virt: Add virt directory to the top Makefile

We need to build files in virt/lib/, which are now used by
KVM and VFIO, so add virt directory to the top Makefile.
Signed-off-by: Feng Wu <feng.wu@intel.com>
Acked-by: Michal Marek <mmarek@suse.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Makefile

@@ -550,6 +550,7 @@ drivers-y	:= drivers/ sound/ firmware/
 net-y		:= net/
 libs-y		:= lib/
 core-y		:= usr/
+virt-y		:= virt/
 endif # KBUILD_EXTMOD
 
 ifeq ($(dot-config),1)
@@ -882,10 +883,10 @@ core-y		+= kernel/ certs/ mm/ fs/ ipc/ security/ crypto/ block/
 
 vmlinux-dirs	:= $(patsubst %/,%,$(filter %/, $(init-y) $(init-m) \
 		     $(core-y) $(core-m) $(drivers-y) $(drivers-m) \
-		     $(net-y) $(net-m) $(libs-y) $(libs-m)))
+		     $(net-y) $(net-m) $(libs-y) $(libs-m) $(virt-y)))
 
 vmlinux-alldirs	:= $(sort $(vmlinux-dirs) $(patsubst %/,%,$(filter %/, \
-		     $(init-) $(core-) $(drivers-) $(net-) $(libs-))))
+		     $(init-) $(core-) $(drivers-) $(net-) $(libs-) $(virt-))))
 
 init-y		:= $(patsubst %/, %/built-in.o, $(init-y))
 core-y		:= $(patsubst %/, %/built-in.o, $(core-y))
@@ -894,14 +895,15 @@ net-y		:= $(patsubst %/, %/built-in.o, $(net-y))
 libs-y1		:= $(patsubst %/, %/lib.a, $(libs-y))
 libs-y2		:= $(patsubst %/, %/built-in.o, $(libs-y))
 libs-y		:= $(libs-y1) $(libs-y2)
+virt-y		:= $(patsubst %/, %/built-in.o, $(virt-y))
 
 # Externally visible symbols (used by link-vmlinux.sh)
 export KBUILD_VMLINUX_INIT := $(head-y) $(init-y)
-export KBUILD_VMLINUX_MAIN := $(core-y) $(libs-y) $(drivers-y) $(net-y)
+export KBUILD_VMLINUX_MAIN := $(core-y) $(libs-y) $(drivers-y) $(net-y) $(virt-y)
 export KBUILD_LDS          := arch/$(SRCARCH)/kernel/vmlinux.lds
 export LDFLAGS_vmlinux
 # used by scripts/pacmage/Makefile
-export KBUILD_ALLDIRS := $(sort $(filter-out arch/%,$(vmlinux-alldirs)) arch Documentation include samples scripts tools virt)
+export KBUILD_ALLDIRS := $(sort $(filter-out arch/%,$(vmlinux-alldirs)) arch Documentation include samples scripts tools)
 
 vmlinux-deps := $(KBUILD_LDS) $(KBUILD_VMLINUX_INIT) $(KBUILD_VMLINUX_MAIN)
 

virt/Makefile

+obj-y	+= lib/