Commit f677b0ef authored by Oliver Upton's avatar Oliver Upton Committed by Marc Zyngier
Browse files

KVM: arm64: selftests: Add basic test for running in VHE EL2 



Add an embarrassingly simple selftest for sanity checking KVM's VHE EL2
and test that the ID register bits are consistent with HCR_EL2.E2H being
RES1.

Signed-off-by: default avatarOliver Upton <oliver.upton@linux.dev>
Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
parent 2de21fb6

tools/testing/selftests/kvm/Makefile.kvm

+1 −0
Original line number Diff line number Diff line
@@ -156,6 +156,7 @@ TEST_GEN_PROGS_arm64 = $(TEST_GEN_PROGS_COMMON) 
TEST_GEN_PROGS_arm64 += arm64/aarch32_id_regs

TEST_GEN_PROGS_arm64 += arm64/arch_timer_edge_cases

TEST_GEN_PROGS_arm64 += arm64/debug-exceptions

TEST_GEN_PROGS_arm64 += arm64/hello_el2

TEST_GEN_PROGS_arm64 += arm64/host_sve

TEST_GEN_PROGS_arm64 += arm64/hypercalls

TEST_GEN_PROGS_arm64 += arm64/external_aborts

tools/testing/selftests/kvm/arm64/hello_el2.c

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+58 −0
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// SPDX-License-Identifier: GPL-2.0-only

/*

 * hello_el2 - Basic KVM selftest for VM running at EL2 with E2H=RES1

 *

 * Copyright 2025 Google LLC

 */

#include "kvm_util.h"

#include "processor.h"

#include "test_util.h"

#include "ucall.h"



#include <asm/sysreg.h>



static void guest_code(void)

{

	u64 mmfr1 = read_sysreg_s(SYS_ID_AA64MMFR1_EL1);

	u64 mmfr4 = read_sysreg_s(SYS_ID_AA64MMFR4_EL1);



	GUEST_ASSERT_EQ(get_current_el(), 2);

	GUEST_ASSERT(read_sysreg(hcr_el2) & HCR_EL2_E2H);

	GUEST_ASSERT_EQ(SYS_FIELD_GET(ID_AA64MMFR1_EL1, VH, mmfr1),

			ID_AA64MMFR1_EL1_VH_IMP);

	GUEST_ASSERT_EQ(SYS_FIELD_GET(ID_AA64MMFR4_EL1, E2H0, mmfr4),

			ID_AA64MMFR4_EL1_E2H0_NI_NV1);



	GUEST_DONE();

}



int main(void)

{

	struct kvm_vcpu_init init;

	struct kvm_vcpu *vcpu;

	struct kvm_vm *vm;

	struct ucall uc;



	TEST_REQUIRE(kvm_check_cap(KVM_CAP_ARM_EL2));



	vm = vm_create(1);



	kvm_get_default_vcpu_target(vm, &init);

	init.features[0] |= BIT(KVM_ARM_VCPU_HAS_EL2);

	vcpu = aarch64_vcpu_add(vm, 0, &init, guest_code);

	kvm_arch_vm_finalize_vcpus(vm);



	vcpu_run(vcpu);

	switch (get_ucall(vcpu, &uc)) {

	case UCALL_DONE:

		break;

	case UCALL_ABORT:

		REPORT_GUEST_ASSERT(uc);

		break;

	default:

		TEST_FAIL("Unhandled ucall: %ld\n", uc.cmd);

	}



	kvm_vm_free(vm);

	return 0;

}