[Qemu-devel] [PATCH] i386/vmmouse: Properly reset state

[Qemu-devel] [PATCH] i386/vmmouse: Properly reset state

[Jan Kiszka]

From: Jan Kiszka <jan.kiszka@siemens.com>

nb_queue was not zeroed so that we no longer delivered events if a
previous guest left the device in an overflow state.

The state of absolute does not matter as the next vmmouse_update_handler
call will align it again.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 hw/i386/vmmouse.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/hw/i386/vmmouse.c b/hw/i386/vmmouse.c
index 5d2d278be4..e335bd07da 100644
--- a/hw/i386/vmmouse.c
+++ b/hw/i386/vmmouse.c
@@ -257,6 +257,7 @@ static void vmmouse_reset(DeviceState *d)
     VMMouseState *s = VMMOUSE(d);

     s->queue_size = VMMOUSE_QUEUE_SIZE;
+    s->nb_queue = 0;

     vmmouse_disable(s);
 }
--
2.16.4

Re: [Qemu-devel] [PATCH] i386/vmmouse: Properly reset state

[Jan Kiszka]

On 21.07.19 10:58, Jan Kiszka wrote:
> From: Jan Kiszka <jan.kiszka@siemens.com>
>
> nb_queue was not zeroed so that we no longer delivered events if a
> previous guest left the device in an overflow state.
>
> The state of absolute does not matter as the next vmmouse_update_handler
> call will align it again.
>
> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
> ---
>   hw/i386/vmmouse.c | 1 +
>   1 file changed, 1 insertion(+)
>
> diff --git a/hw/i386/vmmouse.c b/hw/i386/vmmouse.c
> index 5d2d278be4..e335bd07da 100644
> --- a/hw/i386/vmmouse.c
> +++ b/hw/i386/vmmouse.c
> @@ -257,6 +257,7 @@ static void vmmouse_reset(DeviceState *d)
>       VMMouseState *s = VMMOUSE(d);
>
>       s->queue_size = VMMOUSE_QUEUE_SIZE;
> +    s->nb_queue = 0;
>
>       vmmouse_disable(s);
>   }
> --
> 2.16.4
>
>

Ping - or who is looking after this?

Jan

Re: [Qemu-devel] [PATCH] i386/vmmouse: Properly reset state

[Eduardo Habkost]

On Sun, Aug 25, 2019 at 04:58:18PM +0200, Jan Kiszka wrote:
> On 21.07.19 10:58, Jan Kiszka wrote:
> > From: Jan Kiszka <jan.kiszka@siemens.com>
> > 
> > nb_queue was not zeroed so that we no longer delivered events if a
> > previous guest left the device in an overflow state.
> > 
> > The state of absolute does not matter as the next vmmouse_update_handler
> > call will align it again.
> > 
> > Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
> > ---
> >   hw/i386/vmmouse.c | 1 +
> >   1 file changed, 1 insertion(+)
> > 
> > diff --git a/hw/i386/vmmouse.c b/hw/i386/vmmouse.c
> > index 5d2d278be4..e335bd07da 100644
> > --- a/hw/i386/vmmouse.c
> > +++ b/hw/i386/vmmouse.c
> > @@ -257,6 +257,7 @@ static void vmmouse_reset(DeviceState *d)
> >       VMMouseState *s = VMMOUSE(d);
> > 
> >       s->queue_size = VMMOUSE_QUEUE_SIZE;
> > +    s->nb_queue = 0;
> > 
> >       vmmouse_disable(s);
> >   }
> > --
> > 2.16.4
> > 
> > 
> 
> Ping - or who is looking after this?

Despite being in hw/i386, I think we can say vmmouse.c doesn't
have a maintainer.  Last time someone changed vmmouse.c in a
meaningful way (not just adapting to API changes or removing
duplicate code) was in 2012.

But the change makes sense to me, so:

Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>

I'll queue it.

