KVM: selftests: arm64: Fix ttbr0_el1 encoding for PA bits > 48

Bits [51:48] of the pgd address are stored at bits [5:2] of ttbr0_el1.
page_table_test stores its page tables at the far end of IPA space so
was tripping over this when run on a system that supports FEAT_LPA (or
FEAT_LPA2).

Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230308110948.1820163-4-ryan.roberts@arm.com

Author: ryanhrob

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

@@ -242,7 +242,7 @@ void aarch64_vcpu_setup(struct kvm_vcpu *vcpu, struct kvm_vcpu_init *init)
 {
 	struct kvm_vcpu_init default_init = { .target = -1, };
 	struct kvm_vm *vm = vcpu->vm;
-	uint64_t sctlr_el1, tcr_el1;
+	uint64_t sctlr_el1, tcr_el1, ttbr0_el1;
 
 	if (!init)
 		init = &default_init;
@@ -293,10 +293,13 @@ void aarch64_vcpu_setup(struct kvm_vcpu *vcpu, struct kvm_vcpu_init *init)
 		TEST_FAIL("Unknown guest mode, mode: 0x%x", vm->mode);
 	}
 
+	ttbr0_el1 = vm->pgd & GENMASK(47, vm->page_shift);
+
 	/* Configure output size */
 	switch (vm->mode) {
 	case VM_MODE_P52V48_64K:
 		tcr_el1 |= 6ul << 32; /* IPS = 52 bits */
+		ttbr0_el1 |= FIELD_GET(GENMASK(51, 48), vm->pgd) << 2;
 		break;
 	case VM_MODE_P48V48_4K:
 	case VM_MODE_P48V48_16K:
@@ -326,7 +329,7 @@ void aarch64_vcpu_setup(struct kvm_vcpu *vcpu, struct kvm_vcpu_init *init)
 	vcpu_set_reg(vcpu, KVM_ARM64_SYS_REG(SYS_SCTLR_EL1), sctlr_el1);
 	vcpu_set_reg(vcpu, KVM_ARM64_SYS_REG(SYS_TCR_EL1), tcr_el1);
 	vcpu_set_reg(vcpu, KVM_ARM64_SYS_REG(SYS_MAIR_EL1), DEFAULT_MAIR_EL1);
-	vcpu_set_reg(vcpu, KVM_ARM64_SYS_REG(SYS_TTBR0_EL1), vm->pgd);
+	vcpu_set_reg(vcpu, KVM_ARM64_SYS_REG(SYS_TTBR0_EL1), ttbr0_el1);
 	vcpu_set_reg(vcpu, KVM_ARM64_SYS_REG(SYS_TPIDR_EL1), vcpu->id);
 }