| Message ID | 20240711141851.406677-11-npiggin@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | ppc/pnv: Better big-core model, lpar-per-core, PC unit | expand |
On 7/11/24 16:18, Nicholas Piggin wrote: > The decision to branch out to a slower SMT path in instruction > emulation will become a bit more complicated with the way that > "big-core" topology that will be implemented in subsequent changes. > Hide these details from the wider CPU emulation code with a bool > has_smt_siblings flag that can be set by machine initialisation. > > Signed-off-by: Nicholas Piggin <npiggin@gmail.com> The distinction between what's done in pnv_core_realize() and pnv_core_cpu_realize() is not clear. Not this patch fault though. Reviewed-by: Cédric Le Goater <clg@redhat.com> Thanks, C. > --- > target/ppc/cpu.h | 3 ++- > hw/ppc/pnv_core.c | 3 +++ > hw/ppc/spapr_cpu_core.c | 15 +++++++++++---- > 3 files changed, 16 insertions(+), 5 deletions(-) > > diff --git a/target/ppc/cpu.h b/target/ppc/cpu.h > index a74b753c99..35a1cb65cb 100644 > --- a/target/ppc/cpu.h > +++ b/target/ppc/cpu.h > @@ -1248,6 +1248,7 @@ struct CPUArchState { > int access_type; > > /* For SMT processors */ > + bool has_smt_siblings; > int core_index; > > #if !defined(CONFIG_USER_ONLY) > @@ -1516,7 +1517,7 @@ struct PowerPCCPUClass { > > static inline bool ppc_cpu_core_single_threaded(CPUState *cs) > { > - return cs->nr_threads == 1; > + return !POWERPC_CPU(cs)->env.has_smt_siblings; > } > > static inline bool ppc_cpu_lpar_single_threaded(CPUState *cs) > diff --git a/hw/ppc/pnv_core.c b/hw/ppc/pnv_core.c > index 7bda29b9c7..8cfa94fbfa 100644 > --- a/hw/ppc/pnv_core.c > +++ b/hw/ppc/pnv_core.c > @@ -288,6 +288,9 @@ static void pnv_core_realize(DeviceState *dev, Error **errp) > cpu = POWERPC_CPU(obj); > > pc->threads[i] = POWERPC_CPU(obj); > + if (cc->nr_threads > 1) { > + cpu->env.has_smt_siblings = true; > + } > > snprintf(name, sizeof(name), "thread[%d]", i); > object_property_add_child(OBJECT(pc), name, obj); > diff --git a/hw/ppc/spapr_cpu_core.c b/hw/ppc/spapr_cpu_core.c > index d9116c8409..2c6eeb41a4 100644 > --- a/hw/ppc/spapr_cpu_core.c > +++ b/hw/ppc/spapr_cpu_core.c > @@ -314,12 +314,13 @@ static PowerPCCPU *spapr_create_vcpu(SpaprCpuCore *sc, int i, Error **errp) > * and the rest are explicitly started up by the guest using an RTAS call. > */ > qdev_prop_set_bit(DEVICE(obj), "start-powered-off", true); > - env->core_index = cc->core_id; > cs->cpu_index = cc->core_id + i; > if (!spapr_set_vcpu_id(cpu, cs->cpu_index, errp)) { > return NULL; > } > > + env->core_index = cc->core_id; > + > cpu->node_id = sc->node_id; > > id = g_strdup_printf("thread[%d]", i); > @@ -350,9 +351,15 @@ static void spapr_cpu_core_realize(DeviceState *dev, Error **errp) > qemu_register_reset(spapr_cpu_core_reset_handler, sc); > sc->threads = g_new0(PowerPCCPU *, cc->nr_threads); > for (i = 0; i < cc->nr_threads; i++) { > - sc->threads[i] = spapr_create_vcpu(sc, i, errp); > - if (!sc->threads[i] || > - !spapr_realize_vcpu(sc->threads[i], spapr, sc, i, errp)) { > + PowerPCCPU *cpu; > + > + cpu = spapr_create_vcpu(sc, i, errp); > + sc->threads[i] = cpu; > + if (cpu && cc->nr_threads > 1) { > + cpu->env.has_smt_siblings = true; > + } > + > + if (!cpu || !spapr_realize_vcpu(cpu, spapr, sc, i, errp)) { > spapr_cpu_core_unrealize(dev); > return; > }
