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Re: [Qemu-devel] [PATCH v2 1/6] qerror: add MAX_KEYCODES 16
From: |
Luiz Capitulino |
Subject: |
Re: [Qemu-devel] [PATCH v2 1/6] qerror: add MAX_KEYCODES 16 |
Date: |
Fri, 15 Jun 2012 10:35:31 -0300 |
On Fri, 15 Jun 2012 09:57:49 +0200
Gerd Hoffmann <address@hidden> wrote:
> Hi,
>
> >> It seems we need to notice user when inputted keys are more than 16.
> >
> > Hi Gerd,
> >
> > When I use 'sendkey' command to send key-series to guest, some keyboard
> > events will be send. There is a limitation (16) that was introduced by this
> > old commit c8256f9d (without description). Do you know the reason?
>
> Probably hardware limitation, ps/2 keyboards can buffer up to 16 keys IIRC.
Then the perfect thing to do would be to drop the MAX_KEYCODES check from
the sendkey command and move bounds checking down to the device emulation code.
However, this will require a bit of code churn if we do it for all devices,
and won't buy us much, as the most likely reason for the error is a client/user
trying to send too many keys in parallel to the guest, right?
If this is right, then I think that the best thing to do would be to drop the
MAX_KEYCODES check from the sendkey command and document that devices can drop
keys if too many of them are sent in parallel or too fast (we can mention ps/2
as an example of a 16 bytes limit).
>
> Likewise the usb hid devices can buffer up to 16 events. In that case
> it is just a qemu implementation detail and not a property of the
> hardware we are emulating, so it can be changed. Not trivially though
> as the buffer is part of the migration data, so it is more work that
> just changing a #define.
- [Qemu-devel] [PATCH v2 0/6] convert sendkey to qapi, Amos Kong, 2012/06/01
- [Qemu-devel] [PATCH v2 1/6] qerror: add QERR_OVERFLOW, Amos Kong, 2012/06/01
- Re: [Qemu-devel] [PATCH v2 1/6] qerror: add QERR_OVERFLOW, Anthony Liguori, 2012/06/04
- Re: [Qemu-devel] [PATCH v2 1/6] qerror: add MAX_KEYCODES 16, Amos Kong, 2012/06/05
- Message not available
- Message not available
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- Re: [Qemu-devel] [PATCH v2 1/6] qerror: add MAX_KEYCODES 16, Amos Kong, 2012/06/14
- Re: [Qemu-devel] [PATCH v2 1/6] qerror: add MAX_KEYCODES 16, Amos Kong, 2012/06/15
- Re: [Qemu-devel] [PATCH v2 1/6] qerror: add MAX_KEYCODES 16, Gerd Hoffmann, 2012/06/15
- Re: [Qemu-devel] [PATCH v2 1/6] qerror: add MAX_KEYCODES 16,
Luiz Capitulino <=
- Re: [Qemu-devel] [PATCH v2 1/6] qerror: add MAX_KEYCODES 16, Amos Kong, 2012/06/18
- Re: [Qemu-devel] [PATCH v2 1/6] qerror: add MAX_KEYCODES 16, Amos Kong, 2012/06/19
[Qemu-devel] [PATCH v2 2/6] fix doc of using raw values with sendkey, Amos Kong, 2012/06/01
[Qemu-devel] [PATCH v2 4/6] hmp: rename arguments, Amos Kong, 2012/06/01
[Qemu-devel] [PATCH v2 3/6] rename keyname '<' to 'less', Amos Kong, 2012/06/01
[Qemu-devel] [PATCH v2 5/6] qapi: generate list struct and visit_list for enum, Amos Kong, 2012/06/01