| Message ID | 1528295806-90593-3-git-send-email-babu.moger@amd.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, Jun 06, 2018 at 10:36:44AM -0400, Babu Moger wrote: > topoext feature cannot be supported in certain cases > with large number of cores or threads. Add the check. > > Signed-off-by: Babu Moger <babu.moger@amd.com> > --- > target/i386/cpu.c | 27 +++++++++++++++++++++++++++ > 1 file changed, 27 insertions(+) > > diff --git a/target/i386/cpu.c b/target/i386/cpu.c > index 86fb1a4..fc5c66d 100644 > --- a/target/i386/cpu.c > +++ b/target/i386/cpu.c > @@ -509,6 +509,20 @@ static void encode_topo_cpuid8000001e(CPUState *cs, X86CPU *cpu, > } > > /* > + * Check if we can support this topology > + * Fail if number of cores are beyond the supported config > + * or nr_threads is more than 2 > + */ > +static int topology_supports_topoext(int nr_cores, int nr_threads) > +{ > + if ((nr_cores > (MAX_CORES_IN_NODE * MAX_NODES_PER_SOCKET)) || > + (nr_threads > 2)) { > + return 0; > + } > + return 1; > +} > + > +/* > * Definitions of the hardcoded cache entries we expose: > * These are legacy cache values. If there is a need to change any > * of these values please use builtin_x86_defs > @@ -4941,6 +4955,19 @@ static void x86_cpu_realizefn(DeviceState *dev, Error **errp) > > qemu_init_vcpu(cs); > > + /* On AMD systems, check if we can support topoext feature */ > + if (IS_AMD_CPU(env) && > + (env->features[FEAT_8000_0001_ECX] & CPUID_EXT3_TOPOEXT)) { > + if (!topology_supports_topoext(cs->nr_cores, cs->nr_threads)) { > + /* Cannot support topoext */ > + error_setg(errp, "CPU model does not support topoext feature " > + "with number of cores(%d) and threads(%d). " > + "Please configure -smp options properly.", > + cs->nr_cores, cs->nr_threads); See error.h documentation: * Error reporting system loosely patterned after Glib's GError. * * Create an error: * error_setg(&err, "situation normal, all fouled up"); * * Create an error and add additional explanation: * error_setg(&err, "invalid quark"); * error_append_hint(&err, "Valid quarks are up, down, strange, " * "charm, top, bottom.\n"); * * Do *not* contract this to * error_setg(&err, "invalid quark\n" * "Valid quarks are up, down, strange, charm, top, bottom."); * I suggest something like this: static bool topology_supports_topoext(int nr_cores, int nr_threads, Error **errp) { if (nr_cores > (MAX_CORES_IN_NODE * MAX_NODES_PER_SOCKET))) { error_setg(errp, "TOPOEXT unsupported with %d cores per socket", nr_cores); error_append_hint(errp, "TOPOEXT supports only up to %d cores per socket", (MAX_CORES_IN_NODE * MAX_NODES_PER_SOCKET)); return false; } if (nr_threads > 2) { error_setg(errp, "TOPOEXT unsupported with %d threads per core", nr_threads); error_append_hint(errp, "TOPOEXT supports only up to 2 threads per core"); (MAX_CORES_IN_NODE * MAX_NODES_PER_SOCKET)); return false; } return true; } static void x86_cpu_realizefn(DeviceState *dev, Error **errp) { /* ... */ if (IS_AMD_CPU(env) && (env->features[FEAT_8000_0001_ECX] & CPUID_EXT3_TOPOEXT) && !topology_supports_topoext(cs->nr_cores, cs->nr_threads, errp)) { return; } /* ... */ }
> -----Original Message----- > From: Eduardo Habkost [mailto:ehabkost@redhat.com] > Sent: Wednesday, June 6, 2018 5:06 PM > To: Moger, Babu <Babu.Moger@amd.com> > Cc: mst@redhat.com; marcel.apfelbaum@gmail.com; pbonzini@redhat.com; > rth@twiddle.net; mtosatti@redhat.com; qemu-devel@nongnu.org; > kvm@vger.kernel.org; kash@tripleback.net; geoff@hostfission.com > Subject: Re: [PATCH v12 2/4] i386: Verify if topoext feature can be supported > > On Wed, Jun 06, 2018 at 10:36:44AM -0400, Babu Moger wrote: > > topoext feature cannot be supported in certain cases > > with large number of cores or threads. Add the check. > > > > Signed-off-by: Babu Moger <babu.moger@amd.com> > > --- > > target/i386/cpu.c | 27 +++++++++++++++++++++++++++ > > 1 file changed, 27 insertions(+) > > > > diff --git a/target/i386/cpu.c b/target/i386/cpu.c > > index 86fb1a4..fc5c66d 100644 > > --- a/target/i386/cpu.c > > +++ b/target/i386/cpu.c > > @@ -509,6 +509,20 @@ static void encode_topo_cpuid8000001e(CPUState > *cs, X86CPU *cpu, > > } > > > > /* > > + * Check if we can support this topology > > + * Fail if number of cores are beyond the supported config > > + * or nr_threads is more than 2 > > + */ > > +static int topology_supports_topoext(int nr_cores, int nr_threads) > > +{ > > + if ((nr_cores > (MAX_CORES_IN_NODE * MAX_NODES_PER_SOCKET)) > || > > + (nr_threads > 2)) { > > + return 0; > > + } > > + return 1; > > +} > > + > > +/* > > * Definitions of the hardcoded cache