| Message ID | 20250206164120.4045569-2-gankulkarni@os.amperecomputing.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Add NV Selftest cases | expand |
On Thu, 06 Feb 2025 16:41:19 +0000, Ganapatrao Kulkarni <gankulkarni@os.amperecomputing.com> wrote: > > This patch adds the required changes to init vcpu in vEL2 context. > Also adds a KVM selftest to execute guest code as a guest hypervisor(L1). > > Signed-off-by: Ganapatrao Kulkarni <gankulkarni@os.amperecomputing.com> > --- > tools/testing/selftests/kvm/Makefile.kvm | 1 + > .../selftests/kvm/arm64/nv_guest_hypervisor.c | 83 +++++++++++++++++++ > .../kvm/include/arm64/kvm_util_arch.h | 3 + > .../selftests/kvm/include/arm64/nv_util.h | 28 +++++++ > .../testing/selftests/kvm/include/kvm_util.h | 1 + > .../selftests/kvm/lib/arm64/processor.c | 59 +++++++++---- > 6 files changed, 161 insertions(+), 14 deletions(-) > create mode 100644 tools/testing/selftests/kvm/arm64/nv_guest_hypervisor.c > create mode 100644 tools/testing/selftests/kvm/include/arm64/nv_util.h > > diff --git a/tools/testing/selftests/kvm/Makefile.kvm b/tools/testing/selftests/kvm/Makefile.kvm > index 4277b983cace..a85d3bec9fb1 100644 > --- a/tools/testing/selftests/kvm/Makefile.kvm > +++ b/tools/testing/selftests/kvm/Makefile.kvm > @@ -154,6 +154,7 @@ 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/arm64/nv_guest_hypervisor.c b/tools/testing/selftests/kvm/arm64/nv_guest_hypervisor.c > new file mode 100644 > index 000000000000..5aeefe43aff7 > --- /dev/null > +++ b/tools/testing/selftests/kvm/arm64/nv_guest_hypervisor.c > @@ -0,0 +1,83 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * Copyright (c) 2025 Ampere Computing LLC > + */ > +#include <kvm_util.h> > +#include <nv_util.h> > +#include <processor.h> > +#include <vgic.h> > + > +static void guest_code(void) > +{ > + if (read_sysreg(CurrentEL) == CurrentEL_EL2) > + GUEST_PRINTF("Executing guest code in vEL2\n"); > + else > + GUEST_FAIL("Fail to run in vEL2\n"); > + > + GUEST_DONE(); > +} > + > +static void guest_undef_handler(struct ex_regs *regs) > +{ > + GUEST_FAIL("Unexpected exception far_el1 = 0x%lx", read_sysreg(far_el1)); > +} > + > +static void test_run_vcpu(struct kvm_vcpu *vcpu) > +{ > + struct ucall uc; > + > + do { > + vcpu_run(vcpu); > + > + switch (get_ucall(vcpu, &uc)) { > + case UCALL_ABORT: > + REPORT_GUEST_ASSERT(uc); > + break; > + case UCALL_PRINTF: > + printf("%s", uc.buffer); > + break; > + case UCALL_DONE: > + printf("Test PASS\n"); > + break; > + default: > + TEST_FAIL("Unknown ucall %lu", uc.cmd); > + } > + } while (uc.cmd != UCALL_DONE); > +} > + > +static void test_nv_guest_hypervisor(void) > +{ > + struct kvm_vcpu *vcpu; > + struct kvm_vm *vm; > + struct kvm_vcpu_init init; > + int gic_fd; > + > + vm = vm_create(1); > + vm_ioctl(vm, KVM_ARM_PREFERRED_TARGET, &init); > + > + init.features[0] = 0; > + init_vcpu_nested(&init); > + vcpu = aarch64_vcpu_add(vm, 0, &init, guest_code); > + > + __TEST_REQUIRE(is_vcpu_nested(vcpu), "Failed to Enable NV"); > + > + vm_init_descriptor_tables(vm); > + vcpu_init_descriptor_tables(vcpu); > + gic_fd = vgic_v3_setup(vm, 1, 64); > + __TEST_REQUIRE(gic_fd >= 0, "Failed to create vgic-v3"); > + > + vm_install_sync_handler(vm, VECTOR_SYNC_CURRENT, > + ESR_ELx_EC_UNKNOWN, guest_undef_handler); > + > + test_run_vcpu(vcpu); > + kvm_vm_free(vm); > +} > + > +int main(int argc, char *argv[]) > +{ > + TEST_REQUIRE(kvm_has_cap(KVM_CAP_ARM_EL2)); > + > + test_nv_guest_hypervisor(); > + > + return 0; > +} > 