From: Alexey Kardashevskiy <a...@ozlabs.ru> The ibm,client-architecture-support call is a way for the guest to negotiate capabilities with a hypervisor. It is implemented as: - the guest calls SLOF via client interface; - SLOF calls QEMU (H_CAS hypercall) with an options vector from the guest; - QEMU returns a device tree diff (which uses FDT format with an additional header before it); - SLOF walks through the partial diff tree and updates its internal tree with the values from the diff.
This changes QEMU to simply re-render the entire tree and send it as an update. SLOF can handle this already mostly, [1] is needed before this can be applied. This stores the resulting tree in the spapr machine to have the latest valid FDT copy possible (this should not matter much as H_UPDATE_DT happens right after that but nevertheless). The benefit is reduced code size as there is no need for another set of DT rendering helpers such as spapr_fixup_cpu_dt(). The downside is that the updates are bigger now (as they include all nodes and properties) but the difference on a '-smp 256,threads=1' system before/after is 2.35s vs. 2.5s. [1] https://patchwork.ozlabs.org/patch/1152915/ Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru> Signed-off-by: David Gibson <da...@gibson.dropbear.id.au> --- hw/ppc/spapr.c | 88 ++++++-------------------------------------------- 1 file changed, 9 insertions(+), 79 deletions(-) diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c index 3742a8cf06..43920c140d 100644 --- a/hw/ppc/spapr.c +++ b/hw/ppc/spapr.c @@ -295,64 +295,6 @@ static void spapr_populate_pa_features(SpaprMachineState *spapr, _FDT((fdt_setprop(fdt, offset, "ibm,pa-features", pa_features, pa_size))); } -static int spapr_fixup_cpu_dt(void *fdt, SpaprMachineState *spapr) -{ - MachineState *ms = MACHINE(spapr); - int ret = 0, offset, cpus_offset; - CPUState *cs; - char cpu_model[32]; - uint32_t pft_size_prop[] = {0, cpu_to_be32(spapr->htab_shift)}; - - CPU_FOREACH(cs) { - PowerPCCPU *cpu = POWERPC_CPU(cs); - DeviceClass *dc = DEVICE_GET_CLASS(cs); - int index = spapr_get_vcpu_id(cpu); - int compat_smt = MIN(ms->smp.threads, ppc_compat_max_vthreads(cpu)); - - if (!spapr_is_thread0_in_vcore(spapr, cpu)) { - continue; - } - - snprintf(cpu_model, 32, "%s@%x", dc->fw_name, index); - - cpus_offset = fdt_path_offset(fdt, "/cpus"); - if (cpus_offset < 0) { - cpus_offset = fdt_add_subnode(fdt, 0, "cpus"); - if (cpus_offset < 0) { - return cpus_offset; - } - } - offset = fdt_subnode_offset(fdt, cpus_offset, cpu_model); - if (offset < 0) { - offset = fdt_add_subnode(fdt, cpus_offset, cpu_model); - if (offset < 0) { - return offset; - } - } - - ret = fdt_setprop(fdt, offset, "ibm,pft-size", - pft_size_prop, sizeof(pft_size_prop)); - if (ret < 0) { - return ret; - } - - if (ms->numa_state->num_nodes > 1) { - ret = spapr_fixup_cpu_numa_dt(fdt, offset, cpu); - if (ret < 0) { - return ret; - } - } - - ret = spapr_fixup_cpu_smt_dt(fdt, offset, cpu, compat_smt); - if (ret < 0) { - return ret; - } - - spapr_populate_pa_features(spapr, cpu, fdt, offset); - } - return ret; -} - static hwaddr spapr_node0_size(MachineState *machine) { if (machine->numa_state->num_nodes) { @@ -983,11 +925,13 @@ static bool spapr_hotplugged_dev_before_cas(void) return false; } +static void *spapr_build_fdt(SpaprMachineState *spapr); + int spapr_h_cas_compose_response(SpaprMachineState *spapr, target_ulong addr, target_ulong size, SpaprOptionVector *ov5_updates) { - void *fdt, *fdt_skel; + void *fdt; SpaprDeviceTreeUpdateHeader hdr = { .version_id = 1 }; if (spapr_hotplugged_dev_before_cas()) { @@ -1003,25 +947,7 @@ int spapr_h_cas_compose_response(SpaprMachineState *spapr, size -= sizeof(hdr); - /* Create skeleton */ - fdt_skel = g_malloc0(size); - _FDT((fdt_create(fdt_skel, size))); - _FDT((fdt_finish_reservemap(fdt_skel))); - _FDT((fdt_begin_node(fdt_skel, ""))); - _FDT((fdt_end_node(fdt_skel))); - _FDT((fdt_finish(fdt_skel))); - fdt = g_malloc0(size); - _FDT((fdt_open_into(fdt_skel, fdt, size))); - g_free(fdt_skel); - - /* Fixup cpu nodes */ - _FDT((spapr_fixup_cpu_dt(fdt, spapr))); - - if (spapr_dt_cas_updates(spapr, fdt, ov5_updates)) { - return -1; - } - - /* Pack resulting tree */ + fdt = spapr_build_fdt(spapr); _FDT((fdt_pack(fdt))); if (fdt_totalsize(fdt) + sizeof(hdr) > size) { @@ -1033,7 +959,11 @@ int spapr_h_cas_compose_response(SpaprMachineState *spapr, cpu_physical_memory_write(addr, &hdr, sizeof(hdr)); cpu_physical_memory_write(addr + sizeof(hdr), fdt, fdt_totalsize(fdt)); trace_spapr_cas_continue(fdt_totalsize(fdt) + sizeof(hdr)); - g_free(fdt); + + g_free(spapr->fdt_blob); + spapr->fdt_size = fdt_totalsize(fdt); + spapr->fdt_initial_size = spapr->fdt_size; + spapr->fdt_blob = fdt; return 0; } -- 2.21.0
