From 3e0ea9158250f9d9bfe1f26975a637b2c76fff48 Mon Sep 17 00:00:00 2001 From: Bryan Vaz Date: Fri, 26 Nov 2021 12:11:18 -0500 Subject: [PATCH] docs: update PCI unhide instructions with reboot instructions --- docs/compute.md | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) diff --git a/docs/compute.md b/docs/compute.md index 2a057c97..97bb1a7e 100644 --- a/docs/compute.md +++ b/docs/compute.md @@ -148,8 +148,24 @@ other-config (MRW): base_template_name: Other install media; import_task: Opaque You can now attach the device to another VM or add it back to the `dom0` control domain. -### 6. Reattach PCI device to control domain -Run `/opt/xensource/libexec/xen-cmdline --delete-dom0 xen-pciback.hide` +### 6. Reattach PCI device to control domain (if desired) +Run `/opt/xensource/libexec/xen-cmdline --delete-dom0 xen-pciback.hide`. + +_Note: this command removes all PCI devices hidden from the control domain (`dom0`). If you have multiple devices, you can either: (a) add them back if they are inadvertently removed; or (b) use the previous `--set-dom0` command, to update the list of hidden PCI devices, excluding the device address that you want to add back to the control domain._ + +:::tip +You can use `cat /boot/efi/EFI/xenserver/grub.cfg` see a list of devices currently hidden under during a normal boot (`menuentry 'XCP-ng'`). The grub location will vary depending on how you setup your bootloader._ +::: + +:::tip +This is a kernel parameter, and thus is not retained when you upgrade an XCP-ng host [using the installation ISO](upgrade.md#upgrade-via-installation-iso-recommended). Remember to re-do this step after the upgrade, if you still have some PCI devices you want to hide from the control domain. +::: + +### 7. Reboot the XCP-ng host + +`[root@xen ~]# reboot`. +_Note: Reboot is only necessary if you changed the kernel parameters, i.e. by adding or hiding devices from the control domain._ + ## GPU Passthrough To passthrough a complete graphics card to a VM (not virtualize it into multiple virtual vGPUs, which is different, see the vGPU section below), just follow the regular PCI passthrough instructions, no special steps are needed. Most Nvidia and AMD video cards should work without issue.