KVM: Use new smp_call_function_mask() in kvm_flush_remote_tlbs()

In kvm_flush_remote_tlbs(), replace a loop using smp_call_function_single()
by a single call to smp_call_function_mask() (which is new for x86_64).

Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net>
Signed-off-by: Avi Kivity <avi@qumranet.com>

1 files changed, 3 insertions, 23 deletions

diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index 8c458f262872..07ae280e8fe5 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -198,21 +198,15 @@ static void vcpu_put(struct kvm_vcpu *vcpu)
 
 static void ack_flush(void *_completed)
 {
-        atomic_t *completed = _completed;
-
-        atomic_inc(completed);
 }
 
 void kvm_flush_remote_tlbs(struct kvm *kvm)
 {
-        int i, cpu, needed;
+        int i, cpu;
         cpumask_t cpus;
         struct kvm_vcpu *vcpu;
-        atomic_t completed;
 
-        atomic_set(&completed, 0);
         cpus_clear(cpus);
-        needed = 0;
         for (i = 0; i < KVM_MAX_VCPUS; ++i) {
                 vcpu = kvm->vcpus[i];
                 if (!vcpu)
@@ -221,23 +215,9 @@ void kvm_flush_remote_tlbs(struct kvm *kvm)
                         continue;
                 cpu = vcpu->cpu;
                 if (cpu != -1 && cpu != raw_smp_processor_id())
-                        if (!cpu_isset(cpu, cpus)) {
-                                cpu_set(cpu, cpus);
-                                ++needed;
-                        }
-        }
-
-        /*
-         * We really want smp_call_function_mask() here.  But that's not
-         * available, so ipi all cpus in parallel and wait for them
-         * to complete.
-         */
-        for (cpu = first_cpu(cpus); cpu != NR_CPUS; cpu = next_cpu(cpu, cpus))
-                smp_call_function_single(cpu, ack_flush, &completed, 1, 0);
-        while (atomic_read(&completed) != needed) {
-                cpu_relax();
-                barrier();
+                        cpu_set(cpu, cpus);
         }
+        smp_call_function_mask(cpus, ack_flush, NULL, 1);
 }
 
 int kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id)