From cd9446c7d606b998bb8137bd300a5bdb3250602c Mon Sep 17 00:00:00 2001
From: Brian McClain <brianmmcclain@gmail.com>
Date: Tue, 27 Jun 2023 15:19:10 -0400
Subject: [PATCH] vcsim: apply PCI UnitNumber offset of 7 for ethernet

---
 object/virtual_device_list.go      | 15 +++++++++++++--
 object/virtual_device_list_test.go |  2 +-
 2 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/object/virtual_device_list.go b/object/virtual_device_list.go
index 376550653..92797dcda 100644
--- a/object/virtual_device_list.go
+++ b/object/virtual_device_list.go
@@ -404,9 +404,13 @@ func (l VirtualDeviceList) PickController(kind types.BaseVirtualController) type
 }
 
 // newUnitNumber returns the unit number to use for attaching a new device to the given controller.
-func (l VirtualDeviceList) newUnitNumber(c types.BaseVirtualController) int32 {
+func (l VirtualDeviceList) newUnitNumber(c types.BaseVirtualController, offset int) int32 {
 	units := make([]bool, 30)
 
+	for i := 0; i < offset; i++ {
+		units[i] = true
+	}
+
 	switch sc := c.(type) {
 	case types.BaseVirtualSCSIController:
 		//  The SCSI controller sits on its own bus
@@ -455,7 +459,14 @@ func (l VirtualDeviceList) AssignController(device types.BaseVirtualDevice, c ty
 	d := device.GetVirtualDevice()
 	d.ControllerKey = c.GetVirtualController().Key
 	d.UnitNumber = new(int32)
-	*d.UnitNumber = l.newUnitNumber(c)
+
+	offset := 0
+	switch device.(type) {
+	case types.BaseVirtualEthernetCard:
+		offset = 7
+	}
+	*d.UnitNumber = l.newUnitNumber(c, offset)
+
 	if d.Key == 0 {
 		d.Key = l.newRandomKey()
 	}
diff --git a/object/virtual_device_list_test.go b/object/virtual_device_list_test.go
index fef4db9e8..466fb02d9 100644
--- a/object/virtual_device_list_test.go
+++ b/object/virtual_device_list_test.go
@@ -698,7 +698,7 @@ func TestPickController(t *testing.T) {
 			t.Errorf("expected controller key: %d, got: %d\n", test.key, key)
 		}
 
-		unit := list.newUnitNumber(c)
+		unit := list.newUnitNumber(c, 0)
 		if unit != test.unit {
 			t.Errorf("expected unit number: %d, got: %d\n", test.unit, unit)
 		}