This patch adds support for reading input events directly from linux
evdev devices and forward them to the guest. Unlike virtio-input-host
which simply passes on all events to the guest without looking at them
this will interpret the events and feed them into the qemu input
subsystem.
Therefore this is limited to what the qemu input subsystem and the
emulated input devices are able to handle. Also there is no support for
absolute coordinates (tablet/touchscreen). So we are talking here about
basic mouse and keyboard support.
The advantage is that it'll work without virtio-input drivers in the
guest, the events are delivered to the usual ps/2 or usb input devices
(depending on what the machine happens to have). And for keyboards
qemu is able to switch the keyboard between guest and host on hotkey.
The hotkey is hard-coded for now (both control keys), initialy the
guest owns the keyboard.
Probably most useful when assigning vga devices with vfio and using a
physical monitor instead of vnc/spice/gtk as guest display.
Usage: Add '-input-linux /dev/input/event<nr>' to the qemu command
line. Note that udev has rules which populate /dev/input/by-{id,path}
with static names, which might be more convinient to use.
Signed-off-by: Gerd Hoffmann <kra...@redhat.com>
---
include/ui/input.h | 2 +
qemu-options.hx | 9 +++
ui/Makefile.objs | 1 +
ui/input-linux.c | 194 +++++++++++++++++++++++++++++++++++++++++++++++++++++
vl.c | 11 +++
5 files changed, 217 insertions(+)
create mode 100644 ui/input-linux.c
diff --git a/include/ui/input.h b/include/ui/input.h
index d7afd80..443742e 100644
--- a/include/ui/input.h
+++ b/include/ui/input.h
@@ -68,4 +68,6 @@ void qemu_input_check_mode_change(void);
void qemu_add_mouse_mode_change_notifier(Notifier *notify);
void qemu_remove_mouse_mode_change_notifier(Notifier *notify);
+int input_linux_init(void *opaque, QemuOpts *opts, Error **errp);
+
#endif /* INPUT_H */
diff --git a/qemu-options.hx b/qemu-options.hx
index 0eea4ee..a2d7338 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -1165,6 +1165,15 @@ STEXI
Set the initial graphical resolution and depth (PPC, SPARC only).
ETEXI
+DEF("input-linux", 1, QEMU_OPTION_input_linux,
+ "-input-linux <evdev>\n"
+ " Use input device.\n", QEMU_ARCH_ALL)
+STEXI
+@item -input-linux @var{dev}
+@findex -input-linux
+Use input device.
+ETEXI
+
DEF("vnc", HAS_ARG, QEMU_OPTION_vnc ,
"-vnc display start a VNC server on display\n", QEMU_ARCH_ALL)
STEXI
diff --git a/ui/Makefile.objs b/ui/Makefile.objs
index 728393c..dc936f1 100644
--- a/ui/Makefile.objs
+++ b/ui/Makefile.objs
@@ -9,6 +9,7 @@ vnc-obj-y += vnc-jobs.o
common-obj-y += keymaps.o console.o cursor.o qemu-pixman.o
common-obj-y += input.o input-keymap.o input-legacy.o
+common-obj-$(CONFIG_LINUX) += input-linux.o
common-obj-$(CONFIG_SPICE) += spice-core.o spice-input.o spice-display.o
common-obj-$(CONFIG_SDL) += sdl.mo x_keymap.o
common-obj-$(CONFIG_COCOA) += cocoa.o
diff --git a/ui/input-linux.c b/ui/input-linux.c
new file mode 100644
index 0000000..3c8d587
--- /dev/null
+++ b/ui/input-linux.c
@@ -0,0 +1,194 @@
+/*
+ * This work is licensed under the terms of the GNU GPL, version 2 or
+ * (at your option) any later version. See the COPYING file in the
+ * top-level directory.
+ */
+
+#include "qemu-common.h"
+#include "qemu/config-file.h"
+#include "qemu/sockets.h"
+#include "sysemu/sysemu.h"
+#include "ui/input.h"
+
+#include <sys/ioctl.h>
+#include "standard-headers/linux/input.h"
+
+typedef struct InputLinux InputLinux;
+
+struct InputLinux {
+ const char *evdev;
+ int fd;
+ bool grab_request;
+ bool grab_active;
+ bool keydown[KEY_CNT];
+ int keycount;
+};
+
+static void input_linux_toggle_grab(InputLinux *il)
+{
+ intptr_t request = !il->grab_active;
+ int rc;
+
+ rc = ioctl(il->fd, EVIOCGRAB, request);
+ if (rc < 0) {
+ return;
+ }
+ il->grab_active = !il->grab_active;
+}
+
+static void input_linux_event_keyboard(void *opaque)
+{
+ InputLinux *il = opaque;
+ struct input_event event;
+ int rc;
+
+ for (;;) {
+ rc = read(il->fd, &event, sizeof(event));
+ if (rc != sizeof(event)) {
+ break;
+ }
+
+ switch (event.type) {
+ case EV_KEY:
+ /* keep track of key state */
+ if (!il->keydown[event.code] && event.value) {
+ il->keydown[event.code] = true;
+ il->keycount++;
+ }
+ if (il->keydown[event.code] && !event.value) {
+ il->keydown[event.code] = false;
+ il->keycount--;
+ }
+
+ /* send event to guest when grab is active */
+ if (il->grab_active) {
+ int qcode = qemu_input_linux_to_qcode(event.code);
+ qemu_input_event_send_key_qcode(NULL, qcode, event.value);
+ }
+
+ /* hotkey -> record switch request ... */
+ if (il->keydown[KEY_LEFTCTRL] &&
+ il->keydown[KEY_RIGHTCTRL]) {
+ il->grab_request = true;
+ }
+
+ /*
+ * ... and do the switch when all keys are lifted, so we
+ * confuse neither guest nor host with keys which seem to
+ * be stuck due to missing key-up events.
