From 3cfecff941560b0d62d21a84c627ea126d00e212 Mon Sep 17 00:00:00 2001 From: Harikrishna Patnala Date: Thu, 21 May 2026 18:43:15 +0530 Subject: [PATCH] Add recommendations on UEFI instances controllers --- source/adminguide/virtual_machines.rst | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/source/adminguide/virtual_machines.rst b/source/adminguide/virtual_machines.rst index 0e463b9661..04ae3da5d9 100644 --- a/source/adminguide/virtual_machines.rst +++ b/source/adminguide/virtual_machines.rst @@ -1191,6 +1191,22 @@ UEFI setting - On KVM, it is recommended to set boot type to UEFI, and boot mode to SECURE. - UEFI is required for some Windows versions. +.. note:: + + **Recommendations for UEFI-based instances on KVM (volumes and NICs)** + + UEFI-based instances on KVM may encounter PCI slot exhaustion when attaching additional + volumes or network interfaces, due to high PCI device usage from the default + disk bus and NIC adapter selections. To avoid these issues: + + - **Disk bus**: For Linux-based UEFI guests, it is recommended to use **SCSI** as + the guest disk bus instead of VIRTIO. This reduces PCI device usage and improves + support for attaching additional volumes. + - **NIC adapter**: Set the NIC adapter type to **e1000** for UEFI instances to avoid + NIC attachment issues caused by PCI slot exhaustion. + + Both of these settings can be configured in the **VM Settings** for an instance. + |vm-settings-virtual-tpm-model-kvm.png| TPM model for KVM. There are two options: