HV: modify code for intr storm detect & handling

This patch is to enhance the feature of "interrupt storm
mitigation"; when interrupt storm happens on one UOS
it should keep as smaller effect to SOS as possible.

Add variables in PTdev entry & VM, used to record one
UOS's pass-thru devices' interrupt data; add a function
to collect the data.

Also add a timer used to delay UOS pass-thru devices'
interrupt injection if an "interrupt storm" detected
by SOS.

Tracked-On: #866
Signed-off-by: Minggui Cao <minggui.cao@intel.com>
Reviewed-by: Li Fei1 <fei1.li@intel.com>
Acked-by: Anthony Xu <anthony.xu@intel.com>

hypervisor/include/arch/x86/guest/vm.h

@@ -173,6 +173,7 @@ struct vm {
 
 	spinlock_t softirq_dev_lock;
 	struct list_head softirq_dev_entry_list;
+	uint64_t intr_inject_delay_delta; /* delay of intr injection */
 } __aligned(CPU_PAGE_SIZE);
 
 #ifdef CONFIG_PARTITION_MODE

hypervisor/include/arch/x86/timer.h

@@ -48,6 +48,11 @@ static inline void initialize_timer(struct hv_timer *timer,
 	}
 }
 
+static inline bool timer_expired(const struct hv_timer *timer)
+{
+	return ((timer->fire_tsc == 0UL) || (rdtsc() >= timer->fire_tsc));
+}
+
 /*
  * Don't call add_timer/del_timer in the timer callback function.
  */