$NetBSD: patch-fixpvh,v 1.2 2021/03/30 06:59:03 bouyer Exp $

Fix booting dom0 PVH. Debugged by Xen developpers Jan Beulich and
Roger Pau Monné

diff --git a/xen/drivers/vpci/msix.c b/xen/drivers/vpci/msix.c
index 64dd0a929c..3eb6102a61 100644
--- xen/drivers/vpci/msix.c.orig
+++ xen/drivers/vpci/msix.c
@@ -370,7 +370,7 @@ static int msix_write(struct vcpu *v, unsigned long addr, unsigned int len,
 
             entry->updated = false;
         }
-        else
+        else if ( msix->enabled )
             vpci_msix_arch_mask_entry(entry, pdev, entry->masked);
 
         break;