feat(input): drop absolute-pointer (ABS) support

ABS was glued onto device A alongside the keyboard and never worked right; it is
not needed in practice. Remove it entirely: device A is now keyboard-only, and
device B is the relative mouse (motion + buttons incl. middle + wheel). Drops the
ptr_mode model (one layout remains), VMCTL_EV_ABS/PTR_*, and the absolute axes.

The public input-kind enum keeps its numeric values (MOVE_REL=1, BTN=2, KEY=3,
SCROLL=4) so the wire stays compatible -- only MOVE_ABS (0) is removed and its
slot reserved; an unknown/0 kind is a no-op.

Bump 0.3.11.

CMakeLists.txt

@@ -1,7 +1,7 @@
 cmake_minimum_required(VERSION 3.16)
 # Single source of truth for the version: CI passes -DVMSIG_VERSION=${TAG#v}, so the project
 # version (-> libvgpu-perception SONAME/.so version) and the .deb version come from one tag.
-set(VMSIG_VERSION "0.3.8" CACHE STRING "Release version (MAJOR.MINOR.PATCH); CI passes the tag")
+set(VMSIG_VERSION "0.3.11" CACHE STRING "Release version (MAJOR.MINOR.PATCH); CI passes the tag")
 project(vmsig VERSION ${VMSIG_VERSION} LANGUAGES C)
 
 set(CMAKE_C_STANDARD 17)

include/vmctl.h

@@ -15,10 +15,6 @@ typedef enum {
                            /* via QEMU virtio-input-host-pci (Linux). uinput != virtio. */
 } vmctl_driver;
 
-#define VMCTL_PTR_ABS   1   /* uinput: absolute tablet            */
-#define VMCTL_PTR_REL   2   /* uinput: relative mouse             */
-#define VMCTL_PTR_BOTH  3   /* uinput: two devices A=abs B=rel    */
-
 typedef struct {
     unsigned    bustype;     /* HID bus type, e.g. 0x0003 (USB)    */
     unsigned    vendor;      /* vendor id                          */
@@ -31,7 +27,6 @@ typedef struct {
     vmctl_driver driver;
     const char*  qmp_path;   /* QMP unix socket; required for QMP, optional (passthrough) for UINPUT */
     const char*  input_bus;  /* virtio-input-host-pci bus "pci.0" for passthrough; "" = none         */
-    int          ptr_mode;   /* UINPUT VMCTL_PTR_*; 0 for QMP                                         */
     const vmctl_uinput_id* uinput_id;  /* UINPUT only; NULL = built-in defaults                       */
 } vmctl_config;
 
@@ -39,13 +34,13 @@ vmctl_t* vmctl_open (const vmctl_config* cfg);   /* NULL on error    */
 void     vmctl_close(vmctl_t* v);                /* safe on NULL     */
 
 /* Copy the host evdev node paths of the created uinput devices (UINPUT driver only).
- * a[] receives device A, b[] receives device B (empty if not VMCTL_PTR_BOTH); each buffer
- * must be >=64 bytes. Returns the count of non-empty paths filled (0/1/2), or -1 if the
- * handle's driver is not UINPUT. Paths are valid while the handle is open. */
+ * a[] receives device A (keyboard), b[] receives device B (relative mouse); both are always
+ * created, so count==2 in the normal case. Each buffer must be >=64 bytes. Returns the count
+ * of non-empty paths filled (0/1/2), or -1 if the handle's driver is not UINPUT. Paths are
+ * valid while the handle is open. */
 int vmctl_uinput_evdev(vmctl_t* v, char a[64], char b[64]);
 
 /* ===== Input constants ===== */
-#define VMCTL_ABS_MAX    32767       /* abs coordinates 0..VMCTL_ABS_MAX */
 #define VMCTL_AXIS_X     0
 #define VMCTL_AXIS_Y     1
 #define VMCTL_SCROLL_V   0           /* vertical   */
@@ -67,13 +62,12 @@ int vmctl_uinput_evdev(vmctl_t* v, char a[64], char b[64]);
 typedef struct {
     int    kind;     /* internal event-kind code; set by builders          */
     int    code;     /* axis / button / evdev-code (per kind)              */
-    int    value;    /* abs-value / rel-delta / down(0|1)                  */
+    int    value;    /* rel-delta / down(0|1)                              */
     double scroll;   /* scroll magnitude (scroll only)                     */
 } vmctl_event;
 typedef struct { vmctl_event ev[VMCTL_BATCH_MAX]; int count; } vmctl_batch;
 
 void vmctl_batch_init  (vmctl_batch* b);
-void vmctl_batch_abs   (vmctl_batch* b, int axis, int value);
 void vmctl_batch_rel   (vmctl_batch* b, int axis, int delta);
 void vmctl_batch_btn   (vmctl_batch* b, int btn,  int down);
 void vmctl_batch_key   (vmctl_batch* b, int evdev_code, int down);
@@ -81,7 +75,6 @@ void vmctl_batch_scroll(vmctl_batch* b, int axis, double value);
 int  vmctl_batch_send  (vmctl_t* v, vmctl_batch* b);   /* one round-trip; 0=ok, -1=err */
 
