[PATCH v3 5/5] KVM: arm64: selftests: Test for setting ID register from usersapce

[Oliver Upton <oliver.upton@linux.dev>]

From: Jing Zhang <jingzhangos@google.com>

Add tests to verify setting ID registers from userspace is handled
correctly by KVM. Also add a test case to use ioctl
KVM_ARM_GET_REG_WRITABLE_MASKS to get writable masks.

Signed-off-by: Jing Zhang <jingzhangos@google.com>
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
---
 tools/testing/selftests/kvm/Makefile          |   1 +
 .../selftests/kvm/aarch64/set_id_regs.c       | 479 ++++++++++++++++++
 2 files changed, 480 insertions(+)
 create mode 100644 tools/testing/selftests/kvm/aarch64/set_id_regs.c

diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index 07b3f4dc1a77..4f4f6ad025f4 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -156,6 +156,7 @@ TEST_GEN_PROGS_aarch64 += aarch64/debug-exceptions
 TEST_GEN_PROGS_aarch64 += aarch64/hypercalls
 TEST_GEN_PROGS_aarch64 += aarch64/page_fault_test
 TEST_GEN_PROGS_aarch64 += aarch64/psci_test
+TEST_GEN_PROGS_aarch64 += aarch64/set_id_regs
 TEST_GEN_PROGS_aarch64 += aarch64/smccc_filter
 TEST_GEN_PROGS_aarch64 += aarch64/vcpu_width_config
 TEST_GEN_PROGS_aarch64 += aarch64/vgic_init
diff --git a/tools/testing/selftests/kvm/aarch64/set_id_regs.c b/tools/testing/selftests/kvm/aarch64/set_id_regs.c
new file mode 100644
index 000000000000..5c0718fd1705
--- /dev/null
+++ b/tools/testing/selftests/kvm/aarch64/set_id_regs.c
@@ -0,0 +1,479 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * set_id_regs - Test for setting ID register from usersapce.
+ *
+ * Copyright (c) 2023 Google LLC.
+ *
+ *
+ * Test that KVM supports setting ID registers from userspace and handles the
+ * feature set correctly.
+ */
+
+#include <stdint.h>
+#include "kvm_util.h"
+#include "processor.h"
+#include "test_util.h"
+#include <linux/bitfield.h>
+
+enum ftr_type {
+	FTR_EXACT,			/* Use a predefined safe value */
+	FTR_LOWER_SAFE,			/* Smaller value is safe */
+	FTR_HIGHER_SAFE,		/* Bigger value is safe */
+	FTR_HIGHER_OR_ZERO_SAFE,	/* Bigger value is safe, but 0 is biggest */
+	FTR_END,			/* Mark the last ftr bits */
+};
+
+#define FTR_SIGNED	true	/* Value should be treated as signed */
+#define FTR_UNSIGNED	false	/* Value should be treated as unsigned */
+
+struct reg_ftr_bits {
+	char *name;
+	bool sign;
+	enum ftr_type type;
+	uint8_t shift;
+	uint64_t mask;
+	int64_t safe_val;
+};
+
+struct test_feature_reg {
+	uint32_t reg;
+	const struct reg_ftr_bits *ftr_bits;
+};
+
+#define __REG_FTR_BITS(NAME, SIGNED, TYPE, SHIFT, MASK, SAFE_VAL)	\
+	{								\
+		.name = #NAME,						\
+		.sign = SIGNED,						\
+		.type = TYPE,						\
+		.shift = SHIFT,						\
+		.mask = MASK,						\
+		.safe_val = SAFE_VAL,					\
+	}
+
+#define REG_FTR_BITS(type, reg, field, safe_val) \
+	__REG_FTR_BITS(reg##_##field, FTR_UNSIGNED, type, reg##_##field##_SHIFT, \
+		       reg##_##field##_MASK, safe_val)
+
+#define S_REG_FTR_BITS(type, reg, field, safe_val) \
+	__REG_FTR_BITS(reg##_##field, FTR_SIGNED, type, reg##_##field##_SHIFT, \
+		       reg##_##field##_MASK, safe_val)
+
+#define REG_FTR_END					\
+	{						\
+		.type = FTR_END,			\
+	}
+
+static const struct reg_ftr_bits ftr_id_aa64dfr0_el1[] = {
+	S_REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64DFR0_EL1, PMUVer, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64DFR0_EL1, DebugVer, 0),
