KVM: arm64: vgic-its: Connect LPIs to the VGIC emulation

LPIs are dynamically created (mapped) at guest runtime and their
actual number can be quite high, but is mostly assigned using a very
sparse allocation scheme. So arrays are not an ideal data structure
to hold the information.
We use a spin-lock protected linked list to hold all mapped LPIs,
represented by their struct vgic_irq. This lock is grouped between the
ap_list_lock and the vgic_irq lock in our locking order.
Also we store a pointer to that struct vgic_irq in our struct its_itte,
so we can easily access it.
Eventually we call our new vgic_get_lpi() from vgic_get_irq(), so
the VGIC code gets transparently access to LPIs.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Tested-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index 61867492d361..a6ca326055cf 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -77,6 +77,7 @@ enum vgic_irq_config {
 
 struct vgic_irq {
         spinlock_t irq_lock;            /* Protects the content of the struct */
+        struct list_head lpi_list;      /* Used to link all LPIs together */
         struct list_head ap_list;
 
         struct kvm_vcpu *vcpu;          /* SGIs and PPIs: The VCPU
@@ -193,6 +194,11 @@ struct vgic_dist {
          * GICv3 spec: 6.1.2 "LPI Configuration tables"
          */
         u64                     propbaser;
+
+        /* Protects the lpi_list and the count value below. */
+        spinlock_t              lpi_list_lock;
+        struct list_head        lpi_list_head;
+        int                     lpi_list_count;
 };
 
 struct vgic_v2_cpu_if {