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..4fecf1f18554 > --- /dev/null > +++ b/tools/testing/selftests/kvm/include/arm64/nv_util.h > @@ -0,0 +1,28 @@ > +/* 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> > + > +/* 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/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h > index 4c4e5a847f67..8c53dbc17f8f 100644 > --- a/tools/testing/selftests/kvm/include/kvm_util.h > +++ b/tools/testing/selftests/kvm/include/kvm_util.h > @@ -58,6 +58,7 @@ struct kvm_vcpu { > struct kvm_dirty_gfn *dirty_gfns; > uint32_t fetch_index; > uint32_t dirty_gfns_count; > + bool nested; > }; > > struct userspace_mem_regions { > diff --git a/tools/testing/selftests/kvm/lib/arm64/processor.c b/tools/testing/selftests/kvm/lib/arm64/processor.c > index 7ba3aa3755f3..35ba2ace61a2 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 +259,47 @@ 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_TPIDR_EL2), vcpu->id); How about some of the basics such as HCR_EL2, MDCR_EL2? A bunch of things there do have an impact on how the guest behaves, and relying on defaults feels like a bad idea. This also assumes VHE, without trying to enforce it. Finally, how to you plan to make all the existing tests run as EL2 guests if TPIDR_EL1 isn't populated with the expected value? Surely you need to change the read side... M.
Hi Marc, On 07-02-2025 02:44 am, Marc Zyngier wrote: > On Thu, 06 Feb 2025 16:41:19 +0000, > Ganapatrao Kulkarni <gankulkarni@os.amperecomputing.com> wrote: >> >> This patch adds the required changes to init vcpu in vEL2 context. >> Also adds a KVM selftest to execute guest code as a guest hypervisor(L1). >> >> Signed-off-by: Ganapatrao Kulkarni <gankulkarni@os.amperecomputing.com> >> --- >> tools/testing/selftests/kvm/Makefile.kvm | 1 + >> .../selftests/kvm/arm64/nv_guest_hypervisor.c | 83 +++++++++++++++++++ >> .../kvm/include/arm64/kvm_util_arch.h | 3 + >> .../selftests/kvm/include/arm64/nv_util.h | 28 +++++++ >> .../testing/selftests/kvm/include/kvm_util.h | 1 + >> .../selftests/kvm/lib/arm64/processor.c | 59 +++++++++---- >> 6 files changed, 161 insertions(+), 14 deletions(-) >> create mode 100644 tools/testing/selftests/kvm/arm64/nv_guest_hypervisor.c >> create mode 100644 tools/testing/selftests/kvm/include/arm64/nv_util.h >> >> diff --git a/tools/testing/selftests/kvm/Makefile.kvm b/tools/testing/selftests/kvm/Makefile.kvm >> index 4277b983cace..a85d3bec9fb1 100644 >> --- a/tools/testing/selftests/kvm/Makefile.kvm >> +++ b/tools/testing/selftests/kvm/Makefile.kvm >> @@ -154,6 +154,7 @@ 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/arm64/nv_guest_hypervisor.c b/tools/testing/selftests/kvm/arm64/nv_guest_hypervisor.c >> new file mode 100644 >> index 000000000000..5aeefe43aff7 >> --- /dev/null >> +++ b/tools/testing/selftests/kvm/arm64/nv_guest_hypervisor.c >> @@ -0,0 +1,83 @@ >> +// SPDX-License-Identifier: GPL-2.0-only >> +/* >> + * Copyright (c) 2025 Ampere Computing LLC >> + */ >> +#include <kvm_util.h> >> +#include <nv_util.h> >> +#include <processor.h> >> +#include <vgic.h> >> + >> +static void guest_code(void) >> +{ >> + if (read_sysreg(CurrentEL) == CurrentEL_EL2) >> + GUEST_PRINTF("Executing guest code in vEL2\n"); >> + else >> + GUEST_FAIL("Fail to run in vEL2\n"); >> + >> + GUEST_DONE(); >> +} >> + >> +static void guest_undef_handler(struct ex_regs *regs) >> +{ >> + GUEST_FAIL("Unexpected exception far_el1 = 0x%lx", read_sysreg(far_el1)); >> +} >> + >> +static