+	REG_FTR_END,
+};
+
+static const struct reg_ftr_bits ftr_id_dfr0_el1[] = {
+	S_REG_FTR_BITS(FTR_LOWER_SAFE, ID_DFR0_EL1, PerfMon, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_DFR0_EL1, CopDbg, 0),
+	REG_FTR_END,
+};
+
+static const struct reg_ftr_bits ftr_id_aa64isar0_el1[] = {
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR0_EL1, RNDR, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR0_EL1, TLB, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR0_EL1, TS, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR0_EL1, FHM, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR0_EL1, DP, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR0_EL1, SM4, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR0_EL1, SM3, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR0_EL1, SHA3, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR0_EL1, RDM, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR0_EL1, TME, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR0_EL1, ATOMIC, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR0_EL1, CRC32, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR0_EL1, SHA2, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR0_EL1, SHA1, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR0_EL1, AES, 0),
+	REG_FTR_END,
+};
+
+static const struct reg_ftr_bits ftr_id_aa64isar1_el1[] = {
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR1_EL1, LS64, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR1_EL1, XS, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR1_EL1, I8MM, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR1_EL1, DGH, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR1_EL1, BF16, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR1_EL1, SPECRES, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR1_EL1, SB, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR1_EL1, FRINTTS, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR1_EL1, LRCPC, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR1_EL1, FCMA, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR1_EL1, JSCVT, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR1_EL1, DPB, 0),
+	REG_FTR_END,
+};
+
+static const struct reg_ftr_bits ftr_id_aa64isar2_el1[] = {
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR2_EL1, BC, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR2_EL1, RPRES, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ISAR2_EL1, WFxT, 0),
+	REG_FTR_END,
+};
+
+static const struct reg_ftr_bits ftr_id_aa64pfr0_el1[] = {
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64PFR0_EL1, CSV3, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64PFR0_EL1, CSV2, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64PFR0_EL1, DIT, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64PFR0_EL1, SEL2, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64PFR0_EL1, EL3, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64PFR0_EL1, EL2, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64PFR0_EL1, EL1, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64PFR0_EL1, EL0, 0),
+	REG_FTR_END,
+};
+
+static const struct reg_ftr_bits ftr_id_aa64mmfr0_el1[] = {
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR0_EL1, ECV, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR0_EL1, EXS, 0),
