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

[Alex Williamson <alex.williamson@redhat.com>]

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?

> 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,