[PATCH 1/3] KVM: PPC: Book3S HV: Maintain aggregate context switch values for vCPUs
From: Gautam Menghani <hidden>
Date: 2026-08-11 14:03:46
Also in:
kvm, lkml
Subsystem:
kernel virtual machine for powerpc (kvm/powerpc), linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
The variables in vcpu->arch currently store the latest values read from PACA when the vCPU exits. Change this to instead store aggregate values so that every vCPU has its own record of total context switch latencies it has accumulated. This is essential for the vpa-pmu driver to report correct numbers. Signed-off-by: Gautam Menghani <redacted> --- arch/powerpc/kvm/book3s_hv.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 3cfe9a7be9c6..0e8a959122a8 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c@@ -4164,12 +4164,12 @@ static void do_trace_nested_cs_time(struct kvm_vcpu *vcpu) trace_kvmppc_vcpu_stats(vcpu, l1_to_l2_ns - *l1_to_l2_cs_ptr, l2_to_l1_ns - *l2_to_l1_cs_ptr, l2_runtime_ns - *l2_runtime_agg_ptr); + vcpu->arch.l1_to_l2_cs += (l1_to_l2_ns - *l1_to_l2_cs_ptr); + vcpu->arch.l2_to_l1_cs += (l2_to_l1_ns - *l2_to_l1_cs_ptr); + vcpu->arch.l2_runtime_agg += (l2_runtime_ns - *l2_runtime_agg_ptr); *l1_to_l2_cs_ptr = l1_to_l2_ns; *l2_to_l1_cs_ptr = l2_to_l1_ns; *l2_runtime_agg_ptr = l2_runtime_ns; - vcpu->arch.l1_to_l2_cs = l1_to_l2_ns; - vcpu->arch.l2_to_l1_cs = l2_to_l1_ns; - vcpu->arch.l2_runtime_agg = l2_runtime_ns; } u64 kvmhv_get_l1_to_l2_cs_time(void)
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2.54.0