There is no need to save away the host DEC value, as it is derived
from the host timer subsystem, which maintains the next timer time.
Signed-off-by: Nicholas Piggin <npiggin@xxxxxxxxx>
---
arch/powerpc/include/asm/time.h | 5 +++++
arch/powerpc/kvm/book3s_hv.c | 12 ++++++------
2 files changed, 11 insertions(+), 6 deletions(-)
diff --git a/arch/powerpc/include/asm/time.h b/arch/powerpc/include/asm/time.h
index 68d94711811e..0128cd9769bc 100644
--- a/arch/powerpc/include/asm/time.h
+++ b/arch/powerpc/include/asm/time.h
@@ -101,6 +101,11 @@ extern void __init time_init(void);
DECLARE_PER_CPU(u64, decrementers_next_tb);
+static inline u64 timer_get_next_tb(void)
+{
+ return __this_cpu_read(decrementers_next_tb);
+}
+
/* Convert timebase ticks to nanoseconds */
unsigned long long tb_to_ns(unsigned long long tb_ticks);
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 913582bd848f..735ec40ece86 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3631,16 +3631,16 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
unsigned long host_amr = mfspr(SPRN_AMR);
unsigned long host_fscr = mfspr(SPRN_FSCR);
s64 dec;
- u64 tb;
+ u64 tb, next_timer;
int trap, save_pmu;
- dec = mfspr(SPRN_DEC);
tb = mftb();
- if (dec < 0)
+ next_timer = timer_get_next_tb();
+ if (tb >= next_timer)
return BOOK3S_INTERRUPT_HV_DECREMENTER;
- local_paca->kvm_hstate.dec_expires = dec + tb;
- if (local_paca->kvm_hstate.dec_expires < time_limit)
- time_limit = local_paca->kvm_hstate.dec_expires;
+ local_paca->kvm_hstate.dec_expires = next_timer;
+ if (next_timer < time_limit)
+ time_limit = next_timer;
vcpu->arch.ceded = 0;
--
2.23.0
