[PATCH v2] hw/i386: Allow building machines without IOMMU

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

Commit 6c730e4af9 introduced a stub to build the MicroVM machine
without Intel IOMMU suppport. However when configure with
--without-default-devices, the build fails:

    LINK    x86_64-softmmu/qemu-system-x86_64
  /usr/bin/ld: hw/i386/pc.o: in function `pc_machine_done':
  hw/i386/pc.c:869: undefined reference to `x86_iommu_ir_supported'
  /usr/bin/ld: hw/i386/acpi-build.o: in function `acpi_build':
  hw/i386/acpi-build.c:2844: undefined reference to `x86_iommu_get_type'
  /usr/bin/ld: hw/i386/acpi-build.o: in function `build_dmar_q35':
  hw/i386/acpi-build.c:2478: undefined reference to `x86_iommu_ir_supported'
  /usr/bin/ld: hw/i386/acpi-build.o: in function `build_amd_iommu':
  hw/i386/acpi-build.c:2665: undefined reference to `x86_iommu_ir_supported'
  /usr/bin/ld: hw/i386/acpi-build.c:2700: undefined reference to `x86_iommu_ir_supported'
  collect2: error: ld returned 1 exit status
  make[1]: *** [Makefile:206: qemu-system-x86_64] Error 1

Since currently all PC machines can not be built without IOMMU,
select X86_IOMMU in the PC config, and remove the stubs.

Fixes: 6c730e4af9
Reported-by: Travis-CI
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
v2: simplify, remove the stub.
---
 hw/i386/x86-iommu-stub.c | 34 ----------------------------------
 hw/i386/Kconfig          |  2 +-
 hw/i386/Makefile.objs    |  1 -
 3 files changed, 1 insertion(+), 36 deletions(-)
 delete mode 100644 hw/i386/x86-iommu-stub.c

diff --git a/hw/i386/x86-iommu-stub.c b/hw/i386/x86-iommu-stub.c
deleted file mode 100644
index 03576cdccb..0000000000
--- a/hw/i386/x86-iommu-stub.c
+++ /dev/null
@@ -1,34 +0,0 @@
-/*
- * Stubs for X86 IOMMU emulation
- *
- * Copyright (C) 2019 Red Hat, Inc.
- *
- * Author: Paolo Bonzini <pbonzini@redhat.com>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
-
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
-
- * You should have received a copy of the GNU General Public License along
- * with this program; if not, see <http://www.gnu.org/licenses/>.
- */
-
-#include "qemu/osdep.h"
-#include "hw/i386/x86-iommu.h"
-
-void x86_iommu_iec_register_notifier(X86IOMMUState *iommu,
-                                     iec_notify_fn fn, void *data)
-{
-}
-
-X86IOMMUState *x86_iommu_get_default(void)
-{
-    return NULL;
-}
-
diff --git a/hw/i386/Kconfig b/hw/i386/Kconfig
index 91cf5843b4..e428322a2c 100644
--- a/hw/i386/Kconfig
+++ b/hw/i386/Kconfig
@@ -35,6 +35,7 @@ config PC
     select ACPI_PCI
     select ACPI_VMGENID
     select VIRTIO_PMEM_SUPPORTED
+    select X86_IOMMU
 
 config PC_PCI
     bool
@@ -105,7 +106,6 @@ config MICROVM
 
 config X86_IOMMU
     bool
-    depends on PC
 
 config VTD
     bool
diff --git a/hw/i386/Makefile.objs b/hw/i386/Makefile.objs
index 8ce1b26533..6ebb6d0cf0 100644
--- a/hw/i386/Makefile.objs
+++ b/hw/i386/Makefile.objs
@@ -7,7 +7,6 @@ obj-$(CONFIG_Q35) += pc_q35.o
 obj-$(CONFIG_MICROVM) += microvm.o
 obj-y += fw_cfg.o
 obj-$(CONFIG_X86_IOMMU) += x86-iommu.o
-obj-$(call lnot,$(CONFIG_X86_IOMMU)) += x86-iommu-stub.o
 obj-$(CONFIG_VTD) += intel_iommu.o
 obj-$(CONFIG_AMD_IOMMU) += amd_iommu.o
 obj-$(CONFIG_XEN) += ../xenpv/ xen/
-- 
2.21.0