Re: [Qemu-ppc] [PATCH 20/25] spapr: add device tree support for the XIVE interrupt mode

[Cédric Le Goater]

On 12/04/2017 08:49 AM, David Gibson wrote:
> On Thu, Nov 23, 2017 at 02:29:50PM +0100, Cédric Le Goater wrote:
>> The XIVE interface for the guest is described in the device tree under
>> the "interrupt-controller" node. A couple of new properties are
>> specific to XIVE :
>>
>>  - "reg"
>>
>>    contains the base address and size of the thread interrupt
>>    managnement areas (TIMA), also called rings, for the User level and
>>    for the Guest OS level. Only the Guest OS level is taken into
>>    account today.
>>
>>  - "ibm,xive-eq-sizes"
>>
>>    the size of the event queues. One cell per size supported, contains
>>    log2 of size, in ascending order.
>>
>>  - "ibm,xive-lisn-ranges"
>>
>>    the interrupt numbers ranges assigned to the guest. These are
>>    allocated using a simple bitmap.
>>
>> and also under the root node :
>>
>>  - "ibm,plat-res-int-priorities"
>>
>>    contains a list of priorities that the hypervisor has reserved for
>>    its own use. Simulate ranges as defined by the PowerVM Hypervisor.
>>
>> When the XIVE interrupt mode is activated after the CAS negotiation,
>> the machine will perform a reboot to rebuild the device tree.
>>
>> Signed-off-by: Cédric Le Goater <address@hidden>
>> ---
>>  hw/intc/spapr_xive_hcall.c  | 50 
>> +++++++++++++++++++++++++++++++++++++++++++++
>>  hw/ppc/spapr.c              |  7 ++++++-
>>  hw/ppc/spapr_hcall.c        |  6 ++++++
>>  include/hw/ppc/spapr_xive.h |  2 ++
>>  4 files changed, 64 insertions(+), 1 deletion(-)
>>
>> diff --git a/hw/intc/spapr_xive_hcall.c b/hw/intc/spapr_xive_hcall.c
>> index 676fe0e2d5c7..60c6c9f4be8f 100644
>> --- a/hw/intc/spapr_xive_hcall.c
>> +++ b/hw/intc/spapr_xive_hcall.c
>> @@ -883,3 +883,53 @@ void spapr_xive_hcall_init(sPAPRMachineState *spapr)
>>      spapr_register_hypercall(H_INT_SYNC, h_int_sync);
>>      spapr_register_hypercall(H_INT_RESET, h_int_reset);
>>  }
>> +
>> +void spapr_xive_populate(sPAPRMachineState *spapr, int nr_servers,
>> +                         void *fdt, uint32_t phandle)
> 
> Call it spapr_dt_xive() please, I'm trying to standardize on that
> pattern for functions creating DT pieces.

OK. And what about the first argument : sPAPRMachineState *spapr 
or sPAPRXive *xive ? I tend to prefer the first option because
it's related to the interface with the guest, like the hcalls.

> 
>> +{
>> +    sPAPRXive *xive = spapr->xive;
>> +    int node;
>> +    uint64_t timas[2 * 2];
>> +    uint32_t lisn_ranges[] = {
>> +        cpu_to_be32(0),
>> +        cpu_to_be32(nr_servers),
>> +    };
>> +    uint32_t eq_sizes[] = {
>> +        cpu_to_be32(12), /* 4K */
>> +        cpu_to_be32(16), /* 64K */
>> +        cpu_to_be32(21), /* 2M */
>> +        cpu_to_be32(24), /* 16M */
>> +    };
>> +    uint32_t plat_res_int_priorities[ARRAY_SIZE(reserved_priorities)];
>> +    int i;
>> +
>> +    for (i = 0; i < ARRAY_SIZE(plat_res_int_priorities); i++) {
>> +        plat_res_int_priorities[i] = cpu_to_be32(reserved_priorities[i]);
>> +    }
>> +
>> +    /* Thread Interrupt Management Areas : User and OS */
>> +    for (i = 0; i < 2; i++) {
>> +        timas[i * 2] = cpu_to_be64(xive->tm_base + i * (1 << 
>> xive->tm_shift));
>> +        timas[i * 2 + 1] = cpu_to_be64(1 << xive->tm_shift);
>> +    }
>> +
>> +    _FDT(node = fdt_add_subnode(fdt, 0, "interrupt-controller"));
> 
> You need a unit address here matching the reg property.

