1 files changed, 55 insertions, 0 deletions

diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c
index a80e1f520293..34201d7ef33e 100644
--- a/drivers/idle/intel_idle.c
+++ b/drivers/idle/intel_idle.c
@@ -1288,6 +1288,13 @@ static struct cpuidle_state vmguest_cstates[] __initdata = {
 		.target_residency = 10,
 		.enter = &intel_idle_hlt, },
 	{
+		.name = "C1L",
+		.desc = "Long HLT",
+		.flags = MWAIT2flg(0x00) | CPUIDLE_FLAG_TLB_FLUSHED,
+		.exit_latency = 5,
+		.target_residency = 200,
+		.enter = &intel_idle_hlt, },
+	{
 		.enter = NULL }
 };
 
@@ -2130,6 +2137,45 @@ static void __init intel_idle_cpuidle_devices_uninit(void)
 		cpuidle_unregister_device(per_cpu_ptr(intel_idle_cpuidle_devices, i));
 }
 
+/*
+ * Match up the latency and break even point of the bare metal (cpu based)
+ * states with the deepest VM available state.
+ *
+ * We only want to do this for the deepest state, the ones that has
+ * the TLB_FLUSHED flag set on the .
+ *
+ * All our short idle states are dominated by vmexit/vmenter latencies,
+ * not the underlying hardware latencies so we keep our values for these.
+ */
+static void matchup_vm_state_with_baremetal(void)
+{
+	int cstate;
+
+	for (cstate = 0; cstate < CPUIDLE_STATE_MAX; ++cstate) {
+		int matching_cstate;
+
+		if (intel_idle_max_cstate_reached(cstate))
+			break;
+
+		if (!cpuidle_state_table[cstate].enter)
+			break;
+
+		if (!(cpuidle_state_table[cstate].flags & CPUIDLE_FLAG_TLB_FLUSHED))
+			continue;
+
+		for (matching_cstate = 0; matching_cstate < CPUIDLE_STATE_MAX; ++matching_cstate) {
+			if (!icpu->state_table[matching_cstate].enter)
+				break;
+			if (icpu->state_table[matching_cstate].exit_latency > cpuidle_state_table[cstate].exit_latency) {
+				cpuidle_state_table[cstate].exit_latency = icpu->state_table[matching_cstate].exit_latency;
+				cpuidle_state_table[cstate].target_residency = icpu->state_table[matching_cstate].target_residency;
+			}
+		}
+
+	}
+}
+
+
 static int __init intel_idle_vminit(const struct x86_cpu_id *id)
 {
 	int retval;
@@ -2145,6 +2191,15 @@ static int __init intel_idle_vminit(const struct x86_cpu_id *id)
 	if (!intel_idle_cpuidle_devices)
 		return -ENOMEM;
 
+	/*
+	 * We don't know exactly what the host will do when we go idle, but as a worst estimate
+	 * we can assume that the exit latency of the deepest host state will be hit for our
+	 * deep (long duration) guest idle state.
+	 * The same logic applies to the break even point for the long duration guest idle state.
+	 * So lets copy these two properties from the table we found for the host CPU type.
+	 */
+	matchup_vm_state_with_baremetal();
+
 	intel_idle_cpuidle_driver_init(&intel_idle_driver);
 
 	retval = cpuidle_register_driver(&intel_idle_driver);