On Wed, Oct 23, 2019 at 07:16:22PM +0800, Zhenzhong Duan wrote: > There are cases where a guest tries to switch spinlocks to bare metal > behavior (e.g. by setting "xen_nopvspin" on XEN platform and > "hv_nopvspin" on HYPER_V). > > That feature is missed on KVM, add a new parameter "nopvspin" to disable > PV spinlocks for KVM guest. > > The new 'nopvspin' parameter will also replace Xen and Hyper-V specific > parameters in future patches. > > Define variable nopvsin as global because it will be used in future > patches as above. > > Signed-off-by: Zhenzhong Duan <zhenzhong.duan@xxxxxxxxxx> > Reviewed-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> > Cc: Jonathan Corbet <corbet@xxxxxxx> > Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> > Cc: Ingo Molnar <mingo@xxxxxxxxxx> > Cc: Borislav Petkov <bp@xxxxxxxxx> > Cc: "H. Peter Anvin" <hpa@xxxxxxxxx> > Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx> > Cc: Radim Krcmar <rkrcmar@xxxxxxxxxx> > Cc: Sean Christopherson <sean.j.christopherson@xxxxxxxxx> > Cc: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> > Cc: Wanpeng Li <wanpengli@xxxxxxxxxxx> > Cc: Jim Mattson <jmattson@xxxxxxxxxx> > Cc: Joerg Roedel <joro@xxxxxxxxxx> > Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> > Cc: Will Deacon <will@xxxxxxxxxx> > --- Reviewed-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
