[PATCH v5 for-xen-4.5 3/3] dpci: In hvm_dirq_assist stop using pt_pirq_iterate

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

As we are now called from dpci_softirq with the outstanding
'struct hvm_pirq_dpci' there is no need to call pt_pirq_iterate
which will iterate over all of the PIRQs and call us with every
one that is mapped. And then _hvm_dirq_assist figuring out
which one to execute.

We know which one to execute as 'schedule_dpci_for' is called
for the specific 'struct hvm_pirq_dpci' that has an outstanding
interrupt.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
---
 xen/drivers/passthrough/io.c | 27 +++++++++++----------------
 1 file changed, 11 insertions(+), 16 deletions(-)

diff --git a/xen/drivers/passthrough/io.c b/xen/drivers/passthrough/io.c
index 13433a5..62fdca9 100644
--- a/xen/drivers/passthrough/io.c
+++ b/xen/drivers/passthrough/io.c
@@ -621,9 +621,13 @@ void hvm_dpci_msi_eoi(struct domain *d, int vector)
     spin_unlock(&d->event_lock);
 }
 
-static int _hvm_dirq_assist(struct domain *d, struct hvm_pirq_dpci *pirq_dpci,
-                            void *arg)
+static int hvm_dirq_assist(struct hvm_pirq_dpci *pirq_dpci)
 {
+    struct domain *d = pirq_dpci->dom;
+
+    ASSERT(d && d->arch.hvm_domain.irq.dpci);
+
+    spin_lock(&d->event_lock);
     if ( test_and_clear_bool(pirq_dpci->masked) )
     {
         struct pirq *pirq = dpci_pirq(pirq_dpci);
@@ -634,13 +638,13 @@ static int _hvm_dirq_assist(struct domain *d, struct hvm_pirq_dpci *pirq_dpci,
             send_guest_pirq(d, pirq);
 
             if ( pirq_dpci->flags & HVM_IRQ_DPCI_GUEST_MSI )
-                return 0;
+                goto out;
         }
 
         if ( pirq_dpci->flags & HVM_IRQ_DPCI_GUEST_MSI )
         {
             vmsi_deliver_pirq(d, pirq_dpci);
-            return 0;
+            goto out;
         }
 
         list_for_each_entry ( digl, &pirq_dpci->digl_list, list )
@@ -653,7 +657,7 @@ static int _hvm_dirq_assist(struct domain *d, struct hvm_pirq_dpci *pirq_dpci,
         {
             /* for translated MSI to INTx interrupt, eoi as early as possible */
             __msi_pirq_eoi(pirq_dpci);
-            return 0;
+            goto out;
         }
 
         /*
@@ -666,21 +670,12 @@ static int _hvm_dirq_assist(struct domain *d, struct hvm_pirq_dpci *pirq_dpci,
         ASSERT(pt_irq_need_timer(pirq_dpci->flags));
         set_timer(&pirq_dpci->timer, NOW() + PT_IRQ_TIME_OUT);
     }
+ out:
+    spin_unlock(&d->event_lock);
 
     return 0;
 }
 
-static void hvm_dirq_assist(struct hvm_pirq_dpci *pirq_dpci)
-{
-    struct domain *d = pirq_dpci->dom;
-
-    ASSERT(d && d->arch.hvm_domain.irq.dpci);
-
-    spin_lock(&d->event_lock);
-    pt_pirq_iterate(d, _hvm_dirq_assist, NULL);
-    spin_unlock(&d->event_lock);
-}
-
 static void __hvm_dpci_eoi(struct domain *d,
                            const struct hvm_girq_dpci_mapping *girq,
                            const union vioapic_redir_entry *ent)
-- 
1.9.3