From: Patrick G. Bridges <bridges@cs.unm.edu>
Date: Thu, 20 Oct 2011 15:26:26 +0000 (-0600)
Subject: Working on debugging time management/apic timer code.
X-Git-Url: http://v3vee.org/palacios/gitweb/gitweb.cgi?p=palacios.git;a=commitdiff_plain;h=0e26b3738daf436ba2d9a088ba620a3583d40de3

Working on debugging time management/apic timer code.
---

diff --git a/palacios/include/palacios/vmm_time.h b/palacios/include/palacios/vmm_time.h
index 329fce6..33ffa2c 100644
--- a/palacios/include/palacios/vmm_time.h
+++ b/palacios/include/palacios/vmm_time.h
@@ -91,7 +91,7 @@ static inline uint64_t v3_get_host_time(struct vm_time *t) {
 }
 
 // Returns *monotonic* guest time.
-static inline uint64_t v3_get_guest_time(struct vm_time *t) {
+static inline uint64_t v3_compute_guest_time(struct vm_time *t, uint64_t ht) {
 #ifdef V3_CONFIG_TIME_HIDE_VM_COST
     V3_ASSERT(t->exit_time);
     return t->exit_time + t->guest_host_offset;
@@ -100,9 +100,17 @@ static inline uint64_t v3_get_guest_time(struct vm_time *t) {
 #endif
 }
 
+static inline uint64_t v3_get_guest_time(struct vm_time *t) {
+    return v3_compute_guest_time(t, v3_get_host_time(t));
+}
+
 // Returns the TSC value seen by the guest
+static inline uint64_t v3_compute_guest_tsc(struct vm_time *t, uint64_t ht) {
+    return v3_compute_guest_time(t, ht) + t->tsc_guest_offset;
+}
+
 static inline uint64_t v3_get_guest_tsc(struct vm_time *t) {
-    return v3_get_guest_time(t) + t->tsc_guest_offset;
+    return v3_compute_guest_tsc(t, v3_get_host_time(t));
 }
 
 // Returns offset of guest TSC from host TSC
diff --git a/palacios/src/devices/apic.c b/palacios/src/devices/apic.c
index d83f0bd..f0a9d04 100644
--- a/palacios/src/devices/apic.c
+++ b/palacios/src/devices/apic.c
@@ -1570,9 +1570,9 @@ static void apic_inject_timer_intr(struct guest_info *core,
     struct apic_dev_state * apic_dev = (struct apic_dev_state *)(priv_data);
     struct apic_state * apic = &(apic_dev->apics[core->vcpu_id]); 
     // raise irq
-    PrintDebug("apic %u: core %u: Raising APIC Timer interrupt (periodic=%d) (icnt=%d) (div=%d)\n",
+    PrintDebug("apic %u: core %u: Raising APIC Timer interrupt (periodic=%d) (icnt=%d)\n",
 	       apic->lapic_id.val, core->vcpu_id,
-	       apic->tmr_vec_tbl.tmr_mode, apic->tmr_init_cnt, shift_num);
+	       apic->tmr_vec_tbl.tmr_mode, apic->tmr_init_cnt);
 
     if (apic_intr_pending(core, priv_data)) {
         PrintDebug("apic %u: core %u: Overriding pending IRQ %d\n", 
@@ -1656,6 +1656,8 @@ static void apic_update_time(struct guest_info * core,
     if (tmr_ticks < apic->tmr_cur_cnt) {
 	apic->tmr_cur_cnt -= tmr_ticks;
 	if (apic->missed_ints) {
+	    PrintDebug("apic %u: core %u: Injecting queued APIC timer interrupt.\n",
+		       apic->lapic_id.val, core->vcpu_id);
 	    apic_inject_timer_intr(core, priv_data);
 	    apic->missed_ints--;
 	}
@@ -1666,7 +1668,11 @@ static void apic_update_time(struct guest_info * core,
 	apic_inject_timer_intr(core, priv_data);
 
 	if (apic->tmr_vec_tbl.tmr_mode == APIC_TMR_PERIODIC) {
-	    apic->missed_ints += tmr_ticks / apic->tmr_init_cnt;
+	    int queued_ints = tmr_ticks / apic->tmr_init_cnt;
+	    if (queued_ints)
+	        PrintDebug("apic %u: core %u: Deferring %u APIC timer interrupts.\n",
+			   apic->lapic_id.val, core->vcpu_id, queued_ints);
+	    apic->missed_ints += queued_ints;
 	    tmr_ticks = tmr_ticks % apic->tmr_init_cnt;
 	    apic->tmr_cur_cnt = apic->tmr_init_cnt - tmr_ticks;
 	}
diff --git a/palacios/src/palacios/vmm_time.c b/palacios/src/palacios/vmm_time.c
index fd4a2e8..27bb2fc 100644
--- a/palacios/src/palacios/vmm_time.c
+++ b/palacios/src/palacios/vmm_time.c
@@ -105,12 +105,12 @@ int v3_offset_time( struct guest_info * info, sint64_t offset )
 }
 
 #ifdef V3_CONFIG_TIME_DILATION
-static uint64_t compute_target_host_time(struct guest_info * info)
+static uint64_t compute_target_host_time(struct guest_info * info, uint64_t guest_time)
 {
     struct vm_time * time_state = &(info->time_state);
     uint64_t guest_elapsed, desired_elapsed;
     
-    guest_elapsed = (v3_get_guest_time(time_state) - time_state->initial_time);
+    guest_elapsed = (guest_time - time_state->initial_time);
     desired_elapsed = (guest_elapsed * time_state->host_cpu_freq) / time_state->guest_cpu_freq;
     return time_state->initial_time + desired_elapsed;
 }
@@ -134,24 +134,21 @@ static int yield_host_time(struct guest_info * info) {
     uint64_t host_time, target_host_time;
     uint64_t guest_time, old_guest_time;
 
-    /* Compute the target host time given how much time has *already*
-     * passed in the guest */
-    target_host_time = compute_target_host_time(info);
-    
     /* Now, let the host run while the guest is stopped to make the two
      * sync up. Note that this doesn't assume that guest time is stopped;
      * the offsetting in the next step will change add an offset to guest
      * time to account for the time paused even if the geust isn't 
      * usually paused in the VMM. */
     host_time = v3_get_host_time(time_state);
-    old_guest_time = v3_get_guest_time(time_state);
+    old_guest_time = v3_compute_guest_time(time_state, host_time);
+    target_host_time = compute_target_host_time(info, old_guest_time);
 
     while (target_host_time > host_time) {
 	v3_yield(info);
 	host_time = v3_get_host_time(time_state);
     }
 
-    guest_time = v3_get_guest_time(time_state);
+    guest_time = v3_compute_guest_time(time_state, host_time);
 
     /* We do *not* assume the guest timer was paused in the VM. If it was
      * this offseting is 0. If it wasn't, we need this. */