KVM: PPC: Book3S HV: Move vcore preemption point up into kvmppc_run_vcpu
authorPaul Mackerras <paulus@samba.org>
Sat, 28 Mar 2015 03:21:05 +0000 (14:21 +1100)
committerAlexander Graf <agraf@suse.de>
Tue, 21 Apr 2015 13:21:32 +0000 (15:21 +0200)
commit25fedfca94cfbf2461314c6c34ef58e74a31b025
treef97e12748bccd2e1f9da93f98a4727542d6b132c
parent1f09c3ed86287d40fef90611cbbee055313f52cf
KVM: PPC: Book3S HV: Move vcore preemption point up into kvmppc_run_vcpu

Rather than calling cond_resched() in kvmppc_run_core() before doing
the post-processing for the vcpus that we have just run (that is,
calling kvmppc_handle_exit_hv(), kvmppc_set_timer(), etc.), we now do
that post-processing before calling cond_resched(), and that post-
processing is moved out into its own function, post_guest_process().

The reschedule point is now in kvmppc_run_vcpu() and we define a new
vcore state, VCORE_PREEMPT, to indicate that that the vcore's runner
task is runnable but not running.  (Doing the reschedule with the
vcore in VCORE_INACTIVE state would be bad because there are potentially
other vcpus waiting for the runner in kvmppc_wait_for_exec() which
then wouldn't get woken up.)

Also, we make use of the handy cond_resched_lock() function, which
unlocks and relocks vc->lock for us around the reschedule.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
arch/powerpc/include/asm/kvm_host.h
arch/powerpc/kvm/book3s_hv.c