diff options
| author | Eric Auger <eric.auger@redhat.com> | 2023-11-21 16:44:00 +0800 |
|---|---|---|
| committer | Cédric Le Goater <clg@redhat.com> | 2023-12-19 19:03:38 +0100 |
| commit | 6e6d8ac62b5b38dc9d4b69ffdf073f0a0b43b7be (patch) | |
| tree | ed0a5d7b3b5ba608a2d7b2dd84b03f37c204d219 /qemu-options.hx | |
| parent | dbb9d0c9691d145338686d3e0920da047f2ab3da (diff) | |
backends/iommufd: Introduce the iommufd object
Introduce an iommufd object which allows the interaction
with the host /dev/iommu device.
The /dev/iommu can have been already pre-opened outside of qemu,
in which case the fd can be passed directly along with the
iommufd object:
This allows the iommufd object to be shared accross several
subsystems (VFIO, VDPA, ...). For example, libvirt would open
the /dev/iommu once.
If no fd is passed along with the iommufd object, the /dev/iommu
is opened by the qemu code.
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>
Diffstat (limited to 'qemu-options.hx')
| -rw-r--r-- | qemu-options.hx | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/qemu-options.hx b/qemu-options.hx index 42fd09e4de..5fe8ea57d2 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -5224,6 +5224,18 @@ SRST The ``share`` boolean option is on by default with memfd. + ``-object iommufd,id=id[,fd=fd]`` + Creates an iommufd backend which allows control of DMA mapping + through the ``/dev/iommu`` device. + + The ``id`` parameter is a unique ID which frontends (such as + vfio-pci of vdpa) will use to connect with the iommufd backend. + + The ``fd`` parameter is an optional pre-opened file descriptor + resulting from ``/dev/iommu`` opening. Usually the iommufd is shared + across all subsystems, bringing the benefit of centralized + reference counting. + ``-object rng-builtin,id=id`` Creates a random number generator backend which obtains entropy from QEMU builtin functions. The ``id`` parameter is a unique ID |