Re: [Qemu-devel] [PATCH v2] usb: assign unique serial numbers to hid devices

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

* Gerd Hoffmann (kraxel@redhat.com) wrote:
> Windows guests have trouble dealing with usb devices having identical
> serial numbers.  So, assign unique serial numbers to usb hid devices.
> All other usb devices have this already.
> 
> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
> ---
>  include/hw/compat.h | 14 +++++++++++++-
>  hw/usb/dev-hid.c    | 24 +++++++++++++-----------
>  2 files changed, 26 insertions(+), 12 deletions(-)
> 
> diff --git a/include/hw/compat.h b/include/hw/compat.h
> index 6f4d5fc647..c059459394 100644
> --- a/include/hw/compat.h
> +++ b/include/hw/compat.h
> @@ -2,7 +2,19 @@
>  #define HW_COMPAT_H
>  
>  #define HW_COMPAT_3_0 \
> -    /* empty */
> +    {\
> +        .driver   = "usb-kbd",\
> +        .property = "serial",\
> +        .value    = "42",\
> +    },{\
> +        .driver   = "usb-mouse",\
> +        .property = "serial",\
> +        .value    = "42",\
> +    },{\
> +        .driver   = "usb-tablet",\
> +        .property = "serial",\
> +        .value    = "42",\
> +    },
>  #define HW_COMPAT_2_12 \
>      {\
> diff --git a/hw/usb/dev-hid.c b/hw/usb/dev-hid.c
> index 62d18290dc..7ad6fb33a9 100644
> --- a/hw/usb/dev-hid.c
> +++ b/hw/usb/dev-hid.c
> @@ -61,7 +61,9 @@ enum {
>      STR_PRODUCT_MOUSE,
>      STR_PRODUCT_TABLET,
>      STR_PRODUCT_KEYBOARD,
> -    STR_SERIALNUMBER,
> +    STR_SERIAL_MOUSE,
> +    STR_SERIAL_TABLET,
> +    STR_SERIAL_KEYBOARD,
>      STR_CONFIG_MOUSE,
>      STR_CONFIG_TABLET,
>      STR_CONFIG_KEYBOARD,
> @@ -72,7 +74,9 @@ static const USBDescStrings desc_strings = {
>      [STR_PRODUCT_MOUSE]    = "QEMU USB Mouse",
>      [STR_PRODUCT_TABLET]   = "QEMU USB Tablet",
>      [STR_PRODUCT_KEYBOARD] = "QEMU USB Keyboard",
> -    [STR_SERIALNUMBER]     = "42", /* == remote wakeup works */
> +    [STR_SERIAL_MOUSE]     = "89126",
> +    [STR_SERIAL_TABLET]    = "28754",
> +    [STR_SERIAL_KEYBOARD]  = "68284",

OK, so now I've found the bit about the magic 42; commit 7b074a22 of
yours; recommended checking for 42 for knowing we had autosuspend;
what's actually in the current fedora hid rules is serial!=1 - I wonder
what others have.
It's a shame these are random numbers rather than 2,3,4; but still.

>      [STR_CONFIG_MOUSE]     = "HID Mouse",
>      [STR_CONFIG_TABLET]    = "HID Tablet",
>      [STR_CONFIG_KEYBOARD]  = "HID Keyboard",
> @@ -375,7 +379,7 @@ static const USBDesc desc_mouse = {
>          .bcdDevice         = 0,
>          .iManufacturer     = STR_MANUFACTURER,
>          .iProduct          = STR_PRODUCT_MOUSE,
> -        .iSerialNumber     = STR_SERIALNUMBER,
> +        .iSerialNumber     = STR_SERIAL_MOUSE,
>      },
>      .full = &desc_device_mouse,
>      .str  = desc_strings,
> @@ -389,7 +393,7 @@ static const USBDesc desc_mouse2 = {
>          .bcdDevice         = 0,
>          .iManufacturer     = STR_MANUFACTURER,
>          .iProduct          = STR_PRODUCT_MOUSE,
> -        .iSerialNumber     = STR_SERIALNUMBER,
> +        .iSerialNumber     = STR_SERIAL_MOUSE,
>      },
>      .full = &desc_device_mouse,
>      .high = &desc_device_mouse2,
> @@ -404,7 +408,7 @@ static const USBDesc desc_tablet = {
>          .bcdDevice         = 0,
>          .iManufacturer     = STR_MANUFACTURER,
>          .iProduct          = STR_PRODUCT_TABLET,
> -        .iSerialNumber     = STR_SERIALNUMBER,
> +        .iSerialNumber     = STR_SERIAL_TABLET,
>      },
>      .full = &desc_device_tablet,
>      .str  = desc_strings,
> @@ -418,7 +422,7 @@ static const USBDesc desc_tablet2 = {
>          .bcdDevice         = 0,
>          .iManufacturer     = STR_MANUFACTURER,
>          .iProduct          = STR_PRODUCT_TABLET,
> -        .iSerialNumber     = STR_SERIALNUMBER,
> +        .iSerialNumber     = STR_SERIAL_TABLET,
>      },
>      .full = &desc_device_tablet,
>      .high = &desc_device_tablet2,
> @@ -433,7 +437,7 @@ static const USBDesc desc_keyboard = {
>          .bcdDevice         = 0,
>          .iManufacturer     = STR_MANUFACTURER,
>          .iProduct          = STR_PRODUCT_KEYBOARD,
> -        .iSerialNumber     = STR_SERIALNUMBER,
> +        .iSerialNumber     = STR_SERIAL_TABLET,
>      },
>      .full = &desc_device_keyboard,
>      .str  = desc_strings,
> @@ -447,7 +451,7 @@ static const USBDesc desc_keyboard2 = {
>          .bcdDevice         = 0,
>          .iManufacturer     = STR_MANUFACTURER,
>          .iProduct          = STR_PRODUCT_KEYBOARD,
> -        .iSerialNumber     = STR_SERIALNUMBER,
> +        .iSerialNumber     = STR_SERIAL_TABLET,
>      },
>      .full = &desc_device_keyboard,
>      .high = &desc_device_keyboard2,
> @@ -718,9 +722,7 @@ static void usb_hid_initfn(USBDevice *dev, int kind,
>          return;
>      }
>  
> -    if (dev->serial) {
> -        usb_desc_set_string(dev, STR_SERIALNUMBER, dev->serial);
> -    }
> +    usb_desc_create_serial(dev);

In the cases where I've not passed serial= on the command line, who
wins, does this mean create_serial uses the path or does it use the
magic constants you set above?

Dave

>      usb_desc_init(dev);
>      us->intr = usb_ep_get(dev, USB_TOKEN_IN, 1);
>      hid_init(&us->hid, kind, usb_hid_changed);
> -- 
> 2.9.3
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK