[RFC PATCH v2 1/9] KVM: arm64: nv: selftests: Add support to run guest code in vEL2.
Eric Auger
eauger at redhat.com
Wed May 28 06:33:43 PDT 2025
Hi,
On 5/12/25 12:52 PM, Ganapatrao Kulkarni wrote:
> 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)
nit: not yet used in this patch.
> +
> 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)
ENABLE
> +
> +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)
I am not sure it is worth introducing this helper. Some reg values are
set externally while fpen is set here. That looks odd to me.
> +{
> + 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)
> {
Thanks
Eric
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