nova/releasenotes/notes/configure-amount-of-pcie-ports-486bfa44e9fbdd84.yaml
Marcin Juszkiewicz a234bbf80c Allow to configure amount of PCIe ports
On x86-64/q35 and aarch64/virt instances libvirt adds as many
pcie-root-port entries (aka virtual pcie slots) as it needs and adds one
free. If we want to hotplug network interfaces or storage devices then
we quickly run out of available pcie slots.

This patch allows to configure amount of PCIe slots in instance. Method
was discussed with upstream libvirt developers.

To have requested amount of pcie-root-port entries we have to create
whole PCIe structure starting with pcie-root/0 and then add as many
pcie-root-port/0 entries as we want slots. Too low value may get bumped
by libvirt to same as amount of inserted cards.

Systems not using new option will work same way as they did.

Implements: bp configure-amount-of-pcie-ports

Change-Id: Ic3c8761bcde3e842d1b8e1feff1d158630de59ae
2018-03-08 08:53:48 +01:00

10 lines
449 B
YAML

---
features:
- |
The amount of PCI Express ports (slots in virtual motherboard) can now be
configured using ``num_pcie_ports`` option in ``libvirt`` section of
``nova.conf`` file. This affects x86-64 with ``hw_machine_type`` set to
'pc-q35' value and AArch64 instances of 'virt' ``hw_machine_type`` (which
is default for that architecture). Due to QEMU's memory map limits on
aarch64/virt maximum value is limited to 28.