KVM: selftests: arm64: Rework TCR_EL1 configuration

The current way we initialise TCR_EL1 is a bit cumbersome, as
we mix setting TG0 and IPS in the same swtch statement.

Split it into two statements (one for the base granule size, and
another for the IPA size), allowing new modes to be added in a
more elegant way.

No functional change intended.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Link: https://lore.kernel.org/r/20211227124809.1335409-5-maz@kernel.org

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

@@ -238,6 +238,7 @@ void aarch64_vcpu_setup(struct kvm_vm *vm, uint32_t vcpuid, struct kvm_vcpu_init
 	get_reg(vm, vcpuid, KVM_ARM64_SYS_REG(SYS_SCTLR_EL1), &sctlr_el1);
 	get_reg(vm, vcpuid, KVM_ARM64_SYS_REG(SYS_TCR_EL1), &tcr_el1);
 
+	/* Configure base granule size */
 	switch (vm->mode) {
 	case VM_MODE_P52V48_4K:
 		TEST_FAIL("AArch64 does not support 4K sized pages "
@@ -246,23 +247,29 @@ void aarch64_vcpu_setup(struct kvm_vm *vm, uint32_t vcpuid, struct kvm_vcpu_init
 		TEST_FAIL("AArch64 does not support 4K sized pages "
 			  "with ANY-bit physical address ranges");
 	case VM_MODE_P52V48_64K:
+	case VM_MODE_P48V48_64K:
+	case VM_MODE_P40V48_64K:
 		tcr_el1 |= 1ul << 14; /* TG0 = 64KB */
-		tcr_el1 |= 6ul << 32; /* IPS = 52 bits */
 		break;
 	case VM_MODE_P48V48_4K:
+	case VM_MODE_P40V48_4K:
 		tcr_el1 |= 0ul << 14; /* TG0 = 4KB */
-		tcr_el1 |= 5ul << 32; /* IPS = 48 bits */
 		break;
+	default:
+		TEST_FAIL("Unknown guest mode, mode: 0x%x", vm->mode);
+	}
+
+	/* Configure output size */
+	switch (vm->mode) {
+	case VM_MODE_P52V48_64K:
+		tcr_el1 |= 6ul << 32; /* IPS = 52 bits */
+		break;
+	case VM_MODE_P48V48_4K:
 	case VM_MODE_P48V48_64K:
-		tcr_el1 |= 1ul << 14; /* TG0 = 64KB */
 		tcr_el1 |= 5ul << 32; /* IPS = 48 bits */
 		break;
 	case VM_MODE_P40V48_4K:
-		tcr_el1 |= 0ul << 14; /* TG0 = 4KB */
-		tcr_el1 |= 2ul << 32; /* IPS = 40 bits */
-		break;
 	case VM_MODE_P40V48_64K:
-		tcr_el1 |= 1ul << 14; /* TG0 = 64KB */
 		tcr_el1 |= 2ul << 32; /* IPS = 40 bits */
 		break;
 	default: