KVM: Add reset support for in kernel PIT

Separate the reset part and prepare for reset support.

Signed-off-by: Sheng Yang <sheng.yang@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>

2 files changed, 20 insertions, 11 deletions

diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c
index 8642f9d1206a..9f118e2f350d 100644
--- a/arch/x86/kvm/i8254.c
+++ b/arch/x86/kvm/i8254.c
@@ -478,12 +478,28 @@ static int speaker_in_range(struct kvm_io_device *this, gpa_t addr)
         return (addr == KVM_SPEAKER_BASE_ADDRESS);
 }
 
-struct kvm_pit *kvm_create_pit(struct kvm *kvm)
+void kvm_pit_reset(struct kvm_pit *pit)
 {
         int i;
+        struct kvm_kpit_channel_state *c;
+
+        mutex_lock(&pit->pit_state.lock);
+        for (i = 0; i < 3; i++) {
+                c = &pit->pit_state.channels[i];
+                c->mode = 0xff;
+                c->gate = (i != 2);
+                pit_load_count(pit->kvm, i, 0);
+        }
+        mutex_unlock(&pit->pit_state.lock);
+
+        atomic_set(&pit->pit_state.pit_timer.pending, 0);
+        pit->pit_state.inject_pending = 1;
+}
+
+struct kvm_pit *kvm_create_pit(struct kvm *kvm)
+{
         struct kvm_pit *pit;
         struct kvm_kpit_state *pit_state;
-        struct kvm_kpit_channel_state *c;
 
         pit = kzalloc(sizeof(struct kvm_pit), GFP_KERNEL);
         if (!pit)
@@ -512,17 +528,9 @@ struct kvm_pit *kvm_create_pit(struct kvm *kvm)
         pit_state->pit = pit;
         hrtimer_init(&pit_state->pit_timer.timer,
                      CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
-        atomic_set(&pit_state->pit_timer.pending, 0);
-        for (i = 0; i < 3; i++) {
-                c = &pit_state->channels[i];
-                c->mode = 0xff;
-                c->gate = (i != 2);
-                pit_load_count(kvm, i, 0);
-        }
-
         mutex_unlock(&pit->pit_state.lock);
 
-        pit->pit_state.inject_pending = 1;
+        kvm_pit_reset(pit);
 
         return pit;
 }
diff --git a/arch/x86/kvm/i8254.h b/arch/x86/kvm/i8254.h
index fe09eced7783..db25c2a6c8c4 100644
--- a/arch/x86/kvm/i8254.h
+++ b/arch/x86/kvm/i8254.h
@@ -58,5 +58,6 @@ void kvm_pit_timer_intr_post(struct kvm_vcpu *vcpu, int vec);
 void kvm_pit_load_count(struct kvm *kvm, int channel, u32 val);
 struct kvm_pit *kvm_create_pit(struct kvm *kvm);
 void kvm_free_pit(struct kvm *kvm);
+void kvm_pit_reset(struct kvm_pit *pit);
 
 #endif