hvm: Initialize vlapic->timer_last_update.

Without the fix, before the first vlapic timer interrupt is injected,
the "vlapic->timer_last_update" in vlapic_get_tmcct()  is always 0,
causing a wrong value of counter_passed.

Signed-off-by: Dexuan Cui <dexuan.cui@intel.com>

diff --git a/xen/arch/x86/hvm/vlapic.c b/xen/arch/x86/hvm/vlapic.c
index 8bdb325369d0ecfdad1a87e656cd8b01f8085250..3d27d4684035136754dc627881f83c0b85b5db5e 100644 (file)
--- a/xen/arch/x86/hvm/vlapic.c
+++ b/xen/arch/x86/hvm/vlapic.c
@@ -430,9 +430,9 @@ static uint32_t vlapic_get_tmcct(struct vlapic *vlapic)
     uint32_t tmcct, tmict = vlapic_get_reg(vlapic, APIC_TMICT);
     uint64_t counter_passed;
 
-    counter_passed = (hvm_get_guest_time(v) - vlapic->timer_last_update) // TSC
-                     * 1000000000ULL / ticks_per_sec(v) // NS
-                     / APIC_BUS_CYCLE_NS / vlapic->hw.timer_divisor;
+    counter_passed = ((hvm_get_guest_time(v) - vlapic->timer_last_update)
+                      * 1000000000ULL / ticks_per_sec(v)
+                      / APIC_BUS_CYCLE_NS / vlapic->hw.timer_divisor);
     tmcct = tmict - counter_passed;
 
     HVM_DBG_LOG(DBG_LEVEL_VLAPIC_TIMER,
@@ -668,6 +668,7 @@ static void vlapic_write(struct vcpu *v, unsigned long address,
         create_periodic_time(current, &vlapic->pt, period, vlapic->pt.irq,
                              !vlapic_lvtt_period(vlapic), vlapic_pt_cb,
                              &vlapic->timer_last_update);
+        vlapic->timer_last_update = vlapic->pt.last_plt_gtime;
 
         HVM_DBG_LOG(DBG_LEVEL_VLAPIC,
                     "bus cycle is %uns, "
@@ -831,6 +832,7 @@ static void lapic_rearm(struct vlapic *s)
         create_periodic_time(vlapic_vcpu(s), &s->pt, period, s->pt.irq,
                              !vlapic_lvtt_period(s), vlapic_pt_cb,
                              &s->timer_last_update);
+        s->timer_last_update = s->pt.last_plt_gtime;
 
         printk("lapic_load to rearm the actimer:"
                "bus cycle is %uns, "