[PATCH 4.4 08/56] KVM: PPC: Book 3S: XICS: correct the real mode ICP rejecting counter

From: Greg Kroah-Hartman
Date: Mon Nov 13 2017 - 07:57:30 EST


4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Li Zhong <zhong@xxxxxxxxxxxxxxxxxx>


[ Upstream commit 37451bc95dee0e666927d6ffdda302dbbaaae6fa ]

Some counters are added in Commit 6e0365b78273 ("KVM: PPC: Book3S HV:
Add ICP real mode counters"), to provide some performance statistics to
determine whether further optimizing is needed for real mode functions.

The n_reject counter counts how many times ICP rejects an irq because of
priority in real mode. The redelivery of an lsi that is still asserted
after eoi doesn't fall into this category, so the increasement there is
removed.

Also, it needs to be increased in icp_rm_deliver_irq() if it rejects
another one.

Signed-off-by: Li Zhong <zhong@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Paul Mackerras <paulus@xxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/powerpc/kvm/book3s_hv_rm_xics.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

--- a/arch/powerpc/kvm/book3s_hv_rm_xics.c
+++ b/arch/powerpc/kvm/book3s_hv_rm_xics.c
@@ -280,6 +280,7 @@ static void icp_rm_deliver_irq(struct kv
*/
if (reject && reject != XICS_IPI) {
arch_spin_unlock(&ics->lock);
+ icp->n_reject++;
new_irq = reject;
goto again;
}
@@ -611,10 +612,8 @@ int kvmppc_rm_h_eoi(struct kvm_vcpu *vcp
state = &ics->irq_state[src];

/* Still asserted, resend it */
- if (state->asserted) {
- icp->n_reject++;
+ if (state->asserted)
icp_rm_deliver_irq(xics, icp, irq);
- }

if (!hlist_empty(&vcpu->kvm->irq_ack_notifier_list)) {
icp->rm_action |= XICS_RM_NOTIFY_EOI;