kvm: i8254: Finish time conversion fix

0cdd3d1444 fixed reading back the counter load time from the kernel
while assuming the kernel would always update its load time on writing
the state. That is only true for channel 1, and so pit_get_channel_info
returned wrong output pin states for high counter values.

Fix this by applying the offset also on kvm_pit_put. Now we also need to
update the offset when we write the state while the VM is stopped as it
keeps on changing in that state.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

1 files changed, 10 insertions, 4 deletions

diff --git a/hw/kvm/i8254.c b/hw/kvm/i8254.c
index c235d80..53d13e3 100644
--- a/hw/kvm/i8254.c
+++ b/hw/kvm/i8254.c
@@ -122,17 +122,23 @@ static void kvm_pit_get(PITCommonState *pit)
         pit_get_next_transition_time(sc, sc->count_load_time);
 }
 
-static void kvm_pit_put(PITCommonState *s)
+static void kvm_pit_put(PITCommonState *pit)
 {
+    KVMPITState *s = DO_UPCAST(KVMPITState, pit, pit);
     struct kvm_pit_state2 kpit;
     struct kvm_pit_channel_state *kchan;
     struct PITChannelState *sc;
     int i, ret;
 
-    kpit.flags = s->channels[0].irq_disabled ? KVM_PIT_FLAGS_HPET_LEGACY : 0;
+    /* The offset keeps changing as long as the VM is stopped. */
+    if (s->vm_stopped) {
+        kvm_pit_update_clock_offset(s);
+    }
+
+    kpit.flags = pit->channels[0].irq_disabled ? KVM_PIT_FLAGS_HPET_LEGACY : 0;
     for (i = 0; i < 3; i++) {
         kchan = &kpit.channels[i];
-        sc = &s->channels[i];
+        sc = &pit->channels[i];
         kchan->count = sc->count;
         kchan->latched_count = sc->latched_count;
         kchan->count_latched = sc->count_latched;
@@ -145,7 +151,7 @@ static void kvm_pit_put(PITCommonState *s)
         kchan->mode = sc->mode;
         kchan->bcd = sc->bcd;
         kchan->gate = sc->gate;
-        kchan->count_load_time = sc->count_load_time;
+        kchan->count_load_time = sc->count_load_time - s->kernel_clock_offset;
     }
 
     ret = kvm_vm_ioctl(kvm_state,