On Thu, Jul 30 2026, Ackerley Tng wrote: > Tarun Sahu <[email protected]> writes: > >> Add guest_memfd_preservation_test to verify that KVM VM state and guest >> memory backed by guest_memfd are preserved across a kexec reboot via Live >> Update Orchestrator (LUO). >> >> This test includes multiple tests >> - (A) Test to preserve non-guest_memfd, non-memfd which must fail (/dev/null) >> - (B) Test to preserve guest_memfd with no INIT_SHARED flag which must fail >> - (C) Test to allocate the guest_memfd memory after preservation because >> preservation makes the guest_memfd frozen. Which must fail as well. >> - (D) Test to verify guest_memfd with INIT_SHARED flag preservation across >> kexec: Below is the details of stages in this test. [...] >> +++ b/tools/testing/selftests/kvm/guest_memfd_preservation_test.c >> @@ -0,0 +1,357 @@ >> +// SPDX-License-Identifier: GPL-2.0 >> +/* >> + * Copyright (C) 2026, Google LLC. >> + * >> + * Author: Tarun Sahu <[email protected]> >> + * >> + * Test for VM and guest_memfd preservation across kexec (Live Update) via >> LUO. >> + * >> + * NOTE: This is a MANUAL test and is excluded from automated CI/testing >> + * frameworks because Stage 1 daemonizes into the background to pin >> resources >> + * and requires a human operator to manually trigger kexec before Stage 2 >> + * is executed. Running Stage 1 automatically would leak the background >> daemon >> + * and cause CI runners to falsely interpret it as a passed test. >> + *
I think this is fine as a first step but we really should automate these. We have some infrastructure to automate other live update tests across both stages already by launching a VM under qemu and making the test process as the init task. See tools/testing/selftests/kho/vmtest.sh. For KVM tests you'd need the runner to be able to run nested VMs. The script right now is pretty bare bones, but I really think we should spend time improving it to the point where we can automate all our tests using it. > > Usually there aren't many printfs in tests, but since this is a MANUAL > test, maybe that's ok? > > Would like to know what Sean thinks of this, and printfs in general. -- Regards, Pratyush Yadav