 /* ===== Single events (wrappers over a 1-event batch) ===== */
-int vmctl_abs   (vmctl_t* v, int axis, int value);      /* 0..VMCTL_ABS_MAX */
 int vmctl_rel   (vmctl_t* v, int axis, int delta);
 int vmctl_btn   (vmctl_t* v, int btn,  int down);        /* VMCTL_BTN_* */
 int vmctl_key   (vmctl_t* v, int evdev_code, int down);  /* Linux KEY_* */

include/vmsig_event.h

@@ -159,9 +159,12 @@ enum {
  * encodes vmsig_input into vmsig_event.inln.
  *
  * Pointer motion carries BOTH coordinates in ONE event (a pointer position is a single entity,
- * not two independent axis updates). btn/key/scroll stay single-valued. */
+ * not two independent axis updates). btn/key/scroll stay single-valued.
+ *
+ * Numbering is FROZEN: an external control encodes these on the wire and is not rebuilt from
+ * this header. Removing a member must NOT shift the others. */
 typedef enum {
-    VMSIG_INPUT_MOVE_ABS = 0,  /* absolute pointer: x,y are coordinates (0..VMCTL_ABS_MAX) */
+    /* 0 reserved (was MOVE_ABS, removed) */
     VMSIG_INPUT_MOVE_REL = 1,  /* relative pointer: x,y are deltas (dx,dy)                 */
     VMSIG_INPUT_BTN      = 2,  /* button:  code=button, value=pressed(1)/released(0)       */
     VMSIG_INPUT_KEY      = 3,  /* key:     code=evdev code, value=pressed/released         */
@@ -175,8 +178,8 @@ typedef struct {
     uint16_t kind;     /* vmsig_input_kind                                             */
     uint16_t code;     /* button / evdev code / scroll axis (NOT used by MOVE_*)        */
     int32_t  value;    /* pressed(1)|released(0) for BTN/KEY (not used by MOVE or SCROLL) */
-    int32_t  x;        /* MOVE_ABS: abs X (0..VMCTL_ABS_MAX); MOVE_REL: dx              */
-    int32_t  y;        /* MOVE_ABS: abs Y;                    MOVE_REL: dy              */
+    int32_t  x;        /* MOVE_REL: dx                                                  */
+    int32_t  y;        /* MOVE_REL: dy                                                  */
     double   scroll;   /* SCROLL magnitude only                                        */
     uint32_t flags;    /* VMSIG_INPUT_F_* (see above)                                  */
     uint32_t _pad;     /* reserved; zero on emit                                        */

src/adapter/input/input.c

@@ -22,8 +22,8 @@ typedef struct {
     int      kind;       /* vmsig_input_kind (for cmd==0)               */
     int      code;       /* btn/evdev-code/scroll-axis                  */
     int      value;      /* pressed(1)/released(0) for btn/key          */
-    int      x;          /* MOVE_ABS: abs X; MOVE_REL: dx               */
-    int      y;          /* MOVE_ABS: abs Y; MOVE_REL: dy               */
+    int      x;          /* MOVE_REL: dx                                */
+    int      y;          /* MOVE_REL: dy                                */
     double   scroll;
     int      noack;      /* CMD_INPUT fire-and-forget: emit no ACT_ACK  */
     int      life_op;    /* VMSIG_LIFE_* (powerdown/reset/wakeup/pause/resume) */
@@ -57,10 +57,6 @@ static int input_job(void* user, const void* reqp, void* resp) {
             /* Pointer motion is ONE packet: both axes in a single batch -> one round-trip. */
             vmctl_batch b; vmctl_batch_init(&b);
             switch (rq->kind) {
-            case VMSIG_INPUT_MOVE_ABS:
-                vmctl_batch_abs(&b, VMCTL_AXIS_X, rq->x);
-                vmctl_batch_abs(&b, VMCTL_AXIS_Y, rq->y);
-                break;
             case VMSIG_INPUT_MOVE_REL:
                 vmctl_batch_rel(&b, VMCTL_AXIS_X, rq->x);
                 vmctl_batch_rel(&b, VMCTL_AXIS_Y, rq->y);
@@ -68,7 +64,7 @@ static int input_job(void* user, const void* reqp, void* resp) {
             case VMSIG_INPUT_BTN:    vmctl_batch_btn(&b, rq->code, rq->value);    break;
             case VMSIG_INPUT_KEY:    vmctl_batch_key(&b, rq->code, rq->value);    break;
             case VMSIG_INPUT_SCROLL: vmctl_batch_scroll(&b, rq->code, rq->scroll); break;
-            default: break;
+            default: break;   /* unknown/0 kind (e.g. retired MOVE_ABS): no-op */
             }
             r = vmctl_batch_send(a->vmctl, &b);
         } else {
@@ -112,15 +108,14 @@ static int in_attach(vmsig_adapter* a, const vmsig_emit* emit, vmsig_fd_reg* reg
     if (!a->stub) {
         /* armed: open the actuator. Injection is ALWAYS uinput; the resulting evdev nodes are
          * forwarded into the guest by the vmhost seam's input-linux object (published below).
-         * PTR_BOTH gives both pointer forms a device (A=kbd+abs tablet, B=rel mouse+buttons+
-         * wheel) — the contract now promises both MOVE_ABS and MOVE_REL, so neither may be
-         * disabled. qmp_path serves the SERVICE power/lifecycle path, not input injection. */
+         * uinput always creates two devices: A=keyboard, B=relative mouse+buttons+wheel — the
+         * contract carries MOVE_REL (there is no absolute pointer). qmp_path serves the SERVICE
+         * power/lifecycle path, not input injection. */
         vmctl_config vcfg;
         memset(&vcfg, 0, sizeof vcfg);
         vcfg.driver    = VMCTL_DRIVER_UINPUT;
         vcfg.qmp_path  = a->qmp_path;
         vcfg.input_bus = "";
-        vcfg.ptr_mode  = VMCTL_PTR_BOTH;
         vcfg.uinput_id = NULL;                  /* built-in HID identity defaults */
         a->vmctl = vmctl_open(&vcfg);
         if (!a->vmctl) { vmsig_worker_free(a->worker); a->worker = NULL; return -1; }

