[RFC PATCH v2 1/9] KVM: arm64: nv: selftests: Add support to run guest code in vEL2.

Ganapatrao Kulkarni gankulkarni at os.amperecomputing.com
Mon May 12 03:52:43 PDT 2025


This patch adds required changes to vcpu init to run a guest code
in vEL2 context and also adds NV specific helper functions.

Signed-off-by: Ganapatrao Kulkarni <gankulkarni at os.amperecomputing.com>
---
 tools/testing/selftests/kvm/Makefile.kvm      |  2 +
 .../kvm/include/arm64/kvm_util_arch.h         |  3 +
 .../selftests/kvm/include/arm64/nv_util.h     | 45 ++++++++++++++
 .../selftests/kvm/include/arm64/vgic.h        |  1 +
 .../testing/selftests/kvm/include/kvm_util.h  |  3 +
 tools/testing/selftests/kvm/lib/arm64/nv.c    | 46 ++++++++++++++
 .../selftests/kvm/lib/arm64/processor.c       | 61 ++++++++++++++-----
 tools/testing/selftests/kvm/lib/arm64/vgic.c  |  8 +++
 8 files changed, 155 insertions(+), 14 deletions(-)
 create mode 100644 tools/testing/selftests/kvm/include/arm64/nv_util.h
 create mode 100644 tools/testing/selftests/kvm/lib/arm64/nv.c

diff --git a/tools/testing/selftests/kvm/Makefile.kvm b/tools/testing/selftests/kvm/Makefile.kvm
index f773f8f99249..3348f729d3b2 100644
--- a/tools/testing/selftests/kvm/Makefile.kvm
+++ b/tools/testing/selftests/kvm/Makefile.kvm
@@ -37,6 +37,7 @@ LIBKVM_arm64 += lib/arm64/processor.c
 LIBKVM_arm64 += lib/arm64/spinlock.c
 LIBKVM_arm64 += lib/arm64/ucall.c
 LIBKVM_arm64 += lib/arm64/vgic.c
+LIBKVM_arm64 += lib/arm64/nv.c
 
 LIBKVM_s390 += lib/s390/diag318_test_handler.c
 LIBKVM_s390 += lib/s390/processor.c
@@ -155,6 +156,7 @@ TEST_GEN_PROGS_arm64 += arm64/vgic_irq
 TEST_GEN_PROGS_arm64 += arm64/vgic_lpi_stress
 TEST_GEN_PROGS_arm64 += arm64/vpmu_counter_access
 TEST_GEN_PROGS_arm64 += arm64/no-vgic-v3
+TEST_GEN_PROGS_arm64 += arm64/nv_guest_hypervisor
 TEST_GEN_PROGS_arm64 += access_tracking_perf_test
 TEST_GEN_PROGS_arm64 += arch_timer
 TEST_GEN_PROGS_arm64 += coalesced_io_test
diff --git a/tools/testing/selftests/kvm/include/arm64/kvm_util_arch.h b/tools/testing/selftests/kvm/include/arm64/kvm_util_arch.h
index e43a57d99b56..ab5279c24413 100644
--- a/tools/testing/selftests/kvm/include/arm64/kvm_util_arch.h
+++ b/tools/testing/selftests/kvm/include/arm64/kvm_util_arch.h
@@ -2,6 +2,9 @@
 #ifndef SELFTEST_KVM_UTIL_ARCH_H
 #define SELFTEST_KVM_UTIL_ARCH_H
 
+#define CurrentEL_EL1		(1 << 2)
+#define CurrentEL_EL2		(2 << 2)
+
 struct kvm_vm_arch {};
 
