Index: VirtualBox-6.1.4/src/VBox/HostDrivers/linux/Makefile
===================================================================
--- VirtualBox-6.1.4.orig/src/VBox/HostDrivers/linux/Makefile
+++ VirtualBox-6.1.4/src/VBox/HostDrivers/linux/Makefile
@@ -35,9 +35,6 @@ endif
 ifneq ($(wildcard $(CURDIR)/vboxnetadp/Makefile),)
  obj-m += vboxnetadp/
 endif
-ifneq ($(wildcard $(CURDIR)/vboxpci/Makefile),)
- obj-m += vboxpci/
-endif
 
 else # ! KERNELRELEASE
 
@@ -45,10 +42,11 @@ else # ! KERNELRELEASE
 
 KBUILD_VERBOSE ?=
 KERN_VER ?= $(shell uname -r)
-.PHONY: all install clean check unload load vboxdrv vboxnetflt vboxnetadp \
-    vboxpci
+PWD ?= $(shell pwd)
+
+.PHONY: all install clean check unload load vboxdrv vboxnetflt vboxnetadp
 
-all: vboxdrv vboxnetflt vboxnetadp vboxpci
+all: vboxdrv vboxnetflt vboxnetadp
 
 # We want to build on Linux 2.6.18 and later kernels.
 ifneq ($(filter-out 1.% 2.0.% 2.1.% 2.2.% 2.3.% 2.4.% 2.5.%,$(KERN_VER)),)
@@ -64,6 +62,7 @@ vboxnetflt: vboxdrv
 	    if [ -f vboxdrv/Module.symvers ]; then \
 	        cp vboxdrv/Module.symvers vboxnetflt; \
 	    fi; \
+	    export KBUILD_EXTRA_SYMBOLS=${PWD}/vboxnetflt/Module.symvers; \
 	    echo "=== Building 'vboxnetflt' module ==="; \
 	    $(MAKE) KBUILD_VERBOSE=$(KBUILD_VERBOSE) KBUILD_EXTRA_SYMBOLS=$(abspath vboxnetflt/Module.symvers) -C vboxnetflt || exit 1; \
 	    cp vboxnetflt/vboxnetflt.ko .; \
@@ -75,41 +74,29 @@ vboxnetadp: vboxdrv
 	    if [ -f vboxdrv/Module.symvers ]; then \
 	        cp vboxdrv/Module.symvers vboxnetadp; \
 	    fi; \
+	    export KBUILD_EXTRA_SYMBOLS=${PWD}/vboxnetadp/Module.symvers; \
 	    echo "=== Building 'vboxnetadp' module ==="; \
-	    $(MAKE) KBUILD_VERBOSE=$(KBUILD_VERBOSE) KBUILD_EXTRA_SYMBOLS=$(abspath vboxnetadp/Module.symvers) -C vboxnetadp || exit 1; \
+            $(MAKE) KBUILD_VERBOSE=$(KBUILD_VERBOSE) KBUILD_EXTRA_SYMBOLS=$(abspath vboxpci/Module.symvers) -C vboxnetadp || exit 1; \
 	    cp vboxnetadp/vboxnetadp.ko .; \
 	    echo; \
 	fi
 
-vboxpci: vboxdrv
-	@if [ -d vboxpci ]; then \
-	    if [ -f vboxdrv/Module.symvers ]; then \
-	        cp vboxdrv/Module.symvers vboxpci; \
-	    fi; \
-	    echo "=== Building 'vboxpci' module ==="; \
-	    $(MAKE) KBUILD_VERBOSE=$(KBUILD_VERBOSE) KBUILD_EXTRA_SYMBOLS=$(abspath vboxpci/Module.symvers) -C vboxpci || exit 1; \
-	    cp vboxpci/vboxpci.ko .; \
-	    echo; \
-	fi
-
 install:
 	@$(MAKE) KBUILD_VERBOSE=$(KBUILD_VERBOSE) -C vboxdrv install
 	@if [ -d vboxnetflt ]; then \
+	    export KBUILD_EXTRA_SYMBOLS=${PWD}/vboxnetflt/Module.symvers; \
 	    $(MAKE) KBUILD_VERBOSE=$(KBUILD_VERBOSE) -C vboxnetflt install; \
 	fi
 	@if [ -d vboxnetadp ]; then \
+	    export KBUILD_EXTRA_SYMBOLS=${PWD}/vboxnetadp/Module.symvers; \
 	    $(MAKE) KBUILD_VERBOSE=$(KBUILD_VERBOSE) -C vboxnetadp install; \
 	fi
-	@if [ -d vboxpci ]; then \
-	    $(MAKE) KBUILD_VERBOSE=$(KBUILD_VERBOSE) -C vboxpci install; \
-	fi
 