Indeed. I didn't notice. Curiously it was taking the first address 
specified in the reg property of the node.

>> +
>> +    _FDT(fdt_setprop_string(fdt, node, "name", "interrupt-controller"));
> 
> You don't need to set name properties explicitly for flattened trees.

OK.

Thanks,

C. 



>> +    _FDT(fdt_setprop_string(fdt, node, "device_type", "power-ivpe"));
>> +    _FDT(fdt_setprop(fdt, node, "reg", timas, sizeof(timas)));
>> +
>> +    _FDT(fdt_setprop_string(fdt, node, "compatible", "ibm,power-ivpe"));
>> +    _FDT(fdt_setprop(fdt, node, "ibm,xive-eq-sizes", eq_sizes,
>> +                     sizeof(eq_sizes)));
>> +    _FDT(fdt_setprop(fdt, node, "ibm,xive-lisn-ranges", lisn_ranges,
>> +                     sizeof(lisn_ranges)));
>> +
>> +    /* For SLOF */
>> +    _FDT(fdt_setprop_cell(fdt, node, "linux,phandle", phandle));
>> +    _FDT(fdt_setprop_cell(fdt, node, "phandle", phandle));
>> +
>> +    /* top properties */
>> +    _FDT(fdt_setprop(fdt, 0, "ibm,plat-res-int-priorities",
>> +                     plat_res_int_priorities, 
>> sizeof(plat_res_int_priorities)));
>> +}
>> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
>> index 8b15c0b500d0..3a62369883cc 100644
>> --- a/hw/ppc/spapr.c
>> +++ b/hw/ppc/spapr.c
>> @@ -1127,7 +1127,12 @@ static void *spapr_build_fdt(sPAPRMachineState *spapr,
>>      _FDT(fdt_setprop_cell(fdt, 0, "#size-cells", 2));
>>  
>>      /* /interrupt controller */
>> -    spapr_dt_xics(xics_max_server_number(), fdt, PHANDLE_XICP);
>> +    if (!spapr_ovec_test(spapr->ov5_cas, OV5_XIVE_EXPLOIT)) {
>> +        spapr_dt_xics(xics_max_server_number(), fdt, PHANDLE_XICP);
>> +    } else {
>> +        /* Populate device tree for XIVE */
>> +        spapr_xive_populate(spapr, xics_max_server_number(), fdt, 
>> PHANDLE_XICP);
>> +    }
>>  
>>      ret = spapr_populate_memory(spapr, fdt);
>>      if (ret < 0) {
>> diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c
>> index be22a6b2895f..e2a1665beee9 100644
>> --- a/hw/ppc/spapr_hcall.c
>> +++ b/hw/ppc/spapr_hcall.c
>> @@ -1646,6 +1646,12 @@ static target_ulong 
>> h_client_architecture_support(PowerPCCPU *cpu,
>>              (spapr_h_cas_compose_response(spapr, args[1], args[2],
>>                                            ov5_updates) != 0);
>>      }
>> +
>> +    /* We need to rebuild the device tree for XIVE, generate a reset */
>> +    if (!spapr->cas_reboot) {
>> +        spapr->cas_reboot = spapr_ovec_test(ov5_updates, OV5_XIVE_EXPLOIT);
>> +    }
>> +
>>      spapr_ovec_cleanup(ov5_updates);
>>  
>>      if (spapr->cas_reboot) {
>> diff --git a/include/hw/ppc/spapr_xive.h b/include/hw/ppc/spapr_xive.h
>> index 3f822220647f..f6d4bf26e06a 100644
>> --- a/include/hw/ppc/spapr_xive.h
>> +++ b/include/hw/ppc/spapr_xive.h
>> @@ -82,5 +82,7 @@ void spapr_xive_icp_pic_print_info(sPAPRXiveICP *xicp, 
>> Monitor *mon);
>>  typedef struct sPAPRMachineState sPAPRMachineState;
>>  
>>  void spapr_xive_hcall_init(sPAPRMachineState *spapr);
>> +void spapr_xive_populate(sPAPRMachineState *spapr, int nr_servers, void 
>> *fdt,
>> +                         uint32_t phandle);
>>  
>>  #endif /* PPC_SPAPR_XIVE_H */
>