Re: linux-next: Tree for Jan 24 (kvm)

From: Sean Christopherson
Date: Fri Jan 24 2020 - 16:30:31 EST


On Fri, Jan 24, 2020 at 12:51:31PM -0800, Randy Dunlap wrote:
> On 1/23/20 10:33 PM, Stephen Rothwell wrote:
> > Hi all,
> >
> > Changes since 20200123:
> >
> > The kvm tree gained a conflict against Linus' tree.
> >
>
> on i386:
>
> ../arch/x86/kvm/x86.h:363:16: warning: right shift count >= width of type [-Wshift-count-overflow]

Jim,

This is due to using "unsigned long data" for kvm_dr7_valid() along with
"return !(data >> 32);" to check for bits being set in 63:32. Any
objection to fixing the issue by making @data a u64? Part of me thinks
that's the proper behavior anyways, i.e. the helper is purely a reflection
of the architectural requirements, the caller is responsible for dropping
bits appropriately based on the current mode.

>
>
> --
> ~Randy
> Reported-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>