void test_run_vcpu(struct kvm_vcpu *vcpu) >> +{ >> + struct ucall uc; >> + >> + do { >> + vcpu_run(vcpu); >> + >> + switch (get_ucall(vcpu, &uc)) { >> + case UCALL_ABORT: >> + REPORT_GUEST_ASSERT(uc); >> + break; >> + case UCALL_PRINTF: >> + printf("%s", uc.buffer); >> + break; >> + case UCALL_DONE: >> + printf("Test PASS\n"); >> + break; >> + default: >> + TEST_FAIL("Unknown ucall %lu", uc.cmd); >> + } >> + } while (uc.cmd != UCALL_DONE); >> +} >> + >> +static void test_nv_guest_hypervisor(void) >> +{ >> + struct kvm_vcpu *vcpu; >> + struct kvm_vm *vm; >> + struct kvm_vcpu_init init; >> + int gic_fd; >> + >> + vm = vm_create(1); >> + vm_ioctl(vm, KVM_ARM_PREFERRED_TARGET, &init); >> + >> + init.features[0] = 0; >> + init_vcpu_nested(&init); >> + vcpu = aarch64_vcpu_add(vm, 0, &init, guest_code); >> + >> + __TEST_REQUIRE(is_vcpu_nested(vcpu), "Failed to Enable NV"); >> + >> + vm_init_descriptor_tables(vm); >> + vcpu_init_descriptor_tables(vcpu); >> + gic_fd = vgic_v3_setup(vm, 1, 64); >> + __TEST_REQUIRE(gic_fd >= 0, "Failed to create vgic-v3"); >> + >> + vm_install_sync_handler(vm, VECTOR_SYNC_CURRENT, >> + ESR_ELx_EC_UNKNOWN, guest_undef_handler); >> + >> + test_run_vcpu(vcpu); >> + kvm_vm_free(vm); >> +} >> + >> +int main(int argc, char *argv[]) >> +{ >> + TEST_REQUIRE(kvm_has_cap(KVM_CAP_ARM_EL2)); >> + >> + test_nv_guest_hypervisor(); >> + >> + return 0; >> +} >> 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..4fecf1f18554 >> --- /dev/null >> +++ b/tools/testing/selftests/kvm/include/arm64/nv_util.h >> @@ -0,0 +1,28 @@ >> +/* 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> >> + >> +/* 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/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h >> index 4c4e5a847f67..8c53dbc17f8f 100644 >> --- a/tools/testing/selftests/kvm/include/kvm_util.h >> +++ b/tools/testing/selftests/kvm/include/kvm_util.h >> @@ -58,6 +58,7 @@ struct kvm_vcpu { >> struct kvm_dirty_gfn *dirty_gfns; >> uint32_t fetch_index; >> uint32_t dirty_gfns_count; >> + bool nested; >> }; >> >> struct userspace_mem_regions { >> diff --git a/tools/testing/selftests/kvm/lib/arm64/processor.c b/tools/testing/selftests/kvm/lib/arm64/processor.c >> index 7ba3aa3755f3..35ba2ace61a2 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 +259,47 @@ 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_TPIDR_EL2), vcpu->id); > > How about some of the basics such as HCR_EL2, MDCR_EL2? A bunch of > things there do have an impact on how the guest behaves, and relying > on defaults feels like a bad idea. Sure, I will try to have these registers also set to required value explicitly. > > This also assumes VHE, without trying to enforce it. Ok, I will try to set specific bits of HCR_EL2 to force it run in VHE. > > Finally, how to you plan to make all the existing tests run as EL2 > guests if TPIDR_EL1 isn't populated with the expected value? Surely > you need to change the read side... OK, I have not yet tried running existing tests modifying to run as EL2 guests. I will try to run them modifying to run in vEL2. Should we modify them to run as EL2 guests by default, if the host supports/detected NV? or command line argument based run? either in El1(default) or in EL2? BTW, I have also ran all existing tests on L1, most of the tests are passing(atleast I did not see any failure prints). arm64/debug-exceptions is failing on L1 and needs to be debugged/fixed/skipped. arm64/arch_timer_edge_cases fails on both L0 and L1.
