The previous patch added the common steal_time_change_pid test with x86 support. Add the arm64 support so the same test also covers arm64.
Use KVM_ARM_VCPU_PVTIME_IPA to enable the steal time shared page from userspace, and use the PV_TIME_ST SMCCC call in the guest to retrieve and read that page. Assisted-by: Codex:GPT-5.5 Signed-off-by: Dongli Zhang <[email protected]> --- As I have access to only x86 and arm64 KVM hosts, I created and validated the selftest on those two architectures only. tools/testing/selftests/kvm/Makefile.kvm | 1 + .../selftests/kvm/steal_time_change_pid.c | 54 +++++++++++++++++++ 2 files changed, 55 insertions(+) diff --git a/tools/testing/selftests/kvm/Makefile.kvm b/tools/testing/selftests/kvm/Makefile.kvm index 036c28849f84..1de13c0017e4 100644 --- a/tools/testing/selftests/kvm/Makefile.kvm +++ b/tools/testing/selftests/kvm/Makefile.kvm @@ -205,6 +205,7 @@ TEST_GEN_PROGS_arm64 += guest_memfd_test TEST_GEN_PROGS_arm64 += mmu_stress_test TEST_GEN_PROGS_arm64 += rseq_test TEST_GEN_PROGS_arm64 += steal_time +TEST_GEN_PROGS_arm64 += steal_time_change_pid TEST_GEN_PROGS_s390 = $(TEST_GEN_PROGS_COMMON) TEST_GEN_PROGS_s390 += s390/memop diff --git a/tools/testing/selftests/kvm/steal_time_change_pid.c b/tools/testing/selftests/kvm/steal_time_change_pid.c index 3c39594db398..12d4927d1c01 100644 --- a/tools/testing/selftests/kvm/steal_time_change_pid.c +++ b/tools/testing/selftests/kvm/steal_time_change_pid.c @@ -46,6 +46,60 @@ static void steal_time_enable(struct kvm_vcpu *vcpu) (ulong)st_gva | KVM_MSR_ENABLED); } +#elif defined(__aarch64__) + +#define STEAL_TIME_SIZE ((sizeof(struct st_time) + 63) & ~63) + +#define PV_TIME_ST 0xc5000021 + +struct st_time { + u32 rev; + u32 attr; + u64 st_time; +}; + +static void guest_code(void) +{ + struct arm_smccc_res res; + struct st_time *st; + + do_smccc(PV_TIME_ST, 0, 0, 0, 0, 0, 0, 0, &res); + GUEST_ASSERT_NE(res.a0, -1); + GUEST_ASSERT_EQ(res.a0, (ulong)st_gva); + + st = (struct st_time *)res.a0; + WRITE_ONCE(guest_stolen_time, READ_ONCE(st->st_time)); + GUEST_SYNC(0); + + WRITE_ONCE(guest_stolen_time, READ_ONCE(st->st_time)); + GUEST_SYNC(1); + + WRITE_ONCE(guest_stolen_time, READ_ONCE(st->st_time)); + GUEST_DONE(); +} + +static bool steal_time_supported(struct kvm_vcpu *vcpu) +{ + struct kvm_device_attr dev = { + .group = KVM_ARM_VCPU_PVTIME_CTRL, + .attr = KVM_ARM_VCPU_PVTIME_IPA, + }; + + return !__vcpu_ioctl(vcpu, KVM_HAS_DEVICE_ATTR, &dev); +} + +static void steal_time_enable(struct kvm_vcpu *vcpu) +{ + u64 st_ipa = (ulong)st_gva; + struct kvm_device_attr dev = { + .group = KVM_ARM_VCPU_PVTIME_CTRL, + .attr = KVM_ARM_VCPU_PVTIME_IPA, + .addr = (u64)&st_ipa, + }; + + vcpu_ioctl(vcpu, KVM_SET_DEVICE_ATTR, &dev); +} + #else #error "steal_time_change_pid is not implemented on this architecture" #endif -- 2.43.7
