KVM: selftests: Add an irqfd send+receive (and later IRQ bypass) test

Add a new test, irq_test to verify that KVM correctly delivers interrupts
to a running vCPU, when triggered via an eventfd bound to a KVM GSI using
KVM's irqfd mechanism.

This test is intentionally simple, for now.  Support for sending interrupts
via VFIO devices, for IRQ bypass, and for other features will be added in
the near future.

Add the test in common code, even though it currently will only build and
run on x86, as the concept and the bulk of the host-side code isn't
specific to x86.

Suggested-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/kvm/20250404193923.1413163-68-seanjc@google.com
Signed-off-by: David Matlack <dmatlack@google.com>
Co-developed-by: Josh Hilke <jrhilke@google.com>
Signed-off-by: Josh Hilke <jrhilke@google.com>
[sean: use while() and TEST_ASSERT() instead of if-statement => TEST_FAIL()]
Link: https://patch.msgid.link/20260626213534.3866178-8-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

0 files changed, 0 insertions, 0 deletions