src/adapter/vmhost/include/vmhost.h

@@ -10,7 +10,7 @@ typedef struct {
     const char* qmp_path;
     /* Host->guest input bridge: evdev node paths of the uinput devices (published by the input
      * seam). When non-NULL/non-empty, on reaching READY the seam adds an input-linux QMP object
-     * forwarding them into the guest (A=kbd+abs with grab_all, B=mouse). NULL/"" => no bridge
+     * forwarding them into the guest (A=keyboard with grab_all, B=relative mouse). NULL/"" => no bridge
      * (stub/tests are fail-closed). Pointers are borrowed from the stable per-endpoint home and
      * outlive the adapter. */
     const char* bridge_evdev_a;

src/adapter/vmhost/vmhost.c

@@ -133,7 +133,9 @@ static int bridge_add(struct vmsig_adapter* a, char ab, const char* evdev, int g
     uint32_t qid = ++a->next_id;
     char line[320];
     int len = snprintf(line, sizeof line,
-        "{\"execute\":\"object_add\",\"arguments\":{\"qom-type\":\"input-linux\","
+        /* QMP object commands use HYPHENS (object-add/object-del); only the legacy
+         * device_add/device_del keep underscores. Underscore here => CommandNotFound. */
+        "{\"execute\":\"object-add\",\"arguments\":{\"qom-type\":\"input-linux\","
         "\"id\":\"%s\",\"evdev\":\"%s\"%s},\"id\":%u}\r\n",
         id, evdev, grab_all ? ",\"grab_all\":true" : "", qid);
     p->used = 1; p->id = qid; p->origin = 0; p->corr = 0; p->op = VH_OP_BRIDGE_ADD;
@@ -150,7 +152,7 @@ static void bridge_del_fire(struct vmsig_adapter* a, char ab) {
     bridge_id(id, sizeof id, a->endpoint, ab);
     char line[160];
     int len = snprintf(line, sizeof line,
-        "{\"execute\":\"object_del\",\"arguments\":{\"id\":\"%s\"}}\r\n", id);
+        "{\"execute\":\"object-del\",\"arguments\":{\"id\":\"%s\"}}\r\n", id);
     ssize_t r = write(a->fd, line, (size_t)len);
     (void)r;
 }
@@ -227,7 +229,7 @@ static void handle_line(struct vmsig_adapter* a, const char* line) {
                     /* Bridge infrastructure: never surfaces to control. Log a failed add so the
                      * stand can see it; otherwise silent. */
                     if (p->op == VH_OP_BRIDGE_ADD && strstr(line, "\"error\""))
-                        fprintf(stderr, "vmsig vmhost: input-linux object_add failed: %s\n", line);
+                        fprintf(stderr, "vmsig vmhost: input-linux object-add failed: %s\n", line);
                 } else if (p->op == VMSIG_VMOP_QUERY && strstr(line, "\"return\"")) {
                     char stbuf[32]; uint32_t s = VMSIG_VM_UNKNOWN;
                     if (jstr(line, "\"status\"", stbuf, sizeof stbuf)) s = status_state(stbuf);

src/cli.c

@@ -106,9 +106,9 @@ static int on_event(void* user, const vmsig_event* ev) {
         in.prio = VMSIG_PRIO_HIGH; in.endpoint = 0; in.corr = 0xC0FFEEu;
         in.payload.flags = VMSIG_PL_INLINE;
         vmsig_input act; memset(&act, 0, sizeof act);   /* neutral public input contract */
-        act.kind = VMSIG_INPUT_MOVE_ABS; act.x = 100; act.y = 100;   /* demo: abs pointer (100,100) */
+        act.kind = VMSIG_INPUT_MOVE_REL; act.x = 5; act.y = 5;   /* demo: relative move (dx=5,dy=5) */
         memcpy(in.inln, &act, sizeof act);
-        printf("  DOWN CMD_INPUT     MOVE_ABS x=100 y=100 corr=0x%X\n", (unsigned)in.corr);
+        printf("  DOWN CMD_INPUT     MOVE_REL dx=5 dy=5 corr=0x%X\n", (unsigned)in.corr);
         vmsig_inproc_send(d->ctl, &in);
 
