s390x/tcg: tolerate wrong wakeups due to floating interrupts
commit6ca62eb5982c956b990bf2fa88a82f67bd83da79
authorDavid Hildenbrand <david@redhat.com>
Mon, 29 Jan 2018 12:56:12 +0000 (29 13:56 +0100)
committerCornelia Huck <cohuck@redhat.com>
Fri, 9 Feb 2018 08:37:13 +0000 (9 09:37 +0100)
tree847cfa0c37236fd75787e21e2367b5f3ca37dfb5
parentd8d7942df6b042219c148cc3a86d888794cd18ec
s390x/tcg: tolerate wrong wakeups due to floating interrupts

This is a preparation for floating interrupt support and only applies to
MTTCG, single threaded TCG works just fine. If a floating interrupt wakes
up a VCPU and the CPU thinks it can run (clearing cs->halted), at
the point where the interrupt would be delivered, already another VCPU
might have picked up the interrupt, resulting in a wakeup without an
interrupt (executing wrong code).

It is wrong to let the VCPU continue to execute (the WAIT PSW). Instead,
we have to put the VCPU back to sleep.

Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20180129125623.21729-8-david@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
target/s390x/excp_helper.c