Re: [PATCH v5 11/20] vfio/platform: Allow the selection of a given iommu backend

[Cédric Le Goater]

On 11/9/23 12:45, Zhenzhong Duan wrote:

Now we support two types of iommu backends, let's add the capability
to select one of them. This depends on whether an iommufd object has
been linked with the vfio-platform device:

If the user wants to use the legacy backend, it shall not
link the vfio-platform device with any iommufd object:

  -device vfio-platform,host=XXX

This is called the legacy mode/backend.

If the user wants to use the iommufd backend (/dev/iommu) it
shall pass an iommufd object id in the vfio-platform device options:

  -object iommufd,id=iommufd0
  -device vfio-platform,host=XXX,iommufd=iommufd0

Suggested-by: Alex Williamson <alex.william...@redhat.com>
Signed-off-by: Zhenzhong Duan <zhenzhong.d...@intel.com>
---
  include/hw/vfio/vfio-platform.h | 1 +
  hw/vfio/platform.c              | 5 +++++
  2 files changed, 6 insertions(+)

diff --git a/include/hw/vfio/vfio-platform.h b/include/hw/vfio/vfio-platform.h
index c414c3dffc..f57f4276f2 100644
--- a/include/hw/vfio/vfio-platform.h
+++ b/include/hw/vfio/vfio-platform.h
@@ -18,6 +18,7 @@

#include "hw/sysbus.h"

  #include "hw/vfio/vfio-common.h"
+#include "sysemu/iommufd.h"
  #include "qemu/event_notifier.h"
  #include "qemu/queue.h"
  #include "qom/object.h"

I think we can move this change including "sysemu/iommufd.h" to file
"hw/vfio/platform.c"


Thanks,

C.

diff --git a/hw/vfio/platform.c b/hw/vfio/platform.c
index 8e3d4ac458..86e176ee97 100644
--- a/hw/vfio/platform.c
+++ b/hw/vfio/platform.c
@@ -15,6 +15,7 @@
   */

#include "qemu/osdep.h"

+#include CONFIG_DEVICES /* CONFIG_IOMMUFD */
  #include "qapi/error.h"
  #include <sys/ioctl.h>
  #include <linux/vfio.h>
@@ -649,6 +650,10 @@ static Property vfio_platform_dev_properties[] = {
      DEFINE_PROP_UINT32("mmap-timeout-ms", VFIOPlatformDevice,
                         mmap_timeout, 1100),
      DEFINE_PROP_BOOL("x-irqfd", VFIOPlatformDevice, irqfd_allowed, true),
+#ifdef CONFIG_IOMMUFD
+    DEFINE_PROP_LINK("iommufd", VFIOPlatformDevice, vbasedev.iommufd,
+                     TYPE_IOMMUFD_BACKEND, IOMMUFDBackend *),
+#endif
      DEFINE_PROP_END_OF_LIST(),
  };