[Qemu-devel] [PATCH 2/4] virtio-input: core code & base class

[Gerd Hoffmann <kraxel@redhat.com>]

This patch adds virtio-input support to qemu.  It brings a abstract
base class providing core support, other classes can build on it to
actually implement input devices.

virtio-input basically sends linux input layer events (evdev) over
virtio.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 hw/input/Makefile.objs           |   4 +
 hw/input/virtio-input.c          | 284 +++++++++++++++++++++++++++++++++++++++
 hw/virtio/virtio-pci.c           |  36 +++++
 hw/virtio/virtio-pci.h           |  14 ++
 include/hw/virtio/virtio-input.h | 106 +++++++++++++++
 include/hw/virtio/virtio.h       |   1 +
 6 files changed, 445 insertions(+)
 create mode 100644 hw/input/virtio-input.c
 create mode 100644 include/hw/virtio/virtio-input.h

diff --git a/hw/input/Makefile.objs b/hw/input/Makefile.objs
index e8c80b9..ee8bba9 100644
--- a/hw/input/Makefile.objs
+++ b/hw/input/Makefile.objs
@@ -8,6 +8,10 @@ common-obj-$(CONFIG_STELLARIS_INPUT) += stellaris_input.o
 common-obj-$(CONFIG_TSC2005) += tsc2005.o
 common-obj-$(CONFIG_VMMOUSE) += vmmouse.o
 
