On Wed, Oct 28, 2026 at 12:02:55PM -0700, Sean Christopherson wrote: > Explicitly force an IPI when invoking kvm_vcpu_kick() directly instead of > relying on kvm_arch_vcpu_should_kick() to unconditionally return 1/true. > This will allow dropping kvm_arch_vcpu_should_kick() in favor of > kvm_request_needs_ipi(). > > No functional change intended (1 || 1 == true). > > Signed-off-by: Sean Christopherson <[email protected]> > --- > arch/powerpc/include/asm/kvm_ppc.h | 13 ++++++++++++- > arch/powerpc/kvm/book3s.c | 4 ++-- > arch/powerpc/kvm/book3s_pr.c | 2 +- > arch/powerpc/kvm/booke.c | 6 +++--- > arch/powerpc/kvm/e500_emulate.c | 2 +- > arch/powerpc/kvm/powerpc.c | 2 +- > 6 files changed, 20 insertions(+), 9 deletions(-) > > diff --git a/arch/powerpc/include/asm/kvm_ppc.h > b/arch/powerpc/include/asm/kvm_ppc.h > index 169ea6a7fbad..bbe7378ad0ef 100644 > --- a/arch/powerpc/include/asm/kvm_ppc.h > +++ b/arch/powerpc/include/asm/kvm_ppc.h > @@ -30,6 +30,17 @@ > #endif > #include <asm/inst.h> > > +/* > + * TODO: For unknown reasons, KVM PPC has historically ignored vcpu->mode > when > + * determining if kicking a vCPU needs an IPI. Either document why > that > + * behavior is necessary, or drop this helper and the @force param from > + * __kvm_vcpu_kick(). > + */ > +static inline void kvmppc_vcpu_kick(struct kvm_vcpu *vcpu) > +{ > + __kvm_vcpu_kick(vcpu, false, true); > +} > +
AFAICS, there is no reason for PPC to always return 1. I was looking at the old patches on mailing list and found this - https://lore.kernel.org/kvm/[email protected] ``` How about we return 1 for kvm_arch_vcpu_in_guest_mode() on !x86 always, just like it's done today basically? Then we can worry about needless IPIs later and don't regress from the respective current kick implementations. ``` However, I'll do some testing and get back by mid next week to make sure there are no suprises. Thanks, Gautam
