| Message ID | 1334515144-26485-9-git-send-email-afaerber@suse.de |
|---|---|
| State | New |
| Headers | show |
On 04/15/2012 09:38 PM, Andreas Färber wrote: > From: David Gibson <david@gibson.dropbear.id.au> > > On target-ppc, our table of CPU types and features encodes the features as > found on the hardware, regardless of whether these features are actually > usable under TCG or KVM. We already have cases where the information from > the cpu table must be fixed up to account for limitations in the emulation > method we're using. e.g. TCG does not support the DFP and VSX instructions > and KVM needs different numbering of the CPUs in order to tell it the > correct thread to core mappings. > > This patch cleans up these hacks to handle emulation limitations by > consolidating them into a pair of functions specifically for the purpose. > > env->check_pow = def->check_pow; > + > + if (kvm_enabled()) { > + if (kvmppc_fixup_cpu(env) != 0) { > + fprintf(stderr, "Unable to virtualize selected CPU with KVM\n"); > + exit(1); > + } > + } else { > + if (ppc_fixup_cpu(env) != 0) { > + fprintf(stderr, "Unable to emulate selected CPU with TCG\n"); > + exit(1); > + } > + } > + > I wish we had an error like that for x86. Right now we silently add and drop cpu features.
Am 16.04.2012 12:13, schrieb Avi Kivity: > On 04/15/2012 09:38 PM, Andreas Färber wrote: >> From: David Gibson <david@gibson.dropbear.id.au> >> >> On target-ppc, our table of CPU types and features encodes the features as >> found on the hardware, regardless of whether these features are actually >> usable under TCG or KVM. We already have cases where the information from >> the cpu table must be fixed up to account for limitations in the emulation >> method we're using. e.g. TCG does not support the DFP and VSX instructions >> and KVM needs different numbering of the CPUs in order to tell it the >> correct thread to core mappings. >> >> This patch cleans up these hacks to handle emulation limitations by >> consolidating them into a pair of functions specifically for the purpose. >> >> env->check_pow = def->check_pow; >> + >> + if (kvm_enabled()) { >> + if (kvmppc_fixup_cpu(env) != 0) { >> + fprintf(stderr, "Unable to virtualize selected CPU with KVM\n"); >> + exit(1); >> + } >> + } else { >> + if (ppc_fixup_cpu(env) != 0) { >> + fprintf(stderr, "Unable to emulate selected CPU with TCG\n"); >> + exit(1); >> + } >> + } >> + >> > > I wish we had an error like that for x86. Right now we silently add and > drop cpu features. x86 has an ,+enforce option for that, doesn't it? Andreas
On 04/16/2012 01:19 PM, Andreas Färber wrote: > Am 16.04.2012 12:13, schrieb Avi Kivity: > > On 04/15/2012 09:38 PM, Andreas Färber wrote: > >> From: David Gibson <david@gibson.dropbear.id.au> > >> > >> On target-ppc, our table of CPU types and features encodes the features as > >> found on the hardware, regardless of whether these features are actually > >> usable under TCG or KVM. We already have cases where the information from > >> the cpu table must be fixed up to account for limitations in the emulation > >> method we're using. e.g. TCG does not support the DFP and VSX instructions > >> and KVM needs different numbering of the CPUs in order to tell it the > >> correct thread to core mappings. > >> > >> This patch cleans up these hacks to handle emulation limitations by > >> consolidating them into a pair of functions specifically for the purpose. > >> > >> env->check_pow = def->check_pow; > >> + > >> + if (kvm_enabled()) { > >> + if (kvmppc_fixup_cpu(env) != 0) { > >> + fprintf(stderr, "Unable to virtualize selected CPU with KVM\n"); > >> + exit(1); > >> + } > >> + } else { > >> + if (ppc_fixup_cpu(env) != 0) { > >> + fprintf(stderr, "Unable to emulate selected CPU with TCG\n"); > >> + exit(1); > >> + } > >> + } > >> + > >> > > > > I wish we had an error like that for x86. Right now we silently add and > > drop cpu features. > > x86 has an ,+enforce option for that, doesn't it? > So it does. And one day it will be the default.
