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

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

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On Mon, Dec 04, 2017 at 05:19:03PM +0100, Cédric Le Goater wrote:
> 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 <clg@kaod.org>
> >> ---
> >>  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.

Yes, using the MachineState as the first parameter is fine.

> 
> > 
> >> +{
> >> +    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.

I'm guessing that's SLOF's intervention.

> 
> >> +
> >> +    _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 */
> > 
> 

-- 
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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