fridtjof/qemu-cr16
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

amd_iommu: Document '-device amd-iommu' common options

Browse source 
Document the common parameters used when emulating AMD vIOMMU.
Besides the two amd-iommu specific options: 'xtsup' and 'dma-remap', the
the generic x86 IOMMU option 'intremap' is also included, since it is
typically specified in QEMU command line examples and mailing list threads.

Signed-off-by: Alejandro Jimenez <alejandro.j.jimenez@oracle.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Message-ID: <20250919213515.917111-3-alejandro.j.jimenez@oracle.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Alejandro Jimenez 2025-09-19 21:34:55 +00:00 • committed by Michael S. Tsirkin
parent bc54fb0168
commit 918973f1d4
1 changed files with 23 additions and 0 deletions
Download patch file Download diff file Expand all files Collapse all files

23
qemu-options.hx
View file

@ -1238,6 +1238,29 @@ SRST
Accepts either the default root complex (pcie.0) or a
pxb-pcie based root complex.
``-device amd-iommu[,option=...]``
Enables emulation of an AMD-Vi I/O Memory Management Unit (IOMMU).
Only available with ``-machine q35``, it supports the following options:
``dma-remap=on|off`` (default: off)
Support for DMA address translation and access permission checking for
guests attaching passthrough devices to paging domains, using the AMD v1
I/O Page Table format. This enables ``-device vfio-pci,...`` to work
correctly with a guest using the DMA remapping feature of the vIOMMU.
``intremap=on|off`` (default: auto)
Generic x86 IOMMU functionality implemented by ``amd-iommu`` device.
Enables interrupt remapping feature in guests, which is also required to
enable x2apic support.
Currently only available with ``kernel-irqchip=off|split``, it is
automatically enabled when either of those modes is in use, and disabled
with ``kernel-irqchip=on``.
``xtsup=on|off`` (default: off)
Interrupt remapping table supports x2apic mode, enabling the use of
128-bit IRTE format with 32-bit destination field by the guest. Required
to support routing interrupts to vCPUs with APIC IDs larger than 0xff.
ERST
DEF("name", HAS_ARG, QEMU_OPTION_name,