Start at new guest time representaion

diff --git a/palacios/include/palacios/vmm_time.h b/palacios/include/palacios/vmm_time.h
index e6a88a3..1e3c7fd 100644 (file)
--- a/palacios/include/palacios/vmm_time.h
+++ b/palacios/include/palacios/vmm_time.h
@@ -41,16 +41,15 @@ struct vm_core_time {
     uint32_t host_cpu_freq;    // in kHZ 
     uint32_t guest_cpu_freq;   // can be lower than host CPU freq!
 
-    sint64_t guest_host_offset;// Offset of monotonic guest time from host time
-    sint64_t tsc_guest_offset; // Offset of guest TSC from monotonic guest time
+    uint64_t guest_cycles;
+    sint64_t tsc_guest_offset; // Offset of guest TSC from guest cycles
 
-    uint64_t last_update;      // Last time (in monotonic guest time) the 
+    uint64_t last_update;      // Last time (in guest cycles) the 
                                // timers were updated
 
-    uint64_t initial_time;     // Time when VMM started. 
+    uint64_t initial_time;     // Host time when VMM started. 
     uint64_t enter_time;       // Host time the guest was last entered
     uint64_t exit_time;        // Host time the the VM was exited to
-    uint64_t pause_time;       // Time at which the VM core was paused
     struct v3_msr tsc_aux;     // Auxilliary MSR for RDTSCP
 
     // Installed Timers slaved off of the guest monotonic TSC
@@ -99,8 +98,6 @@ struct v3_timer * v3_add_timer(struct guest_info * info, struct v3_timer_ops * o
 int v3_remove_timer(struct guest_info * info, struct v3_timer * timer);
 void v3_update_timers(struct guest_info * info);
 
-
-
 // Functions to return the different notions of time in Palacios.
 static inline uint64_t v3_get_host_time(struct vm_core_time *t) {
     uint64_t tmp;
@@ -109,29 +106,18 @@ static inline uint64_t v3_get_host_time(struct vm_core_time *t) {
 }
 
 // Returns *monotonic* guest time.
-static inline uint64_t v3_compute_guest_time(struct vm_core_time *t, uint64_t ht) {
-    if (t->pause_time)
-       return t->pause_time + t->guest_host_offset;
-    else
-       return ht + t->guest_host_offset;
-}
-
 static inline uint64_t v3_get_guest_time(struct vm_core_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_core_time *t, uint64_t ht) {
-    return v3_compute_guest_time(t, ht) + t->tsc_guest_offset;
+    return t->guest_cycles;
 }
 
 static inline uint64_t v3_get_guest_tsc(struct vm_core_time *t) {
-    return v3_compute_guest_tsc(t, v3_get_host_time(t));
+    return v3_get_guest_time(t) + t->tsc_guest_offset;
 }
 
 // Returns offset of guest TSC from host TSC
 static inline sint64_t v3_tsc_host_offset(struct vm_core_time *time_state) {
-    return time_state->guest_host_offset + time_state->tsc_guest_offset;
+    uint64_t host_time = v3_get_host_time(time_state);
+    return ((sint64_t)host_time - (sint64_t)time_state->guest_cycles) + time_state->tsc_guest_offset;
 }
 
 // Functions for handling exits on the TSC when fully virtualizing 

diff --git a/palacios/src/palacios/vmm_time.c b/palacios/src/palacios/vmm_time.c
index 9c0fe18..0466172 100644 (file)
--- a/palacios/src/palacios/vmm_time.c
+++ b/palacios/src/palacios/vmm_time.c
@@ -91,46 +91,16 @@ int v3_start_time(struct guest_info * info) {
     /* We start running with guest_time == host_time */
     uint64_t t = v3_get_host_time(&info->time_state); 
 
-    PrintDebug("Starting initial guest time as %llu\n", t);
-
     info->time_state.enter_time = 0;
     info->time_state.exit_time = t; 
-    info->time_state.last_update = t;
     info->time_state.initial_time = t;
     info->yield_start_cycle = t;
 
-    return 0;
-}
-
-int v3_pause_time( struct guest_info * info )
-{
-    struct vm_core_time * time_state = &(info->time_state);
-    if (time_state->pause_time != 0) {
-       PrintError("Attempted to pause time when time already paused.\n");
-       return -1;
-    }
-    time_state->pause_time = v3_get_host_time( time_state );
-
-    return 0;
-}
-
-int v3_resume_time( struct guest_info * info )
-{
-    struct vm_core_time * time_state = &(info->time_state);
-    uint64_t host_time, guest_time;
-    sint64_t offset;
-
-    if (time_state->pause_time == 0) {
-       PrintError("Attempted to resume time when time not paused.\n");
-       return -1;
-    }
-
-    host_time = v3_get_host_time(time_state);
-    guest_time = v3_compute_guest_time(time_state, host_time);
-    offset = (sint64_t)guest_time - (sint64_t)host_time;
-    time_state->guest_host_offset = offset;
-    time_state->pause_time = 0;
-
+    info->time_state.last_update = 0;
+    info->time_state.guest_cycles = 0;
+    PrintDebug("Starting time for core %d at host time %llu/guest time %llu.\n",
+              info->vcpu_id, t, info->time_state.guest_cycles); 
+    v3_yield(info);
     return 0;
 }
 