On Fri, 07 Feb 2025 13:26:41 +0000, Ganapatrao Kulkarni <gankulkarni@os.amperecomputing.com> wrote: > > >> + 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_TPIDR_EL2), vcpu->id); > > > > How about some of the basics such as HCR_EL2, MDCR_EL2? A bunch of > > things there do have an impact on how the guest behaves, and relying > > on defaults feels like a bad idea. > > Sure, I will try to have these registers also set to required value > explicitly. > > > > > This also assumes VHE, without trying to enforce it. > > Ok, I will try to set specific bits of HCR_EL2 to force it run in VHE. > > > > > Finally, how to you plan to make all the existing tests run as EL2 > > guests if TPIDR_EL1 isn't populated with the expected value? Surely > > you need to change the read side... > > OK, I have not yet tried running existing tests modifying to run as > EL2 guests. I will try to run them modifying to run in vEL2. You shouldn't try to modify them. Just make them take a parameter so that the initialisation is done by configuring everything at EL2. > > Should we modify them to run as EL2 guests by default, if the host > supports/detected NV? or command line argument based run? either in > El1(default) or in EL2? EL1 by default. > > BTW, I have also ran all existing tests on L1, most of the tests are > passing(atleast I did not see any failure prints). > > arm64/debug-exceptions is failing on L1 and needs to be > debugged/fixed/skipped. > arm64/arch_timer_edge_cases fails on both L0 and L1. Then I guess you have some work to do to debug these problems, and it once more means that NV is not ready for merging. M.
On 07-02-2025 07:29 pm, Marc Zyngier wrote: > On Fri, 07 Feb 2025 13:26:41 +0000, > Ganapatrao Kulkarni <gankulkarni@os.amperecomputing.com> wrote: >> >>>> + 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_TPIDR_EL2), vcpu->id); >>> >>> How about some of the basics such as HCR_EL2, MDCR_EL2? A bunch of >>> things there do have an impact on how the guest behaves, and relying >>> on defaults feels like a bad idea. >> >> Sure, I will try to have these registers also set to required value >> explicitly. >> >>> >>> This also assumes VHE, without trying to enforce it. >> >> Ok, I will try to set specific bits of HCR_EL2 to force it run in VHE. >> >>> >>> Finally, how to you plan to make all the existing tests run as EL2 >>> guests if TPIDR_EL1 isn't populated with the expected value? Surely >>> you need to change the read side... >> >> OK, I have not yet tried running existing tests modifying to run as >> EL2 guests. I will try to run them modifying to run in vEL2. > > You shouldn't try to modify them. Just make them take a parameter so > that the initialisation is done by configuring everything at EL2. > OK, make sense, thanks. I will work on one of the test case and post it in the v2. >> >> Should we modify them to run as EL2 guests by default, if the host >> supports/detected NV? or command line argument based run? either in >> El1(default) or in EL2? > > EL1 by default. OK. > >> >> BTW, I have also ran all existing tests on L1, most of the tests are >> passing(atleast I did not see any failure prints). >> >> arm64/debug-exceptions is failing on L1 and needs to be >> debugged/fixed/skipped. >> arm64/arch_timer_edge_cases fails on both L0 and L1. > > Then I guess you have some work to do to debug these problems, and it > once more means that NV is not ready for merging. I will debug and share the findings/fix at the earliest.
On 07-02-2025 10:16 pm, Ganapatrao Kulkarni wrote: > > > On 07-02-2025 07:29 pm, Marc Zyngier wrote: >> On Fri, 07 Feb 2025 13:26:41 +0000, >> Ganapatrao Kulkarni <gankulkarni@os.amperecomputing.com> wrote: >>> >>>>> + 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_TPIDR_EL2), vcpu- >>>>> >id); >>>> >>>> How about some of the basics such as HCR_EL2, MDCR_EL2? A bunch of >>>> things there do have an impact on how the guest behaves, and relying >>>> on defaults feels like a bad idea. >>> >>> Sure, I will try to have these registers also set to required value >>> explicitly. >>> >>>> >>>> This also assumes VHE, without trying to enforce it. >>> >>> Ok, I will try to set specific bits of HCR_EL2 to force it run in VHE. >>> >>>> >>>> Finally, how to you plan to make all the existing tests run as EL2 >>>> guests if TPIDR_EL1 isn't populated with the expected value? Surely >>>> you need to change the read side... >>> IIUC, we need not write to TPIDR_EL2, instead write always to TPIDR_EL1 and in guest code(like function cpu_copy_el2regs in Linux kernel) copy TPIDR_EL1 value to TPIDR_EL2. OR, Write to both TPIDR_EL1 and TPIDR_EL2 in the test code itself during vcpu setup.
