On 01/08/2012 05:11 PM, Alexander Graf wrote: > On 08.01.2012, at 14:18, Avi Kivity wrote: > > > On 01/04/2012 03:10 AM, Alexander Graf wrote: > >> From: Scott Wood <[email protected]> > >> > >> Currently we check prior to returning from a lightweight exit, > >> but not prior to initial entry. > >> > >> book3s already does a similar test. > >> > >> Signed-off-by: Scott Wood <[email protected]> > >> Signed-off-by: Alexander Graf <[email protected]> > >> --- > >> arch/powerpc/kvm/booke.c | 10 +++++++++- > >> 1 files changed, 9 insertions(+), 1 deletions(-) > >> > >> diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c > >> index b642200..9c78589 100644 > >> --- a/arch/powerpc/kvm/booke.c > >> +++ b/arch/powerpc/kvm/booke.c > >> @@ -322,11 +322,19 @@ int kvmppc_vcpu_run(struct kvm_run *kvm_run, struct > >> kvm_vcpu *vcpu) > >> } > >> > >> local_irq_disable(); > >> + > >> + if (signal_pending(current)) { > >> + kvm_run->exit_reason = KVM_EXIT_INTR; > >> + ret = -EINTR; > >> + goto out; > >> + } > >> + > >> kvm_guest_enter(); > >> ret = __kvmppc_vcpu_run(kvm_run, vcpu); > >> kvm_guest_exit(); > >> - local_irq_enable(); > >> > >> > > > > In general a single check prior to entry is sufficient (well, in > > addition to the one in kvm_vcpu_block()). > > Yes, and IIUC this is the single check prior to entry. On lightweight exit, > we don't return from __kvmppc_vcpu_run, but only call kvmppc_handle_exit() > and if that exits that we return to the guest, we stay inside of > __kvmppc_vcpu_run and don't return from here.
It means you check twice per heavyweight exit, no? Once here, and once when kvmppc_handle_exit() returns. If, instead, you move the check to just before the lightweight entry, you check just once per entry, like x86. -- error compiling committee.c: too many arguments to function -- To unsubscribe from this list: send the line "unsubscribe kvm-ppc" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