+ */
+ if (il->grab_request && !il->keycount) {
+ il->grab_request = false;
+ input_linux_toggle_grab(il);
+ }
+ break;
+ }
+ }
+}
+
+static void input_linux_event_mouse(void *opaque)
+{
+ InputLinux *il = opaque;
+ struct input_event event;
+ int rc;
+
+ for (;;) {
+ rc = read(il->fd, &event, sizeof(event));
+ if (rc != sizeof(event)) {
+ break;
+ }
+
+ switch (event.type) {
+ case EV_KEY:
+ switch (event.code) {
+ case BTN_LEFT:
+ qemu_input_queue_btn(NULL, INPUT_BUTTON_LEFT, event.value);
+ break;
+ case BTN_RIGHT:
+ qemu_input_queue_btn(NULL, INPUT_BUTTON_RIGHT, event.value);
+ break;
+ case BTN_MIDDLE:
+ qemu_input_queue_btn(NULL, INPUT_BUTTON_MIDDLE, event.value);
+ break;
+ };
+ break;
+ case EV_REL:
+ switch (event.code) {
+ case REL_X:
+ qemu_input_queue_rel(NULL, INPUT_AXIS_X, event.value);
+ break;
+ case REL_Y:
+ qemu_input_queue_rel(NULL, INPUT_AXIS_Y, event.value);
+ break;
+ }
+ break;
+ case EV_SYN:
+ qemu_input_event_sync();
+ break;
+ }
+ }
+}
+
+int input_linux_init(void *opaque, QemuOpts *opts, Error **errp)
+{
+ InputLinux *il = g_new0(InputLinux, 1);
+ uint32_t evtmap;
+ int rc, ver;
+
+ il->evdev = qemu_opt_get(opts, "evdev");
+ if (!il->evdev) {
+ error_setg(errp, "no input device specified");
+ goto err_free;
+ }
+
+ il->fd = open(il->evdev, O_RDWR);
+ if (il->fd < 0) {
+ error_setg_file_open(errp, errno, il->evdev);
+ goto err_free;
+ }
+ qemu_set_nonblock(il->fd);
+
+ rc = ioctl(il->fd, EVIOCGVERSION, &ver);
+ if (rc < 0) {
+ error_setg(errp, "%s: is not an evdev device", il->evdev);
+ goto err_close;
+ }
+
+ rc = ioctl(il->fd, EVIOCGBIT(0, sizeof(evtmap)), &evtmap);
+
+ if (evtmap & (1 << EV_ABS)) {
+ error_setg(errp, "tablet/touchscreen not supported");
+ goto err_close;
+ } else if (evtmap & (1 << EV_REL)) {
+ qemu_set_fd_handler(il->fd, input_linux_event_mouse, NULL, il);
+ } else {
+ qemu_set_fd_handler(il->fd, input_linux_event_keyboard, NULL, il);
+ }
+ input_linux_toggle_grab(il);
+ return 0;
+
+err_close:
+ close(il->fd);
+err_free:
+ g_free(il);
+ return -1;
+}
+
+static QemuOptsList qemu_input_linux_opts = {
+ .name = "input-linux",
+ .head = QTAILQ_HEAD_INITIALIZER(qemu_input_linux_opts.head),
+ .implied_opt_name = "evdev",
+ .desc = {
+ {
+ .name = "evdev",
+ .type = QEMU_OPT_STRING,
+ },
+ { /* end of list */ }
+ },
+};
+
+static void input_linux_register_config(void)
+{
+ qemu_add_opts(&qemu_input_linux_opts);
+}
+machine_init(input_linux_register_config);
diff --git a/vl.c b/vl.c
index 7d993a5..3db515d 100644
--- a/vl.c
+++ b/vl.c
@@ -78,6 +78,7 @@ int main(int argc, char **argv)
#include "net/slirp.h"
#include "monitor/monitor.h"
#include "ui/console.h"
+#include "ui/input.h"
#include "sysemu/sysemu.h"
#include "sysemu/numa.h"
#include "exec/gdbstub.h"
@@ -3739,6 +3740,12 @@ int main(int argc, char **argv, char **envp)
#endif
break;
}
+ case QEMU_OPTION_input_linux:
+ if (!qemu_opts_parse_noisily(qemu_find_opts("input-linux"),
+ optarg, true)) {
+ exit(1);
+ }
+ break;
case QEMU_OPTION_no_acpi:
acpi_enabled = 0;
break;
@@ -4619,6 +4626,10 @@ int main(int argc, char **argv, char **envp)
qemu_spice_display_init();
}
#endif
+#ifdef CONFIG_LINUX
+ qemu_opts_foreach(qemu_find_opts("input-linux"),
+ input_linux_init, NULL, &error_fatal);
+#endif
if (foreach_device_config(DEV_GDB, gdbserver_start) < 0) {
exit(1);
--
1.8.3.1
