vmsig: management daemon, runtime endpoint lifecycle, roster, discovery, in-tree drivers, packaging

- core: runtime attach/detach of a per-endpoint adapter trio (runtime-safe add_adapter + vmsig_core_detach_endpoint, deferred reap)
- roster: VMSIG_EV_ROSTER + CAP_ROSTER, retained per-endpoint and replayed to late subscribers
- discovery: inotify trigger dir, vmid/endpoint slot allocator, host probe; vmsigd daemon with config + per-uid admission
- input driver and vgpu perception built in-tree; vgpu perception as a separate library
- memctx: own the supplied ro_fd (closed at detach)
- deb packaging: install rules, systemd unit, tmpfiles, default config

src/adapter/input/input.c

@@ -3,19 +3,17 @@
  * Mechanism (recommended): vmctl is a blocking QMP round-trip; we run it on a
  * worker thread, completion ack via a completion-eventfd. The uinput path is a
  * local instantaneous write; when armed it would be done inline (see comment in submit).
- * Real actuation is under VMSIG_WITH_VMCTL; otherwise the stub acks (spine without a VM). */
+ * Real actuation when cfg.stub==0 (vmctl opened); otherwise the stub acks (spine without a VM).
+ * vmctl is the in-tree input driver (src/si/input/, absorbed); cfg.stub gates opening it. */
 #include "vmsig_adapter.h"
 #include "adapter_util.h"
 #include "input.h"
+#include "vmctl.h"
 #include <stdlib.h>
 #include <string.h>
 #include <stdint.h>
 #include <sys/epoll.h>
 
-#ifdef VMSIG_WITH_VMCTL
-#include "vmctl.h"
-#endif
-
 /* POD request/result of the worker. */
 typedef struct {
     int      cmd;        /* 0 = input event, 1 = lifecycle             */
@@ -40,9 +38,7 @@ struct vmsig_adapter {
     vmsig_emit    emit;
     vmsig_worker* worker;
     const char*   qmp_path;     /* borrowed from cfg (valid through attach); SERVICE power/lifecycle */
-#ifdef VMSIG_WITH_VMCTL
-    vmctl_t*      vmctl;
-#endif
+    vmctl_t*      vmctl;        /* NULL in stub mode (cfg.stub) — no actuator opened */
 };
 
 static int input_job(void* user, const void* reqp, void* resp) {
@@ -53,7 +49,6 @@ static int input_job(void* user, const void* reqp, void* resp) {
     rs->corr = rq->corr;
     rs->origin = rq->origin;
     rs->noack = rq->noack;
-#ifdef VMSIG_WITH_VMCTL
     if (a->vmctl) {
         int r = -1;
         if (rq->cmd == 0) {
@@ -87,9 +82,8 @@ static int input_job(void* user, const void* reqp, void* resp) {
         rs->ok = (r == 0);
         return r;
     }
-#endif
     (void)a;
-    rs->ok = 1;          /* stub: ack without actuation */
+    rs->ok = 1;          /* stub: ack without actuation (vmctl not opened) */
     return 0;
 }
 
@@ -109,7 +103,6 @@ static int in_attach(vmsig_adapter* a, const vmsig_emit* emit, vmsig_fd_reg* reg
     a->worker = vmsig_worker_new(input_job, a, 1, 64);   /* QMP is a serial channel, cap 64 */
     if (!a->worker) return -1;
 
-#ifdef VMSIG_WITH_VMCTL
     if (!a->stub) {
         /* armed: open the actuator. Injection is ALWAYS uinput (orphaned host uinput + external
          * QEMU input-linux). PTR_BOTH gives both pointer forms a device (A=abs tablet, B=rel
@@ -125,7 +118,6 @@ static int in_attach(vmsig_adapter* a, const vmsig_emit* emit, vmsig_fd_reg* reg
         a->vmctl = vmctl_open(&vcfg);
         if (!a->vmctl) { vmsig_worker_free(a->worker); a->worker = NULL; return -1; }
     }
-#endif
 
     reg[0].fd           = vmsig_worker_evfd(a->worker);
     reg[0].epoll_events = EPOLLIN;
@@ -166,7 +158,6 @@ static int in_submit(vmsig_adapter* a, const vmsig_event* ev) {
          * actuate — nothing to hold). */
         vmsig_input_held h;
         memset(&h, 0, sizeof h);
-#ifdef VMSIG_WITH_VMCTL
         if (a->vmctl) {
             const uint32_t capn = (uint32_t)(sizeof h.ent / sizeof h.ent[0]);
             unsigned char bits[VMCTL_KEYS_SNAPSHOT_BYTES];
@@ -184,7 +175,6 @@ static int in_submit(vmsig_adapter* a, const vmsig_event* ev) {
                 else h.flags |= VMSIG_INPUT_HELD_TRUNC;
             }
         }
-#endif
         vmsig_event up;
         memset(&up, 0, sizeof up);
         up.kind = VMSIG_EV_INPUT_HELD; up.source = VMSIG_SRC_INPUT; up.dir = VMSIG_DIR_UP;
@@ -223,9 +213,7 @@ static int in_submit(vmsig_adapter* a, const vmsig_event* ev) {
 static void in_close(vmsig_adapter* a) {
     if (!a) return;
     vmsig_worker_free(a->worker);
-#ifdef VMSIG_WITH_VMCTL
     if (a->vmctl) vmctl_close(a->vmctl);
-#endif
     free(a);
 }