From 0519787f88b53d2595f1bfdd85d0e55160a0af3b Mon Sep 17 00:00:00 2001 From: Tim Wiederhake Date: Tue, 14 Dec 2021 17:21:16 +0100 Subject: [PATCH] docs: domain: Clarify on the dangers of migrating with hyperv-passthrough enabled Signed-off-by: Tim Wiederhake Reviewed-by: Michal Privoznik --- docs/formatdomain.rst | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/docs/formatdomain.rst b/docs/formatdomain.rst index 0c5e33c78f..2e9c450606 100644 --- a/docs/formatdomain.rst +++ b/docs/formatdomain.rst @@ -1929,7 +1929,14 @@ are: Set exactly the specified features. ``passthrough`` - Enable all features currently supported by the hypervisor. + Enable all features currently supported by the hypervisor, even those that + libvirt does not understand. Migration of a guest using passthrough is + dangerous if the source and destination hosts are not identical in both + hardware, QEMU version, microcode version and configuration. If such a + migration is attempted then the guest may hang or crash upon resuming + execution on the destination host. Depending on hypervisor version the + virtual CPU may or may not contain features which may block migration + even to an identical host. The ``mode`` attribute can be omitted and will default to ``custom``.