From: Jan Beulich <jbeulich@suse.com>
Date: Thu, 6 Jun 2019 14:05:27 +0000 (+0200)
Subject: x86/IRQ: ACKTYPE_NONE cannot make it into irq_guest_eoi_timer_fn()
X-Git-Tag: archive/raspbian/4.14.0+80-gd101b417b7-1+rpi1^2~63^2~2116
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=c22c073d39dee841a3d2f3ae9a1e957404c3af80;p=xen.git

x86/IRQ: ACKTYPE_NONE cannot make it into irq_guest_eoi_timer_fn()

action->ack_type is set once before the timer even gets initialized, and
is never changed later. The timer gets activated only for EOI and UNMASK
types. Hence there's no need to have a respective if() in there. Replace
it by an ASSERT().

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
---

diff --git a/xen/arch/x86/irq.c b/xen/arch/x86/irq.c
index be486a6ce4..4042caaa00 100644
--- a/xen/arch/x86/irq.c
+++ b/xen/arch/x86/irq.c
@@ -1106,7 +1106,7 @@ static void set_eoi_ready(void *data);
 static void irq_guest_eoi_timer_fn(void *data)
 {
     struct irq_desc *desc = data;
-    unsigned int irq = desc - irq_desc;
+    unsigned int i, irq = desc - irq_desc;
     irq_guest_action_t *action;
     cpumask_t cpu_eoi_map;
 
@@ -1117,6 +1117,8 @@ static void irq_guest_eoi_timer_fn(void *data)
 
     action = (irq_guest_action_t *)desc->action;
 
+    ASSERT(action->ack_type != ACKTYPE_NONE);
+
     /*
      * Is no IRQ in flight at all, or another instance of this timer already
      * running? Skip everything to avoid forcing an EOI early.
@@ -1124,16 +1126,13 @@ static void irq_guest_eoi_timer_fn(void *data)
     if ( !action->in_flight || timer_is_active(&action->eoi_timer) )
         goto out;
 
-    if ( action->ack_type != ACKTYPE_NONE )
+    for ( i = 0; i < action->nr_guests; i++ )
     {
-        unsigned int i;
-        for ( i = 0; i < action->nr_guests; i++ )
-        {
-            struct domain *d = action->guest[i];
-            unsigned int pirq = domain_irq_to_pirq(d, irq);
-            if ( test_and_clear_bool(pirq_info(d, pirq)->masked) )
-                action->in_flight--;
-        }
+        struct domain *d = action->guest[i];
+        unsigned int pirq = domain_irq_to_pirq(d, irq);
+
+        if ( test_and_clear_bool(pirq_info(d, pirq)->masked) )
+            action->in_flight--;
     }
 
     if ( action->in_flight )