[Libguestfs] [PATCH] v2v:windows: prevent Parallels drivers from loading at boot

[Roman Kagan]

On Mon, Jun 06, 2016 at 01:15:01PM +0100, Richard W.M. Jones wrote:
> On Mon, Jun 06, 2016 at 03:12:36PM +0300, Roman Kagan wrote:
> > Parallels proprietary hypervisor uses RDPMC as the hypercall
> > instruction.  As this instruction is supported since early P6 family,
> > the drivers didn't even bother to check for the presence of the
> > corresponding feature in CPUID.
> > 
> > In QEMU/KVM, however, this instruction triggers #GP unless the VM is run
> > with PMU (performance monitoring unit) enabled, which is often not the
> > case (due to its impact on perfromance and migratability).
> > 
> > So, to prevent crashes upon conversion, stop respective drivers from
> > loading by disabling the corresponding services.  Note that the services
> > are being disabled ("Start" value set to 4) rather than their node
> > removed, to avoid confusing the uninstaller which is scheduled to run
> > from a firstboot script.
> > 
> > In addition, prl_strg (storage filter driver) is unlinked from the
> > storage subsystem following the DelReg directive from its .inf file,
> > otherwise Windows crashes with BSOD 0x7b due to missing dependency of
> > the storage subsystem.
> > 
> > Signed-off-by: Roman Kagan <rkagan at virtuozzo.com>
> 
> ACK.
> 
> Rich.

Thanks, pushed.

Roman.