With this command the introspection tool enables/disables VM events (ie. KVMI_EVENT_UNHOOK), because no event (neither VM event, nor vCPU event) will be sent to the introspection tool unless enabled/requested.
Signed-off-by: Adalbert Lazăr <[email protected]> --- Documentation/virt/kvm/kvmi.rst | 44 +++++++++++++++-- include/linux/kvmi_host.h | 2 + include/uapi/linux/kvmi.h | 18 +++++-- .../testing/selftests/kvm/x86_64/kvmi_test.c | 48 +++++++++++++++++++ virt/kvm/introspection/kvmi.c | 14 ++++++ virt/kvm/introspection/kvmi_int.h | 9 ++++ virt/kvm/introspection/kvmi_msg.c | 43 +++++++++++++---- 7 files changed, 161 insertions(+), 17 deletions(-) diff --git a/Documentation/virt/kvm/kvmi.rst b/Documentation/virt/kvm/kvmi.rst index 949e940487ab..7039f4d2b782 100644 --- a/Documentation/virt/kvm/kvmi.rst +++ b/Documentation/virt/kvm/kvmi.rst @@ -333,11 +333,45 @@ This command is always allowed. Returns the number of online vCPUs. +5. KVMI_VM_CONTROL_EVENTS +------------------------- + +:Architectures: all +:Versions: >= 1 +:Parameters: + +:: + + struct kvmi_vm_control_events { + __u16 event_id; + __u8 enable; + __u8 padding1; + __u32 padding2; + }; + +:Returns: + +:: + + struct kvmi_error_code + +Enables/disables VM introspection events. This command can be used with +the following events:: + + KVMI_EVENT_UNHOOK + +:Errors: + +* -KVM_EINVAL - the event ID is invalid/unknown (use *KVMI_VM_CHECK_EVENT* first) +* -KVM_EINVAL - padding is not zero +* -KVM_EPERM - the access is restricted by the host + Events ====== All introspection events (VM or vCPU related) are sent -using the *KVMI_EVENT* message id. +using the *KVMI_EVENT* message id. No event will be sent unless +it is explicitly enabled. The *KVMI_EVENT_UNHOOK* event doesn't have a reply and share the kvmi_event structure, for consistency with the vCPU events. @@ -391,6 +425,8 @@ Specific data can follow these common structures. :Returns: none -This event is sent when the device manager has to pause/stop/migrate the -guest (see **Unhooking**). The introspection tool has a chance to unhook -and close the KVMI channel (signaling that the operation can proceed). +This event is sent when the device manager has to pause/stop/migrate +the guest (see **Unhooking**) and the introspection has been enabled +for this event (see **KVMI_VM_CONTROL_EVENTS**). The introspection tool +has a chance to unhook and close the KVMI channel (signaling that the +operation can proceed). diff --git a/include/linux/kvmi_host.h b/include/linux/kvmi_host.h index 180e26335a8f..41b22af771fb 100644 --- a/include/linux/kvmi_host.h +++ b/include/linux/kvmi_host.h @@ -22,6 +22,8 @@ struct kvm_introspection { DECLARE_BITMAP(cmd_allow_mask, KVMI_NUM_COMMANDS); DECLARE_BITMAP(event_allow_mask, KVMI_NUM_EVENTS); + DECLARE_BITMAP(vm_event_enable_mask, KVMI_NUM_EVENTS); + atomic_t ev_seq; }; diff --git a/include/uapi/linux/kvmi.h b/include/uapi/linux/kvmi.h index e74240aff5b7..da9bf30ae513 100644 --- a/include/uapi/linux/kvmi.h +++ b/include/uapi/linux/kvmi.h @@ -15,12 +15,13 @@ enum { }; enum { - KVMI_EVENT = 1, + KVMI_EVENT = 1, - KVMI_GET_VERSION = 2, - KVMI_VM_CHECK_COMMAND = 3, - KVMI_VM_CHECK_EVENT = 4, - KVMI_VM_GET_INFO = 5, + KVMI_GET_VERSION = 2, + KVMI_VM_CHECK_COMMAND = 3, + KVMI_VM_CHECK_EVENT = 4, + KVMI_VM_GET_INFO = 5, + KVMI_VM_CONTROL_EVENTS = 6, KVMI_NUM_MESSAGES }; @@ -68,6 +69,13 @@ struct kvmi_vm_get_info_reply { __u32 padding[3]; }; +struct kvmi_vm_control_events { + __u16 event_id; + __u8 enable; + __u8 padding1; + __u32 padding2; +}; + 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 f5d67fd0cde8..23dba71e7dc6 100644 --- a/tools/testing/selftests/kvm/x86_64/kvmi_test.c +++ b/tools/testing/selftests/kvm/x86_64/kvmi_test.c @@ -298,15 +298,62 @@ static void receive_event(struct kvmi_msg_hdr *hdr, struct kvmi_event *ev, ev->event, event_id); } +static int cmd_vm_control_events(__u16 event_id, bool enable) +{ + struct { + struct kvmi_msg_hdr hdr; + struct kvmi_vm_control_events cmd; + } req = {}; + + req.cmd.event_id = event_id; + req.cmd.enable = enable ? 1 : 0; + + return do_command(KVMI_VM_CONTROL_EVENTS, &req.hdr, sizeof(req), + NULL, 0); +} + +static void enable_vm_event(__u16 event_id) +{ + int r; + + r = cmd_vm_control_events(event_id, true); + TEST_ASSERT(r == 0, + "KVMI_VM_CONTROL_EVENTS failed to enable VM event %d, error %d (%s)\n", + event_id, -r, kvm_strerror(-r)); +} + +static void disable_vm_event(__u16 event_id) +{ + int r; + + r = cmd_vm_control_events(event_id, false); + TEST_ASSERT(r == 0, + "KVMI_VM_CONTROL_EVENTS failed to disable VM event %d, error %d (%s)\n", + event_id, -r, kvm_strerror(-r)); +} + static void test_event_unhook(struct kvm_vm *vm) { __u16 id = KVMI_EVENT_UNHOOK; struct kvmi_msg_hdr hdr; struct kvmi_event ev; + enable_vm_event(id); + trigger_event_unhook_notification(vm); receive_event(&hdr, &ev, sizeof(ev), id); + + disable_vm_event(id); +} + +static void test_cmd_vm_control_events(void) +{ + __u16 id = KVMI_EVENT_UNHOOK; + + enable_vm_event(id); + + disable_vm_event(id); } static void test_introspection(struct kvm_vm *vm) @@ -320,6 +367,7 @@ static void test_introspection(struct kvm_vm *vm) test_cmd_check_event(); test_cmd_get_vm_info(); test_event_unhook(vm); + test_cmd_vm_control_events(); unhook_introspection(vm); } diff --git a/virt/kvm/introspection/kvmi.c b/virt/kvm/introspection/kvmi.c index 74e3e1aa326b..9d246152c5e8 100644 --- a/virt/kvm/introspection/kvmi.c +++ b/virt/kvm/introspection/kvmi.c @@ -331,6 +331,9 @@ static bool kvmi_unhook_event(struct kvm_introspection *kvmi) { int err; + if (!is_vm_event_enabled(kvmi, KVMI_EVENT_UNHOOK)) + return false; + err = kvmi_msg_send_unhook(kvmi); return !err; @@ -354,3 +357,14 @@ int kvmi_ioctl_preunhook(struct kvm *kvm) return err; } + +int kvmi_cmd_vm_control_events(struct kvm_introspection *kvmi, + unsigned int event_id, bool enable) +{ + if (enable) + set_bit(event_id, kvmi->vm_event_enable_mask); + else + clear_bit(event_id, kvmi->vm_event_enable_mask); + + return 0; +} diff --git a/virt/kvm/introspection/kvmi_int.h b/virt/kvm/introspection/kvmi_int.h index 3ea8e8250f7d..d1c143334626 