 #endif  // SELFTEST_KVM_UTIL_ARCH_H
diff --git a/tools/testing/selftests/kvm/include/arm64/nv_util.h b/tools/testing/selftests/kvm/include/arm64/nv_util.h
new file mode 100644
index 000000000000..622a17c9d142
--- /dev/null
+++ b/tools/testing/selftests/kvm/include/arm64/nv_util.h
@@ -0,0 +1,45 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2025 Ampere Computing
+ */
+#ifndef SELFTEST_NV_UTIL_H
+#define SELFTEST_NV_UTIL_H
+
+#include <linux/bitmap.h>
+#include <vgic.h>
+
+#define HCR_NV2		(UL(1) << 45)
+#define HCR_AT		(UL(1) << 44)
+#define HCR_NV		(UL(1) << 42)
+#define HCR_E2H		(UL(1) << 34)
+#define HCR_TTLB        (UL(1) << 25)
+
+/* Enable NV2 and guest in VHE mode */
+#define HCR_EL2_NV_EANBLE (HCR_E2H | HCR_NV | HCR_NV2 | HCR_AT | HCR_TTLB)
+
+struct kvm_vm *nv_vm_create_with_vcpus_gic(uint32_t nr_vcpus,
+		struct kvm_vcpu **vcpus, int *gic_fd, void *guest_code);
+
+struct kvm_vm *__nv_vm_create_with_vcpus_gic(struct vm_shape shape,
+		uint32_t nr_vcpus, struct kvm_vcpu **vcpus,
+		uint64_t extra_mem_pages, int *gic_fd, void *guest_code);
+
+/* NV helpers */
+static inline void init_vcpu_nested(struct kvm_vcpu_init *init)
+{
+	init->features[0] |= (1 << KVM_ARM_VCPU_HAS_EL2);
+}
+
+static inline bool kvm_arm_vcpu_has_el2(struct kvm_vcpu_init *init)
+{
+	unsigned long features = init->features[0];
+
+	return test_bit(KVM_ARM_VCPU_HAS_EL2, &features);
+}
+
+static inline bool is_vcpu_nested(struct kvm_vcpu *vcpu)
+{
+	return vcpu->nested;
+}
+
+#endif /* SELFTEST_NV_UTIL_H */
diff --git a/tools/testing/selftests/kvm/include/arm64/vgic.h b/tools/testing/selftests/kvm/include/arm64/vgic.h
index c481d0c00a5d..46142fa36199 100644
--- a/tools/testing/selftests/kvm/include/arm64/vgic.h
+++ b/tools/testing/selftests/kvm/include/arm64/vgic.h
@@ -17,6 +17,7 @@
 	index)
 
 int vgic_v3_setup(struct kvm_vm *vm, unsigned int nr_vcpus, uint32_t nr_irqs);
+void vgic_v3_close(int gic_fd);
 
 #define VGIC_MAX_RESERVED	1023
 
diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h
index 373912464fb4..9b26b9124dc3 100644
--- a/tools/testing/selftests/kvm/include/kvm_util.h
+++ b/tools/testing/selftests/kvm/include/kvm_util.h
@@ -65,6 +65,9 @@ struct kvm_vcpu {
 	struct kvm_dirty_gfn *dirty_gfns;
 	uint32_t fetch_index;
 	uint32_t dirty_gfns_count;
+#ifdef __aarch64__
+	bool nested;
+#endif
 };
 
