From f4e219876726e5af03294952a399a19ad352c0f4 Mon Sep 17 00:00:00 2001 From: Sebastien Boeuf Date: Tue, 26 Jul 2022 16:56:14 +0200 Subject: [PATCH] docs: Extend the list of TDX guest limitations Adding a new limitation related to the TDX guest kernel as it doesn't allow for most ACPI devices, meaning the PCI hotplug through ACPI isn't supported unless we use 'tdx_disable_filter' boot parameter. Signed-off-by: Sebastien Boeuf --- docs/intel_tdx.md | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/docs/intel_tdx.md b/docs/intel_tdx.md index 5bf9dc22d..31c5fd9fd 100644 --- a/docs/intel_tdx.md +++ b/docs/intel_tdx.md @@ -103,8 +103,18 @@ option as well. --disk path=tdx_guest_img ``` -### Guest kernel disables serial ports +### Guest kernel limitations + +#### Serial ports disabled The latest guest kernel that can be found in the latest image `td-guest-rhel8.5.raw` disabled the support for serial ports. This means adding -`console=ttyS0` will have no effect and will not print any log from the guest. \ No newline at end of file +`console=ttyS0` will have no effect and will not print any log from the guest. + +#### PCI hotplug through ACPI + +Unless you run the guest kernel with the parameter `tdx_disable_filter`, ACPI +devices responsible for handling PCI hotplug (PCI hotplug controller, PCI +Express Bus and Generic Event Device) will not be allowed, therefore the +corresponding drivers will not be loaded and the PCI hotplug feature will not +be supported.