KVM: selftests: Add helper for enabling LPIs on a redistributor

The selftests GIC library presently does not support LPIs. Add a
userspace helper for configuring a redistributor for LPIs, installing
an LPI configuration table and LPI pending table.
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20240422200158.2606761-18-oliver.upton@linux.devSigned-off-by: Marc Zyngier <maz@kernel.org>

tools/testing/selftests/kvm/include/aarch64/gic.h

@@ -58,4 +58,7 @@ void gic_irq_clear_pending(unsigned int intid);
 bool gic_irq_get_pending(unsigned int intid);
 void gic_irq_set_config(unsigned int intid, bool is_edge);
 
+void gic_rdist_enable_lpis(vm_paddr_t cfg_table, size_t cfg_table_size,
+			   vm_paddr_t pend_table);
+
 #endif /* SELFTEST_KVM_GIC_H */

tools/testing/selftests/kvm/lib/aarch64/gic_v3.c

@@ -401,3 +401,27 @@ const struct gic_common_ops gicv3_ops = {
 	.gic_irq_get_pending = gicv3_irq_get_pending,
 	.gic_irq_set_config = gicv3_irq_set_config,
 };
+
+void gic_rdist_enable_lpis(vm_paddr_t cfg_table, size_t cfg_table_size,
+			   vm_paddr_t pend_table)
+{
+	volatile void *rdist_base = gicr_base_cpu(guest_get_vcpuid());
+
+	u32 ctlr;
+	u64 val;
+
+	val = (cfg_table |
+	       GICR_PROPBASER_InnerShareable |
+	       GICR_PROPBASER_RaWaWb |
+	       ((ilog2(cfg_table_size) - 1) & GICR_PROPBASER_IDBITS_MASK));
+	writeq_relaxed(val, rdist_base + GICR_PROPBASER);
+
+	val = (pend_table |
+	       GICR_PENDBASER_InnerShareable |
+	       GICR_PENDBASER_RaWaWb);
+	writeq_relaxed(val, rdist_base + GICR_PENDBASER);
+
+	ctlr = readl_relaxed(rdist_base + GICR_CTLR);
+	ctlr |= GICR_CTLR_ENABLE_LPIS;
+	writel_relaxed(ctlr, rdist_base + GICR_CTLR);
+}

tools/testing/selftests/kvm/lib/aarch64/vgic.c

@@ -3,8 +3,10 @@
  * ARM Generic Interrupt Controller (GIC) v3 host support
  */
 
+#include <linux/kernel.h>
 #include <linux/kvm.h>
 #include <linux/sizes.h>
+#include <asm/cputype.h>
 #include <asm/kvm_para.h>
 #include <asm/kvm.h>