Re: [Qemu-devel] [Qemu-ppc] [RFC 03/12] spapr_pci: Eliminate class callbacks

[Alexander Graf <agraf@suse.de>]

On 19.11.15 05:29, David Gibson wrote:
> The EEH operations in the spapr-vfio-pci-host-bridge no longer rely on the
> special groupid field in sPAPRPHBVFIOState.  So we can simplify, removing
> the class specific callbacks with direct calls based on a simple
> spapr_phb_eeh_enabled() helper.  For now we implement that in terms of
> a boolean in the class, but we'll continue to clean that up later.
> 
> On its own this is a rather strange way of doing things, but it's a useful
> intermediate step to further cleanups.
> 
> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
> ---
>  hw/ppc/spapr_pci.c          | 44 ++++++++++++++++++++++----------------------
>  hw/ppc/spapr_pci_vfio.c     | 18 +++++++-----------
>  include/hw/pci-host/spapr.h | 13 +++++++++----
>  3 files changed, 38 insertions(+), 37 deletions(-)
> 
> diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
> index 55fa8db..9203d15 100644
> --- a/hw/ppc/spapr_pci.c
> +++ b/hw/ppc/spapr_pci.c
> @@ -91,6 +91,13 @@ PCIDevice *spapr_pci_find_dev(sPAPRMachineState *spapr, uint64_t buid,
>      return pci_find_device(phb->bus, bus_num, devfn);
>  }
>  
> +static bool spapr_phb_eeh_available(sPAPRPHBState *sphb)
> +{
> +    sPAPRPHBClass *spc = SPAPR_PCI_HOST_BRIDGE_GET_CLASS(sphb);
> +
> +    return spc->eeh_available;
> +}
> +
>  static uint32_t rtas_pci_cfgaddr(uint32_t arg)
>  {
>      /* This handles the encoding of extended config space addresses */
> @@ -430,7 +437,6 @@ static void rtas_ibm_set_eeh_option(PowerPCCPU *cpu,
>                                      target_ulong rets)
>  {
>      sPAPRPHBState *sphb;
> -    sPAPRPHBClass *spc;
>      uint32_t addr, option;
>      uint64_t buid;
>      int ret;
> @@ -448,12 +454,11 @@ static void rtas_ibm_set_eeh_option(PowerPCCPU *cpu,
>          goto param_error_exit;
>      }
>  
> -    spc = SPAPR_PCI_HOST_BRIDGE_GET_CLASS(sphb);
> -    if (!spc->eeh_set_option) {
> +    if (!spapr_phb_eeh_available(sphb)) {
>          goto param_error_exit;
>      }
>  
> -    ret = spc->eeh_set_option(sphb, addr, option);
> +    ret = spapr_phb_vfio_eeh_set_option(sphb, addr, option);

First of all, I think the direction you're taking with this series is sound.

However the hunk above would break compilation on systems that don't
have VFIO enabled (such as Windows hosts for example).

The same holds true for the defines you're using later in the series.
Things like VFIO_EEH_PE_GET_STATE are not defined for non-Linux hosts.

I think the best path to get to where we really want to be is to define
qemu internal defines and eeh helpers for emulated phb mode. Make sure
the constants match the VFIO constants and use them interchangibly (with
a big fat comment saying that they are, and a number of ifdefs making
sure they stay identical).


Alex