+ifeq ($(CONFIG_LINUX),y)
+common-obj-$(CONFIG_VIRTIO) += virtio-input.o
+endif
+
 obj-$(CONFIG_MILKYMIST) += milkymist-softusb.o
 obj-$(CONFIG_PXA2XX) += pxa2xx_keypad.o
 obj-$(CONFIG_TSC210X) += tsc210x.o
diff --git a/hw/input/virtio-input.c b/hw/input/virtio-input.c
new file mode 100644
index 0000000..8df7afb
--- /dev/null
+++ b/hw/input/virtio-input.c
@@ -0,0 +1,284 @@
+/*
+ * 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/iov.h"
+
+#include "hw/qdev.h"
+#include "hw/virtio/virtio.h"
+#include "hw/virtio/virtio-input.h"
+
+#include "ui/console.h"
+
+#include <linux/input.h>
+
+/* ----------------------------------------------------------------- */
+
+void virtio_input_send(VirtIOInput *vinput, virtio_input_event *event)
+{
+    VirtQueueElement elem;
+    unsigned have, need;
+    int i, len;
+
+    /* queue up events ... */
+    if (vinput->qindex == vinput->qsize) {
+        vinput->qsize++;
+        vinput->queue = realloc(vinput->queue, vinput->qsize *
+                                sizeof(virtio_input_event));
+    }
+    vinput->queue[vinput->qindex++] = *event;
+
+    /* ... until we see a report sync ... */
+    if (event->type != cpu_to_le16(EV_SYN) ||
+        event->code != cpu_to_le16(SYN_REPORT)) {
+        return;
+    }
+
+    /* ... then check available space ... */
+    need = sizeof(virtio_input_event) * vinput->qindex;
+    virtqueue_get_avail_bytes(vinput->evt, &have, NULL, need, 0);
+    if (have < need) {
+        vinput->qindex = 0;
+        fprintf(stderr, "%s: ENOSPC in vq, dropping events\n", __func__);
+        return;
+    }
+
+    /* ... and finally pass them to the guest */
+    for (i = 0; i < vinput->qindex; i++) {
+        if (!virtqueue_pop(vinput->evt, &elem)) {
+            /* should not happen, we've checked for space beforehand */
+            fprintf(stderr, "%s: Huh?  No vq elem available ...\n", __func__);
+            return;
+        }
+        len = iov_from_buf(elem.in_sg, elem.in_num,
+                           0, vinput->queue+i, sizeof(virtio_input_event));
+        virtqueue_push(vinput->evt, &elem, len);
+    }
+    virtio_notify(VIRTIO_DEVICE(vinput), vinput->evt);
+    vinput->qindex = 0;
+}
+
+static void virtio_input_handle_evt(VirtIODevice *vdev, VirtQueue *vq)
+{
+    /* nothing */
+}
+
+static void virtio_input_handle_sts(VirtIODevice *vdev, VirtQueue *vq)
+{
+    VirtIOInputClass *vic = VIRTIO_INPUT_GET_CLASS(vdev);
+    VirtIOInput *vinput = VIRTIO_INPUT(vdev);
+    virtio_input_event event;
+    VirtQueueElement elem;
+    int len;
+
+    while (virtqueue_pop(vinput->sts, &elem)) {
+        memset(&event, 0, sizeof(event));
+        len = iov_to_buf(elem.out_sg, elem.out_num,
+                         0, &event, sizeof(event));
+        if (vic->handle_status) {
+            vic->handle_status(vinput, &event);
+        }
+        virtqueue_push(vinput->sts, &elem, len);
+    }
+    virtio_notify(vdev, vinput->sts);
+}
+
+static virtio_input_config *virtio_input_find_config(VirtIOInput *vinput,
+                                                     uint8_t select,
+                                                     uint8_t subsel)
+{
+    VirtIOInputConfig *cfg;
+
+    QTAILQ_FOREACH(cfg, &vinput->cfg_list, node) {
+        if (select == cfg->config.select &&
+            subsel == cfg->config.subsel) {
+            return &cfg->config;
+        }
+    }
+    return NULL;
+}
+
+void virtio_input_add_config(VirtIOInput *vinput,
+                             virtio_input_config *config)
+{
+    VirtIOInputConfig *cfg;
+
+    if (virtio_input_find_config(vinput, config->select, config->subsel)) {
+        /* should not happen */
+        fprintf(stderr, "%s: duplicate config: %d/%d\n",
+                __func__, config->select, config->subsel);
+        abort();
+    }
+
+    cfg = g_new0(VirtIOInputConfig, 1);
+    cfg->config = *config;
+    QTAILQ_INSERT_TAIL(&vinput->cfg_list, cfg, node);
+}
+
+void virtio_input_init_config(VirtIOInput *vinput,
+                              virtio_input_config *config)
+{
+    int i = 0;
+
+    QTAILQ_INIT(&vinput->cfg_list);
+    while (config[i].select) {
+        virtio_input_add_config(vinput, config + i);
+        i++;
+    }
+}
+
+void virtio_input_idstr_config(VirtIOInput *vinput,
+                               uint8_t select, const char *string)
+{
+    virtio_input_config id;
+
+    if (!string) {
+        return;
+    }
+    memset(&id, 0, sizeof(id));
+    id.select = select;
+    id.size = snprintf(id.u.string, sizeof(id.u.string), "%s", string);
+    virtio_input_add_config(vinput, &id);
+}
+
+static void virtio_input_get_config(VirtIODevice *vdev, uint8_t *config_data)
+{
+    VirtIOInput *vinput = VIRTIO_INPUT(vdev);
+    virtio_input_config *config;
+
+    config = virtio_input_find_config(vinput, vinput->cfg_select,
+                                      vinput->cfg_subsel);
+    if (config) {
+        memcpy(config_data, config, vinput->cfg_size);
+    } else {
+        memset(config_data, 0, vinput->cfg_size);
+    }
+}
+
+static void virtio_input_set_config(VirtIODevice *vdev,
+                                    const uint8_t *config_data)
+{
+    VirtIOInput *vinput = VIRTIO_INPUT(vdev);
+    virtio_input_config *config = (virtio_input_config *)config_data;
+
+    vinput->cfg_select = config->select;
+    vinput->cfg_subsel = config->subsel;
+    virtio_notify_config(vdev);
+}
+
+static uint64_t virtio_input_get_features(VirtIODevice *vdev, uint64_t f)
+{
+    return f;
+}
+
+static void virtio_input_set_status(VirtIODevice *vdev, uint8_t val)
+{
+    VirtIOInputClass *vic = VIRTIO_INPUT_GET_CLASS(vdev);
+    VirtIOInput *vinput = VIRTIO_INPUT(vdev);
+
+    if (val & VIRTIO_CONFIG_S_DRIVER_OK) {
+        if (!vinput->active) {
+            vinput->active = true;
+            if (vic->change_active) {
+                vic->change_active(vinput);
+            }
+        }
+    }
+}
+
+static void virtio_input_reset(VirtIODevice *vdev)
+{
+    VirtIOInputClass *vic = VIRTIO_INPUT_GET_CLASS(vdev);
+    VirtIOInput *vinput = VIRTIO_INPUT(vdev);
+
+    if (vinput->active) {
+        vinput->active = false;
+        if (vic->change_active) {
+            vic->change_active(vinput);
+        }
+    }
+}
+
+static void virtio_input_device_realize(DeviceState *dev, Error **errp)
+{
+    VirtIOInputClass *vic = VIRTIO_INPUT_GET_CLASS(dev);
+    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+    VirtIOInput *vinput = VIRTIO_INPUT(dev);
+    VirtIOInputConfig *cfg;
+    Error *local_err = NULL;
+
+    if (vic->realize) {
+        vic->realize(dev, &local_err);
+        if (local_err) {
+            error_propagate(errp, local_err);
+            return;
+        }
+    }
+
+    virtio_input_idstr_config(vinput, VIRTIO_INPUT_CFG_ID_SERIAL,
+                              vinput->input.serial);
+
+    QTAILQ_FOREACH(cfg, &vinput->cfg_list, node) {
+        if (vinput->cfg_size < cfg->config.size) {
+            vinput->cfg_size = cfg->config.size;
+        }
+    }
+    vinput->cfg_size += 4;
+    assert(vinput->cfg_size <= sizeof(virtio_input_config));
+
+    virtio_init(vdev, "virtio-input", VIRTIO_ID_INPUT,
+                vinput->cfg_size);
+    vinput->evt = virtio_add_queue(vdev, 64, virtio_input_handle_evt);
+    vinput->sts = virtio_add_queue(vdev, 64, virtio_input_handle_sts);
+}
+
+static void virtio_input_device_unrealize(DeviceState *dev, Error **errp)
+{
+    VirtIOInputClass *vic = VIRTIO_INPUT_GET_CLASS(dev);
+    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+    Error *local_err = NULL;
+
+    if (vic->unrealize) {
+        vic->unrealize(dev, &local_err);
+        if (local_err) {
+            error_propagate(errp, local_err);
+            return;
+        }
+    }
+    virtio_cleanup(vdev);
+}
+
+static void virtio_input_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
+
+    set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
+    vdc->realize      = virtio_input_device_realize;
+    vdc->unrealize    = virtio_input_device_unrealize;
+    vdc->get_config   = virtio_input_get_config;
+    vdc->set_config   = virtio_input_set_config;
+    vdc->get_features = virtio_input_get_features;
+    vdc->set_status   = virtio_input_set_status;
+    vdc->reset        = virtio_input_reset;
+}
+
+static const TypeInfo virtio_input_info = {
+    .name          = TYPE_VIRTIO_INPUT,
+    .parent        = TYPE_VIRTIO_DEVICE,
+    .instance_size = sizeof(VirtIOInput),
+    .class_size    = sizeof(VirtIOInputClass),
+    .class_init    = virtio_input_class_init,
+    .abstract      = true,
+};
+
+/* ----------------------------------------------------------------- */
+
+static void virtio_register_types(void)
+{
+    type_register_static(&virtio_input_info);
+}
+
+type_init(virtio_register_types)
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index 4c653fe..4bfd927 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -24,6 +24,7 @@
 #include "hw/virtio/virtio-serial.h"
 #include "hw/virtio/virtio-scsi.h"
 #include "hw/virtio/virtio-balloon.h"
+#include "hw/virtio/virtio-input.h"
 #include "hw/pci/pci.h"
 #include "qemu/error-report.h"
 #include "hw/pci/msi.h"
@@ -1888,6 +1889,40 @@ static const TypeInfo virtio_rng_pci_info = {
     .class_init    = virtio_rng_pci_class_init,
 };
 