-- 
Eduardo

Re: [Qemu-devel] [PATCH] i386/vmmouse: Properly reset state

[Philippe Mathieu-Daudé]

Hi Jan,

On 8/27/19 9:49 PM, Eduardo Habkost wrote:
> On Sun, Aug 25, 2019 at 04:58:18PM +0200, Jan Kiszka wrote:
>> On 21.07.19 10:58, Jan Kiszka wrote:
>>> From: Jan Kiszka <jan.kiszka@siemens.com>
>>>
>>> nb_queue was not zeroed so that we no longer delivered events if a
>>> previous guest left the device in an overflow state.
>>>
>>> The state of absolute does not matter as the next vmmouse_update_handler
>>> call will align it again.
>>>
>>> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
>>> ---
>>>   hw/i386/vmmouse.c | 1 +
>>>   1 file changed, 1 insertion(+)
>>>
>>> diff --git a/hw/i386/vmmouse.c b/hw/i386/vmmouse.c
>>> index 5d2d278be4..e335bd07da 100644
>>> --- a/hw/i386/vmmouse.c
>>> +++ b/hw/i386/vmmouse.c
>>> @@ -257,6 +257,7 @@ static void vmmouse_reset(DeviceState *d)
>>>       VMMouseState *s = VMMOUSE(d);
>>>
>>>       s->queue_size = VMMOUSE_QUEUE_SIZE;
>>> +    s->nb_queue = 0;

Don't we also need to reset the status in case vmmouse_get_status() is
called directly after reset?

         s->status = 0;

With it:
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

>>>
>>>       vmmouse_disable(s);
>>>   }
>>> --
>>> 2.16.4
>>>
>>>
>>
>> Ping - or who is looking after this?
> 
> Despite being in hw/i386, I think we can say vmmouse.c doesn't
> have a maintainer.  Last time someone changed vmmouse.c in a
> meaningful way (not just adapting to API changes or removing
> duplicate code) was in 2012.
> 

Well it does has a few:

$ ./scripts/get_maintainer.pl -f hw/i386/vmmouse.c
"Michael S. Tsirkin" <mst@redhat.com> (supporter:PC)
Marcel Apfelbaum <marcel.apfelbaum@gmail.com> (supporter:PC)
Paolo Bonzini <pbonzini@redhat.com> (maintainer:X86 TCG CPUs)
Richard Henderson <rth@twiddle.net> (maintainer:X86 TCG CPUs)
Eduardo Habkost <ehabkost@redhat.com> (maintainer:X86 TCG CPUs)

However the correct section should rather be "PC Chipset".

> But the change makes sense to me, so:
> 
> Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
> 
> I'll queue it.
> 

Re: [Qemu-devel] [PATCH] i386/vmmouse: Properly reset state

[Jan Kiszka]

On 29.08.19 20:00, Philippe Mathieu-Daudé wrote:
> Hi Jan,
>
> On 8/27/19 9:49 PM, Eduardo Habkost wrote:
>> On Sun, Aug 25, 2019 at 04:58:18PM +0200, Jan Kiszka wrote:
>>> On 21.07.19 10:58, Jan Kiszka wrote:
>>>> From: Jan Kiszka <jan.kiszka@siemens.com>
>>>>
>>>> nb_queue was not zeroed so that we no longer delivered events if a
>>>> previous guest left the device in an overflow state.
>>>>
>>>> The state of absolute does not matter as the next vmmouse_update_handler
>>>> call will align it again.
>>>>
>>>> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
>>>> ---
>>>>    hw/i386/vmmouse.c | 1 +
>>>>    1 file changed, 1 insertion(+)
>>>>
>>>> diff --git a/hw/i386/vmmouse.c b/hw/i386/vmmouse.c
>>>> index 5d2d278be4..e335bd07da 100644
>>>> --- a/hw/i386/vmmouse.c
>>>> +++ b/hw/i386/vmmouse.c
>>>> @@ -257,6 +257,7 @@ static void vmmouse_reset(DeviceState *d)
>>>>        VMMouseState *s = VMMOUSE(d);
>>>>
>>>>        s->queue_size = VMMOUSE_QUEUE_SIZE;
>>>> +    s->nb_queue = 0;
>
> Don't we also need to reset the status in case vmmouse_get_status() is
> called directly after reset?
>
>           s->status = 0;
>

Thanks for checking. We call vmmouse_disable() here, and that sets status to
0xffff anyway.

