Re: [Qemu-devel] [PATCH v5] ppc: spapr-rtas - implement os-term rtas call

[Tyrel Datwyler <turtle.in.the.kernel@gmail.com>]

On 06/30/2014 01:35 AM, Nikunj A Dadhania wrote:
> PAPR compliant guest calls this in absence of kdump. This finally
> reaches the guest and can be handled according to the policies set by
> higher level tools(like taking dump) for further analysis by tools like
> crash.
> 
> Linux kernel calls ibm,os-term when extended property of os-term is set.
> This makes sure that a return to the linux kernel is gauranteed.
> 
> CC: Benjamin Herrenschmidt <benh@au1.ibm.com>
> CC: Anton Blanchard <anton@samba.org>
> CC: Alexander Graf <agraf@suse.de>
> CC: Tyrel Datwyler <turtle.in.the.kernel@gmail.com>
> Signed-off-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
> 
> ---
> 
> v2: rebase to ppcnext
> v3: Do not stop the VM, and update comments
> v4: update spapr_register_rtas and qapi_event changes
> v5: set ibm,extended-os-term as null encoded property
> ---
>  hw/ppc/spapr.c         |  9 +++++++++
>  hw/ppc/spapr_rtas.c    | 15 +++++++++++++++
>  include/hw/ppc/spapr.h |  1 -
>  3 files changed, 24 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index 307c58d..e6c9014 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -520,6 +520,15 @@ static void *spapr_create_fdt_skel(hwaddr initrd_base,
>  
>      _FDT((fdt_property_cell(fdt, "rtas-error-log-max", RTAS_ERROR_LOG_MAX)));
>  
> +    /*
> +     * According to PAPR, rtas ibm,os-term, does not gaurantee a return
> +     * back to the guest cpu.
> +     *
> +     * While an additional ibm,extended-os-term property indicates that
> +     * rtas call return will always occur. Set this property.
> +     */
> +    _FDT((fdt_property(fdt, "ibm,extended-os-term", NULL, 0)));
> +
>      _FDT((fdt_end_node(fdt)));
>  
>      /* interrupt controller */
> diff --git a/hw/ppc/spapr_rtas.c b/hw/ppc/spapr_rtas.c
> index 9ba1ba6..2ec2a8e 100644
> --- a/hw/ppc/spapr_rtas.c
> +++ b/hw/ppc/spapr_rtas.c
> @@ -277,6 +277,19 @@ static void rtas_ibm_set_system_parameter(PowerPCCPU *cpu,
>      rtas_st(rets, 0, ret);
>  }
>  
> +static void rtas_ibm_os_term(PowerPCCPU *cpu,
> +                            sPAPREnvironment *spapr,
> +                            uint32_t token, uint32_t nargs,
> +                            target_ulong args,
> +                            uint32_t nret, target_ulong rets)
> +{
> +    target_ulong ret = 0;
> +
> +    qapi_event_send_guest_panicked(GUEST_PANIC_ACTION_PAUSE, &error_abort);
> +
> +    rtas_st(rets, 0, ret);
> +}
> +
>  static struct rtas_call {
>      const char *name;
>      spapr_rtas_fn fn;
> @@ -404,6 +417,8 @@ static void core_rtas_register_types(void)
>      spapr_rtas_register(RTAS_IBM_SET_SYSTEM_PARAMETER,
>                          "ibm,set-system-parameter",
>                          rtas_ibm_set_system_parameter);
> +    spapr_rtas_register(RTAS_IBM_OS_TERM, "ibm,os-term",
> +                        rtas_ibm_os_term);
>  }
>  
>  type_init(core_rtas_register_types)
> diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
> index bbba51a..4e96381 100644
> --- a/include/hw/ppc/spapr.h
> +++ b/include/hw/ppc/spapr.h
> @@ -382,7 +382,6 @@ int spapr_allocate_irq_block(int num, bool lsi, bool msi);
>  #define RTAS_GET_SENSOR_STATE                   (RTAS_TOKEN_BASE + 0x1D)
>  #define RTAS_IBM_CONFIGURE_CONNECTOR            (RTAS_TOKEN_BASE + 0x1E)
>  #define RTAS_IBM_OS_TERM                        (RTAS_TOKEN_BASE + 0x1F)
> -#define RTAS_IBM_EXTENDED_OS_TERM               (RTAS_TOKEN_BASE + 0x20)
>  
>  #define RTAS_TOKEN_MAX                          (RTAS_TOKEN_BASE + 0x21)

With the removal of RTAS_IBM_EXTENDED_OS_TERM doesn't RTAS_TOKEN_MAX
need to be decremented to (RTAS_TOKEN_BASE + 0x20)?

-Tyrel