diff --git a/target/ppc/cpu.h b/target/ppc/cpu.h index a74b753c99..35a1cb65cb 100644 --- a/target/ppc/cpu.h +++ b/target/ppc/cpu.h @@ -1248,6 +1248,7 @@ struct CPUArchState { int access_type; /* For SMT processors */ + bool has_smt_siblings; int core_index; #if !defined(CONFIG_USER_ONLY) @@ -1516,7 +1517,7 @@ struct PowerPCCPUClass { static inline bool ppc_cpu_core_single_threaded(CPUState *cs) { - return cs->nr_threads == 1; + return !POWERPC_CPU(cs)->env.has_smt_siblings; } static inline bool ppc_cpu_lpar_single_threaded(CPUState *cs) diff --git a/hw/ppc/pnv_core.c b/hw/ppc/pnv_core.c index 7bda29b9c7..8cfa94fbfa 100644 --- a/hw/ppc/pnv_core.c +++ b/hw/ppc/pnv_core.c @@ -288,6 +288,9 @@ static void pnv_core_realize(DeviceState *dev, Error **errp) cpu = POWERPC_CPU(obj); pc->threads[i] = POWERPC_CPU(obj); + if (cc->nr_threads > 1) { + cpu->env.has_smt_siblings = true; + } snprintf(name, sizeof(name), "thread[%d]", i); object_property_add_child(OBJECT(pc), name, obj); diff --git a/hw/ppc/spapr_cpu_core.c b/hw/ppc/spapr_cpu_core.c index d9116c8409..2c6eeb41a4 100644 --- a/hw/ppc/spapr_cpu_core.c +++ b/hw/ppc/spapr_cpu_core.c @@ -314,12 +314,13 @@ static PowerPCCPU *spapr_create_vcpu(SpaprCpuCore *sc, int i, Error **errp) * and the rest are explicitly started up by the guest using an RTAS call. */ qdev_prop_set_bit(DEVICE(obj), "start-powered-off", true); - env->core_index = cc->core_id; cs->cpu_index = cc->core_id + i; if (!spapr_set_vcpu_id(cpu, cs->cpu_index, errp)) { return NULL; } + env->core_index = cc->core_id; + cpu->node_id = sc->node_id; id = g_strdup_printf("thread[%d]", i); @@ -350,9 +351,15 @@ static void spapr_cpu_core_realize(DeviceState *dev, Error **errp) qemu_register_reset(spapr_cpu_core_reset_handler, sc); sc->threads = g_new0(PowerPCCPU *, cc->nr_threads); for (i = 0; i < cc->nr_threads; i++) { - sc->threads[i] = spapr_create_vcpu(sc, i, errp); - if (!sc->threads[i] || - !spapr_realize_vcpu(sc->threads[i], spapr, sc, i, errp)) { + PowerPCCPU *cpu; + + cpu = spapr_create_vcpu(sc, i, errp); + sc->threads[i] = cpu; + if (cpu && cc->nr_threads > 1) { + cpu->env.has_smt_siblings = true; + } + + if (!cpu || !spapr_realize_vcpu(cpu, spapr, sc, i, errp)) { spapr_cpu_core_unrealize(dev); return; }
The decision to branch out to a slower SMT path in instruction emulation will become a bit more complicated with the way that "big-core" topology that will be implemented in subsequent changes. Hide these details from the wider CPU emulation code with a bool has_smt_siblings flag that can be set by machine initialisation. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> --- target/ppc/cpu.h | 3 ++- hw/ppc/pnv_core.c | 3 +++ hw/ppc/spapr_cpu_core.c | 15 +++++++++++---- 3 files changed, 16 insertions(+), 5 deletions(-)