100644 --- a/virt/kvm/introspection/kvmi_int.h +++ b/virt/kvm/introspection/kvmi_int.h @@ -29,11 +29,18 @@ BIT(KVMI_GET_VERSION) \ | BIT(KVMI_VM_CHECK_COMMAND) \ | BIT(KVMI_VM_CHECK_EVENT) \ + | BIT(KVMI_VM_CONTROL_EVENTS) \ | BIT(KVMI_VM_GET_INFO) \ ) #define KVMI(kvm) ((struct kvm_introspection *)((kvm)->kvmi)) +static inline bool is_vm_event_enabled(struct kvm_introspection *kvmi, + int event) +{ + return test_bit(event, kvmi->vm_event_enable_mask); +} + /* kvmi_msg.c */ bool kvmi_sock_get(struct kvm_introspection *kvmi, int fd); void kvmi_sock_shutdown(struct kvm_introspection *kvmi); @@ -45,5 +52,7 @@ int kvmi_msg_send_unhook(struct kvm_introspection *kvmi); void *kvmi_msg_alloc(void); void *kvmi_msg_alloc_check(size_t size); void kvmi_msg_free(void *addr); +int kvmi_cmd_vm_control_events(struct kvm_introspection *kvmi, + unsigned int event_id, bool enable); #endif diff --git a/virt/kvm/introspection/kvmi_msg.c b/virt/kvm/introspection/kvmi_msg.c index dbc2ba9a1399..79b26853b5cb 100644 --- a/virt/kvm/introspection/kvmi_msg.c +++ b/virt/kvm/introspection/kvmi_msg.c @@ -9,10 +9,11 @@ #include "kvmi_int.h" static const char *const msg_IDs[] = { - [KVMI_GET_VERSION] = "KVMI_GET_VERSION", - [KVMI_VM_CHECK_COMMAND] = "KVMI_VM_CHECK_COMMAND", - [KVMI_VM_CHECK_EVENT] = "KVMI_VM_CHECK_EVENT", - [KVMI_VM_GET_INFO] = "KVMI_VM_GET_INFO", + [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", }; static bool is_known_message(u16 id) @@ -181,15 +182,41 @@ static int handle_get_info(struct kvm_introspection *kvmi, return kvmi_msg_vm_reply(kvmi, msg, 0, &rpl, sizeof(rpl)); } +static int handle_vm_control_events(struct kvm_introspection *kvmi, + const struct kvmi_msg_hdr *msg, + const void *_req) +{ + const struct kvmi_vm_control_events *req = _req; + DECLARE_BITMAP(known_events, KVMI_NUM_EVENTS); + int ec; + + bitmap_from_u64(known_events, KVMI_KNOWN_VM_EVENTS); + + if (req->padding1 || req->padding2) + ec = -KVM_EINVAL; + else if (req->event_id >= KVMI_NUM_EVENTS) + ec = -KVM_EINVAL; + else if (!test_bit(req->event_id, known_events)) + ec = -KVM_EINVAL; + else if (!is_event_allowed(kvmi, req->event_id)) + ec = -KVM_EPERM; + else + ec = kvmi_cmd_vm_control_events(kvmi, req->event_id, + req->enable); + + return kvmi_msg_vm_reply(kvmi, msg, ec, NULL, 0); +} + /* * These commands are executed by the receiving thread/worker. */ static int(*const msg_vm[])(struct kvm_introspection *, const struct kvmi_msg_hdr *, const void *) = { - [KVMI_GET_VERSION] = handle_get_version, - [KVMI_VM_CHECK_COMMAND] = handle_check_command, - [KVMI_VM_CHECK_EVENT] = handle_check_event, - [KVMI_VM_GET_INFO] = handle_get_info, + [KVMI_GET_VERSION] = handle_get_version, + [KVMI_VM_CHECK_COMMAND] = handle_check_command, + [KVMI_VM_CHECK_EVENT] = handle_check_event, + [KVMI_VM_CONTROL_EVENTS] = handle_vm_control_events, + [KVMI_VM_GET_INFO] = handle_get_info, }; static bool is_vm_message(u16 id) _______________________________________________ Virtualization mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/virtualization