Jan

> With it:
> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
>
>>>>
>>>>        vmmouse_disable(s);
>>>>    }
>>>> --
>>>> 2.16.4
>>>>
>>>>
>>>
>>> Ping - or who is looking after this?
>>
>> Despite being in hw/i386, I think we can say vmmouse.c doesn't
>> have a maintainer.  Last time someone changed vmmouse.c in a
>> meaningful way (not just adapting to API changes or removing
>> duplicate code) was in 2012.
>>
>
> Well it does has a few:
>
> $ ./scripts/get_maintainer.pl -f hw/i386/vmmouse.c
> "Michael S. Tsirkin" <mst@redhat.com> (supporter:PC)
> Marcel Apfelbaum <marcel.apfelbaum@gmail.com> (supporter:PC)
> Paolo Bonzini <pbonzini@redhat.com> (maintainer:X86 TCG CPUs)
> Richard Henderson <rth@twiddle.net> (maintainer:X86 TCG CPUs)
> Eduardo Habkost <ehabkost@redhat.com> (maintainer:X86 TCG CPUs)
>
> However the correct section should rather be "PC Chipset".
>
>> But the change makes sense to me, so:
>>
>> Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
>>
>> I'll queue it.
>>

Re: [Qemu-devel] [PATCH] i386/vmmouse: Properly reset state

[Philippe Mathieu-Daudé]

On 8/29/19 8:12 PM, Jan Kiszka wrote:
> On 29.08.19 20:00, Philippe Mathieu-Daudé wrote:
>> Hi Jan,
>>
>> On 8/27/19 9:49 PM, Eduardo Habkost wrote:
>>> On Sun, Aug 25, 2019 at 04:58:18PM +0200, Jan Kiszka wrote:
>>>> On 21.07.19 10:58, Jan Kiszka wrote:
>>>>> From: Jan Kiszka <jan.kiszka@siemens.com>
>>>>>
>>>>> nb_queue was not zeroed so that we no longer delivered events if a
>>>>> previous guest left the device in an overflow state.
>>>>>
>>>>> The state of absolute does not matter as the next
>>>>> vmmouse_update_handler
>>>>> call will align it again.
>>>>>
>>>>> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
>>>>> ---
>>>>>    hw/i386/vmmouse.c | 1 +
>>>>>    1 file changed, 1 insertion(+)
>>>>>
>>>>> diff --git a/hw/i386/vmmouse.c b/hw/i386/vmmouse.c
>>>>> index 5d2d278be4..e335bd07da 100644
>>>>> --- a/hw/i386/vmmouse.c
>>>>> +++ b/hw/i386/vmmouse.c
>>>>> @@ -257,6 +257,7 @@ static void vmmouse_reset(DeviceState *d)
>>>>>        VMMouseState *s = VMMOUSE(d);
>>>>>
>>>>>        s->queue_size = VMMOUSE_QUEUE_SIZE;
>>>>> +    s->nb_queue = 0;
>>
>> Don't we also need to reset the status in case vmmouse_get_status() is
>> called directly after reset?
>>
>>           s->status = 0;
>>
> 
> Thanks for checking. We call vmmouse_disable() here, and that sets
> status to
> 0xffff anyway.

I missed that, you are correct :)

So:
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

>>>>>
>>>>>        vmmouse_disable(s);
>>>>>    }
>>>>> -- 
>>>>> 2.16.4
>>>>>
>>>>>
>>>>
>>>> Ping - or who is looking after this?
>>>
>>> Despite being in hw/i386, I think we can say vmmouse.c doesn't
>>> have a maintainer.  Last time someone changed vmmouse.c in a
>>> meaningful way (not just adapting to API changes or removing
>>> duplicate code) was in 2012.
>>>
>>
>> Well it does has a few:
>>
>> $ ./scripts/get_maintainer.pl -f hw/i386/vmmouse.c
>> "Michael S. Tsirkin" <mst@redhat.com> (supporter:PC)
>> Marcel Apfelbaum <marcel.apfelbaum@gmail.com> (supporter:PC)
>> Paolo Bonzini <pbonzini@redhat.com> (maintainer:X86 TCG CPUs)
>> Richard Henderson <rth@twiddle.net> (maintainer:X86 TCG CPUs)
>> Eduardo Habkost <ehabkost@redhat.com> (maintainer:X86 TCG CPUs)
>>
>> However the correct section should rather be "PC Chipset".
>>
>>> But the change makes sense to me, so:
>>>
>>> Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
>>>
>>> I'll queue it.
>>>