Re: [Qemu-devel] [PATCH qemu 5/6] virtio-input: control device

["Michael S. Tsirkin" <mst@redhat.com>]

On Thu, Apr 10, 2014 at 11:07:53AM +0200, Gerd Hoffmann wrote:
> Device for sending non-input control messages to the guest.  For now
> this is only a single event: shutdown requests are sent as power button
> press to the guest.
> 
> Possible other use is signaling sound volume changes to the guest (via
> EV_ABS / ABS_VOLUME).  I expect we'll find more over time.
> 
> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

Why not use a keyboard device for this?

> ---
>  hw/input/Makefile.objs           |   1 +
>  hw/input/virtio-input-control.c  | 112 +++++++++++++++++++++++++++++++++++++++
>  hw/virtio/virtio-pci.c           |  29 ++++++++++
>  hw/virtio/virtio-pci.h           |  10 ++++
>  include/hw/virtio/virtio-input.h |  12 +++++
>  5 files changed, 164 insertions(+)
>  create mode 100644 hw/input/virtio-input-control.c
> 
> diff --git a/hw/input/Makefile.objs b/hw/input/Makefile.objs
> index 0dae710..0179154 100644
> --- a/hw/input/Makefile.objs
> +++ b/hw/input/Makefile.objs
> @@ -11,6 +11,7 @@ common-obj-$(CONFIG_VMMOUSE) += vmmouse.o
>  ifeq ($(CONFIG_LINUX),y)
>  common-obj-$(CONFIG_VIRTIO) += virtio-input.o
>  common-obj-$(CONFIG_VIRTIO) += virtio-input-hid.o
> +common-obj-$(CONFIG_VIRTIO) += virtio-input-control.o
>  endif
>  
>  obj-$(CONFIG_MILKYMIST) += milkymist-softusb.o
> diff --git a/hw/input/virtio-input-control.c b/hw/input/virtio-input-control.c
> new file mode 100644
> index 0000000..3e439e6
> --- /dev/null
> +++ b/hw/input/virtio-input-control.c
> @@ -0,0 +1,112 @@
> +/*
> + * 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>
> +
> +#define VIRTIO_ID_NAME_CTRL "QEMU Virtio Control Panel"
> +
> +/* ----------------------------------------------------------------- */
> +
> +static void virtio_input_key_config(VirtIOInput *vinput)
> +{
> +    static const int keylist[] = { KEY_POWER };
> +    virtio_input_config keys;
> +    int i, bit, byte, bmax = 0;
> +
> +    memset(&keys, 0, sizeof(keys));
> +    for (i = 0; i < ARRAY_SIZE(keylist); i++) {
> +        byte = keylist[i] / 8;
> +        bit  = keylist[i] % 8;
> +        keys.u.bitmap[byte] |= (1 << bit);
> +        if (bmax < byte+1) {
> +            bmax = byte+1;
> +        }
> +    }
> +    keys.select = VIRTIO_INPUT_CFG_EV_BITS;
> +    keys.subsel = EV_KEY;
> +    keys.size   = bmax;
> +    virtio_input_add_config(vinput, &keys);
> +}
> +
> +static void virtio_input_ctrl_keypress(VirtIOInput *vinput, int keycode)
> +{
> +    virtio_input_event key_down = {
> +        .type  = cpu_to_le16(EV_KEY),
> +        .code  = cpu_to_le16(keycode),
> +        .value = 1,
> +    };
> +    virtio_input_event key_up = {
> +        .type  = cpu_to_le16(EV_KEY),
> +        .code  = cpu_to_le16(keycode),
> +        .value = 0,
> +    };
> +    virtio_input_event sync = {
> +        .type  = cpu_to_le16(EV_SYN),
> +        .code  = cpu_to_le16(SYN_REPORT),
> +        .value = 0,
> +    };
> +
> +    virtio_input_send(vinput, &key_down);
> +    virtio_input_send(vinput, &sync);
> +    virtio_input_send(vinput, &key_up);
> +    virtio_input_send(vinput, &sync);