         vmsig_event vm;

src/si/input/include/driver.h

@@ -8,7 +8,7 @@
  * driver switches on (never on magic numbers). */
 
 typedef enum {
-    VMCTL_EV_ABS, VMCTL_EV_REL, VMCTL_EV_BTN, VMCTL_EV_KEY, VMCTL_EV_SCROLL
+    VMCTL_EV_REL, VMCTL_EV_BTN, VMCTL_EV_KEY, VMCTL_EV_SCROLL
 } vmctl_ev_kind;
 
 typedef struct {
@@ -20,9 +20,8 @@ struct vmctl {
     vmctl_driver_ops ops;
     vmctl_driver     driver;
     qmp_conn*        qmp;       /* control channel; NULL if none            */
-    int              ui_fd_a;   /* uinput driver: device A; -1 for QMP      */
-    int              ui_fd_b;   /* uinput driver: device B (BOTH); -1       */
-    int              ptr_mode;  /* uinput driver: VMCTL_PTR_*; 0 for QMP    */
+    int              ui_fd_a;   /* uinput driver: device A (keyboard); -1 for QMP */
+    int              ui_fd_b;   /* uinput driver: device B (relative mouse); -1   */
     char             ui_evdev_a[64];  /* uinput driver: /dev/input/eventN of A ("" if none) */
     char             ui_evdev_b[64];  /* uinput driver: /dev/input/eventN of B ("" if none) */
 

src/si/input/include/uinput_layout.h

@@ -3,39 +3,37 @@
 #include "vmctl.h"
 
 /* uinput_layout.h — DECLARATIVE capability split for the uinput driver, kept pure (no ioctl)
- * so it is unit-testable without /dev/uinput. The roles are derived from ptr_mode, NOT inferred
- * as a side effect of rel_motion; the hot path's button/wheel carrier follows the same rule.
+ * so it is unit-testable without /dev/uinput. The roles are passed into the driver as DATA, not
+ * inferred as a side effect of one another; the hot path's button/wheel carrier follows the same
+ * rule.
  *
- * Layout: device A always carries the keyboard. Mouse buttons + scroll wheel ride the device
- * carrying the relative pointer (B in BOTH, A in REL-only); with no relative pointer (ABS-only)
- * they fall back to A. So in BOTH: A=keyboard+abs, B=rel+buttons+wheel. */
+ * Layout is CONSTANT (no absolute pointer): device A = keyboard only; device B = relative pointer
+ * + mouse buttons + scroll wheel. Buttons + wheel ride device B (the relative-pointer carrier). */
 
 typedef struct {
-    int present;         /* 1 if this device is created for the given ptr_mode */
-    int rel_motion;      /* advertise relative X/Y (else absolute X/Y)          */
+    int present;         /* 1 if this device is created                         */
+    int rel_motion;      /* advertise relative X/Y (no device advertises abs)   */
     int want_keyboard;   /* advertise the keyboard keymap                       */
     int want_buttons;    /* advertise the 8 mouse buttons                       */
     int want_wheel;      /* advertise REL_WHEEL / REL_HWHEEL                     */
 } uinput_role;
 
-/* Fill role_a/role_b from ptr_mode (VMCTL_PTR_*). Sets *btn_on_b to 1 when the button/wheel
- * carrier on the hot path is device B (only in PTR_BOTH). role_b.present is 0 unless BOTH. */
-static inline void vmctl_uinput_layout(int ptr_mode, uinput_role* role_a, uinput_role* role_b,
-                                       int* btn_on_b) {
-    int both = (ptr_mode == VMCTL_PTR_BOTH);
+/* Fill role_a/role_b with the constant layout. *btn_on_b is always 1: the button/wheel carrier
+ * on the hot path is device B (the relative-pointer device). Both devices are always present. */
+static inline void vmctl_uinput_layout(uinput_role* role_a, uinput_role* role_b, int* btn_on_b) {
     role_a->present       = 1;
-    role_a->rel_motion    = (ptr_mode == VMCTL_PTR_REL);
+    role_a->rel_motion    = 0;   /* keyboard-only: no pointer on A */
     role_a->want_keyboard = 1;
-    role_a->want_buttons  = !both;   /* B carries buttons when there are two devices */
-    role_a->want_wheel    = !both;
+    role_a->want_buttons  = 0;
+    role_a->want_wheel    = 0;
 
-    role_b->present       = both;
+    role_b->present       = 1;
     role_b->rel_motion    = 1;
     role_b->want_keyboard = 0;
-    role_b->want_buttons  = both;
-    role_b->want_wheel    = both;
+    role_b->want_buttons  = 1;
+    role_b->want_wheel    = 1;
 
-    if (btn_on_b) *btn_on_b = both;
+    if (btn_on_b) *btn_on_b = 1;
 }
 
 #endif /* VMCTL_UINPUT_LAYOUT_H */

src/si/input/linux/uinput_driver.c

@@ -14,12 +14,10 @@
  * connection (the evdev paths are exported via vmctl_uinput_evdev). The driver
  * switches on vmctl_ev_kind (never on magic numbers).
  *
- * Capability layout (VMCTL_PTR_BOTH): keyboard + absolute pointer on device A;
- * relative pointer + mouse buttons + scroll wheel on device B. Buttons/wheel ride
- * the device carrying the relative pointer (B in BOTH, A in REL-only); with no
- * relative pointer (ABS-only) they fall back to A. This split is DECLARATIVE: the
- * roles (want_buttons/want_wheel/rel_motion) are passed into uinput_create, not
- * inferred from rel_motion as a side effect. */
+ * Capability layout (constant, no absolute pointer): device A = keyboard only;
+ * device B = relative pointer + mouse buttons + scroll wheel. Buttons/wheel ride
+ * device B (the relative-pointer carrier). This split is DECLARATIVE: the roles
+ * (want_buttons/want_wheel/rel_motion) are passed into uinput_create as data. */
 
 #include "driver.h"
 #include "keymap.h"
@@ -31,6 +29,7 @@
 #include <string.h>
 #include <fcntl.h>
 #include <unistd.h>
+#include <dirent.h>
 #include <sys/ioctl.h>
 #include <linux/uinput.h>
 #include <linux/input-event-codes.h>
@@ -59,7 +58,7 @@ static void emit(int fd, uint16_t type, uint16_t code, int32_t val) {
 
 static void syn(int fd) { emit(fd, EV_SYN, SYN_REPORT, 0); }
 
-/* The declarative per-device role (uinput_role) and the ptr_mode -> A/B split live in
+/* The declarative per-device role (uinput_role) and the constant A/B split live in
  * uinput_layout.h so the layout is unit-testable without /dev/uinput. */
 static int uinput_create(const uinput_role* role, const vmctl_uinput_id* id,
                          const char* name, char evdev[64]) {
@@ -90,21 +89,6 @@ static int uinput_create(const uinput_role* role, const vmctl_uinput_id* id,
         ioctl(fd, UI_SET_RELBIT, REL_Y);
     }
 
-    if (!role->rel_motion) {
-        ioctl(fd, UI_SET_EVBIT, EV_ABS);
-        ioctl(fd, UI_SET_ABSBIT, ABS_X);
-        ioctl(fd, UI_SET_ABSBIT, ABS_Y);
-
-        struct uinput_abs_setup ax;
-        memset(&ax, 0, sizeof ax);
-        ax.code = ABS_X;
-        ax.absinfo.minimum = 0;
-        ax.absinfo.maximum = VMCTL_ABS_MAX;
-        ioctl(fd, UI_ABS_SETUP, &ax);
-        ax.code = ABS_Y;
-        ioctl(fd, UI_ABS_SETUP, &ax);
-    }
-
     struct uinput_setup us;
     memset(&us, 0, sizeof us);
     us.id.bustype = (uint16_t)id->bustype;
@@ -120,8 +104,28 @@ static int uinput_create(const uinput_role* role, const vmctl_uinput_id* id,
 
     char sysname[64] = {0};
     evdev[0] = '\0';
-    if (ioctl(fd, UI_GET_SYSNAME(sizeof sysname), sysname) >= 0)
-        snprintf(evdev, 64, "/dev/input/%s", sysname);
+    /* UI_GET_SYSNAME returns the input-class directory name (e.g. "input174"), NOT the usable
+     * device node: a bare /dev/input/<sysname> does not exist (QEMU input-linux fails to open
+     * it). The evdev character device is /dev/input/eventN, exposed as the "event*" child of
+     * /sys/class/input/<sysname>/ — resolve it there. */
+    if (ioctl(fd, UI_GET_SYSNAME(sizeof sysname), sysname) >= 0) {
+        char dpath[128];
+        snprintf(dpath, sizeof dpath, "/sys/class/input/%s", sysname);
+        DIR* dir = opendir(dpath);
+        if (dir) {
+            struct dirent* de;
+            while ((de = readdir(dir)) != NULL)
+                if (strncmp(de->d_name, "event", 5) == 0) {
+                    size_t nl = strlen(de->d_name);
+                    if (nl + 11 < 64) {            /* "/dev/input/" is 11 chars + name + NUL */
+                        memcpy(evdev, "/dev/input/", 11);
+                        memcpy(evdev + 11, de->d_name, nl + 1);
+                    }
+                    break;
+                }
+            closedir(dir);
+        }
+    }
 
