Re: [PATCH] device-assignment: register a reset function

[Bernhard Kohl <bernhard.kohl@nsn.com>]

Am 17.09.2010 18:16, schrieb ext Alex Williamson:
> On Fri, 2010-09-17 at 17:27 +0200, Bernhard Kohl wrote:
>    
>> This is necessary because during reboot of a VM the assigned devices
>> continue DMA transfers which causes memory corruption.
>>
>> Signed-off-by: Thomas Ostler<thomas.ostler@nsn.com>
>> Signed-off-by: Bernhard Kohl<bernhard.kohl@nsn.com>
>> ---
>>   hw/device-assignment.c |   14 ++++++++++++++
>>   1 files changed, 14 insertions(+), 0 deletions(-)
>>
>> diff --git a/hw/device-assignment.c b/hw/device-assignment.c
>> index 87f7418..fb47813 100644
>> --- a/hw/device-assignment.c
>> +++ b/hw/device-assignment.c
>> @@ -1450,6 +1450,17 @@ static void assigned_dev_unregister_msix_mmio(AssignedDevice *dev)
>>       dev->msix_table_page = NULL;
>>   }
>>
>> +static void reset_assigned_device(void *opaque)
>> +{
>> +    PCIDevice *d = (PCIDevice *)opaque;
>> +    uint32_t conf;
>> +
>> +    /* reset the bus master bit to avoid further DMA transfers */
>> +    conf = assigned_dev_pci_read_config(d, PCI_COMMAND, 2);
>> +    conf&= ~PCI_COMMAND_MASTER;
>> +    assigned_dev_pci_write_config(d, PCI_COMMAND, conf, 2);
>> +}
>> +
>>   static int assigned_initfn(struct PCIDevice *pci_dev)
>>   {
>>       AssignedDevice *dev = DO_UPCAST(AssignedDevice, dev, pci_dev);
>> @@ -1499,6 +1510,9 @@ static int assigned_initfn(struct PCIDevice *pci_dev)
>>       if (r<  0)
>>           goto assigned_out;
>>
>> +    /* register reset function for the device */
>> +    qemu_register_reset(reset_assigned_device, pci_dev);
>> +
>>       /* intercept MSI-X entry page in the MMIO */
>>       if (dev->cap.available&  ASSIGNED_DEVICE_CAP_MSIX)
>>           if (assigned_dev_register_msix_mmio(dev))
>>      
> Hmm, at a minimum, we need a qemu_unregister_reset() in the exitfn, but
> upon further inspection, we should probably just do it the qdev way.
> That would mean simply setting qdev.reset to reset_assigned_device() in
> assign_info, then we can leave the registration/de-registration to qdev.
> Does that work?  Sorry I missed that the first time.  Thanks,
>
> Alex
>    

OK, we will rework the patch for qdev.
This might take 2 weeks because of vacation.

Thanks
Bernhard