Re: [PATCH v2] device-assignment: register a reset function

[Jan Kiszka <jan.kiszka@siemens.com>]

Am 16.11.2010 15:37, Alex Williamson wrote:
> On Tue, 2010-11-16 at 15:05 +0100, 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>
>> ---
>> Changes v1 -> v2:
>> - use defined macros, e.g. PCI_COMMAND
>> - write all zero to the command register to disconnect the device logically
>> ---
>>  hw/device-assignment.c |   12 ++++++++++++
>>  1 files changed, 12 insertions(+), 0 deletions(-)
> 
> Looks good to me.
> 
> Acked-by: Alex Williamson <alex.williamson@redhat.com>

Acked-by: Jan Kiszka <jan.kiszka@siemens.com>

> 
>> diff --git a/hw/device-assignment.c b/hw/device-assignment.c
>> index 5f5bde1..8d5a609 100644
>> --- a/hw/device-assignment.c
>> +++ b/hw/device-assignment.c
>> @@ -1434,6 +1434,17 @@ static void assigned_dev_unregister_msix_mmio(AssignedDevice *dev)
>>      dev->msix_table_page = NULL;
>>  }
>>  
>> +static void reset_assigned_device(DeviceState *dev)
>> +{
>> +    PCIDevice *d = DO_UPCAST(PCIDevice, qdev, dev);
>> +
>> +    /*
>> +     * When a 0 is written to the command register, the device is logically
>> +     * disconnected from the PCI bus. This avoids further DMA transfers.
>> +     */
>> +    assigned_dev_pci_write_config(d, PCI_COMMAND, 0, 2);
>> +}
>> +
>>  static int assigned_initfn(struct PCIDevice *pci_dev)
>>  {
>>      AssignedDevice *dev = DO_UPCAST(AssignedDevice, dev, pci_dev);
>> @@ -1544,6 +1555,7 @@ static PCIDeviceInfo assign_info = {
>>      .qdev.name    = "pci-assign",
>>      .qdev.desc    = "pass through host pci devices to the guest",
>>      .qdev.size    = sizeof(AssignedDevice),
>> +    .qdev.reset   = reset_assigned_device,
>>      .init         = assigned_initfn,
>>      .exit         = assigned_exitfn,
>>      .config_read  = assigned_dev_pci_read_config,

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