     if (!evdev[0]) {
         ioctl(fd, UI_DEV_DESTROY);
@@ -162,14 +166,10 @@ static void qmp_unplug(qmp_conn* qmp, const char* id) {
 static int uinput_driver_send(vmctl_t* v, const vmctl_batch* b) {
     int fd_a = v->ui_fd_a;
     int fd_b = v->ui_fd_b;
-    int both = (fd_b >= 0);
-    /* Relative motion, mouse buttons and the scroll wheel all ride ONE carrier device — the
-     * relative-pointer device. Selected once from the same declarative layout used at create
-     * time (btn_on_b == carrier is B), so the hot path and the advertised capabilities agree. */
-    uinput_role ra, rb; int btn_on_b = 0;
-    vmctl_uinput_layout(v->ptr_mode, &ra, &rb, &btn_on_b);
-    int fd_rel = btn_on_b ? fd_b : fd_a;
-    int fd_btn = fd_rel;
+    /* Relative motion, mouse buttons and the scroll wheel all ride device B (the relative-pointer
+     * carrier), matching the constant layout used at create time; the keyboard rides device A. */
+    int fd_rel = fd_b;
+    int fd_btn = fd_b;
 
     for (int i = 0; i < b->count; i++) {
         int    code  = b->ev[i].code;
@@ -177,13 +177,7 @@ static int uinput_driver_send(vmctl_t* v, const vmctl_batch* b) {
         double scl   = b->ev[i].scroll;
 
         switch ((vmctl_ev_kind)b->ev[i].kind) {
-        case VMCTL_EV_ABS:
-            if (v->ptr_mode == VMCTL_PTR_REL) return -1;
-            emit(fd_a, EV_ABS, code == VMCTL_AXIS_X ? ABS_X : ABS_Y, value);
-            syn(fd_a);
-            break;
         case VMCTL_EV_REL: {
-            if (!both && v->ptr_mode == VMCTL_PTR_ABS) return -1;
             emit(fd_rel, EV_REL, code == VMCTL_AXIS_X ? REL_X : REL_Y, value);
             syn(fd_rel);
             break;
@@ -236,13 +230,13 @@ vmctl_t* vmctl_open_uinput_driver(const vmctl_config* cfg) {
     const char* base = (cfg->uinput_id && cfg->uinput_id->name && cfg->uinput_id->name[0])
                        ? cfg->uinput_id->name : NULL;
 
-    /* A/B suffix is added by the library only when two devices are created
-     * (VMCTL_PTR_BOTH) and only over a caller-supplied base name. */
+    /* Two devices are always created (A=keyboard, B=relative mouse); the A/B suffix is added by
+     * the library over a caller-supplied base name. */
     char name_a[UINPUT_MAX_NAME_SIZE];
     char name_b[UINPUT_MAX_NAME_SIZE];
     const char* dev_a = base ? base : HWID_NAME_A;
     const char* dev_b = HWID_NAME_B;
-    if (cfg->ptr_mode == VMCTL_PTR_BOTH && base) {
+    if (base) {
         int base_max = (int)(sizeof name_a - 1 /*NUL*/ - 2 /*"-A"*/);
         snprintf(name_a, sizeof name_a, "%.*s-A", base_max, base);
         snprintf(name_b, sizeof name_b, "%.*s-B", base_max, base);
@@ -252,7 +246,7 @@ vmctl_t* vmctl_open_uinput_driver(const vmctl_config* cfg) {
 
     char evdev_a[64], evdev_b[64];
     uinput_role role_a, role_b;
-    vmctl_uinput_layout(cfg->ptr_mode, &role_a, &role_b, NULL);   /* declarative A/B split */
+    vmctl_uinput_layout(&role_a, &role_b, NULL);   /* constant A/B split */
 
     v->ui_fd_a = uinput_create(&role_a, id, dev_a, evdev_a);
     if (v->ui_fd_a < 0) { free(v); return NULL; }
@@ -284,19 +278,16 @@ vmctl_t* vmctl_open_uinput_driver(const vmctl_config* cfg) {
                 free(v);
                 return NULL;
             }
-            if (cfg->ptr_mode == VMCTL_PTR_BOTH) {
-                if (qmp_plug(v->qmp, cfg->input_bus, evdev_b, PLUG_ID_B) < 0) {
-                    qmp_unplug(v->qmp, PLUG_ID_A);
-                    uinput_driver_close(v);
-                    free(v);
-                    return NULL;
-                }
+            if (qmp_plug(v->qmp, cfg->input_bus, evdev_b, PLUG_ID_B) < 0) {
+                qmp_unplug(v->qmp, PLUG_ID_A);
+                uinput_driver_close(v);
+                free(v);
+                return NULL;
             }
         }
     }
 
     v->ops.send  = uinput_driver_send;
     v->ops.close = uinput_driver_close;
-    v->ptr_mode  = cfg->ptr_mode;
     return v;
 }

src/si/input/open.c

@@ -29,12 +29,6 @@ void vmctl_batch_init(vmctl_batch* b) {
     b->count = 0;
 }
 
-void vmctl_batch_abs(vmctl_batch* b, int axis, int value) {
-    if (b->count >= VMCTL_BATCH_MAX) return;
-    vmctl_event* e = &b->ev[b->count++];
-    e->kind = VMCTL_EV_ABS; e->code = axis; e->value = value; e->scroll = 0.0;
-}
-
 void vmctl_batch_rel(vmctl_batch* b, int axis, int delta) {
     if (b->count >= VMCTL_BATCH_MAX) return;
     vmctl_event* e = &b->ev[b->count++];
@@ -65,7 +59,7 @@ int vmctl_batch_send(vmctl_t* v, vmctl_batch* b) {
     if (rc != 0) return rc;   /* not sent = not recorded; never touch the receipt */
 
