x86, vt-d: Move out isa irq mapping from hvm_do_IRQ_dpci()

Setting isa irq mapping in hvm_do_IRQ_dpci() costs time when each
interrupt occurs, and it doesn't update isa irq mapping when pci_link
is updated.

Signed-off-by: Weidong Han <weidong.han@intel.com>
Signed-off-by: Keir Fraser <keir@xensource.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/xen/arch/x86/hvm/irq.c b/xen/arch/x86/hvm/irq.c
index c19d23724e..9d1d2d7e49 100644
--- a/xen/arch/x86/hvm/irq.c
+++ b/xen/arch/x86/hvm/irq.c
@@ -191,6 +191,18 @@ void hvm_set_pci_link_route(struct domain *d, u8 link, u8 isa_irq)
         goto out;
     hvm_irq->pci_link.route[link] = isa_irq;
 
+    /* PCI pass-through fixup. */
+    if ( hvm_irq->dpci && hvm_irq->dpci->girq[old_isa_irq].valid )
+    {
+        uint32_t device = hvm_irq->dpci->girq[old_isa_irq].device;
+        uint32_t intx = hvm_irq->dpci->girq[old_isa_irq].intx;
+        if ( link == hvm_pci_intx_link(device, intx) )
+        {
+            hvm_irq->dpci->girq[isa_irq] = hvm_irq->dpci->girq[old_isa_irq];
+            hvm_irq->dpci->girq[old_isa_irq].valid = 0;
+        }
+    }
+
     if ( hvm_irq->pci_link_assert_count[link] == 0 )
         goto out;