Re: [Qemu-devel] [PATCH v18 1/2] sPAPR: Implement EEH RTAS calls

[David Gibson <david@gibson.dropbear.id.au>]

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On Mon, Feb 16, 2015 at 10:16:01AM +1100, Gavin Shan wrote:
> The emulation for EEH RTAS requests from guest isn't covered
> by QEMU yet and the patch implements them.
> 
> The patch defines constants used by EEH RTAS calls and adds
> callbacks sPAPRPHBClass::{eeh_set_option, eeh_get_state, eeh_reset,
> eeh_configure}, which are going to be used as follows:
> 
>   * RTAS calls are received in spapr_pci.c, sanity check is done
>     there.
>   * RTAS handlers handle what they can. If there is something it
>     cannot handle and the corresponding sPAPRPHBClass callback is
>     defined, it is called.
>   * Those callbacks are only implemented for VFIO now. They do ioctl()
>     to the IOMMU container fd to complete the calls. Error codes from
>     that ioctl() are transferred back to the guest.
> 
> [aik: defined RTAS tokens for EEH RTAS calls]
> Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
> ---
>  hw/ppc/spapr_pci.c          | 281 ++++++++++++++++++++++++++++++++++++++++++++
>  include/hw/pci-host/spapr.h |   4 +
>  include/hw/ppc/spapr.h      |  43 ++++++-
>  3 files changed, 326 insertions(+), 2 deletions(-)
> 
> diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
> index cebdeb3..29b071d 100644
> --- a/hw/ppc/spapr_pci.c
> +++ b/hw/ppc/spapr_pci.c
> @@ -406,6 +406,268 @@ static void rtas_ibm_query_interrupt_source_number(PowerPCCPU *cpu,
>      rtas_st(rets, 2, 1);/* 0 == level; 1 == edge */
>  }
>  
> +static void rtas_ibm_set_eeh_option(PowerPCCPU *cpu,
> +                                    sPAPREnvironment *spapr,
> +                                    uint32_t token, uint32_t nargs,
> +                                    target_ulong args, uint32_t nret,
> +                                    target_ulong rets)
> +{
> +    sPAPRPHBState *sphb;
> +    sPAPRPHBClass *spc;
> +    uint32_t addr, option;
> +    uint64_t buid;
> +    int ret;
> +
> +    if ((nargs != 4) || (nret != 1)) {
> +        goto param_error_exit;
> +    }
> +
> +    buid = ((uint64_t)rtas_ld(args, 1) << 32) | rtas_ld(args, 2);
> +    addr = rtas_ld(args, 0);
> +    option = rtas_ld(args, 3);
> +
> +    sphb = find_phb(spapr, buid);
> +    if (!sphb) {
> +        goto param_error_exit;
> +    }
> +
> +    spc = SPAPR_PCI_HOST_BRIDGE_GET_CLASS(sphb);
> +    if (!spc->eeh_set_option) {
> +        goto param_error_exit;
> +    }
> +
> +    /*
> +     * The EEH functionality is enabled on basis of PCI device,
> +     * instead of PE. We need check the validity of the PCI
> +     * device address.
> +     */
> +    if (option == RTAS_EEH_ENABLE &&
> +        !find_dev(spapr, buid, addr)) {
> +        goto param_error_exit;
> +    }

You're still breaking your layering by doing checks dependent on the
specific option both here and in the callback.

What I meant by my comments on the previous version was that this
find_dev() test should also move into the eeh_set_option callback.
Obviously that means adding addr into the parameters - but surely if
the addr has any meaning whatsoever, it must be at least potentially
needed by the callback anyway.

Apart from that,

Reviewed-by: David Gibson <david@gibson.dropbear.id.au>

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

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