From: Wanpeng Li <[email protected]> vCPUs are very unlikely to get preempted when they are the only task running on a CPU. PV TLB flush is slower that the native flush in that case. In addition, avoid traversing all the cpus for pv tlb flush when steal time is disabled since pv tlb flush depends on the field in steal time for shared data.
Cc: Paolo Bonzini <[email protected]> Cc: Radim Krčmář <[email protected]> Cc: Eduardo Habkost <[email protected]> Signed-off-by: Wanpeng Li <[email protected]> --- arch/x86/kernel/kvm.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c index c5566d9..285822f 100644 --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c @@ -545,7 +545,9 @@ static void __init kvm_guest_init(void) pv_time_ops.steal_clock = kvm_steal_clock; } - if (kvm_para_has_feature(KVM_FEATURE_PV_TLB_FLUSH)) + if (kvm_para_has_feature(KVM_FEATURE_PV_TLB_FLUSH) && + !kvm_para_has_feature(KVM_HINTS_DEDICATED) && + !kvm_para_has_feature(KVM_FEATURE_STEAL_TIME)) pv_mmu_ops.flush_tlb_others = kvm_flush_tlb_others; if (kvm_para_has_feature(KVM_FEATURE_PV_EOI)) @@ -638,7 +640,9 @@ static __init int kvm_setup_pv_tlb_flush(void) { int cpu; - if (kvm_para_has_feature(KVM_FEATURE_PV_TLB_FLUSH)) { + if (kvm_para_has_feature(KVM_FEATURE_PV_TLB_FLUSH) && + !kvm_para_has_feature(KVM_HINTS_DEDICATED) && + !kvm_para_has_feature(KVM_FEATURE_STEAL_TIME)) { for_each_possible_cpu(cpu) { zalloc_cpumask_var_node(per_cpu_ptr(&__pv_tlb_mask, cpu), GFP_KERNEL, cpu_to_node(cpu)); -- 2.7.4
