Red Hat Summit Red Hat Summitサポートコンソール開発者トライアルの開始お問い合わせ

15.5. PCI passthrough for para-virtualized Xen guests on Red Hat Enterprise Linux

PCI passthrough is used to allow a Xen guest exclusive access to a PCI device, rather than sharing with other guests or with dom0. PCI passthrough for para-virtualized Xen guests is supported on all Red Hat Enterprise Linux 5 systems, however PCI passthrough with fully virtualized guests is only supported on Red Hat Enterprise Linux 5.4 and newer.

Warning

PCI passthrough to para-virtualized guests is considered insecure and is not supported for Red Hat Enterprise Linux 6 guests.
Limitations of Xen PCI passthrough:

Any guest using PCI passthrough will no longer be available for save, restore, or migration capabilities, as it will be tied to a particular non-virtualized hardware configuration.

A guest which has access to a non-virtualized PCI device via PCI passthrough also has the potential to access the DMA address space of dom0, which is a potential security concern.
To link a PCI device to a guest the device must first be hidden from the host. If the host is using the device, the device cannot be assigned to the guest.

Procedure 15.3. Example: attaching a PCI device

  1. Given a network device which uses the bnx2 driver and has a PCI id of 0000:09:00.0, the following lines added to /etc/modprobe.conf hides the device from dom0. Either the bnx2 module must be reloaded or the host must be restarted. 
    install bnx2 /sbin/modprobe pciback; /sbin/modprobe --first-time --ignore-install bnx2
options pciback hide=(0000:09:00.0)
    Copy to Clipboard Toggle word wrap
  2. Multiple PCI identifiers can be added to /etc/modprobe.conf to hide multiple devices. 
    options pciback hide=(0000:09:00.0)(0000:0a:04.1)
    Copy to Clipboard Toggle word wrap
  3. Use one of the following methods to add the passed-through device to the guest's configuration file:

Warning

Due to interrupt tracking, repeatedly hotplugging or hotunplugging an assigned device more than 512 times in a brief period of time can cause a kernel error. Please do not repeatedly hotplug/hotunplug an assigned device.

Note

When running Red Hat Enterprise Linux 5 as a KVM guest, the acpiphp kernel module must be loaded in the guest to support dynamic addition and removal of PCI devices. This module enables the guest to receive insertion and removal notifications from qemu. To manually load this module, run the following command in the guest: 
# modprobe acpiphp
Copy to Clipboard Toggle word wrap
To enable this module to be loaded automatically on every guest boot, perform the following commands in the guest: 
# echo 'modprobe acpiphp' > /etc/sysconfig/modules/acpiphp.modules
Copy to Clipboard Toggle word wrap 
# chmod +x /etc/sysconfig/modules/acpiphp.modules
Copy to Clipboard Toggle word wrap
After reboot, the module should be loaded and can be confirmed with the lsmod | grep acpiphp command. More information on persistent module loading in Red Hat Enterprise Linux 5 can be found in the Red Hat Enterprise Linux 5 Deployment Guide.
トップに戻る
Red Hat logoGithubredditYoutubeTwitter

詳細情報

試用、購入および販売

コミュニティー

Red Hat ドキュメントについて

Red Hat をお使いのお客様が、信頼できるコンテンツが含まれている製品やサービスを活用することで、イノベーションを行い、目標を達成できるようにします。 最新の更新を見る.

多様性を受け入れるオープンソースの強化

Red Hat では、コード、ドキュメント、Web プロパティーにおける配慮に欠ける用語の置き換えに取り組んでいます。このような変更は、段階的に実施される予定です。詳細情報: Red Hat ブログ.

会社概要

Red Hat は、企業がコアとなるデータセンターからネットワークエッジに至るまで、各種プラットフォームや環境全体で作業を簡素化できるように、強化されたソリューションを提供しています。

Theme

© 2025 Red Hat