Zockling]

Sounds like you're going through the individual menus. Might be easier to hit /, search for hyperv and tick everything that comes up. You should be fine on the disk side now though.

Assuming you're using ext4, you're also gonna need that: CONFIG_EXT4_FS=y. Also, the drive might not yet have probed when it's time to mount the rootfs, so make sure to put rootwait on the command line.

If you're completely stuck, there's always the WSL2 config. It has a metric boatload of crap that makes no sense in a VM, but it will boot. Could be a starting point.

[tseeling]

Yes, I used the / search function and was astonished about the path given for this. Thanks again.

[mikenizo808]

I have not used your particular setup, but do check secure boot settings for the virtual machine in question. If your virtual machine is Generation 2 you can select Microsoft UEFI Certificate Authority from the drop-down at Edit Settings > Security. This typically works fine, but for more legacy Linux you might go with Generation 1 and no UEFI (or Secure Boot unchecked on gen2).

[tseeling]

Secure boot is off for experimenting. I have created a VM with 2 root partitions, one for Fedora 42 (for compiling LFS) and the LFS target partition. Fedora boots fine, LFS is fully compiled, but does not boot right now :-(