| Message ID | 20181020095455.GA12489@blackberry |
|---|---|
| State | Accepted |
| Headers | show |
| Series | [v2] KVM: PPC: Use exported tb_to_ns() function in decrementer emulation | expand |
On Sat, 2018-10-20 at 09:54:55 UTC, Paul Mackerras wrote: > This changes the KVM code that emulates the decrementer function to do > the conversion of decrementer values to time intervals in nanoseconds > by calling the tb_to_ns() function exported by the powerpc timer code, > in preference to open-coded arithmetic using values from the > decrementer_clockevent struct. Similarly, the HV-KVM code that did > the same conversion using arithmetic on tb_ticks_per_sec also now > uses tb_to_ns(). > > Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Applied to powerpc next, thanks. https://git.kernel.org/powerpc/c/c43befca86ae35cc82bd889484bd17 cheers
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index bf8def2..d65b961 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -2337,8 +2337,7 @@ static void kvmppc_set_timer(struct kvm_vcpu *vcpu) kvmppc_core_prepare_to_enter(vcpu); return; } - dec_nsec = (vcpu->arch.dec_expires - now) * NSEC_PER_SEC - / tb_ticks_per_sec; + dec_nsec = tb_to_ns(vcpu->arch.dec_expires - now); hrtimer_start(&vcpu->arch.dec_timer, dec_nsec, HRTIMER_MODE_REL); vcpu->arch.timer_running = 1; } diff --git a/arch/powerpc/kvm/emulate.c b/arch/powerpc/kvm/emulate.c index fa888bf..9f5b8c0 100644 --- a/arch/powerpc/kvm/emulate.c +++ b/arch/powerpc/kvm/emulate.c @@ -61,11 +61,10 @@ void kvmppc_emulate_dec(struct kvm_vcpu *vcpu) dec_time = vcpu->arch.dec; /* - * Guest timebase ticks at the same frequency as host decrementer. - * So use the host decrementer calculations for decrementer emulation. + * Guest timebase ticks at the same frequency as host timebase. + * So use the host timebase calculations for decrementer emulation. */ - dec_time = dec_time << decrementer_clockevent.shift; - do_div(dec_time, decrementer_clockevent.mult); + dec_time = tb_to_ns(dec_time); dec_nsec = do_div(dec_time, NSEC_PER_SEC); hrtimer_start(&vcpu->arch.dec_timer, ktime_set(dec_time, dec_nsec), HRTIMER_MODE_REL);
This changes the KVM code that emulates the decrementer function to do the conversion of decrementer values to time intervals in nanoseconds by calling the tb_to_ns() function exported by the powerpc timer code, in preference to open-coded arithmetic using values from the decrementer_clockevent struct. Similarly, the HV-KVM code that did the same conversion using arithmetic on tb_ticks_per_sec also now uses tb_to_ns(). Signed-off-by: Paul Mackerras <paulus@ozlabs.org> --- v2: don't delete the second do_div in kvmppc_emulate_dec(), we need it. arch/powerpc/kvm/book3s_hv.c | 3 +-- arch/powerpc/kvm/emulate.c | 7 +++---- 2 files changed, 4 insertions(+), 6 deletions(-)