     /* Record the actuated key/btn down-bits (write-only; the send path above
-     * never reads this map). abs/rel/scroll have no held state. */
+     * never reads this map). rel/scroll have no held state. */
     for (int i = 0; i < b->count; i++) {
         const vmctl_event* e = &b->ev[i];
         int down = e->value ? 1 : 0;
@@ -86,7 +80,7 @@ int vmctl_batch_send(vmctl_t* v, vmctl_batch* b) {
             else      v->btns_held &= ~mask;
             break;
         }
-        default: break;   /* abs/rel/scroll: no-op for receipt */
+        default: break;   /* rel/scroll: no-op for receipt */
         }
     }
     return rc;
@@ -94,13 +88,6 @@ int vmctl_batch_send(vmctl_t* v, vmctl_batch* b) {
 
 /* ===== Single-event wrappers ===== */
 
-int vmctl_abs(vmctl_t* v, int axis, int value) {
-    vmctl_batch b;
-    vmctl_batch_init(&b);
-    vmctl_batch_abs(&b, axis, value);
-    return vmctl_batch_send(v, &b);
-}
-
 int vmctl_rel(vmctl_t* v, int axis, int delta) {
     vmctl_batch b;
     vmctl_batch_init(&b);

src/si/input/qmp_driver.c

@@ -29,11 +29,6 @@ static int qmp_driver_send(vmctl_t* v, const vmctl_batch* b) {
         double scl   = b->ev[i].scroll;
 
         switch ((vmctl_ev_kind)b->ev[i].kind) {
-        case VMCTL_EV_ABS:
-            pos += snprintf(json + pos, (int)sizeof json - pos,
-                            "{\"type\":\"abs\",\"data\":{\"axis\":\"%s\",\"value\":%d}}",
-                            code == VMCTL_AXIS_X ? "x" : "y", value);
-            break;
         case VMCTL_EV_REL:
             pos += snprintf(json + pos, (int)sizeof json - pos,
                             "{\"type\":\"rel\",\"data\":{\"axis\":\"%s\",\"value\":%d}}",
@@ -87,7 +82,6 @@ vmctl_t* vmctl_open_qmp_driver(const vmctl_config* cfg) {
     v->qmp        = qmp;
     v->ui_fd_a    = -1;
     v->ui_fd_b    = -1;
-    v->ptr_mode   = 0;
     v->ops.send   = qmp_driver_send;
     v->ops.close  = qmp_driver_close;
     return v;

src/test/test_uinputlayout.c

@@ -1,10 +1,10 @@
 /* test_uinputlayout.c — DECLARATIVE uinput capability split (pure, no /dev/uinput).
  *
- * Verifies the ptr_mode -> A/B role mapping that drives both device creation and the hot-path
- * button/wheel carrier selection: in PTR_BOTH A is keyboard+abs and B is rel+buttons+wheel, and
- * the button/wheel carrier is B; single-pointer modes keep buttons+wheel on the sole device.
- * The actuation ioctls remain armed-only (they need a real /dev/uinput); this covers the logic
- * that decides the layout, which is the part that single-mode regressions would break. */
+ * Verifies the CONSTANT A/B role mapping that drives both device creation and the hot-path
+ * button/wheel carrier selection: device A = keyboard only, device B = relative pointer + buttons
+ * + wheel, and the button/wheel carrier is B. There is no absolute pointer anywhere — the abs role
+ * has been removed and is unrepresentable (no abs field exists in uinput_role). The actuation
+ * ioctls remain armed-only (they need a real /dev/uinput); this covers the layout logic. */
 #include "vmctl.h"
 #include "uinput_layout.h"
 #include <stdio.h>
@@ -17,37 +17,25 @@ static int g_fail = 0;
 int main(void) {
     uinput_role a, b; int btn_on_b;
 
