diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c index 067f571416..caffa12763 100644 --- a/hw/ppc/spapr.c +++ b/hw/ppc/spapr.c @@ -26,6 +26,7 @@ */ #include "qemu/osdep.h" #include "qapi/error.h" +#include "qapi/visitor.h" #include "sysemu/sysemu.h" #include "sysemu/numa.h" #include "hw/hw.h" @@ -2165,6 +2166,61 @@ static void spapr_init_cpus(sPAPRMachineState *spapr) g_free(type); } +static void spapr_set_vsmt_mode(sPAPRMachineState *spapr, Error **errp) +{ + Error *local_err = NULL; + bool vsmt_user = !!spapr->vsmt; + int kvm_smt = kvmppc_smt_threads(); + int ret; + + if (!kvm_enabled() && (smp_threads > 1)) { + error_setg(&local_err, "TCG cannot support more than 1 thread/core " + "on a pseries machine"); + goto out; + } + if (!is_power_of_2(smp_threads)) { + error_setg(&local_err, "Cannot support %d threads/core on a pseries " + "machine because it must be a power of 2", smp_threads); + goto out; + } + + /* Detemine the VSMT mode to use: */ + if (vsmt_user) { + if (spapr->vsmt < smp_threads) { + error_setg(&local_err, "Cannot support VSMT mode %d" + " because it must be >= threads/core (%d)", + spapr->vsmt, smp_threads); + goto out; + } + /* In this case, spapr->vsmt has been set by the command line */ + } else { + /* Choose a VSMT mode that may be higher than necessary but is + * likely to be compatible with hosts that don't have VSMT. */ + spapr->vsmt = MAX(kvm_smt, smp_threads); + } + + /* KVM: If necessary, set the SMT mode: */ + if (kvm_enabled() && (spapr->vsmt != kvm_smt)) { + ret = kvmppc_set_smt_threads(spapr->vsmt); + if (ret) { + error_setg(&local_err, + "Failed to set KVM's VSMT mode to %d (errno %d)", + spapr->vsmt, ret); + if (!vsmt_user) { + error_append_hint(&local_err, "On PPC, a VM with %d threads/" + "core on a host with %d threads/core requires " + " the use of VSMT mode %d.\n", + smp_threads, kvm_smt, spapr->vsmt); + } + kvmppc_hint_smt_possible(&local_err); + goto out; + } + } + /* else TCG: nothing to do currently */ +out: + error_propagate(errp, local_err); +} + /* pSeries LPAR / sPAPR hardware init */ static void ppc_spapr_init(MachineState *machine) { @@ -2297,6 +2353,8 @@ static void ppc_spapr_init(MachineState *machine) spapr_cpu_parse_features(spapr); + spapr_set_vsmt_mode(spapr, &error_fatal); + spapr_init_cpus(spapr); if (kvm_enabled()) { @@ -2681,6 +2739,18 @@ static void spapr_set_resize_hpt(Object *obj, const char *value, Error **errp) } } +static void spapr_get_vsmt(Object *obj, Visitor *v, const char *name, + void *opaque, Error **errp) +{ + visit_type_uint32(v, name, (uint32_t *)opaque, errp); +} + +static void spapr_set_vsmt(Object *obj, Visitor *v, const char *name, + void *opaque, Error **errp) +{ + visit_type_uint32(v, name, (uint32_t *)opaque, errp); +} + static void spapr_machine_initfn(Object *obj) { sPAPRMachineState *spapr = SPAPR_MACHINE(obj); @@ -2711,6 +2781,11 @@ static void spapr_machine_initfn(Object *obj) object_property_set_description(obj, "resize-hpt", "Resizing of the Hash Page Table (enabled, disabled, required)", NULL); + object_property_add(obj, "vsmt", "uint32", spapr_get_vsmt, + spapr_set_vsmt, NULL, &spapr->vsmt, &error_abort); + object_property_set_description(obj, "vsmt", + "Virtual SMT: KVM behaves as if this were" + " the host's SMT mode", &error_abort); } static void spapr_machine_finalizefn(Object *obj) diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h index 91617e3277..c1b365f564 100644 --- a/include/hw/ppc/spapr.h +++ b/include/hw/ppc/spapr.h @@ -99,6 +99,7 @@ struct sPAPRMachineState { uint64_t rtc_offset; /* Now used only during incoming migration */ struct PPCTimebase tb; bool has_graphics; + uint32_t vsmt; /* Virtual SMT mode (KVM's "core stride") */ Notifier epow_notifier; QTAILQ_HEAD(, sPAPREventLogEntry) pending_events; diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c index f1d54106ac..b6bd0fa7a6 100644 --- a/target/ppc/kvm.c +++ b/target/ppc/kvm.c @@ -74,6 +74,7 @@ static int cap_interrupt_level = false; static int cap_segstate; static int cap_booke_sregs; static int cap_ppc_smt; +static int cap_ppc_smt_possible; static int cap_ppc_rma; static int cap_spapr_tce; static int cap_spapr_tce_64; @@ -130,7 +131,7 @@ int kvm_arch_init(MachineState *ms, KVMState *s) cap_interrupt_level = kvm_check_extension(s, KVM_CAP_PPC_IRQ_LEVEL); cap_segstate = kvm_check_extension(s, KVM_CAP_PPC_SEGSTATE); cap_booke_sregs = kvm_check_extension(s, KVM_CAP_PPC_BOOKE_SREGS); - cap_ppc_smt = kvm_check_extension(s, KVM_CAP_PPC_SMT); + cap_ppc_smt_possible = kvm_check_extension(s, KVM_CAP_PPC_SMT_POSSIBLE); cap_ppc_rma = kvm_check_extension(s, KVM_CAP_PPC_RMA); cap_spapr_tce = kvm_check_extension(s, KVM_CAP_SPAPR_TCE); cap_spapr_tce_64 = kvm_check_extension(s, KVM_CAP_SPAPR_TCE_64); @@ -144,6 +145,7 @@ int kvm_arch_init(MachineState *ms, KVMState *s) * only activated after this by kvmppc_set_papr() */ cap_htab_fd = kvm_check_extension(s, KVM_CAP_PPC_HTAB_FD); cap_fixup_hcalls = kvm_check_extension(s, KVM_CAP_PPC_FIXUP_HCALL); + cap_ppc_smt = kvm_vm_check_extension(s, KVM_CAP_PPC_SMT); cap_htm = kvm_vm_check_extension(s, KVM_CAP_PPC_HTM); cap_mmu_radix = kvm_vm_check_extension(s, KVM_CAP_PPC_MMU_RADIX); cap_mmu_hash_v3 = kvm_vm_check_extension(s, KVM_CAP_PPC_MMU_HASH_V3); @@ -2134,6 +2136,41 @@ int kvmppc_smt_threads(void) return cap_ppc_smt ? cap_ppc_smt : 1; } +int kvmppc_set_smt_threads(int smt) +{ + int ret; + + ret = kvm_vm_enable_cap(kvm_state, KVM_CAP_PPC_SMT, 0, smt, 0); + if (!ret) { + cap_ppc_smt = smt; + } + return ret; +} + +void kvmppc_hint_smt_possible(Error **errp) +{ + int i; + GString *g; + char *s; + + assert(kvm_enabled()); + if (cap_ppc_smt_possible) { + g = g_string_new("Available VSMT modes:"); + for (i = 63; i >= 0; i--) { + if ((1UL << i) & cap_ppc_smt_possible) { + g_string_append_printf(g, " %lu", (1UL << i)); + } + } + s = g_string_free(g, false); + error_append_hint(errp, "%s.\n", s); + g_free(s); + } else { + error_append_hint(errp, + "This KVM seems to be too old to support VSMT.\n"); + } +} + + #ifdef TARGET_PPC64 off_t kvmppc_alloc_rma(void **rma) { diff --git a/target/ppc/kvm_ppc.h b/target/ppc/kvm_ppc.h index 381afe6240..e6711fc2b7 100644 --- a/target/ppc/kvm_ppc.h +++ b/target/ppc/kvm_ppc.h @@ -29,6 +29,8 @@ void kvmppc_set_papr(PowerPCCPU *cpu); int kvmppc_set_compat(PowerPCCPU *cpu, uint32_t compat_pvr); void kvmppc_set_mpic_proxy(PowerPCCPU *cpu, int mpic_proxy); int kvmppc_smt_threads(void); +void kvmppc_hint_smt_possible(Error **errp); +int kvmppc_set_smt_threads(int smt); int kvmppc_clear_tsr_bits(PowerPCCPU *cpu, uint32_t tsr_bits); int kvmppc_or_tsr_bits(PowerPCCPU *cpu, uint32_t tsr_bits); int kvmppc_set_tcr(PowerPCCPU *cpu); @@ -148,6 +150,16 @@ static inline int kvmppc_smt_threads(void) return 1; } +static inline void kvmppc_hint_smt_possible(Error **errp) +{ + return; +} + +static inline int kvmppc_set_smt_threads(int smt) +{ + return 0; +} + static inline int kvmppc_or_tsr_bits(PowerPCCPU *cpu, uint32_t tsr_bits) { return 0; diff --git a/target/ppc/translate_init.c b/target/ppc/translate_init.c index 08ef74f064..703ea12f2a 100644 --- a/target/ppc/translate_init.c +++ b/target/ppc/translate_init.c @@ -9907,20 +9907,6 @@ static void ppc_cpu_realizefn(DeviceState *dev, Error **errp) int max_smt = kvmppc_smt_threads(); #endif -#if !defined(CONFIG_USER_ONLY) - if (smp_threads > max_smt) { - error_setg(errp, "Cannot support more than %d threads on PPC with %s", - max_smt, kvm_enabled() ? "KVM" : "TCG"); - return; - } - if (!is_power_of_2(smp_threads)) { - error_setg(errp, "Cannot support %d threads on PPC with %s, " - "threads count must be a power of 2.", - smp_threads, kvm_enabled() ? "KVM" : "TCG"); - return; - } -#endif - cpu_exec_realizefn(cs, &local_err); if (local_err != NULL) { error_propagate(errp, local_err);