vfio/pci: Allow the selection of a given iommu backend

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-pci device:

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

 -device vfio-pci,host=0000:02:00.0

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-pci device options:

 -object iommufd,id=iommufd0
 -device vfio-pci,host=0000:02:00.0,iommufd=iommufd0

Suggested-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Tested-by: Eric Auger <eric.auger@redhat.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>
This commit is contained in:
Eric Auger 2023-11-21 16:44:09 +08:00 committed by Cédric Le Goater
parent 96d6f85ff0
commit ee42b261b0

View File

@ -19,6 +19,7 @@
*/
#include "qemu/osdep.h"
#include CONFIG_DEVICES /* CONFIG_IOMMUFD */
#include <linux/vfio.h>
#include <sys/ioctl.h>
@ -42,6 +43,7 @@
#include "qapi/error.h"
#include "migration/blocker.h"
#include "migration/qemu-file.h"
#include "sysemu/iommufd.h"
#define TYPE_VFIO_PCI_NOHOTPLUG "vfio-pci-nohotplug"
@ -3386,6 +3388,10 @@ static Property vfio_pci_dev_properties[] = {
* DEFINE_PROP_STRING("vfiofd", VFIOPCIDevice, vfiofd_name),
* DEFINE_PROP_STRING("vfiogroupfd, VFIOPCIDevice, vfiogroupfd_name),
*/
#ifdef CONFIG_IOMMUFD
DEFINE_PROP_LINK("iommufd", VFIOPCIDevice, vbasedev.iommufd,
TYPE_IOMMUFD_BACKEND, IOMMUFDBackend *),
#endif
DEFINE_PROP_END_OF_LIST(),
};