-    /* PTR_BOTH: A = keyboard + absolute pointer, no buttons/wheel; B = relative pointer +
-     * buttons + wheel; carrier is B. This is the requested layout (mouse buttons incl. middle
-     * and the wheel moved off A onto B). */
-    vmctl_uinput_layout(VMCTL_PTR_BOTH, &a, &b, &btn_on_b);
-    CHECK(a.present && b.present,        "BOTH: two devices");
-    CHECK(a.want_keyboard,               "BOTH: A has keyboard");
-    CHECK(!a.rel_motion,                 "BOTH: A is absolute");
-    CHECK(!a.want_buttons,               "BOTH: A has NO mouse buttons");
-    CHECK(!a.want_wheel,                 "BOTH: A has NO wheel");
-    CHECK(!b.want_keyboard,              "BOTH: B has no keyboard");
-    CHECK(b.rel_motion,                  "BOTH: B is relative");
-    CHECK(b.want_buttons,                "BOTH: B has mouse buttons");
-    CHECK(b.want_wheel,                  "BOTH: B has wheel");
-    CHECK(btn_on_b == 1,                 "BOTH: button/wheel carrier is B");
+    /* Constant layout: A = keyboard only (no pointer, no buttons/wheel); B = relative pointer +
+     * buttons + wheel; the button/wheel carrier is B. */
+    vmctl_uinput_layout(&a, &b, &btn_on_b);
+    CHECK(a.present && b.present,        "two devices");
+    CHECK(a.want_keyboard,               "A has keyboard");
+    CHECK(!a.rel_motion,                 "A has no pointer (keyboard-only)");
+    CHECK(!a.want_buttons,               "A has NO mouse buttons");
+    CHECK(!a.want_wheel,                 "A has NO wheel");
+    CHECK(!b.want_keyboard,              "B has no keyboard");
+    CHECK(b.rel_motion,                  "B is relative");
+    CHECK(b.want_buttons,                "B has mouse buttons");
+    CHECK(b.want_wheel,                  "B has wheel");
+    CHECK(btn_on_b == 1,                 "button/wheel carrier is B");
 
-    /* PTR_REL: single relative device A carries motion + buttons + wheel (no B). */
-    vmctl_uinput_layout(VMCTL_PTR_REL, &a, &b, &btn_on_b);
-    CHECK(a.present && !b.present,       "REL: single device A");
-    CHECK(a.rel_motion,                  "REL: A is relative");
-    CHECK(a.want_buttons,                "REL: A has buttons");
-    CHECK(a.want_wheel,                  "REL: A has wheel");
-    CHECK(a.want_keyboard,               "REL: A has keyboard");
-    CHECK(btn_on_b == 0,                 "REL: carrier is A");
-
-    /* PTR_ABS: single absolute device A carries abs + buttons + wheel (the only device). */
-    vmctl_uinput_layout(VMCTL_PTR_ABS, &a, &b, &btn_on_b);
-    CHECK(a.present && !b.present,       "ABS: single device A");
-    CHECK(!a.rel_motion,                 "ABS: A is absolute");
-    CHECK(a.want_buttons,                "ABS: A has buttons (sole device)");
-    CHECK(a.want_wheel,                  "ABS: A has wheel (sole device)");
-    CHECK(btn_on_b == 0,                 "ABS: carrier is A");
+    /* No absolute pointer: the abs role is removed and unrepresentable (uinput_role carries no abs
+     * field). The invariant is that each device is either relative or has no pointer at all — A is
+     * keyboard-only (no pointer), B is relative. Neither advertises an absolute axis. */
+    CHECK(!a.rel_motion && !a.want_buttons && !a.want_wheel, "A is keyboard-only (no pointer)");
+    CHECK(b.rel_motion,                  "B is the relative pointer (not absolute)");
 
     /* evdev export contract: a NULL handle reports "not a uinput handle" (-1). The populated
      * path (real /dev/input/eventN) is armed-only — it needs a created uinput device. */

src/test/test_vmhost.c

@@ -142,7 +142,7 @@ int main(void) {
 
         /* On READY the seam adds the input-linux bridge BEFORE the SEAM_UP-driven CMD_VM query
          * (bridge ids 1,2; query id 3). Verify both object_add lines and their properties. */
-        CHECK(srv_expect(c, "object_add"),  "seam sent object_add (input-linux bridge)");
+        CHECK(srv_expect(c, "object-add"),  "seam sent object-add (input-linux bridge)");
         CHECK(srv_expect(c, "\"input-linux\""), "bridge object uses qom-type input-linux");
         CHECK(srv_expect(c, "\"vmsig-in-a-0\""), "bridge A has neutral per-endpoint id");
         CHECK(srv_expect(c, "\"vmsig-in-b-0\""), "bridge B has neutral per-endpoint id");
@@ -224,12 +224,12 @@ int main(void) {
                 pthread_join(th2, NULL);
                 vmsig_core_free(core2);
 
-                for (int i = 0; i < 50 && !strstr(g_rx, "object_del"); i++) {
+                for (int i = 0; i < 50 && !strstr(g_rx, "object-del"); i++) {
                     rx_pump(c2);
                     struct timespec t = { 0, 10 * 1000000 }; nanosleep(&t, NULL);
                 }
-                const char* d = strstr(g_rx, "object_del");
-                CHECK(d != NULL,                       "scenario2: teardown fired object_del");
+                const char* d = strstr(g_rx, "object-del");
+                CHECK(d != NULL,                       "scenario2: teardown fired object-del");
                 CHECK(strstr(g_rx, "vmsig-in-a-0"),    "scenario2: object_del for bridge A");
                 CHECK(strstr(g_rx, "vmsig-in-b-0"),    "scenario2: object_del for bridge B");
                 close(c2);