Advisory: XSA-277

Before XSA-277, an error path in the P2M code left a spinlock held when the guest tried to remove a page which was already not present.

Attempt to balloon out the same frame three times, to try and force a deadlock.

For debug builds of Xen, this should hit an assertion on the return to guest path. For release builds, the test should never complete, and will either stall the entire system in the TSC rendezvous, or cause a crash from the watchdog (if activated).

See also: tests/xsa-277/main.c