[Qemu-devel] New crash (was: Re: [PATCH qemu v5 2/3] hw/arm/sysbus-fdt: Allow device matching with DT compatible value)

[Qemu-devel] New crash (was: Re: [PATCH qemu v5 2/3] hw/arm/sysbus-fdt: Allow device matching with DT compatible value)

[Thomas Huth]

On 2018-09-27 13:54, Geert Uytterhoeven wrote:
> From: Auger Eric <eric.auger@redhat.com>
> 
> Up to now we have relied on the device type to identify a device tree
> node creation function.  Since we would like the vfio-platform device to
> be instantiable with different compatible strings we introduce the
> capability to specialize the node creation depending on actual
> compatible value.
> 
> NodeCreationPair is renamed into BindingEntry. The struct is enhanced
> with compat and match_fn() fields.  We introduce a new matching function
> adapted to the vfio-platform generic device.
> 
> Soon, the AMD XGBE can be instantiated with either manner, i.e.:
> 
>     -device vfio-amd-xgbe,host=e0900000.xgmac
> 
> or using the new option line:
> 
>     -device vfio-platform,host=e0900000.xgmac
> 
> Signed-off-by: Eric Auger <eric.auger@redhat.com>
> [geert: Match using compatible values in sysfs instead of user-supplied
> 	manufacturer/model options, reword]
> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
> Reviewed-by: Eric Auger <eric.auger@redhat.com>
> Tested-by: Eric Auger <eric.auger@redhat.com>

scripts/device-crash-test reports a new "crash" with current QEMU master
branch, where QEMU aborts like this:

aarch64-softmmu/qemu-system-aarch64 -S -machine virt-2.9,accel=tcg
-device ramfb
hw/arm/sysbus-fdt.c:422:vfio_platform_match: Object 0x564cf9ae8f80 is
not an instance of type vfio-platform
Aborted (core dumped)

I think it is likely due to this patch here ... any chance that you
could make this a little bit more user friendly instead of aborting the
hard way here?

 Thanks,
  Thomas

Re: [Qemu-devel] New crash

[Auger Eric]

Hi Thomas,

On 11/5/18 10:17 AM, Thomas Huth wrote:
> On 2018-09-27 13:54, Geert Uytterhoeven wrote:
>> From: Auger Eric <eric.auger@redhat.com>
>>
>> Up to now we have relied on the device type to identify a device tree
>> node creation function.  Since we would like the vfio-platform device to
>> be instantiable with different compatible strings we introduce the
>> capability to specialize the node creation depending on actual
>> compatible value.
>>
>> NodeCreationPair is renamed into BindingEntry. The struct is enhanced
>> with compat and match_fn() fields.  We introduce a new matching function
>> adapted to the vfio-platform generic device.
>>
>> Soon, the AMD XGBE can be instantiated with either manner, i.e.:
>>
>>     -device vfio-amd-xgbe,host=e0900000.xgmac
>>
>> or using the new option line:
>>
>>     -device vfio-platform,host=e0900000.xgmac
>>
>> Signed-off-by: Eric Auger <eric.auger@redhat.com>
>> [geert: Match using compatible values in sysfs instead of user-supplied
>> 	manufacturer/model options, reword]
>> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
>> Reviewed-by: Eric Auger <eric.auger@redhat.com>
>> Tested-by: Eric Auger <eric.auger@redhat.com>
> 
> scripts/device-crash-test reports a new "crash" with current QEMU master
> branch, where QEMU aborts like this:
> 
> aarch64-softmmu/qemu-system-aarch64 -S -machine virt-2.9,accel=tcg
> -device ramfb
> hw/arm/sysbus-fdt.c:422:vfio_platform_match: Object 0x564cf9ae8f80 is
> not an instance of type vfio-platform
> Aborted (core dumped)
> 
> I think it is likely due to this patch here ... any chance that you
> could make this a little bit more user friendly instead of aborting the
> hard way here?

thank you for spotting the bug. We should use object_dynamic_cast() to
test if the device is a VFIO_PLATFORM one.

I will prepare a patch.

Thanks

Eric
> 
>  Thanks,
>   Thomas
>