Commit 606af829 authored by Oliver Upton's avatar Oliver Upton Committed by Marc Zyngier
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KVM: selftests: arm64: Test vCPU-scoped feature ID registers 



Test that CLIDR_EL1 and MPIDR_EL1 are modifiable from userspace and that
the values are preserved across a vCPU reset like the other feature ID
registers.

Signed-off-by: default avatarOliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20240502233529.1958459-8-oliver.upton@linux.dev


Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
parent 07eabd8a

tools/testing/selftests/kvm/aarch64/set_id_regs.c

+52 −1
Original line number Diff line number Diff line
@@ -457,6 +457,53 @@ static void test_guest_reg_read(struct kvm_vcpu *vcpu) 
	}

}



/* Politely lifted from arch/arm64/include/asm/cache.h */

/* Ctypen, bits[3(n - 1) + 2 : 3(n - 1)], for n = 1 to 7 */

#define CLIDR_CTYPE_SHIFT(level)	(3 * (level - 1))

#define CLIDR_CTYPE_MASK(level)		(7 << CLIDR_CTYPE_SHIFT(level))

#define CLIDR_CTYPE(clidr, level)	\

	(((clidr) & CLIDR_CTYPE_MASK(level)) >> CLIDR_CTYPE_SHIFT(level))



static void test_clidr(struct kvm_vcpu *vcpu)

{

	uint64_t clidr;

	int level;



	vcpu_get_reg(vcpu, KVM_ARM64_SYS_REG(SYS_CLIDR_EL1), &clidr);



	/* find the first empty level in the cache hierarchy */

	for (level = 1; level < 7; level++) {

		if (!CLIDR_CTYPE(clidr, level))

			break;

	}



	/*

	 * If you have a mind-boggling 7 levels of cache, congratulations, you

	 * get to fix this.

	 */

	TEST_ASSERT(level <= 7, "can't find an empty level in cache hierarchy");



	/* stick in a unified cache level */

	clidr |= BIT(2) << CLIDR_CTYPE_SHIFT(level);



	vcpu_set_reg(vcpu, KVM_ARM64_SYS_REG(SYS_CLIDR_EL1), clidr);

	test_reg_vals[encoding_to_range_idx(SYS_CLIDR_EL1)] = clidr;

}



static void test_vcpu_ftr_id_regs(struct kvm_vcpu *vcpu)

{

	u64 val;



	test_clidr(vcpu);



	vcpu_get_reg(vcpu, KVM_ARM64_SYS_REG(SYS_MPIDR_EL1), &val);

	val++;

	vcpu_set_reg(vcpu, KVM_ARM64_SYS_REG(SYS_MPIDR_EL1), val);



	test_reg_vals[encoding_to_range_idx(SYS_MPIDR_EL1)] = val;

	ksft_test_result_pass("%s\n", __func__);

}



static void test_assert_id_reg_unchanged(struct kvm_vcpu *vcpu, uint32_t encoding)

{

	size_t idx = encoding_to_range_idx(encoding);
@@ -477,6 +524,8 @@ static void test_reset_preserves_id_regs(struct kvm_vcpu *vcpu) 
	for (int i = 0; i < ARRAY_SIZE(test_regs); i++)

		test_assert_id_reg_unchanged(vcpu, test_regs[i].reg);



	test_assert_id_reg_unchanged(vcpu, SYS_CLIDR_EL1);



	ksft_test_result_pass("%s\n", __func__);

}
@@ -504,11 +553,13 @@ int main(void) 
		   ARRAY_SIZE(ftr_id_aa64isar2_el1) + ARRAY_SIZE(ftr_id_aa64pfr0_el1) +

		   ARRAY_SIZE(ftr_id_aa64mmfr0_el1) + ARRAY_SIZE(ftr_id_aa64mmfr1_el1) +

		   ARRAY_SIZE(ftr_id_aa64mmfr2_el1) + ARRAY_SIZE(ftr_id_aa64zfr0_el1) -

		   ARRAY_SIZE(test_regs) + 1;

		   ARRAY_SIZE(test_regs) + 2;



	ksft_set_plan(test_cnt);



	test_vm_ftr_id_regs(vcpu, aarch64_only);

	test_vcpu_ftr_id_regs(vcpu);



	test_guest_reg_read(vcpu);



	test_reset_preserves_id_regs(vcpu);