Re: [Qemu-devel] [RFC PATCH 3/4] vfio-pci: add aer capability support

[Chen Fan <chen.fan.fnst@cn.fujitsu.com>]

On 01/12/2015 11:26 PM, Alex Williamson wrote:
> On Mon, 2015-01-12 at 11:04 +0800, Chen Fan wrote:
>
> This patch isn't trivial enough for a blank commit log.  Why do we need
> to make those bits emulated?  Do we only care about AER for now?
I think the vfio extend capabilities control registers should be 
manipulated by qemu self.
BTW, it is guest driver's responsibility to set PCI_EXP_DEVCTL bits, 
right? so here
only need to initialize configration sapces and set corresponding bits 
attributes.
I will change it in my next version patches.

I think AER is a good start.

Thanks,
Chen
>
>> Signed-off-by: Chen Fan <chen.fan.fnst@cn.fujitsu.com>
>> ---
>>   hw/vfio/pci.c | 40 ++++++++++++++++++++++++++++++++++++++++
>>   1 file changed, 40 insertions(+)
>>
>> diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
>> index b4e73d1..0ee6326 100644
>> --- a/hw/vfio/pci.c
>> +++ b/hw/vfio/pci.c
>> @@ -2667,6 +2667,41 @@ static int vfio_add_capabilities(VFIOPCIDevice *vdev)
>>       return vfio_add_std_cap(vdev, pdev->config[PCI_CAPABILITY_LIST]);
>>   }
>>   
>> +static int vfio_add_ext_capabilities(VFIOPCIDevice *vdev)
>> +{
>> +    PCIDevice *pdev = &vdev->pdev;
>> +    PCIExpressDevice *exp;
>> +    uint32_t header;
>> +    uint16_t next = PCI_CONFIG_SPACE_SIZE;
>> +
>> +    if (pci_config_size(pdev) <= PCI_CONFIG_SPACE_SIZE) {
>> +        return 0;
>> +    }
>> +
>> +    header = pci_get_long(pdev->config + next);
>> +    while (header) {
>> +        switch (PCI_EXT_CAP_ID(header)) {
>> +        case PCI_EXT_CAP_ID_ERR:
>> +             exp = &pdev->exp;
>> +             exp->aer_cap = next;
>> +
>> +             /* enable the error report */
>> +             vfio_add_emulated_long(vdev, exp->exp_cap + PCI_EXP_DEVCTL,
>> +                 PCI_EXP_DEVCTL_CERE | PCI_EXP_DEVCTL_NFERE |
>> +                 PCI_EXP_DEVCTL_FERE | PCI_EXP_DEVCTL_URRE, ~0);
>> +             break;
>> +        };
>> +
>> +        next = PCI_EXT_CAP_NEXT(header);
>> +        if (!next) {
>> +            return 0;
>> +        }
>> +        header = pci_get_long(pdev->config + next);
>> +    }
>> +
>> +    return 0;
>> +}
>> +
>>   static void vfio_pci_pre_reset(VFIOPCIDevice *vdev)
>>   {
>>       PCIDevice *pdev = &vdev->pdev;
>> @@ -3293,6 +3328,11 @@ static int vfio_initfn(PCIDevice *pdev)
>>           goto out_teardown;
>>       }
>>   
>> +    ret = vfio_add_ext_capabilities(vdev);
>> +    if (ret) {
>> +        goto out_teardown;
>> +    }
>> +
>>       /* QEMU emulates all of MSI & MSIX */
>>       if (pdev->cap_present & QEMU_PCI_CAP_MSIX) {
>>           memset(vdev->emulated_config_bits + pdev->msix_cap, 0xff,
>
>
> .
>