From 520fe9c607d3acea96391aad27e17518bd7d39bd Mon Sep 17 00:00:00 2001 From: "Suresh E. Warrier" Date: Mon, 21 Dec 2015 16:33:57 -0600 Subject: KVM: PPC: Book3S HV: Add tunable to control H_IPI redirection Redirecting the wakeup of a VCPU from the H_IPI hypercall to a core running in the host is usually a good idea, most workloads seemed to benefit. However, in one heavily interrupt-driven SMT1 workload, some regression was observed. This patch adds a kvm_hv module parameter called h_ipi_redirect to control this feature. The default value for this tunable is 1 - that is enable the feature. Signed-off-by: Suresh Warrier Signed-off-by: Paul Mackerras --- arch/powerpc/kvm/book3s_hv_rm_xics.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'arch/powerpc/kvm/book3s_hv_rm_xics.c') diff --git a/arch/powerpc/kvm/book3s_hv_rm_xics.c b/arch/powerpc/kvm/book3s_hv_rm_xics.c index e673fb9fee98..980d8a6f7284 100644 --- a/arch/powerpc/kvm/book3s_hv_rm_xics.c +++ b/arch/powerpc/kvm/book3s_hv_rm_xics.c @@ -24,6 +24,9 @@ #define DEBUG_PASSUP +int h_ipi_redirect = 1; +EXPORT_SYMBOL(h_ipi_redirect); + static void icp_rm_deliver_irq(struct kvmppc_xics *xics, struct kvmppc_icp *icp, u32 new_irq); @@ -148,7 +151,7 @@ static void icp_rm_set_vcpu_irq(struct kvm_vcpu *vcpu, cpu = vcpu->arch.thread_cpu; if (cpu < 0 || cpu >= nr_cpu_ids) { hcore = -1; - if (kvmppc_host_rm_ops_hv) + if (kvmppc_host_rm_ops_hv && h_ipi_redirect) hcore = find_available_hostcore(XICS_RM_KICK_VCPU); if (hcore != -1) { icp_send_hcore_msg(hcore, vcpu); -- cgit