KVM: arm/arm64: vgic-new: Add GICv3 redistributor IIDR and TYPER handler

The redistributor TYPER tells the OS about the associated MPIDR,
also the LAST bit is crucial to determine the number of redistributors.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>

virt/kvm/arm/vgic/vgic-mmio-v3.c

@@ -22,6 +22,13 @@
 #include "vgic.h"
 #include "vgic-mmio.h"
 
+/* extract @num bytes at @offset bytes offset in data */
+static unsigned long extract_bytes(unsigned long data, unsigned int offset,
+				   unsigned int num)
+{
+	return (data >> (offset * 8)) & GENMASK_ULL(num * 8 - 1, 0);
+}
+
 static unsigned long vgic_mmio_read_v3_misc(struct kvm_vcpu *vcpu,
 					    gpa_t addr, unsigned int len)
 {
@@ -68,6 +75,27 @@ static void vgic_mmio_write_v3_misc(struct kvm_vcpu *vcpu,
 	}
 }
 
+static unsigned long vgic_mmio_read_v3r_typer(struct kvm_vcpu *vcpu,
+					      gpa_t addr, unsigned int len)
+{
+	unsigned long mpidr = kvm_vcpu_get_mpidr_aff(vcpu);
+	int target_vcpu_id = vcpu->vcpu_id;
+	u64 value;
+
+	value = (mpidr & GENMASK(23, 0)) << 32;
+	value |= ((target_vcpu_id & 0xffff) << 8);
+	if (target_vcpu_id == atomic_read(&vcpu->kvm->online_vcpus) - 1)
+		value |= GICR_TYPER_LAST;
+
+	return extract_bytes(value, addr & 7, len);
+}
+
+static unsigned long vgic_mmio_read_v3r_iidr(struct kvm_vcpu *vcpu,
+					     gpa_t addr, unsigned int len)
+{
+	return (PRODUCT_ID_KVM << 24) | (IMPLEMENTER_ARM << 0);
+}
+
 /*
  * The GICv3 per-IRQ registers are split to control PPIs and SGIs in the
  * redistributors, while SPIs are covered by registers in the distributor
@@ -142,10 +170,10 @@ static const struct vgic_register_region vgic_v3_rdbase_registers[] = {
 		vgic_mmio_read_raz, vgic_mmio_write_wi, 4,
 		VGIC_ACCESS_32bit),
 	REGISTER_DESC_WITH_LENGTH(GICR_IIDR,
-		vgic_mmio_read_raz, vgic_mmio_write_wi, 4,
+		vgic_mmio_read_v3r_iidr, vgic_mmio_write_wi, 4,
 		VGIC_ACCESS_32bit),
 	REGISTER_DESC_WITH_LENGTH(GICR_TYPER,
-		vgic_mmio_read_raz, vgic_mmio_write_wi, 8,
+		vgic_mmio_read_v3r_typer, vgic_mmio_write_wi, 8,
 		VGIC_ACCESS_64bit | VGIC_ACCESS_32bit),
 	REGISTER_DESC_WITH_LENGTH(GICR_PROPBASER,
 		vgic_mmio_read_raz, vgic_mmio_write_wi, 8,