sim-se: (Re)add support for retrying system calls.

The previous incarnation of this support used faults to make the CPU
reexecute the system call instruction again and again to prevent
emulating/passing through blocking system calls from blocking gem5 as
a whole. That support was accidentally removed a while ago. This new
version suspends the thread context executing the system call, and
periodically wakes it up to retry using a periodically scheduled event.

Jira Issue:

Change-Id: I155fa8205d7ea45e3d102216aeca6ee1979a522f
Reviewed-by: Giacomo Travaglini <>
Maintainer: Giacomo Travaglini <>
Tested-by: kokoro <>
2 files changed