Hello, In the detailed page, the Performance tab is using the "utilities-system-monitor" icon (https://github.com/virt-manager/virt-manager/blob/master/virtManager/details/details.py#L2693) Looks like this icon is not part of the modern/adwaita GNOME icon theme meaning that the icon is missing for some users (it's the case for me on debian unstable) This icon should either be shipped in virt-manager source code or an other icon should be used
Thanks for the report, fixed upstream now by using a fallback icon if the preferred one is not available: commit 3538a8df793c6b3652162d5202b49104236444fd (HEAD -> master) Author: Cole Robinson <crobinso> Date: Sun Jan 26 15:41:21 2020 -0500 details: Fix perf icon with adwaita-icon-theme