+/* virtio-input-pci */
+
+static void virtio_input_pci_realize(VirtIOPCIProxy *vpci_dev, Error **errp)
+{
+    VirtIOInputPCI *vinput = VIRTIO_INPUT_PCI(vpci_dev);
+    DeviceState *vdev = DEVICE(&vinput->vdev);
+
+    qdev_set_parent_bus(vdev, BUS(&vpci_dev->bus));
+    /* force virtio-1.0 */
+    vpci_dev->flags &= ~VIRTIO_PCI_FLAG_DISABLE_MODERN;
+    vpci_dev->flags |= VIRTIO_PCI_FLAG_DISABLE_LEGACY;
+    object_property_set_bool(OBJECT(vdev), true, "realized", errp);
+}
+
+static void virtio_input_pci_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    VirtioPCIClass *k = VIRTIO_PCI_CLASS(klass);
+    PCIDeviceClass *pcidev_k = PCI_DEVICE_CLASS(klass);
+
+    k->realize = virtio_input_pci_realize;
+    set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
+
+    pcidev_k->class_id = PCI_CLASS_INPUT_OTHER;
+}
+
+static const TypeInfo virtio_input_pci_info = {
+    .name          = TYPE_VIRTIO_INPUT_PCI,
+    .parent        = TYPE_VIRTIO_PCI,
+    .instance_size = sizeof(VirtIOInputPCI),
+    .class_init    = virtio_input_pci_class_init,
+    .abstract      = true,
+};
+
 /* virtio-pci-bus */
 
