| Message ID | 20180112120747.27999-16-christoffer.dall@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, Jan 12, 2018 at 01:07:21PM +0100, Christoffer Dall wrote: > VHE kernels run completely in EL2 and therefore don't have a notion of > kernel and hyp addresses, they are all just kernel addresses. Therefore > don't call kern_hyp_va() in the VHE switch function. Isn't this an example of avoidable forkage? This looks like it's probably just saving a couple of nops, though I may have misunderstood how this interfacts with alternatives. Cheers ---Dave > > Reviewed-by: Andrew Jones <drjones@redhat.com> > Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> > Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> > --- > arch/arm64/kvm/hyp/switch.c | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) > > diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c > index accfe9a016f9..05fba76ec918 100644 > --- a/arch/arm64/kvm/hyp/switch.c > +++ b/arch/arm64/kvm/hyp/switch.c > @@ -345,9 +345,7 @@ int kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu) > struct kvm_cpu_context *guest_ctxt; > u64 exit_code; > > - vcpu = kern_hyp_va(vcpu); > - > - host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context); > + host_ctxt = vcpu->arch.host_cpu_context; > host_ctxt->__hyp_running_vcpu = vcpu; > guest_ctxt = &vcpu->arch.ctxt; > > -- > 2.14.2 > > _______________________________________________ > kvmarm mailing list > kvmarm@lists.cs.columbia.edu > https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
On Wed, Jan 24, 2018 at 04:24:15PM +0000, Dave Martin wrote: > On Fri, Jan 12, 2018 at 01:07:21PM +0100, Christoffer Dall wrote: > > VHE kernels run completely in EL2 and therefore don't have a notion of > > kernel and hyp addresses, they are all just kernel addresses. Therefore > > don't call kern_hyp_va() in the VHE switch function. > > Isn't this an example of avoidable forkage? > > This looks like it's probably just saving a couple of nops, though I may > have misunderstood how this interfacts with alternatives. In isolation, and if we stopped here, you're absolutely right, it doesn't make sense. But this is just a step on the way to significantly reduce the _vhe version. Have a look at the following patches and the end result and let me know if you still have concerns. Thanks, -Christoffer > > > > > Reviewed-by: Andrew Jones <drjones@redhat.com> > > Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> > > Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> > > --- > > arch/arm64/kvm/hyp/switch.c | 4 +--- > > 1 file changed, 1 insertion(+), 3 deletions(-) > > > > diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c > > index accfe9a016f9..05fba76ec918 100644 > > --- a/arch/arm64/kvm/hyp/switch.c > > +++ b/arch/arm64/kvm/hyp/switch.c > > @@ -345,9 +345,7 @@ int kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu) > > struct kvm_cpu_context *guest_ctxt; > > u64 exit_code; > > > > - vcpu = kern_hyp_va(vcpu); > > - > > - host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context); > > + host_ctxt = vcpu->arch.host_cpu_context; > > host_ctxt->__hyp_running_vcpu = vcpu; > > guest_ctxt = &vcpu->arch.ctxt; > > > > -- > > 2.14.2 > > > > _______________________________________________ > > kvmarm mailing list > > kvmarm@lists.cs.columbia.edu > > https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c index accfe9a016f9..05fba76ec918 100644 --- a/arch/arm64/kvm/hyp/switch.c +++ b/arch/arm64/kvm/hyp/switch.c @@ -345,9 +345,7 @@ int kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu) struct kvm_cpu_context *guest_ctxt; u64 exit_code; - vcpu = kern_hyp_va(vcpu); - - host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context); + host_ctxt = vcpu->arch.host_cpu_context; host_ctxt->__hyp_running_vcpu = vcpu; guest_ctxt = &vcpu->arch.ctxt;