+	S_REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR0_EL1, TGRAN4, 0),
+	S_REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR0_EL1, TGRAN64, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR0_EL1, TGRAN16, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR0_EL1, BIGENDEL0, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR0_EL1, SNSMEM, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR0_EL1, BIGEND, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR0_EL1, ASIDBITS, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR0_EL1, PARANGE, 0),
+	REG_FTR_END,
+};
+
+static const struct reg_ftr_bits ftr_id_aa64mmfr1_el1[] = {
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR1_EL1, TIDCP1, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR1_EL1, AFP, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR1_EL1, ETS, 0),
+	REG_FTR_BITS(FTR_HIGHER_SAFE, ID_AA64MMFR1_EL1, SpecSEI, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR1_EL1, PAN, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR1_EL1, LO, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR1_EL1, HPDS, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR1_EL1, HAFDBS, 0),
+	REG_FTR_END,
+};
+
+static const struct reg_ftr_bits ftr_id_aa64mmfr2_el1[] = {
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR2_EL1, E0PD, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR2_EL1, BBM, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR2_EL1, TTL, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR2_EL1, AT, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR2_EL1, ST, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR2_EL1, VARange, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR2_EL1, IESB, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR2_EL1, LSM, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR2_EL1, UAO, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64MMFR2_EL1, CnP, 0),
+	REG_FTR_END,
+};
+
+static const struct reg_ftr_bits ftr_id_aa64zfr0_el1[] = {
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ZFR0_EL1, F64MM, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ZFR0_EL1, F32MM, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ZFR0_EL1, I8MM, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ZFR0_EL1, SM4, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ZFR0_EL1, SHA3, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ZFR0_EL1, BF16, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ZFR0_EL1, BitPerm, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ZFR0_EL1, AES, 0),
+	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64ZFR0_EL1, SVEver, 0),
+	REG_FTR_END,
+};
+
+#define TEST_REG(id, table)			\
+	{					\
+		.reg = id,			\
+		.ftr_bits = &((table)[0]),	\
+	}
+
+static struct test_feature_reg test_regs[] = {
+	TEST_REG(SYS_ID_AA64DFR0_EL1, ftr_id_aa64dfr0_el1),
+	TEST_REG(SYS_ID_DFR0_EL1, ftr_id_dfr0_el1),
+	TEST_REG(SYS_ID_AA64ISAR0_EL1, ftr_id_aa64isar0_el1),
+	TEST_REG(SYS_ID_AA64ISAR1_EL1, ftr_id_aa64isar1_el1),
+	TEST_REG(SYS_ID_AA64ISAR2_EL1, ftr_id_aa64isar2_el1),
+	TEST_REG(SYS_ID_AA64PFR0_EL1, ftr_id_aa64pfr0_el1),
+	TEST_REG(SYS_ID_AA64MMFR0_EL1, ftr_id_aa64mmfr0_el1),
+	TEST_REG(SYS_ID_AA64MMFR1_EL1, ftr_id_aa64mmfr1_el1),
+	TEST_REG(SYS_ID_AA64MMFR2_EL1, ftr_id_aa64mmfr2_el1),
+	TEST_REG(SYS_ID_AA64ZFR0_EL1, ftr_id_aa64zfr0_el1),