 static void virtio_pci_bus_new(VirtioBusState *bus, size_t bus_size,
@@ -1929,6 +1964,7 @@ static const TypeInfo virtio_pci_bus_info = {
 static void virtio_pci_register_types(void)
 {
     type_register_static(&virtio_rng_pci_info);
+    type_register_static(&virtio_input_pci_info);
     type_register_static(&virtio_pci_bus_info);
     type_register_static(&virtio_pci_info);
 #ifdef CONFIG_VIRTFS
diff --git a/hw/virtio/virtio-pci.h b/hw/virtio/virtio-pci.h
index b382688..8a744eb 100644
--- a/hw/virtio/virtio-pci.h
+++ b/hw/virtio/virtio-pci.h
@@ -24,6 +24,7 @@
 #include "hw/virtio/virtio-balloon.h"
 #include "hw/virtio/virtio-bus.h"
 #include "hw/virtio/virtio-9p.h"
+#include "hw/virtio/virtio-input.h"
 #ifdef CONFIG_VIRTFS
 #include "hw/9pfs/virtio-9p.h"
 #endif
@@ -39,6 +40,7 @@ typedef struct VirtIOSerialPCI VirtIOSerialPCI;
 typedef struct VirtIONetPCI VirtIONetPCI;
 typedef struct VHostSCSIPCI VHostSCSIPCI;
 typedef struct VirtIORngPCI VirtIORngPCI;
+typedef struct VirtIOInputPCI VirtIOInputPCI;
 
 /* virtio-pci-bus */
 
@@ -225,6 +227,18 @@ struct VirtIORngPCI {
     VirtIORNG vdev;
 };
 
+/*
+ * virtio-input-pci: This extends VirtioPCIProxy.
+ */
+#define TYPE_VIRTIO_INPUT_PCI "virtio-input-pci"
+#define VIRTIO_INPUT_PCI(obj) \
+        OBJECT_CHECK(VirtIOInputPCI, (obj), TYPE_VIRTIO_INPUT_PCI)
+
+struct VirtIOInputPCI {
+    VirtIOPCIProxy parent_obj;
+    VirtIOInput vdev;
+};
+
 /* Virtio ABI version, if we increment this, we break the guest driver. */
 #define VIRTIO_PCI_ABI_VERSION          0
 