> +    virtio_notify(VIRTIO_DEVICE(vinput), vinput->evt);
> +}
> +
> +static void virtio_input_ctrl_powerdown(Notifier *n, void *opaque)
> +{
> +    VirtIOInputCtrl *vctrl =
> +        container_of(n, VirtIOInputCtrl, powerdown);
> +
> +    virtio_input_ctrl_keypress(VIRTIO_INPUT(vctrl), KEY_POWER);
> +}
> +
> +/* ----------------------------------------------------------------- */
> +
> +static struct virtio_input_config virtio_ctrl_config[] = {
> +    {
> +        .select    = VIRTIO_INPUT_CFG_ID_NAME,
> +        .size      = sizeof(VIRTIO_ID_NAME_CTRL),
> +        .u.string  = VIRTIO_ID_NAME_CTRL,
> +    },
> +    { /* end of list */ },
> +};
> +
> +static void virtio_ctrl_init(Object *obj)
> +{
> +    VirtIOInput *vinput = VIRTIO_INPUT(obj);
> +    VirtIOInputCtrl *vctrl = VIRTIO_INPUT_CTRL(obj);
> +
> +    virtio_input_init_config(vinput, virtio_ctrl_config);
> +    virtio_input_key_config(vinput);
> +
> +    vctrl->powerdown.notify = virtio_input_ctrl_powerdown;
> +    qemu_register_powerdown_notifier(&vctrl->powerdown);
> +}
> +
> +static const TypeInfo virtio_ctrl_info = {
> +    .name          = TYPE_VIRTIO_INPUT_CTRL,
> +    .parent        = TYPE_VIRTIO_INPUT,
> +    .instance_size = sizeof(VirtIOInputCtrl),
> +    .instance_init = virtio_ctrl_init,
> +};
> +
> +/* ----------------------------------------------------------------- */
> +
> +static void virtio_register_types(void)
> +{
> +    type_register_static(&virtio_ctrl_info);
> +}
> +
> +type_init(virtio_register_types)
> diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
> index b421c01..9446d45 100644
> --- a/hw/virtio/virtio-pci.c
> +++ b/hw/virtio/virtio-pci.c
> @@ -1541,6 +1541,12 @@ static Property virtio_input_hid_pci_properties[] = {
>      DEFINE_PROP_END_OF_LIST(),
>  };
>  
> +static Property virtio_input_ctrl_pci_properties[] = {
> +    DEFINE_VIRTIO_COMMON_FEATURES(VirtIOPCIProxy, host_features),
> +    DEFINE_PROP_UINT32("vectors", VirtIOPCIProxy, nvectors, 2),
> +    DEFINE_PROP_END_OF_LIST(),
> +};
> +
>  static int virtio_input_pci_init(VirtIOPCIProxy *vpci_dev)
>  {
>      VirtIOInputPCI *vinput = VIRTIO_INPUT_PCI(vpci_dev);
> @@ -1572,6 +1578,13 @@ static void virtio_input_hid_pci_class_init(ObjectClass *klass, void *data)
>      dc->props = virtio_input_hid_pci_properties;
>  }
>  
> +static void virtio_input_ctrl_pci_class_init(ObjectClass *klass, void *data)
> +{
> +    DeviceClass *dc = DEVICE_CLASS(klass);
> +
> +    dc->props = virtio_input_ctrl_pci_properties;
> +}
> +
>  static void virtio_keyboard_initfn(Object *obj)
>  {
>      VirtIOInputHIDPCI *dev = VIRTIO_INPUT_HID_PCI(obj);
> @@ -1593,6 +1606,13 @@ static void virtio_tablet_initfn(Object *obj)
>      object_property_add_child(obj, "virtio-backend", OBJECT(&dev->vdev), NULL);
>  }
>  
> +static void virtio_ctrl_initfn(Object *obj)
> +{
> +    VirtIOInputCtrlPCI *dev = VIRTIO_INPUT_CTRL_PCI(obj);
> +    object_initialize(&dev->vdev, sizeof(dev->vdev), TYPE_VIRTIO_INPUT_CTRL);
> +    object_property_add_child(obj, "virtio-backend", OBJECT(&dev->vdev), NULL);
> +}
> +
>  static const TypeInfo virtio_input_pci_info = {
>      .name          = TYPE_VIRTIO_INPUT_PCI,
>      .parent        = TYPE_VIRTIO_PCI,
