Re: VMI not initializing in certain configurations

[Zachary Amsden <zach@vmware.com>]

On Wed, 2008-12-10 at 15:32 -0800, Daniel Drake wrote:
> Hi Zach,
> 
> Thanks for your help on the VMI-related 2.6.27.x regression. I'm hoping
> to now pick your mind on a similar but unrelated issue:
> 
> Norman has found that with certain kernel configurations, 2.6.27 (plain,
> as released by Linus) does not initialize VMI properly, witnessed as
> missing initialization messages in the kernel logs. Other configurations
> work fine. These are the messages that go missing:
> 
>     VMI: Found VMware, Inc. Hypervisor OPROM, API version 3.0, ROM 
> version 1.0
>     vmi: registering clock event vmi-timer. mult=12582912 shift=22
>     Booting paravirtualized kernel on vmi
> 
> Do you have any immediate ideas as to what the responsible config 
> option(s) might be? It may well be a configuration error, but if that's 
> the case then perhaps we could produce a CONFIG_VMI documentation patch 
> for that.

Make sure you do a clean compile for each build - ideally use
KBUILD_OUTPUT=/some/dir and keep the kernel tree completely clean at all
times.

It doesn't look like a configuration error.  Both configurations share
this:

CONFIG_PARAVIRT_GUEST=y
# CONFIG_XEN is not set
CONFIG_XEN_SAVE_RESTORE=y
CONFIG_VMI=y
# CONFIG_KVM_CLOCK is not set
# CONFIG_KVM_GUEST is not set
CONFIG_PARAVIRT=y
# CONFIG_PARAVIRT_CLOCK is not set
CONFIG_PARAVIRT_DEBUG=y

Which should be fine.  However, when upgrading kernels, you should always sanitize your .config - just run make menuconfig, save and exit, and it will fix any deselected options.
Could be this .config isn't valid under 2.6.27.