 struct userspace_mem_regions {
diff --git a/tools/testing/selftests/kvm/lib/arm64/nv.c b/tools/testing/selftests/kvm/lib/arm64/nv.c
new file mode 100644
index 000000000000..e930808a7ed4
--- /dev/null
+++ b/tools/testing/selftests/kvm/lib/arm64/nv.c
@@ -0,0 +1,46 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2025 Ampere Computing LLC
+ */
+
+#include <linux/compiler.h>
+#include <assert.h>
+
+#include "guest_modes.h"
+#include "kvm_util.h"
+#include "nv_util.h"
+#include "processor.h"
+
+struct kvm_vm *__nv_vm_create_with_vcpus_gic(struct vm_shape shape, uint32_t nr_vcpus,
+		struct kvm_vcpu **vcpus, uint64_t extra_mem_pages, int *gic_fd, void *guest_code)
+{
+	struct kvm_vcpu_init init;
+	struct kvm_vm *vm;
+	int i;
+
+	TEST_REQUIRE(kvm_has_cap(KVM_CAP_ARM_EL2));
+
+	vm = __vm_create(shape, nr_vcpus, extra_mem_pages);
+	vm_ioctl(vm, KVM_ARM_PREFERRED_TARGET, &init);
+	init_vcpu_nested(&init);
+
+	for (i = 0; i < nr_vcpus; ++i) {
+		vcpus[i] = aarch64_vcpu_add(vm, i, &init, guest_code);
+		__TEST_REQUIRE(is_vcpu_nested(vcpus[i]), "Failed to Enable NV");
+	}
+
+	/* vgic is not created, If gic_fd argument is NULL */
+	if (gic_fd) {
+		*gic_fd = vgic_v3_setup(vm, nr_vcpus, 64);
+		__TEST_REQUIRE(*gic_fd >= 0, "Failed to create vgic-v3");
+	}
+
+	return vm;
+}
+
+struct kvm_vm *nv_vm_create_with_vcpus_gic(uint32_t nr_vcpus,
+		struct kvm_vcpu **vcpus, int *gic_fd, void *guest_code)
+{
+	return __nv_vm_create_with_vcpus_gic(VM_SHAPE_DEFAULT,
+				nr_vcpus, vcpus, 0, gic_fd, guest_code);
+}
diff --git a/tools/testing/selftests/kvm/lib/arm64/processor.c b/tools/testing/selftests/kvm/lib/arm64/processor.c
index 7ba3aa3755f3..6e759981bf9e 100644
--- a/tools/testing/selftests/kvm/lib/arm64/processor.c
+++ b/tools/testing/selftests/kvm/lib/arm64/processor.c
@@ -10,6 +10,7 @@
 
 #include "guest_modes.h"
 #include "kvm_util.h"
+#include "nv_util.h"
 #include "processor.h"
 #include "ucall_common.h"
 
@@ -258,14 +259,49 @@ void virt_arch_dump(FILE *stream, struct kvm_vm *vm, uint8_t indent)
 	}
 }
 
+static void aarch64_vcpu_set_reg(struct kvm_vcpu *vcpu, uint64_t sctlr_el1,
+			uint64_t tcr_el1, uint64_t ttbr0_el1)
+{
+	uint64_t fpen;
+
+	/*
+	 * Enable FP/ASIMD to avoid trapping when accessing Q0-Q15
+	 * registers, which the variable argument list macros do.
+	 */
+	fpen = 3 << 20;
+
+	if (is_vcpu_nested(vcpu)) {
+		vcpu_set_reg(vcpu, KVM_ARM64_SYS_REG(SYS_CPTR_EL2), fpen);
+		vcpu_set_reg(vcpu, KVM_ARM64_SYS_REG(SYS_SCTLR_EL2), sctlr_el1);
+		vcpu_set_reg(vcpu, KVM_ARM64_SYS_REG(SYS_TCR_EL2), tcr_el1);
+		vcpu_set_reg(vcpu, KVM_ARM64_SYS_REG(SYS_MAIR_EL2), DEFAULT_MAIR_EL1);
+		vcpu_set_reg(vcpu, KVM_ARM64_SYS_REG(SYS_TTBR0_EL2), ttbr0_el1);
+		vcpu_set_reg(vcpu, KVM_ARM64_SYS_REG(SYS_HCR_EL2), HCR_EL2_NV_EANBLE);
+	} else {
+		vcpu_set_reg(vcpu, KVM_ARM64_SYS_REG(SYS_CPACR_EL1), fpen);
+		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), ttbr0_el1);
+
+	}
+
+	vcpu_set_reg(vcpu, KVM_ARM64_SYS_REG(SYS_TPIDR_EL1), vcpu->id);
+}
+
 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, ttbr0_el1;
 
