On Thu, 18 Jul 2019 13:42:14 +1000
Nicholas Piggin <npig...@gmail.com> wrote:
> This has been useful to modify and test the Linux pseries suspend
> code but it requires modification to the guest to call it (due to
> being gated by other unimplemented features). It is not otherwise
> used by Linux yet, but work is slowly progressing there.
>
> Signed-off-by: Nicholas Piggin <npig...@gmail.com>
> ---
Reviewed-by: Greg Kurz <gr...@kaod.org>
> Changes since v5:
> - Fix prod bit semantics.
> - Factor out the h_confer_self common code
>
> Changes since v4:
> - Style
>
> hw/ppc/spapr.c | 1 +
> hw/ppc/spapr_hcall.c | 74 ++++++++++++++++++++++++++++++++++++--------
> 2 files changed, 62 insertions(+), 13 deletions(-)
>
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index 68341c128d..00f7735a31 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -1066,6 +1066,7 @@ static void spapr_dt_rtas(SpaprMachineState *spapr,
> void *fdt)
> add_str(hypertas, "hcall-tce");
> add_str(hypertas, "hcall-vio");
> add_str(hypertas, "hcall-splpar");
> + add_str(hypertas, "hcall-join");
> add_str(hypertas, "hcall-bulk");
> add_str(hypertas, "hcall-set-mode");
> add_str(hypertas, "hcall-sprg0");
> diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c
> index 7c659dc75c..9b72ea8b68 100644
> --- a/hw/ppc/spapr_hcall.c
> +++ b/hw/ppc/spapr_hcall.c
> @@ -1069,6 +1069,62 @@ static target_ulong h_cede(PowerPCCPU *cpu,
> SpaprMachineState *spapr,
> return H_SUCCESS;
> }
>
> +/*
> + * Confer to self, aka join. Cede could use the same pattern as well, if
> + * EXCP_HLT can be changed to ECXP_HALTED.
> + */
> +static target_ulong h_confer_self(PowerPCCPU *cpu)
> +{
> + CPUState *cs = CPU(cpu);
> + SpaprCpuState *spapr_cpu = spapr_cpu_state(cpu);
> +
> + if (spapr_cpu->prod) {
> + spapr_cpu->prod = false;
> + return H_SUCCESS;
> + }
> + cs->halted = 1;
> + cs->exception_index = EXCP_HALTED;
> + cs->exit_request = 1;
> +
> + return H_SUCCESS;
> +}
> +
> +static target_ulong h_join(PowerPCCPU *cpu, SpaprMachineState *spapr,
> + target_ulong opcode, target_ulong *args)
> +{
> + CPUPPCState *env = &cpu->env;
> + CPUState *cs;
> + bool last_unjoined = true;
> +
> + if (env->msr & (1ULL << MSR_EE)) {
> + return H_BAD_MODE;
> + }
> +
> + /*
> + * Must not join the last CPU running. Interestingly, no such restriction
> + * for H_CONFER-to-self, but that is probably not intended to be used
> + * when H_JOIN is available.
> + */
> + CPU_FOREACH(cs) {
> + PowerPCCPU *c = POWERPC_CPU(cs);
> + CPUPPCState *e = &c->env;
> + if (c == cpu) {
> + continue;
> + }
> +
> + /* Don't have a way to indicate joined, so use halted && MSR[EE]=0 */
> + if (!cs->halted || (e->msr & (1ULL << MSR_EE))) {
> + last_unjoined = false;
> + break;
> + }
> + }
> + if (last_unjoined) {
> + return H_CONTINUE;
> + }
> +
> + return h_confer_self(cpu);
> +}
> +
> static target_ulong h_confer(PowerPCCPU *cpu, SpaprMachineState *spapr,
> target_ulong opcode, target_ulong *args)
> {
> @@ -1089,26 +1145,15 @@ static target_ulong h_confer(PowerPCCPU *cpu,
> SpaprMachineState *spapr,
> return H_PARAMETER;
> }
>
> - spapr_cpu = spapr_cpu_state(target_cpu);
> -
> /*
> * target == self is a special case, we wait until prodded, without
> * dispatch counter check.
> */
> if (cpu == target_cpu) {
> - if (spapr_cpu->prod) {
> - spapr_cpu->prod = false;
> -
> - return H_SUCCESS;
> - }
> -
> - cs->halted = 1;
> - cs->exception_index = EXCP_HALTED;
> - cs->exit_request = 1;
> -
> - return H_SUCCESS;
> + return h_confer_self(cpu);
> }
>
> + spapr_cpu = spapr_cpu_state(target_cpu);
> if (!spapr_cpu->vpa_addr || ((dispatch & 1) == 0)) {
> return H_SUCCESS;
> }
> @@ -1981,6 +2026,9 @@ static void hypercall_register_types(void)
> spapr_register_hypercall(H_CONFER, h_confer);
> spapr_register_hypercall(H_PROD, h_prod);
>
> + /* hcall-join */
> + spapr_register_hypercall(H_JOIN, h_join);
> +
> spapr_register_hypercall(H_SIGNAL_SYS_RESET, h_signal_sys_reset);
>
> /* processor register resource access h-calls */