diff --git a/tools/testing/selftests/kvm/Makefile.kvm b/tools/testing/selftests/kvm/Makefile.kvm index 4277b983cace..a85d3bec9fb1 100644 --- a/tools/testing/selftests/kvm/Makefile.kvm +++ b/tools/testing/selftests/kvm/Makefile.kvm @@ -154,6 +154,7 @@ 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/arm64/nv_guest_hypervisor.c b/tools/testing/selftests/kvm/arm64/nv_guest_hypervisor.c new file mode 100644 index 000000000000..5aeefe43aff7 --- /dev/null +++ b/tools/testing/selftests/kvm/arm64/nv_guest_hypervisor.c @@ -0,0 +1,83 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2025 Ampere Computing LLC + */ +#include <kvm_util.h> +#include <nv_util.h> +#include <processor.h> +#include <vgic.h> + +static void guest_code(void) +{ + if (read_sysreg(CurrentEL) == CurrentEL_EL2) + GUEST_PRINTF("Executing guest code in vEL2\n"); + else + GUEST_FAIL("Fail to run in vEL2\n"); + + GUEST_DONE(); +} + +static void guest_undef_handler(struct ex_regs *regs) +{ + GUEST_FAIL("Unexpected exception far_el1 = 0x%lx", read_sysreg(far_el1)); +} + +static void test_run_vcpu(struct kvm_vcpu *vcpu) +{ + struct ucall uc; + + do { + vcpu_run(vcpu); + + switch (get_ucall(vcpu, &uc)) { + case UCALL_ABORT: + REPORT_GUEST_ASSERT(uc); + break; + case UCALL_PRINTF: + printf("%s", uc.buffer); + break; + case UCALL_DONE: + printf("Test PASS\n"); + break; + default: + TEST_FAIL("Unknown ucall %lu", uc.cmd); + } + } while (uc.cmd != UCALL_DONE); +} + +static void test_nv_guest_hypervisor(void) +{ + struct kvm_vcpu *vcpu; + struct kvm_vm *vm; + struct kvm_vcpu_init init; + int gic_fd; + + vm = vm_create(1); + vm_ioctl(vm, KVM_ARM_PREFERRED_TARGET, &init); + + init.features[0] = 0; + init_vcpu_nested(&init); + vcpu = aarch64_vcpu_add(vm, 0, &init, guest_code); + + __TEST_REQUIRE(is_vcpu_nested(vcpu), "Failed to Enable NV"); + + vm_init_descriptor_tables(vm); + vcpu_init_descriptor_tables(vcpu); + gic_fd = vgic_v3_setup(vm, 1, 64); + __TEST_REQUIRE(gic_fd >= 0, "Failed to create vgic-v3"); + + vm_install_sync_handler(vm, VECTOR_SYNC_CURRENT, + ESR_ELx_EC_UNKNOWN, guest_undef_handler); + + test_run_vcpu(vcpu); + kvm_vm_free(vm); +} + +int main(int argc, char *argv[]) +{ + TEST_REQUIRE(kvm_has_cap(KVM_CAP_ARM_EL2)); + + test_nv_guest_hypervisor(); + + return 0; +} 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..4fecf1f18554 --- /dev/null +++ b/tools/testing/selftests/kvm/include/arm64/nv_util.h @@ -0,0 +1,28 @@ +/* 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> + +/* 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/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h index 4c4e5a847f67..8c53dbc17f8f 100644 --- a/tools/testing/selftests/kvm/include/kvm_util.h +++ b/tools/testing/selftests/kvm/include/kvm_util.h @@ -58,6 +58,7 @@ struct kvm_vcpu { struct kvm_dirty_gfn *dirty_gfns; uint32_t fetch_index; uint32_t dirty_gfns_count; + bool nested; }; struct userspace_mem_regions { diff --git a/tools/testing/selftests/kvm/lib/arm64/processor.c b/tools/testing/selftests/kvm/lib/arm64/processor.c index 7ba3aa3755f3..35ba2ace61a2 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 +259,47 @@ 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_TPIDR_EL2), vcpu->id); + } 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 +309,6 @@ 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 +377,7 @@ 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 +411,11 @@ 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 +485,10 @@ 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)
This patch adds the required changes to init vcpu in vEL2 context. Also adds a KVM selftest to execute guest code as a guest hypervisor(L1). Signed-off-by: Ganapatrao Kulkarni <gankulkarni@os.amperecomputing.com> --- tools/testing/selftests/kvm/Makefile.kvm | 1 + .../selftests/kvm/arm64/nv_guest_hypervisor.c | 83 +++++++++++++++++++ .../kvm/include/arm64/kvm_util_arch.h | 3 + .../selftests/kvm/include/arm64/nv_util.h | 28 +++++++ .../testing/selftests/kvm/include/kvm_util.h | 1 + .../selftests/kvm/lib/arm64/processor.c | 59 +++++++++---- 6 files changed, 161 insertions(+), 14 deletions(-) create mode 100644 tools/testing/selftests/kvm/arm64/nv_guest_hypervisor.c create mode 100644 tools/testing/selftests/kvm/include/arm64/nv_util.h