diff --git a/include/hw/virtio/virtio-input.h b/include/hw/virtio/virtio-input.h
new file mode 100644
index 0000000..718ebfd
--- /dev/null
+++ b/include/hw/virtio/virtio-input.h
@@ -0,0 +1,106 @@
+#ifndef _QEMU_VIRTIO_INPUT_H
+#define _QEMU_VIRTIO_INPUT_H
+
+#include "ui/input.h"
+
+/* ----------------------------------------------------------------- */
+/* virtio input protocol                                             */
+
+/* The Virtio ID for the virtio input device */
+#define VIRTIO_ID_INPUT 18
+
+enum virtio_input_config_select {
+    VIRTIO_INPUT_CFG_UNSET      = 0x00,
+    VIRTIO_INPUT_CFG_ID_NAME    = 0x01,
+    VIRTIO_INPUT_CFG_ID_SERIAL  = 0x02,
+    VIRTIO_INPUT_CFG_PROP_BITS  = 0x10,
+    VIRTIO_INPUT_CFG_EV_BITS    = 0x11,
+    VIRTIO_INPUT_CFG_ABS_INFO   = 0x12,
+};
+
+typedef struct virtio_input_absinfo {
+    uint32_t       min;
+    uint32_t       max;
+    uint32_t       fuzz;
+    uint32_t       flat;
+} virtio_input_absinfo;
+
+typedef struct virtio_input_config {
+    uint8_t        select;
+    uint8_t        subsel;
+    uint8_t        size;
+    uint8_t        reserved;
+    union {
+        char       string[128];
+        uint8_t    bitmap[128];
+        virtio_input_absinfo abs;
+    } u;
+} virtio_input_config;
+
+typedef struct virtio_input_event {
+    uint16_t       type;
+    uint16_t       code;
+    int32_t        value;
+} virtio_input_event;
+
+/* ----------------------------------------------------------------- */
+/* qemu internals                                                    */
+
+#define TYPE_VIRTIO_INPUT "virtio-input-device"
+#define VIRTIO_INPUT(obj) \
+        OBJECT_CHECK(VirtIOInput, (obj), TYPE_VIRTIO_INPUT)
+#define VIRTIO_INPUT_GET_PARENT_CLASS(obj) \
+        OBJECT_GET_PARENT_CLASS(obj, TYPE_VIRTIO_INPUT)
+#define VIRTIO_INPUT_GET_CLASS(obj) \
+        OBJECT_GET_CLASS(VirtIOInputClass, obj, TYPE_VIRTIO_INPUT)
+#define VIRTIO_INPUT_CLASS(klass) \
+        OBJECT_CLASS_CHECK(VirtIOInputClass, klass, TYPE_VIRTIO_INPUT)
+
+typedef struct VirtIOInput VirtIOInput;
+typedef struct VirtIOInputClass VirtIOInputClass;
+typedef struct VirtIOInputConfig VirtIOInputConfig;
+
+struct virtio_input_conf {
+    char *serial;
+};
+
+struct VirtIOInputConfig {
+    virtio_input_config               config;
+    QTAILQ_ENTRY(VirtIOInputConfig)   node;
+};
+
+struct VirtIOInput {
+    VirtIODevice                      parent_obj;
+    uint8_t                           cfg_select;
+    uint8_t                           cfg_subsel;
+    uint32_t                          cfg_size;
+    QTAILQ_HEAD(, VirtIOInputConfig)  cfg_list;
+    VirtQueue                         *evt, *sts;
+    virtio_input_conf                 input;
+
+    virtio_input_event                *queue;
+    uint32_t                          qindex, qsize;
+
+    bool                              active;
+};
+
+struct VirtIOInputClass {
+    /*< private >*/
+    VirtioDeviceClass parent;
+    /*< public >*/
+
+    DeviceRealize realize;
+    DeviceUnrealize unrealize;
+    void (*change_active)(VirtIOInput *vinput);
+    void (*handle_status)(VirtIOInput *vinput, virtio_input_event *event);
+};
+
+void virtio_input_send(VirtIOInput *vinput, virtio_input_event *event);
+void virtio_input_init_config(VirtIOInput *vinput,
+                              virtio_input_config *config);
+void virtio_input_add_config(VirtIOInput *vinput,
+                             virtio_input_config *config);
+void virtio_input_idstr_config(VirtIOInput *vinput,
+                               uint8_t select, const char *string);
+
+#endif /* _QEMU_VIRTIO_INPUT_H */
diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
index a4ade5c..8e33fe4 100644
--- a/include/hw/virtio/virtio.h
+++ b/include/hw/virtio/virtio.h
@@ -201,6 +201,7 @@ int virtio_set_features(VirtIODevice *vdev, uint64_t val);
 typedef struct VirtIOBlkConf VirtIOBlkConf;
 struct virtio_net_conf;
 typedef struct virtio_serial_conf virtio_serial_conf;
+typedef struct virtio_input_conf virtio_input_conf;
 typedef struct VirtIOSCSIConf VirtIOSCSIConf;
 typedef struct VirtIORNGConf VirtIORNGConf;
 
-- 
1.8.3.1