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.jime...@oracle.com>
---
qemu-options.hx | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)
diff --git a/qemu-options.hx b/qemu-options.hx
index dc694a99a30a..198acab48e8e 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -1226,6 +1226,29 @@ SRST
``aw-bits=val`` (val between 32 and 64, default depends on machine)
This decides the address width of the IOVA address space.
+``-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,
--
2.43.5