@@ -138,7 +108,7 @@ int v3_offset_time( struct guest_info * info, sint64_t offset )
 {
     struct vm_core_time * time_state = &(info->time_state);
     PrintDebug("Adding additional offset of %lld to guest time.\n", offset);
-    time_state->guest_host_offset += offset;
+    time_state->guest_cycles += offset;
     return 0;
 }
 
@@ -178,7 +148,7 @@ static int yield_host_time(struct guest_info * info) {
      * 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_compute_guest_time(time_state, host_time);
+    old_guest_time = v3_get_guest_time(time_state);
     target_host_time = compute_target_host_time(info, old_guest_time);
 
     while (target_host_time > host_time) {
@@ -186,7 +156,7 @@ static int yield_host_time(struct guest_info * info) {
        host_time = v3_get_host_time(time_state);
     }
 
-    guest_time = v3_compute_guest_time(time_state, host_time);
+    guest_time = v3_get_guest_time(time_state);
 
     /* 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. */
@@ -255,11 +225,13 @@ v3_time_exit_vm( struct guest_info * info, uint64_t * guest_cycles )
     struct vm_core_time * time_state = &(info->time_state);
     
     time_state->exit_time = v3_get_host_time(time_state);
-
-#ifdef V3_CONFIG_TIME_DILATION
-    v3_pause_time( info );
-#endif
-
+    if (guest_cycles) {
+       time_state->guest_cycles += *guest_cycles;
+    } else {
+       uint64_t cycles_exec;
+       cycles_exec = time_state->exit_time - time_state->enter_time;
+       time_state->guest_cycles += cycles_exec;
+    }
     return 0;
 }
 
@@ -268,16 +240,15 @@ int
 v3_time_enter_vm( struct guest_info * info )
 {
     struct vm_core_time * time_state = &(info->time_state);
-    uint64_t host_time;
+    uint64_t host_time, vmm_cycles;
 
     host_time = v3_get_host_time(time_state);
     time_state->enter_time = host_time;
-#ifdef V3_CONFIG_TIME_DILATION
-    v3_resume_time( info );
-#else
-    time_state->guest_host_offset = 0;
-#endif
-
+    vmm_cycles = host_time - time_state->exit_time;
+    /* XXX How do we want to take into account host/guest CPU speed differences
+     * and time dilation here? Probably time just won't advance in the VMM in that
+     * case so its irrelvant XXX */
+    time_state->guest_cycles += vmm_cycles; 
     return 0;
 }
        
@@ -465,8 +436,8 @@ int v3_init_time_vm(struct v3_vm_info * vm) {
     ret = v3_register_hypercall(vm, TIME_CPUFREQ_HCALL, 
                                handle_cpufreq_hcall, NULL);
 
-    PrintDebug("Setting base time dilation factor.\n");
     vm->time_state.td_mult = 1;
+    PrintDebug("Setting base time dilation factor to %d.\n", vm->time_state.td_mult);
 
     return ret;
 }
@@ -506,12 +477,10 @@ void v3_init_time_core(struct guest_info * info) {
 
     time_state->initial_time = 0;
     time_state->last_update = 0;
-    time_state->guest_host_offset = 0;
     time_state->tsc_guest_offset = 0;
     time_state->enter_time = 0;
     time_state->exit_time = 0;
-    time_state->pause_time = 0;
-
+    time_state->guest_cycles = 0;
 
     INIT_LIST_HEAD(&(time_state->timers));
     time_state->num_timers = 0;

diff --git a/palacios/src/palacios/vmx.c b/palacios/src/palacios/vmx.c
index b5ec768..2eb4ae1 100644 (file)
--- a/palacios/src/palacios/vmx.c
+++ b/palacios/src/palacios/vmx.c
@@ -894,7 +894,7 @@ int v3_vmx_enter(struct guest_info * info) {
 
     // Perform last-minute time bookkeeping prior to entering the VM
     v3_time_enter_vm(info);
-
+    
     tsc_offset = v3_tsc_host_offset(&info->time_state);
     tsc_offset_high = (uint32_t)(( tsc_offset >> 32) & 0xffffffff);
     tsc_offset_low = (uint32_t)(tsc_offset & 0xffffffff);