diff --git a/target-ppc/helper.c b/target-ppc/helper.c index f61b8b2..b34dcbe 100644 --- a/target-ppc/helper.c +++ b/target-ppc/helper.c @@ -3198,15 +3198,6 @@ CPUPPCState *cpu_ppc_init (const char *cpu_model) if (tcg_enabled()) { ppc_translate_init(); } - /* Adjust cpu index for SMT */ -#if !defined(CONFIG_USER_ONLY) - if (kvm_enabled()) { - int smt = kvmppc_smt_threads(); - - env->cpu_index = (env->cpu_index / smp_threads)*smt - + (env->cpu_index % smp_threads); - } -#endif /* !CONFIG_USER_ONLY */ env->cpu_model_str = cpu_model; cpu_ppc_register_internal(env, def); diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c index d929213..c09cc39 100644 --- a/target-ppc/kvm.c +++ b/target-ppc/kvm.c @@ -27,6 +27,7 @@ #include "kvm.h" #include "kvm_ppc.h" #include "cpu.h" +#include "cpus.h" #include "device_tree.h" #include "hw/sysbus.h" #include "hw/spapr.h" @@ -938,6 +939,19 @@ const ppc_def_t *kvmppc_host_cpu_def(void) return spec; } +int kvmppc_fixup_cpu(CPUPPCState *env) +{ + int smt; + + /* Adjust cpu index for SMT */ + smt = kvmppc_smt_threads(); + env->cpu_index = (env->cpu_index / smp_threads) * smt + + (env->cpu_index % smp_threads); + + return 0; +} + + bool kvm_arch_stop_on_emulation_error(CPUPPCState *env) { return true; diff --git a/target-ppc/kvm_ppc.h b/target-ppc/kvm_ppc.h index 8f1267c..34ecad3 100644 --- a/target-ppc/kvm_ppc.h +++ b/target-ppc/kvm_ppc.h @@ -29,6 +29,7 @@ void *kvmppc_create_spapr_tce(uint32_t liobn, uint32_t window_size, int *pfd); int kvmppc_remove_spapr_tce(void *table, int pfd, uint32_t window_size); #endif /* !CONFIG_USER_ONLY */ const ppc_def_t *kvmppc_host_cpu_def(void); +int kvmppc_fixup_cpu(CPUPPCState *env); #else @@ -95,6 +96,10 @@ static inline const ppc_def_t *kvmppc_host_cpu_def(void) return NULL; } +static inline int kvmppc_fixup_cpu(CPUPPCState *env) +{ + return -1; +} #endif #ifndef CONFIG_KVM diff --git a/target-ppc/translate_init.c b/target-ppc/translate_init.c index b1f8785..067e07e 100644 --- a/target-ppc/translate_init.c +++ b/target-ppc/translate_init.c @@ -9889,6 +9889,28 @@ static int gdb_set_spe_reg(CPUPPCState *env, uint8_t *mem_buf, int n) return 0; } +static int ppc_fixup_cpu(CPUPPCState *env) +{ + /* TCG doesn't (yet) emulate some groups of instructions that + * are implemented on some otherwise supported CPUs (e.g. VSX + * and decimal floating point instructions on POWER7). We + * remove unsupported instruction groups from the cpu state's + * instruction masks and hope the guest can cope. For at + * least the pseries machine, the unavailability of these + * instructions can be advertised to the guest via the device + * tree. */ + if ((env->insns_flags & ~PPC_TCG_INSNS) + || (env->insns_flags2 & ~PPC_TCG_INSNS2)) { + fprintf(stderr, "Warning: Disabling some instructions which are not " + "emulated by TCG (0x%" PRIx64 ", 0x%" PRIx64 ")\n", + env->insns_flags & ~PPC_TCG_INSNS, + env->insns_flags2 & ~PPC_TCG_INSNS2); + } + env->insns_flags &= PPC_TCG_INSNS; + env->insns_flags2 &= PPC_TCG_INSNS2; + return 0; +} + int cpu_ppc_register_internal (CPUPPCState *env, const ppc_def_t *def) { env->msr_mask = def->msr_mask; @@ -9897,25 +9919,22 @@ int cpu_ppc_register_internal (CPUPPCState *env, const ppc_def_t *def) env->bus_model = def->bus_model; env->insns_flags = def->insns_flags; env->insns_flags2 = def->insns_flags2; - if (!kvm_enabled()) { - /* TCG doesn't (yet) emulate some groups of instructions that - * are implemented on some otherwise supported CPUs (e.g. VSX - * and decimal floating point instructions on POWER7). We - * remove unsupported instruction groups from the cpu state's - * instruction masks and hope the guest can cope. For at - * least the pseries machine, the unavailability of these - * instructions can be advertise to the guest via the device - * tree. - * - * FIXME: we should have a similar masking for CPU features - * not accessible under KVM, but so far, there aren't any of - * those. */ - env->insns_flags &= PPC_TCG_INSNS; - env->insns_flags2 &= PPC_TCG_INSNS2; - } env->flags = def->flags; env->bfd_mach = def->bfd_mach; env->check_pow = def->check_pow; + + if (kvm_enabled()) { + if (kvmppc_fixup_cpu(env) != 0) { + fprintf(stderr, "Unable to virtualize selected CPU with KVM\n"); + exit(1); + } + } else { + if (ppc_fixup_cpu(env) != 0) { + fprintf(stderr, "Unable to emulate selected CPU with TCG\n"); + exit(1); + } + } + if (create_ppc_opcodes(env, def) < 0) return -1; init_ppc_proc(env, def);