From ad256f9540e0ddef66e97b2a3802eeda5269e909 Mon Sep 17 00:00:00 2001
From: Anthony PERARD <anthony.perard@citrix.com>
Date: Tue, 13 Aug 2019 12:31:12 +0100
Subject: [PATCH] OvmfPkg/PlatformBootManagerLib: Handle the absence of PCI bus
 on Xen PVH

When running in a Xen PVH guest, there's nothing to do in
PciAcpiInitialization() because there isn't any PCI bus. When the Host
Bridge DID isn't recognised, simply continue. (The value of
PcdOvmfHostBridgePciDevId would be 0 because it isn't set.)

Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1689
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20190813113119.14804-29-anthony.perard@citrix.com>
---
 OvmfPkg/Library/PlatformBootManagerLib/BdsPlatform.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/OvmfPkg/Library/PlatformBootManagerLib/BdsPlatform.c b/OvmfPkg/Library/PlatformBootManagerLib/BdsPlatform.c
index d5d5d20fd8..1eba304f09 100644
--- a/OvmfPkg/Library/PlatformBootManagerLib/BdsPlatform.c
+++ b/OvmfPkg/Library/PlatformBootManagerLib/BdsPlatform.c
@@ -1208,6 +1208,12 @@ PciAcpiInitialization (
       PciWrite8 (PCI_LIB_ADDRESS (0, 0x1f, 0, 0x6b), 0x0b); // H
       break;
     default:
+      if (XenDetected ()) {
+        //
+        // There is no PCI bus in this case.
+        //
+        return;
+      }
       DEBUG ((EFI_D_ERROR, "%a: Unknown Host Bridge Device ID: 0x%04x\n",
         __FUNCTION__, mHostBridgeDevId));
       ASSERT (FALSE);