Only call hvm_isa_irq_to_gsi for ISA interrupts, interrupts
originating from an IO APIC pin already use a GSI and don't need to be
translated.

I haven't observed any issues from this, but I think it's better to
use it correctly.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
---
Changes since v1:
 - Delay the setting of gsi a bit.
---
 xen/arch/x86/hvm/vpt.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/xen/arch/x86/hvm/vpt.c b/xen/arch/x86/hvm/vpt.c
index 62c87867c5..c68bbd1558 100644
--- a/xen/arch/x86/hvm/vpt.c
+++ b/xen/arch/x86/hvm/vpt.c
@@ -86,13 +86,13 @@ static int pt_irq_vector(struct periodic_time *pt, enum hvm_intsrc src)
         return pt->irq;
 
     isa_irq = pt->irq;
-    gsi = hvm_isa_irq_to_gsi(isa_irq);
 
     if ( src == hvm_intsrc_pic )
         return (v->domain->arch.hvm.vpic[isa_irq >> 3].irq_base
                 + (isa_irq & 7));
 
     ASSERT(src == hvm_intsrc_lapic);
+    gsi = pt->source == PTSRC_isa ? hvm_isa_irq_to_gsi(isa_irq) : pt->irq;
     vector = vioapic_get_vector(v->domain, gsi);
     if ( vector < 0 )
     {
-- 
2.27.0