 else
 
 vboxdrv:
 vboxnetflt:
 vboxnetadp:
-vboxpci:
 install:
 
 endif
@@ -122,16 +109,13 @@ clean:
 	@if [ -d vboxnetadp ]; then \
 	    $(MAKE) -C vboxnetadp clean; \
 	fi
-	@if [ -d vboxpci ]; then \
-	    $(MAKE) -C vboxpci clean; \
-	fi
-	rm -f vboxdrv.ko vboxnetflt.ko vboxnetadp.ko vboxpci.ko
+	rm -f vboxdrv.ko vboxnetflt.ko vboxnetadp.ko
 
 check:
 	@$(MAKE) KBUILD_VERBOSE=$(KBUILD_VERBOSE) -C vboxdrv check
 
 unload:
-	@for module in vboxpci vboxnetadp vboxnetflt vboxdrv; do \
+	@for module in vboxnetadp vboxnetflt vboxdrv; do \
 		if grep "^$$module " /proc/modules >/dev/null; then \
 			echo "Removing previously installed $$module module"; \
 			/sbin/rmmod $$module; \
@@ -139,7 +123,7 @@ unload:
 	done
 
 load: unload
-	@for module in vboxdrv vboxnetflt vboxnetadp vboxpci; do \
+	@for module in vboxdrv vboxnetflt vboxnetadp; do \
 		if test -f $$module.ko; then \
 			echo "Installing $$module module"; \
 			/sbin/insmod $$module.ko; \
Index: VirtualBox-6.1.4/src/VBox/Additions/linux/Makefile
===================================================================
--- VirtualBox-6.1.4.orig/src/VBox/Additions/linux/Makefile
+++ VirtualBox-6.1.4/src/VBox/Additions/linux/Makefile
@@ -24,6 +24,7 @@ obj-m = vboxguest/ vboxsf/ vboxvideo/
 else # ! KERNELRELEASE
 
 KBUILD_VERBOSE =
+PWD ?= $(shell pwd)
  ifeq ($(KBUILD_VERBOSE),)
 VBOX_QUIET    := @
 VBOX_QUIET_SH := @
@@ -49,6 +50,7 @@ vboxsf: vboxguest
 	    if [ -f vboxguest/Module.symvers ]; then \
 	        cp vboxguest/Module.symvers vboxsf; \
 	    fi; \
+	    export KBUILD_EXTRA_SYMBOLS=${PWD}/vboxsf/Module.symvers; \
 	    echo "=== Building 'vboxsf' module ==="; \
 	    $(MAKE) KBUILD_VERBOSE=$(KBUILD_VERBOSE) KBUILD_EXTRA_SYMBOLS=$(abspath vboxsf/Module.symvers) -C vboxsf || exit 1; \
 	    if [ -f vboxsf/vboxsf.ko ]; then \
@@ -64,6 +66,7 @@ vboxvideo:
 	    if [ -f vboxguest/Module.symvers ]; then \
 	        cp vboxguest/Module.symvers vboxvideo; \
 	    fi; \
+	    export KBUILD_EXTRA_SYMBOLS=${PWD}/vboxvideo/Module.symvers; \
 	    echo "=== Building 'vboxvideo' module ==="; \
 	    $(MAKE) KBUILD_VERBOSE=$(KBUILD_VERBOSE) KBUILD_EXTRA_SYMBOLS=$(abspath vboxvideo/Module.symvers) -C vboxvideo || exit 1; \
 	    if [ -f vboxvideo/vboxvideo.ko ]; then \
@@ -77,9 +80,11 @@ vboxvideo:
 install:
 	$(VBOX_QUIET)$(MAKE) KBUILD_VERBOSE=$(KBUILD_VERBOSE) -C vboxguest install
 	$(VBOX_QUIET_SH)if [ -d vboxsf ]; then \
+	    export KBUILD_EXTRA_SYMBOLS=${PWD}/vboxsf/Module.symvers; \
 	    $(MAKE) KBUILD_VERBOSE=$(KBUILD_VERBOSE) -C vboxsf install; \
 	fi
 	$(VBOX_QUIET_SH)if [ -d vboxvideo ]; then \
+	    export KBUILD_EXTRA_SYMBOLS=${PWD}/vboxvideo/Module.symvers; \
 	    $(MAKE) KBUILD_VERBOSE=$(KBUILD_VERBOSE) -C vboxvideo install; \
 	fi