KVM: vgic-v4: Track the number of VLPIs per vcpu
In order to find out whether a vcpu is likely to be the target of
VLPIs (and to further optimize the way we deal with those), let's
track the number of VLPIs a vcpu can receive.
This gets implemented with an atomic variable that gets incremented
or decremented on map, unmap and move of a VLPI.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Zenghui Yu <yuzenghui@huawei.com>
Reviewed-by: Christoffer Dall <christoffer.dall@arm.com>
Link: https://lore.kernel.org/r/20191107160412.30301-2-maz@kernel.org
diff --git a/include/linux/irqchip/arm-gic-v4.h b/include/linux/irqchip/arm-gic-v4.h
index ab1396a..5dbcfc6 100644
--- a/include/linux/irqchip/arm-gic-v4.h
+++ b/include/linux/irqchip/arm-gic-v4.h
@@ -32,6 +32,8 @@ struct its_vm {
struct its_vpe {
struct page *vpt_page;
struct its_vm *its_vm;
+ /* per-vPE VLPI tracking */
+ atomic_t vlpi_count;
/* Doorbell interrupt */
int irq;
irq_hw_number_t vpe_db_lpi;