From: Nicușor Cîțu <[email protected]> This command is useful for debuggers.
Signed-off-by: Nicușor Cîțu <[email protected]> Co-developed-by: Adalbert Lazăr <[email protected]> Signed-off-by: Adalbert Lazăr <[email protected]> --- Documentation/virt/kvm/kvmi.rst | 32 +++++++ arch/x86/kvm/kvmi.c | 18 ++++ arch/x86/kvm/x86.c | 7 ++ include/linux/kvmi_host.h | 7 ++ include/uapi/linux/kvmi.h | 7 ++ .../testing/selftests/kvm/x86_64/kvmi_test.c | 23 +++++ virt/kvm/introspection/kvmi.c | 23 +++++ virt/kvm/introspection/kvmi_int.h | 2 + virt/kvm/introspection/kvmi_msg.c | 94 ++++++++++++------- 9 files changed, 181 insertions(+), 32 deletions(-) diff --git a/Documentation/virt/kvm/kvmi.rst b/Documentation/virt/kvm/kvmi.rst index b211ae0ed86a..5e013ee4a79b 100644 --- a/Documentation/virt/kvm/kvmi.rst +++ b/Documentation/virt/kvm/kvmi.rst @@ -954,6 +954,38 @@ In order to 'forget' an address, all three bits ('rwx') must be set. * -KVM_EAGAIN - the selected vCPU can't be introspected yet * -KVM_ENOMEM - there is not enough memory to add the page tracking structures +20. KVMI_VCPU_CONTROL_SINGLESTEP +-------------------------------- + +:Architectures: x86 (vmx) +:Versions: >= 1 +:Parameters: + +:: + + struct kvmi_vcpu_hdr; + struct kvmi_vcpu_control_singlestep { + __u8 enable; + __u8 padding[7]; + }; + +:Returns: + +:: + + struct kvmi_error_code; + +Enables/disables singlestep for the selected vCPU. + +The introspection tool should use *KVMI_GET_VERSION*, to check +if the hardware supports singlestep (see **KVMI_GET_VERSION**). + +:Errors: + +* -KVM_EOPNOTSUPP - the hardware doesn't support singlestep +* -KVM_EINVAL - the padding is not zero +* -KVM_EAGAIN - the selected vCPU can't be introspected yet + Events ====== diff --git a/arch/x86/kvm/kvmi.c b/arch/x86/kvm/kvmi.c index d7e1c0690c43..729f91a66405 100644 --- a/arch/x86/kvm/kvmi.c +++ b/arch/x86/kvm/kvmi.c @@ -1210,3 +1210,21 @@ bool kvmi_arch_pf_of_interest(struct kvm_vcpu *vcpu) !kvm_x86_ops->gpt_translation_fault(vcpu); } +bool kvmi_arch_start_singlestep(struct kvm_vcpu *vcpu) +{ + if (!kvm_x86_ops->control_singlestep) + return false; + + kvm_x86_ops->control_singlestep(vcpu, true); + return true; +} + +bool kvmi_arch_stop_singlestep(struct kvm_vcpu *vcpu) +{ + if (!kvm_x86_ops->control_singlestep) + return false; + + kvm_x86_ops->control_singlestep(vcpu, false); + return true; +} + diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index ce2f9d47d6f6..12e9b4689025 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -7738,6 +7738,13 @@ static int inject_pending_event(struct kvm_vcpu *vcpu, bool req_int_win) { int r; + if (kvmi_vcpu_running_singlestep(vcpu)) + /* + * We cannot inject events during single-stepping. + * Try again later. + */ + return -1; + /* try to reinject previous events if any */ if (vcpu->arch.exception.injected) diff --git a/include/linux/kvmi_host.h b/include/linux/kvmi_host.h index c9dd2d57033b..23784611996e 100644 --- a/include/linux/kvmi_host.h +++ b/include/linux/kvmi_host.h @@ -50,6 +50,10 @@ struct kvm_vcpu_introspection { bool pending; bool send_event; } exception; + + struct { + bool loop; + } singlestep; }; struct kvm_introspection { @@ -90,6 +94,7 @@ void kvmi_handle_requests(struct kvm_vcpu *vcpu); bool kvmi_hypercall_event(struct kvm_vcpu *vcpu); bool kvmi_breakpoint_event(struct kvm_vcpu *vcpu, u64 gva, u8 insn_len); bool kvmi_enter_guest(struct kvm_vcpu *vcpu); +bool kvmi_vcpu_running_singlestep(struct kvm_vcpu *vcpu); #else @@ -106,6 +111,8 @@ static inline bool kvmi_breakpoint_event(struct kvm_vcpu *vcpu, u64 gva, { return true; } static inline bool kvmi_enter_guest(struct kvm_vcpu *vcpu) { return true; } +static inline bool kvmi_vcpu_running_singlestep(struct kvm_vcpu *vcpu) + { return false; } #endif /* CONFIG_KVM_INTROSPECTION */ diff --git a/include/uapi/linux/kvmi.h b/include/uapi/linux/kvmi.h index caf166e7ddff..97c4ef67bfe4 100644 --- a/include/uapi/linux/kvmi.h +++ b/include/uapi/linux/kvmi.h @@ -42,6 +42,8 @@ enum { KVMI_VM_SET_PAGE_ACCESS = 21, + KVMI_VCPU_CONTROL_SINGLESTEP = 22, + KVMI_NUM_MESSAGES }; @@ -178,6 +180,11 @@ struct kvmi_vm_set_page_access { struct kvmi_page_access_entry entries[0]; }; +struct kvmi_vcpu_control_singlestep { + __u8 enable; + __u8 padding[7]; +}; + struct kvmi_event { __u16 size; __u16 vcpu; diff --git a/tools/testing/selftests/kvm/x86_64/kvmi_test.c b/tools/testing/selftests/kvm/x86_64/kvmi_test.c index d4cfe595821d..27642000c4e4 100644 --- a/tools/testing/selftests/kvm/x86_64/kvmi_test.c +++ b/tools/testing/selftests/kvm/x86_64/kvmi_test.c @@ -1668,6 +1668,28 @@ static void test_event_pf(struct kvm_vm *vm) test_pf(vm, cbk_test_event_pf); } +static void test_cmd_vcpu_control_singlestep(struct kvm_vm *vm) +{ + struct { + struct kvmi_msg_hdr hdr; + struct kvmi_vcpu_hdr vcpu_hdr; + struct kvmi_vcpu_control_singlestep cmd; + } req = {}; + + if (!features.singlestep) { + DEBUG("Skip %s()\n", __func__); + return; + } + + req.cmd.enable = true; + test_vcpu0_command(vm, KVMI_VCPU_CONTROL_SINGLESTEP, + &req.hdr, sizeof(req), NULL, 0); + + req.cmd.enable = false; + test_vcpu0_command(vm, KVMI_VCPU_CONTROL_SINGLESTEP, + &req.hdr, sizeof(req), NULL, 0); +} + static void test_introspection(struct kvm_vm *vm) { srandom(time(0)); @@ -1700,6 +1722,7 @@ static void test_introspection(struct kvm_vm *vm) test_cmd_vcpu_control_msr(vm); test_cmd_vm_set_page_access(vm); test_event_pf(vm); + test_cmd_vcpu_control_singlestep(vm); unhook_introspection(vm); } diff --git a/virt/kvm/introspection/kvmi.c b/virt/kvm/introspection/kvmi.c index e13b55856e9c..90e6c2d3dd4f 100644 --- a/virt/kvm/introspection/kvmi.c +++ b/virt/kvm/introspection/kvmi.c @@ -401,6 +401,9 @@ static void kvmi_job_release_vcpu(struct kvm_vcpu *vcpu, void *ctx) atomic_set(&vcpui->pause_requests, 0); vcpui->waiting_for_reply = false; + + if (vcpui->singlestep.loop) + kvmi_arch_stop_singlestep(vcpu); } static void kvmi_release_vcpus(struct kvm *kvm) @@ -1019,6 +1022,9 @@ bool kvmi_enter_guest(struct kvm_vcpu *vcpu) if (!kvmi) return true; + if (VCPUI(vcpu)->singlestep.loop) + kvmi_arch_start_singlestep(vcpu); + if (kvmi_inject_pending_exception(vcpu)) r = false; @@ -1297,3 +1303,20 @@ static void kvmi_track_flush_slot(struct kvm *kvm, struct kvm_memory_slot *slot, kvmi_put(kvm); } + +bool kvmi_vcpu_running_singlestep(struct kvm_vcpu *vcpu) +{ + struct kvm_introspection *kvmi; + bool ret; + + kvmi = kvmi_get(vcpu->kvm); + if (!kvmi) + return false; + + ret = VCPUI(vcpu)->singlestep.loop; + + kvmi_put(vcpu->kvm); + + return ret; +} +EXPORT_SYMBOL(kvmi_vcpu_running_singlestep); diff --git a/virt/kvm/introspection/kvmi_int.h b/virt/kvm/introspection/kvmi_int.h index e0cb58c60697..820081f8e3f1 100644 --- a/virt/kvm/introspection/kvmi_int.h +++ b/virt/kvm/introspection/kvmi_int.h @@ -128,5 +128,7 @@ bool kvmi_arch_pf_event(struct kvm_vcpu *vcpu, gpa_t gpa, gva_t gva, u8 access); bool kvmi_arch_pf_of_interest(struct kvm_vcpu *vcpu); void kvmi_arch_features(struct kvmi_features *feat); +bool kvmi_arch_start_singlestep(struct kvm_vcpu *vcpu); +bool kvmi_arch_stop_singlestep(struct kvm_vcpu *vcpu); #endif diff --git a/virt/kvm/introspection/kvmi_msg.c b/virt/kvm/introspection/kvmi_msg.c index 71a67154542f..14c063869c29 100644 --- a/virt/kvm/introspection/kvmi_msg.c +++ b/virt/kvm/introspection/kvmi_msg.c @@ -20,27 +20,28 @@ struct kvmi_vcpu_cmd_job { }; static const char *const msg_IDs[] = { - [KVMI_EVENT] = "KVMI_EVENT", - [KVMI_GET_VERSION] = "KVMI_GET_VERSION", - [KVMI_VM_CHECK_COMMAND] = "KVMI_VM_CHECK_COMMAND", - [KVMI_VM_CHECK_EVENT] = "KVMI_VM_CHECK_EVENT", - [KVMI_VM_CONTROL_EVENTS] = "KVMI_VM_CONTROL_EVENTS", - [KVMI_VM_GET_INFO] = "KVMI_VM_GET_INFO", - [KVMI_VM_GET_MAX_GFN] = "KVMI_VM_GET_MAX_GFN", - [KVMI_VM_READ_PHYSICAL] = "KVMI_VM_READ_PHYSICAL", - [KVMI_VM_SET_PAGE_ACCESS] = "KVMI_VM_SET_PAGE_ACCESS", - [KVMI_VM_WRITE_PHYSICAL] = "KVMI_VM_WRITE_PHYSICAL", - [KVMI_VCPU_CONTROL_CR] = "KVMI_VCPU_CONTROL_CR", - [KVMI_VCPU_CONTROL_EVENTS] = "KVMI_VCPU_CONTROL_EVENTS", - [KVMI_VCPU_CONTROL_MSR] = "KVMI_VCPU_CONTROL_MSR", - [KVMI_VCPU_GET_CPUID] = "KVMI_VCPU_GET_CPUID", - [KVMI_VCPU_GET_INFO] = "KVMI_VCPU_GET_INFO", - [KVMI_VCPU_GET_MTRR_TYPE] = "KVMI_VCPU_GET_MTRR_TYPE", - [KVMI_VCPU_GET_REGISTERS] = "KVMI_VCPU_GET_REGISTERS", - [KVMI_VCPU_GET_XSAVE] = "KVMI_VCPU_GET_XSAVE", - [KVMI_VCPU_INJECT_EXCEPTION] = "KVMI_VCPU_INJECT_EXCEPTION", - [KVMI_VCPU_PAUSE] = "KVMI_VCPU_PAUSE", - [KVMI_VCPU_SET_REGISTERS] = "KVMI_VCPU_SET_REGISTERS", + [KVMI_EVENT] = "KVMI_EVENT", + [KVMI_GET_VERSION] = "KVMI_GET_VERSION", + [KVMI_VM_CHECK_COMMAND] = "KVMI_VM_CHECK_COMMAND", + [KVMI_VM_CHECK_EVENT] = "KVMI_VM_CHECK_EVENT", + [KVMI_VM_CONTROL_EVENTS] = "KVMI_VM_CONTROL_EVENTS", + [KVMI_VM_GET_INFO] = "KVMI_VM_GET_INFO", + [KVMI_VM_GET_MAX_GFN] = "KVMI_VM_GET_MAX_GFN", + [KVMI_VM_READ_PHYSICAL] = "KVMI_VM_READ_PHYSICAL", + [KVMI_VM_SET_PAGE_ACCESS] = "KVMI_VM_SET_PAGE_ACCESS", + [KVMI_VM_WRITE_PHYSICAL] = "KVMI_VM_WRITE_PHYSICAL", + [KVMI_VCPU_CONTROL_CR] = "KVMI_VCPU_CONTROL_CR", + [KVMI_VCPU_CONTROL_EVENTS] = "KVMI_VCPU_CONTROL_EVENTS", + [KVMI_VCPU_CONTROL_MSR] = "KVMI_VCPU_CONTROL_MSR", + [KVMI_VCPU_CONTROL_SINGLESTEP] = "KVMI_VCPU_CONTROL_SINGLESTEP", + [KVMI_VCPU_GET_CPUID] = "KVMI_VCPU_GET_CPUID", + [KVMI_VCPU_GET_INFO] = "KVMI_VCPU_GET_INFO", + [KVMI_VCPU_GET_MTRR_TYPE] = "KVMI_VCPU_GET_MTRR_TYPE", + [KVMI_VCPU_GET_REGISTERS] = "KVMI_VCPU_GET_REGISTERS", + [KVMI_VCPU_GET_XSAVE] = "KVMI_VCPU_GET_XSAVE", + [KVMI_VCPU_INJECT_EXCEPTION] = "KVMI_VCPU_INJECT_EXCEPTION", + [KVMI_VCPU_PAUSE] = "KVMI_VCPU_PAUSE", + [KVMI_VCPU_SET_REGISTERS] = "KVMI_VCPU_SET_REGISTERS", }; static const char *id2str(u16 id) @@ -619,6 +620,34 @@ static int handle_vcpu_control_msr(const struct kvmi_vcpu_cmd_job *job, return kvmi_msg_vcpu_reply(job, msg, ec, NULL, 0); } +static int handle_vcpu_control_singlestep(const struct kvmi_vcpu_cmd_job *job, + const struct kvmi_msg_hdr *msg, + const void *_req) +{ + const struct kvmi_vcpu_control_singlestep *req = _req; + struct kvm_vcpu *vcpu = job->vcpu; + int ec = -KVM_EINVAL; + bool done; + int i; + + for (i = 0; i < sizeof(req->padding); i++) + if (req->padding[i]) + goto reply; + + if (req->enable) + done = kvmi_arch_start_singlestep(vcpu); + else + done = kvmi_arch_stop_singlestep(vcpu); + + if (done) { + ec = 0; + VCPUI(vcpu)->singlestep.loop = !!req->enable; + } + +reply: + return kvmi_msg_vcpu_reply(job, msg, ec, NULL, 0); +} + /* * These commands are executed from the vCPU thread. The receiving thread * passes the messages using a newly allocated 'struct kvmi_vcpu_cmd_job' @@ -627,17 +656,18 @@ static int handle_vcpu_control_msr(const struct kvmi_vcpu_cmd_job *job, */ static int(*const msg_vcpu[])(const struct kvmi_vcpu_cmd_job *, const struct kvmi_msg_hdr *, const void *) = { - [KVMI_EVENT] = handle_event_reply, - [KVMI_VCPU_CONTROL_CR] = handle_vcpu_control_cr, - [KVMI_VCPU_CONTROL_EVENTS] = handle_vcpu_control_events, - [KVMI_VCPU_CONTROL_MSR] = handle_vcpu_control_msr, - [KVMI_VCPU_GET_CPUID] = handle_get_cpuid, - [KVMI_VCPU_GET_INFO] = handle_get_vcpu_info, - [KVMI_VCPU_GET_MTRR_TYPE] = handle_vcpu_get_mtrr_type, - [KVMI_VCPU_GET_REGISTERS] = handle_get_registers, - [KVMI_VCPU_GET_XSAVE] = handle_vcpu_get_xsave, - [KVMI_VCPU_INJECT_EXCEPTION] = handle_vcpu_inject_exception, - [KVMI_VCPU_SET_REGISTERS] = handle_set_registers, + [KVMI_EVENT] = handle_event_reply, + [KVMI_VCPU_CONTROL_CR] = handle_vcpu_control_cr, + [KVMI_VCPU_CONTROL_EVENTS] = handle_vcpu_control_events, + [KVMI_VCPU_CONTROL_MSR] = handle_vcpu_control_msr, + [KVMI_VCPU_CONTROL_SINGLESTEP] = handle_vcpu_control_singlestep, + [KVMI_VCPU_GET_CPUID] = handle_get_cpuid, + [KVMI_VCPU_GET_INFO] = handle_get_vcpu_info, + [KVMI_VCPU_GET_MTRR_TYPE] = handle_vcpu_get_mtrr_type, + [KVMI_VCPU_GET_REGISTERS] = handle_get_registers, + [KVMI_VCPU_GET_XSAVE] = handle_vcpu_get_xsave, + [KVMI_VCPU_INJECT_EXCEPTION] = handle_vcpu_inject_exception, + [KVMI_VCPU_SET_REGISTERS] = handle_set_registers, }; static bool is_vcpu_command(u16 id) _______________________________________________ Virtualization mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/virtualization