-	if (!init)
+	if (!init) {
 		init = &default_init;
+	} else {
+		/* Is this vcpu a Guest-Hypersior */
+		if (kvm_arm_vcpu_has_el2(init))
+			vcpu->nested = true;
+	}
 
 	if (init->target == -1) {
 		struct kvm_vcpu_init preferred;
@@ -275,12 +311,6 @@ void aarch64_vcpu_setup(struct kvm_vcpu *vcpu, struct kvm_vcpu_init *init)
 
 	vcpu_ioctl(vcpu, KVM_ARM_VCPU_INIT, init);
 
-	/*
-	 * Enable FP/ASIMD to avoid trapping when accessing Q0-Q15
-	 * registers, which the variable argument list macros do.
-	 */
-	vcpu_set_reg(vcpu, KVM_ARM64_SYS_REG(SYS_CPACR_EL1), 3 << 20);
-
 	sctlr_el1 = vcpu_get_reg(vcpu, KVM_ARM64_SYS_REG(SYS_SCTLR_EL1));
 	tcr_el1 = vcpu_get_reg(vcpu, KVM_ARM64_SYS_REG(SYS_TCR_EL1));
 
@@ -349,11 +379,7 @@ void aarch64_vcpu_setup(struct kvm_vcpu *vcpu, struct kvm_vcpu_init *init)
 	if (use_lpa2_pte_format(vm))
 		tcr_el1 |= (1ul << 59) /* DS */;
 
-	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), ttbr0_el1);
-	vcpu_set_reg(vcpu, KVM_ARM64_SYS_REG(SYS_TPIDR_EL1), vcpu->id);
+	aarch64_vcpu_set_reg(vcpu, sctlr_el1, tcr_el1, ttbr0_el1);
 }
 
 void vcpu_arch_dump(FILE *stream, struct kvm_vcpu *vcpu, uint8_t indent)
@@ -387,7 +413,11 @@ static struct kvm_vcpu *__aarch64_vcpu_add(struct kvm_vm *vm, uint32_t vcpu_id,
 
 	aarch64_vcpu_setup(vcpu, init);
 
-	vcpu_set_reg(vcpu, ARM64_CORE_REG(sp_el1), stack_vaddr + stack_size);
+	if (is_vcpu_nested(vcpu))
+		vcpu_set_reg(vcpu, KVM_ARM64_SYS_REG(SYS_SP_EL2), stack_vaddr + stack_size);
+	else
+		vcpu_set_reg(vcpu, ARM64_CORE_REG(sp_el1), stack_vaddr + stack_size);
+
 	return vcpu;
 }
 
@@ -457,7 +487,10 @@ void vcpu_init_descriptor_tables(struct kvm_vcpu *vcpu)
 {
 	extern char vectors;
 
-	vcpu_set_reg(vcpu, KVM_ARM64_SYS_REG(SYS_VBAR_EL1), (uint64_t)&vectors);
+	if (is_vcpu_nested(vcpu))
+		vcpu_set_reg(vcpu, KVM_ARM64_SYS_REG(SYS_VBAR_EL2), (uint64_t)&vectors);
+	else
+		vcpu_set_reg(vcpu, KVM_ARM64_SYS_REG(SYS_VBAR_EL1), (uint64_t)&vectors);
 }
 
 void route_exception(struct ex_regs *regs, int vector)
diff --git a/tools/testing/selftests/kvm/lib/arm64/vgic.c b/tools/testing/selftests/kvm/lib/arm64/vgic.c
index 4427f43f73ea..67822b803d0f 100644
--- a/tools/testing/selftests/kvm/lib/arm64/vgic.c
+++ b/tools/testing/selftests/kvm/lib/arm64/vgic.c
@@ -79,6 +79,14 @@ int vgic_v3_setup(struct kvm_vm *vm, unsigned int nr_vcpus, uint32_t nr_irqs)
 	return gic_fd;
 }
 
+void  vgic_v3_close(int gic_fd)
+{
+	if (gic_fd < 0)
+		return;
+
+	close(gic_fd);
+}
+
 /* should only work for level sensitive interrupts */
 int _kvm_irq_set_level_info(int gic_fd, uint32_t intid, int level)
 {
-- 
2.48.1




More information about the linux-arm-kernel mailing list