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

[Chen Fan]

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 <address@hidden>
> > ---
> >   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,
>
>
> .