+};
+
+#define GUEST_REG_SYNC(id) GUEST_SYNC_ARGS(0, id, read_sysreg_s(id), 0, 0);
+
+static void guest_code(void)
+{
+	GUEST_REG_SYNC(SYS_ID_AA64DFR0_EL1);
+	GUEST_REG_SYNC(SYS_ID_DFR0_EL1);
+	GUEST_REG_SYNC(SYS_ID_AA64ISAR0_EL1);
+	GUEST_REG_SYNC(SYS_ID_AA64ISAR1_EL1);
+	GUEST_REG_SYNC(SYS_ID_AA64ISAR2_EL1);
+	GUEST_REG_SYNC(SYS_ID_AA64PFR0_EL1);
+	GUEST_REG_SYNC(SYS_ID_AA64MMFR0_EL1);
+	GUEST_REG_SYNC(SYS_ID_AA64MMFR1_EL1);
+	GUEST_REG_SYNC(SYS_ID_AA64MMFR2_EL1);
+	GUEST_REG_SYNC(SYS_ID_AA64ZFR0_EL1);
+
+	GUEST_DONE();
+}
+
+/* Return a safe value to a given ftr_bits an ftr value */
+uint64_t get_safe_value(const struct reg_ftr_bits *ftr_bits, uint64_t ftr)
+{
+	uint64_t ftr_max = GENMASK_ULL(ARM64_FEATURE_FIELD_BITS - 1, 0);
+
+	if (ftr_bits->type == FTR_UNSIGNED) {
+		switch (ftr_bits->type) {
+		case FTR_EXACT:
+			ftr = ftr_bits->safe_val;
+			break;
+		case FTR_LOWER_SAFE:
+			if (ftr > 0)
+				ftr--;
+			break;
+		case FTR_HIGHER_SAFE:
+			if (ftr < ftr_max)
+				ftr++;
+			break;
+		case FTR_HIGHER_OR_ZERO_SAFE:
+			if (ftr == ftr_max)
+				ftr = 0;
+			else if (ftr != 0)
+				ftr++;
+			break;
+		default:
+			break;
+		}
+	} else if (ftr != ftr_max) {
+		switch (ftr_bits->type) {
+		case FTR_EXACT:
+			ftr = ftr_bits->safe_val;
+			break;
+		case FTR_LOWER_SAFE:
+			if (ftr > 0)
+				ftr--;
+			break;
+		case FTR_HIGHER_SAFE:
+			if (ftr < ftr_max - 1)
+				ftr++;
+			break;
+		case FTR_HIGHER_OR_ZERO_SAFE:
+			if (ftr != 0 && ftr != ftr_max - 1)
+				ftr++;
+			break;
+		default:
+			break;
+		}
+	}
+
+	return ftr;
+}
+
+/* Return an invalid value to a given ftr_bits an ftr value */
+uint64_t get_invalid_value(const struct reg_ftr_bits *ftr_bits, uint64_t ftr)
+{
+	uint64_t ftr_max = GENMASK_ULL(ARM64_FEATURE_FIELD_BITS - 1, 0);
+
+	if (ftr_bits->type == FTR_UNSIGNED) {
+		switch (ftr_bits->type) {
+		case FTR_EXACT:
+			ftr = max((uint64_t)ftr_bits->safe_val + 1, ftr + 1);
+			break;
+		case FTR_LOWER_SAFE:
+			ftr++;
+			break;
+		case FTR_HIGHER_SAFE:
+			ftr--;
+			break;
+		case FTR_HIGHER_OR_ZERO_SAFE:
+			if (ftr == 0)
+				ftr = ftr_max;
+			else
+				ftr--;
+			break;
+		default:
+			break;
+		}
+	} else if (ftr != ftr_max) {
+		switch (ftr_bits->type) {
+		case FTR_EXACT:
+			ftr = max((uint64_t)ftr_bits->safe_val + 1, ftr + 1);
+			break;
+		case FTR_LOWER_SAFE:
+			ftr++;
+			break;
+		case FTR_HIGHER_SAFE:
+			ftr--;
+			break;
+		case FTR_HIGHER_OR_ZERO_SAFE:
+			if (ftr == 0)
+				ftr = ftr_max - 1;
+			else
+				ftr--;
+			break;
+		default:
+			break;
+		}
+	} else {
+		ftr = 0;
+	}
+
+	return ftr;
+}
+
+static void test_reg_set_success(struct kvm_vcpu *vcpu, uint64_t reg,
+				 const struct reg_ftr_bits *ftr_bits)
+{
+	uint8_t shift = ftr_bits->shift;
+	uint64_t mask = ftr_bits->mask;
+	uint64_t val, new_val, ftr;
+
+	vcpu_get_reg(vcpu, reg, &val);
+	ftr = (val & mask) >> shift;
+
+	ftr = get_safe_value(ftr_bits, ftr);
+
+	ftr <<= shift;
+	val &= ~mask;
+	val |= ftr;
+
+	vcpu_set_reg(vcpu, reg, val);
+	vcpu_get_reg(vcpu, reg, &new_val);
+	TEST_ASSERT_EQ(new_val, val);
+}
+
+static void test_reg_set_fail(struct kvm_vcpu *vcpu, uint64_t reg,
+			      const struct reg_ftr_bits *ftr_bits)
+{
+	uint8_t shift = ftr_bits->shift;
+	uint64_t mask = ftr_bits->mask;
+	uint64_t val, old_val, ftr;
+	int r;
+
+	vcpu_get_reg(vcpu, reg, &val);
+	ftr = (val & mask) >> shift;
