running command in any VM and interrupting doesn't change the running command in the VM. (so e.g. firefox will continue running)

[marmarek]

Right now qrexec protocol does not support "interrupt" signal of any kind, which is intentional in most cases. qrexec is meant as a transport layer between domains potentially with different trust levels. Interrupting a service in wrong time may have serious implications, including security issues.
qubes.VMShell service, especially when called from dom0, is somehow special case here, because

1. most shell command are expecting to be interrupted with SIGINT/Ctrl+C if necessary
2. this service already gives the ultimate control over its target, so nothing worse can happen

Maybe the way forward would be a per-service configuration if given service call can be interrupted - by default enabled only for qubes.VMShell. But this is not a simple change, involve protocol change etc.

Originally posted by @marmarek in https://github.com/QubesOS/qubes-issues/issue_comments#issuecomment-445056975