Provide a descriptions of the options that control the emulation of option ROMS for PCIe devices.
Signed-off-by: Heinrich Schuchardt <heinrich.schucha...@canonical.com> --- docs/pcie.txt | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/docs/pcie.txt b/docs/pcie.txt index 89e3502075..a22c1f69f7 100644 --- a/docs/pcie.txt +++ b/docs/pcie.txt @@ -292,6 +292,31 @@ PCI-PCI Bridge slots can be used for legacy PCI host devices. If you can see the "Express Endpoint" capability in the output, then the device is indeed PCI Express. +8. Option ROM +============= +PCIe devices may provide an option ROM. The following properties control the +emulation of the option ROM: + +``rombar`` (default: ``1``) + Specifies that an option ROM is available. If set to ``0``, no option ROM + is present. + +``romsize`` (default: ``-1``) + Specifies the size of the option ROM in bytes. The value must be either + ``-1`` or a power of two. ``-1`` signifies unlimited size. + +``romfile`` + Defines the name of the file to be loaded as option ROM. + Some devices like virtio-net-pci define a default file name. + The file size may neither exceed 2 GiB nor ``romsize``. + +Some QEMU PCIe devices like virtio-net-pci use an option ROM by default. In the +following example the option ROM of a virtio-net-pci device is disabled. This +is useful for architectures where QEMU does not supply an option ROM file. + +.. code-block:: console + + -device virtio-net-pci,netdev=eth1,mq=on,rombar=0 7. Virtio devices ================= -- 2.36.1
