KVM: s390: no timer interrupts when single-stepping a guest
authorDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Tue, 18 Mar 2014 09:06:14 +0000 (10:06 +0100)
committerChristian Borntraeger <borntraeger@de.ibm.com>
Tue, 22 Apr 2014 11:24:52 +0000 (13:24 +0200)
commitf71d0dc5084b4de761b5be1aef1a855136cecd15
treebee07d8a60a7a01c8556fd102ca8572fd8ab8dba
parentbb78c5ec9161561586f8d81d53258b251aab324a
KVM: s390: no timer interrupts when single-stepping a guest

When a guest is single-stepped, we want to disable timer interrupts. Otherwise,
the guest will continuously execute the external interrupt handler and make
debugging of code where timer interrupts are enabled almost impossible.

The delivery of timer interrupts can be enforced in such sections by setting a
breakpoint and continuing execution.

In order to disable timer interrupts, they are disabled in the control register
of the guest just before SIE entry and are suppressed in the interrupt
check/delivery methods.

Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
arch/s390/kvm/guestdbg.c
arch/s390/kvm/interrupt.c