[PATCH 04/16] KVM: arm64: timers: Use a per-vcpu, per-timer accumulator for fractional ns

[Marc Zyngier]

Instead of accumulating the fractionnal ns value generated everytime
we compute a ns delta in a global variable, use a per-vcpu, per-timer
variable. This keeps the fractional ns local to the timer instead of
contributing to any odd, unrelated timer.

Signed-off-by: Marc Zyngier <maz at kernel.org>
---
 arch/arm64/kvm/arch_timer.c  | 2 +-
 include/kvm/arm_arch_timer.h | 1 +
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/arch_timer.c b/arch/arm64/kvm/arch_timer.c
index 00610477ec7b..329a8444724f 100644
--- a/arch/arm64/kvm/arch_timer.c
+++ b/arch/arm64/kvm/arch_timer.c
@@ -219,7 +219,7 @@ static u64 kvm_counter_compute_delta(struct arch_timer_context *timer_ctx,
 		ns = cyclecounter_cyc2ns(timecounter->cc,
 					 val - now,
 					 timecounter->mask,
-					 &timecounter->frac);
+					 &timer_ctx->ns_frac);
 		return ns;
 	}
 
diff --git a/include/kvm/arm_arch_timer.h b/include/kvm/arm_arch_timer.h
index 71916de7c6c4..76174f4fb646 100644
--- a/include/kvm/arm_arch_timer.h
+++ b/include/kvm/arm_arch_timer.h
@@ -31,6 +31,7 @@ struct arch_timer_context {
 
 	/* Emulated Timer (may be unused) */
 	struct hrtimer			hrtimer;
+	u64				ns_frac;
 
 	/*
 	 * We have multiple paths which can save/restore the timer state onto
-- 
2.34.1