> @@ -1630,6 +1650,14 @@ static const TypeInfo virtio_tablet_pci_info = {
>      .instance_init = virtio_tablet_initfn,
>  };
>  
> +static const TypeInfo virtio_ctrl_pci_info = {
> +    .name          = TYPE_VIRTIO_INPUT_CTRL_PCI,
> +    .parent        = TYPE_VIRTIO_INPUT_PCI,
> +    .instance_size = sizeof(VirtIOInputCtrlPCI),
> +    .instance_init = virtio_ctrl_initfn,
> +    .class_init    = virtio_input_ctrl_pci_class_init,
> +};
> +
>  /* virtio-pci-bus */
>  
>  static void virtio_pci_bus_new(VirtioBusState *bus, size_t bus_size,
> @@ -1679,6 +1707,7 @@ static void virtio_pci_register_types(void)
>      type_register_static(&virtio_keyboard_pci_info);
>      type_register_static(&virtio_mouse_pci_info);
>      type_register_static(&virtio_tablet_pci_info);
> +    type_register_static(&virtio_ctrl_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 f615ae6..0c26e64 100644
> --- a/hw/virtio/virtio-pci.h
> +++ b/hw/virtio/virtio-pci.h
> @@ -42,6 +42,7 @@ typedef struct VHostSCSIPCI VHostSCSIPCI;
>  typedef struct VirtIORngPCI VirtIORngPCI;
>  typedef struct VirtIOInputPCI VirtIOInputPCI;
>  typedef struct VirtIOInputHIDPCI VirtIOInputHIDPCI;
> +typedef struct VirtIOInputCtrlPCI VirtIOInputCtrlPCI;
>  
>  /* virtio-pci-bus */
>  
> @@ -226,6 +227,15 @@ struct VirtIOInputHIDPCI {
>      VirtIOInputHID vdev;
>  };
>  
> +#define TYPE_VIRTIO_INPUT_CTRL_PCI "virtio-input-control-pci"
> +#define VIRTIO_INPUT_CTRL_PCI(obj) \
> +        OBJECT_CHECK(VirtIOInputCtrlPCI, (obj), TYPE_VIRTIO_INPUT_CTRL_PCI)
> +
> +struct VirtIOInputCtrlPCI {
> +    VirtIOPCIProxy parent_obj;
> +    VirtIOInputCtrl 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
> index 4b819c3..d753834 100644
> --- a/include/hw/virtio/virtio-input.h
> +++ b/include/hw/virtio/virtio-input.h
> @@ -67,6 +67,12 @@ typedef struct virtio_input_event {
>  #define VIRTIO_INPUT_HID_GET_PARENT_CLASS(obj) \
>          OBJECT_GET_PARENT_CLASS(obj, TYPE_VIRTIO_INPUT_HID)
>  
> +#define TYPE_VIRTIO_INPUT_CTRL   "virtio-input-control"
> +#define VIRTIO_INPUT_CTRL(obj) \
> +        OBJECT_CHECK(VirtIOInputCtrl, (obj), TYPE_VIRTIO_INPUT_CTRL)
> +#define VIRTIO_INPUT_CTRL_GET_PARENT_CLASS(obj) \
> +        OBJECT_GET_PARENT_CLASS(obj, TYPE_VIRTIO_INPUT_CTRL)
> +
>  #define DEFINE_VIRTIO_INPUT_PROPERTIES(_state, _field)       \
>          DEFINE_PROP_STRING("serial", _state, _field.serial), \
>          DEFINE_PROP_STRING("seat", _state, _field.seat)
> @@ -75,6 +81,7 @@ typedef struct VirtIOInput VirtIOInput;
>  typedef struct VirtIOInputClass VirtIOInputClass;
>  typedef struct VirtIOInputConfig VirtIOInputConfig;
>  typedef struct VirtIOInputHID VirtIOInputHID;
> +typedef struct VirtIOInputCtrl VirtIOInputCtrl;
>  
>  struct virtio_input_conf {
>      char *serial;
> @@ -116,6 +123,11 @@ struct VirtIOInputHID {
>      int                               ledstate;
>  };
>  
> +struct VirtIOInputCtrl {
> +    VirtIOInput                       parent_obj;
> +    Notifier                          powerdown;
> +};
> +
>  void virtio_input_send(VirtIOInput *vinput, virtio_input_event *event);
>  void virtio_input_init_config(VirtIOInput *vinput,
>                                virtio_input_config *config);
> -- 
> 1.8.3.1