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/core/include/core_internal.h

@@ -1,6 +1,7 @@
 #ifndef VMSIG_CORE_INTERNAL_H
 #define VMSIG_CORE_INTERNAL_H
 #include "vmsig_core.h"
+#include "vmsig_roster.h"
 #include <signal.h>
 
 /* Private internals of the epoll core. Each registered fd carries a
@@ -41,6 +42,11 @@ typedef struct {
     const vmsig_adapter_ops* ops;
     vmsig_adapter*           a;
     uint32_t                 endpoint;
+    int                      active;   /* 0 = free/reaped slot (reusable)         */
+    int                      reap;     /* deferred runtime detach requested       */
+    uint16_t                 gen;      /* +1 on each (re)use (ABA guard / debug)  */
+    core_slot*               slots[VMSIG_ADAPTER_FDS]; /* epoll slots we registered */
+    int                      nslot;
 } core_adapter_ent;
 
 
@@ -57,6 +63,15 @@ typedef struct {
     vmsig_memctx_reg reg;          /* valid when registered                            */
 } core_memctx_cell;
 
+/* ===== Retained VM roster (inventory coherence; daemon-published) =====
+ * One value snapshot per endpoint: the last published roster datum. Simpler than the
+ * MEMCTX cell — roster carries no fd and no borrowed buffer, so the cell is pure POD and
+ * delivery is the ordinary broadcast (no re-describe / re-share). valid=0 on DETACH. */
+typedef struct {
+    int          valid;            /* a roster entry is published for this endpoint     */
+    vmsig_roster entry;            /* last published {vmid,state,action,name} (by value) */
+} core_roster_cell;
+
 /* ===== Lease layer (arbitration of exclusive ownership of destructive resources) =====
  * One cell per (endpoint, lease-class): who owns it (origin) + a snapshot of arb_prio at
  * acquisition time. owner=0 => free. The snapshot (rather than the live grant) makes the
@@ -108,6 +123,7 @@ struct vmsig_core {
 
     uint32_t            epoch[64];                       /* per-endpoint VM session epoch */
     core_memctx_cell    memctx[64];                      /* per-endpoint retained context */
+    core_roster_cell    roster[64];                      /* per-endpoint retained roster  */
 
     core_lease_cell     lease[64][VMSIG_LEASE_CLASSES]; /* lease per (endpoint, class) */
     vmsig_arb_policy    arb_cb;                          /* preemption policy (NULL=default) */
@@ -150,6 +166,14 @@ void core_memctx_route(vmsig_core* c, const vmsig_event* trigger);
  * defined in loop.c). */
 void core_memctx_replay(vmsig_core* c, int ctl_id);
 
+/* ===== VM roster (inventory coherence; defined in loop.c alongside the memctx seam) ===== */
+/* Publish a roster transition for `endpoint`: retain the datum (valid=0 on DETACH) and
+ * broadcast VMSIG_EV_ROSTER to qualified subscribers (CAP_ROSTER + source + endpoint). */
+void core_roster_publish(vmsig_core* c, uint32_t endpoint, const vmsig_roster* entry);
+
+/* Replay the retained roster to a single (late) subscriber (from vmsig_core_add_control). */
+void core_roster_replay(vmsig_core* c, int ctl_id);
+
 /* Bump the endpoint's epoch on a destructive lifecycle transition: epoch++, invalidate
  * the retain cell, emit MEMCTX_INVALIDATED, request re-bootstrap from the adapter.
  * Observed by the core in pump_up on UP VM_LIFECYCLE (defined in loop.c). */