From: Jan Kiszka <[email protected]> Micro optimization to avoid calling wbinvd twice on the CPU that has to emulate it. As we might be preempted between smp_call_function_many and the local wbinvd, the cache might be filled again so that real work could be done uselessly.
Signed-off-by: Jan Kiszka <[email protected]> Signed-off-by: Marcelo Tosatti <[email protected]> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index db2423f..34a1737 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -4012,13 +4012,15 @@ int kvm_emulate_wbinvd(struct kvm_vcpu *vcpu) return X86EMUL_CONTINUE; if (kvm_x86_ops->has_wbinvd_exit()) { - preempt_disable(); + int cpu = get_cpu(); + + cpumask_set_cpu(cpu, vcpu->arch.wbinvd_dirty_mask); smp_call_function_many(vcpu->arch.wbinvd_dirty_mask, wbinvd_ipi, NULL, 1); - preempt_enable(); + put_cpu(); cpumask_clear(vcpu->arch.wbinvd_dirty_mask); - } - wbinvd(); + } else + wbinvd(); return X86EMUL_CONTINUE; } EXPORT_SYMBOL_GPL(kvm_emulate_wbinvd); -- To unsubscribe from this list: send the line "unsubscribe kvm-commits" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
