These implementations have a few deficiencies that are noted, but are good enough for Linux to use.
Signed-off-by: Nicholas Piggin <npig...@gmail.com> --- Cleaned up checkpatch warnings, sorry I didn't realise that exists. hw/ppc/spapr_hcall.c | 88 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 88 insertions(+) diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c index 8a736797b9..e985bb694d 100644 --- a/hw/ppc/spapr_hcall.c +++ b/hw/ppc/spapr_hcall.c @@ -1065,6 +1065,90 @@ static target_ulong h_cede(PowerPCCPU *cpu, SpaprMachineState *spapr, return H_SUCCESS; } +static target_ulong h_join(PowerPCCPU *cpu, SpaprMachineState *spapr, + target_ulong opcode, target_ulong *args) +{ + CPUPPCState *env = &cpu->env; + CPUState *cs = CPU(cpu); + + if (env->msr & (1ULL << MSR_EE)) { + return H_BAD_MODE; + } + + /* + * This should check for single-threaded mode. In practice, Linux + * does not try to H_JOIN all CPUs. + */ + + cs->halted = 1; + cs->exception_index = EXCP_HALTED; + cs->exit_request = 1; + + return H_SUCCESS; +} + +static target_ulong h_confer(PowerPCCPU *cpu, SpaprMachineState *spapr, + target_ulong opcode, target_ulong *args) +{ + target_long target = args[0]; + CPUState *cs = CPU(cpu); + + /* + * This does not do a targeted yield or confer, but check the parameter + * anyway. -1 means confer to all/any other CPUs. + */ + if (target != -1 && !CPU(spapr_find_cpu(target))) { + return H_PARAMETER; + } + + /* + * H_CONFER with target == this is not exactly the same as H_JOIN + * according to PAPR (e.g., MSR[EE] check and single threaded check + * is not done in this case), but unlikely to matter. + */ + if (cpu == spapr_find_cpu(target)) { + return h_join(cpu, spapr, opcode, args); + } + + /* + * This does not implement the dispatch sequence check that PAPR calls for, + * but PAPR also specifies a stronger implementation where the target must + * be run (or EE, or H_PROD) before H_CONFER returns. Without such a hard + * scheduling requirement implemented, there is no correctness reason to + * implement the dispatch sequence check. + */ + cs->exception_index = EXCP_YIELD; + cpu_loop_exit(cs); + + return H_SUCCESS; +} + +/* + * H_PROD and H_CONFER are specified to only modify GPR r3, which is not + * achievable running under KVM, although KVM already implements H_CONFER + * this way. + */ +static target_ulong h_prod(PowerPCCPU *cpu, SpaprMachineState *spapr, + target_ulong opcode, target_ulong *args) +{ + target_long target = args[0]; + CPUState *cs; + + /* + * Should set the prod flag in the VPA. + */ + + cs = CPU(spapr_find_cpu(target)); + if (!cs) { + return H_PARAMETER; + } + + cs->halted = 0; + qemu_cpu_kick(cs); + + return H_SUCCESS; +} + static target_ulong h_rtas(PowerPCCPU *cpu, SpaprMachineState *spapr, target_ulong opcode, target_ulong *args) { @@ -1860,6 +1944,10 @@ static void hypercall_register_types(void) /* hcall-splpar */ spapr_register_hypercall(H_REGISTER_VPA, h_register_vpa); spapr_register_hypercall(H_CEDE, h_cede); + spapr_register_hypercall(H_CONFER, h_confer); + spapr_register_hypercall(H_JOIN, h_join); + spapr_register_hypercall(H_PROD, h_prod); + spapr_register_hypercall(H_SIGNAL_SYS_RESET, h_signal_sys_reset); /* processor register resource access h-calls */ -- 2.20.1