+
+	ftr = get_invalid_value(ftr_bits, ftr);
+
+	old_val = val;
+	ftr <<= shift;
+	val &= ~mask;
+	val |= ftr;
+
+	r = __vcpu_set_reg(vcpu, reg, val);
+	TEST_ASSERT(r < 0 && errno == EINVAL,
+		    "Unexpected KVM_SET_ONE_REG error: r=%d, errno=%d", r, errno);
+
+	vcpu_get_reg(vcpu, reg, &val);
+	TEST_ASSERT_EQ(val, old_val);
+}
+
+static void test_user_set_reg(struct kvm_vcpu *vcpu, bool aarch64_only)
+{
+	uint64_t masks[KVM_ARM_FEATURE_ID_RANGE_SIZE];
+	struct reg_mask_range range = {
+		.addr = (__u64)masks,
+	};
+	int ret;
+
+	/* KVM should return error when reserved field is not zero */
+	range.reserved[0] = 1;
+	ret = __vm_ioctl(vcpu->vm, KVM_ARM_GET_REG_WRITABLE_MASKS, &range);
+	TEST_ASSERT(ret, "KVM doesn't check invalid parameters.");
+
+	/* Get writable masks for feature ID registers */
+	memset(range.reserved, 0, sizeof(range.reserved));
+	vm_ioctl(vcpu->vm, KVM_ARM_GET_REG_WRITABLE_MASKS, &range);
+
+	for (int i = 0; i < ARRAY_SIZE(test_regs); i++) {
+		const struct reg_ftr_bits *ftr_bits = test_regs[i].ftr_bits;
+		uint32_t reg_id = test_regs[i].reg;
+		uint64_t reg = KVM_ARM64_SYS_REG(reg_id);
+		int idx;
+
+		/* Get the index to masks array for the idreg */
+		idx = KVM_ARM_FEATURE_ID_RANGE_IDX(sys_reg_Op0(reg_id), sys_reg_Op1(reg_id),
+						   sys_reg_CRn(reg_id), sys_reg_CRm(reg_id),
+						   sys_reg_Op2(reg_id));
+
+		for (int j = 0;  ftr_bits[j].type != FTR_END; j++) {
+			/* Skip aarch32 reg on aarch64 only system, since they are RAZ/WI. */
+			if (aarch64_only && sys_reg_CRm(reg_id) < 4) {
+				ksft_test_result_skip("%s on AARCH64 only system\n",
+						      ftr_bits[j].name);
+				continue;
+			}
+
+			/* Make sure the feature field is writable */
+			TEST_ASSERT_EQ(masks[idx] & ftr_bits[j].mask, ftr_bits[j].mask);
+
+			test_reg_set_fail(vcpu, reg, &ftr_bits[j]);
+			test_reg_set_success(vcpu, reg, &ftr_bits[j]);
+
+			ksft_test_result_pass("%s\n", ftr_bits[j].name);
+		}
+	}
+}
+
+static void test_guest_reg_read(struct kvm_vcpu *vcpu)
+{
+	bool done = false;
+	struct ucall uc;
+	uint64_t val;
+
+	while (!done) {
+		vcpu_run(vcpu);
+
+		switch (get_ucall(vcpu, &uc)) {
+		case UCALL_ABORT:
+			REPORT_GUEST_ASSERT(uc);
+			break;
+		case UCALL_SYNC:
+			/* Make sure the written values are seen by guest */
+			vcpu_get_reg(vcpu, KVM_ARM64_SYS_REG(uc.args[2]), &val);
+			TEST_ASSERT_EQ(val, uc.args[3]);
+			break;
+		case UCALL_DONE:
+			done = true;
+			break;
+		default:
+			TEST_FAIL("Unexpected ucall: %lu", uc.cmd);
+		}
+	}
+}
+
+int main(void)
+{
+	struct kvm_vcpu *vcpu;
+	struct kvm_vm *vm;
+	bool aarch64_only;
+	uint64_t val, el0;
+	int ftr_cnt;
+
+	vm = vm_create_with_one_vcpu(&vcpu, guest_code);
+
+	/* Check for AARCH64 only system */
+	vcpu_get_reg(vcpu, KVM_ARM64_SYS_REG(SYS_ID_AA64PFR0_EL1), &val);
+	el0 = FIELD_GET(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_EL0), val);
+	aarch64_only = (el0 == ID_AA64PFR0_EL1_ELx_64BIT_ONLY);
+
+	ksft_print_header();
+
+	ftr_cnt = ARRAY_SIZE(ftr_id_aa64dfr0_el1) + ARRAY_SIZE(ftr_id_dfr0_el1) +
+		  ARRAY_SIZE(ftr_id_aa64isar0_el1) + ARRAY_SIZE(ftr_id_aa64isar1_el1) +
+		  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);
+
+	ksft_set_plan(ftr_cnt);
+
+	test_user_set_reg(vcpu, aarch64_only);
+	test_guest_reg_read(vcpu);
+
+	kvm_vm_free(vm);
+
+	ksft_finished();
+}
-- 
2.42.0.609.gbb76f46606-goog