entries we expose: > > * These are legacy cache values. If there is a need to change any > > * of these values please use builtin_x86_defs > > @@ -4941,6 +4955,19 @@ static void x86_cpu_realizefn(DeviceState *dev, > Error **errp) > > > > qemu_init_vcpu(cs); > > > > + /* On AMD systems, check if we can support topoext feature */ > > + if (IS_AMD_CPU(env) && > > + (env->features[FEAT_8000_0001_ECX] & CPUID_EXT3_TOPOEXT)) { > > + if (!topology_supports_topoext(cs->nr_cores, cs->nr_threads)) { > > + /* Cannot support topoext */ > > + error_setg(errp, "CPU model does not support topoext feature " > > + "with number of cores(%d) and threads(%d). " > > + "Please configure -smp options properly.", > > + cs->nr_cores, cs->nr_threads); > > See error.h documentation: > > * Error reporting system loosely patterned after Glib's GError. > * > * Create an error: > * error_setg(&err, "situation normal, all fouled up"); > * > * Create an error and add additional explanation: > * error_setg(&err, "invalid quark"); > * error_append_hint(&err, "Valid quarks are up, down, strange, " > * "charm, top, bottom.\n"); > * > * Do *not* contract this to > * error_setg(&err, "invalid quark\n" > * "Valid quarks are up, down, strange, charm, top, bottom."); > * > > I suggest something like this: Sure. I will make these changes. Thanks > > static bool topology_supports_topoext(int nr_cores, int nr_threads, Error > **errp) > { > if (nr_cores > (MAX_CORES_IN_NODE * MAX_NODES_PER_SOCKET))) { > error_setg(errp, "TOPOEXT unsupported with %d cores per socket", > nr_cores); > error_append_hint(errp, "TOPOEXT supports only up to %d cores per > socket", > (MAX_CORES_IN_NODE * MAX_NODES_PER_SOCKET)); > return false; > } > if (nr_threads > 2) { > error_setg(errp, "TOPOEXT unsupported with %d threads per core", > nr_threads); > error_append_hint(errp, "TOPOEXT supports only up to 2 threads per > core"); > (MAX_CORES_IN_NODE * MAX_NODES_PER_SOCKET)); > return false; > } > return true; > } > > static void x86_cpu_realizefn(DeviceState *dev, Error **errp) > { > /* ... */ > if (IS_AMD_CPU(env) && > (env->features[FEAT_8000_0001_ECX] & CPUID_EXT3_TOPOEXT) && > !topology_supports_topoext(cs->nr_cores, cs->nr_threads, errp)) { > return; > } > /* ... */ > } > > -- > Eduardo
On Thu, Jun 07, 2018 at 02:24:18PM +0000, Moger, Babu wrote: [...] > > > + /* On AMD systems, check if we can support topoext feature */ > > > + if (IS_AMD_CPU(env) && > > > + (env->features[FEAT_8000_0001_ECX] & CPUID_EXT3_TOPOEXT)) { > > > + if (!topology_supports_topoext(cs->nr_cores, cs->nr_threads)) { > > > + /* Cannot support topoext */ > > > + error_setg(errp, "CPU model does not support topoext feature " > > > + "with number of cores(%d) and threads(%d). " > > > + "Please configure -smp options properly.", > > > + cs->nr_cores, cs->nr_threads); > > > > See error.h documentation: > > > > * Error reporting system loosely patterned after Glib's GError. > > * > > * Create an error: > > * error_setg(&err, "situation normal, all fouled up"); > > * > > * Create an error and add additional explanation: > > * error_setg(&err, "invalid quark"); > > * error_append_hint(&err, "Valid quarks are up, down, strange, " > > * "charm, top, bottom.\n"); > > * > > * Do *not* contract this to > > * error_setg(&err, "invalid quark\n" > > * "Valid quarks are up, down, strange, charm, top, bottom."); > > * > > > > I suggest something like this: > > Sure. I will make these changes. Thanks Thanks. Note that I have made a mistake below, by not including a newline in error_append_hint(). Also, I'm not sure if it's better to mention the current value of nr_cores in error_setg() or just in the error hint. Markus, do you have any suggestion? > > > > > static bool topology_supports_topoext(int nr_cores, int nr_threads, Error > > **errp) > > { > > if (nr_cores > (MAX_CORES_IN_NODE * MAX_NODES_PER_SOCKET))) { > > error_setg(errp, "TOPOEXT unsupported with %d cores per socket", > > nr_cores); > > error_append_hint(errp, "TOPOEXT supports only up to %d cores per > > socket", > > (MAX_CORES_IN_NODE * MAX_NODES_PER_SOCKET)); > > return false; > > } > > if (nr_threads > 2) { > > error_setg(errp, "TOPOEXT unsupported with %d threads per core", > > nr_threads); > > error_append_hint(errp, "TOPOEXT supports only up to 2 threads per > > core"); > > (MAX_CORES_IN_NODE * MAX_NODES_PER_SOCKET)); > > return false; > > } > > return true; > > } > > > > static void x86_cpu_realizefn(DeviceState *dev, Error **errp) > > { > > /* ... */ > > if (IS_AMD_CPU(env) && > > (env->features[FEAT_8000_0001_ECX] & CPUID_EXT3_TOPOEXT) && > > !topology_supports_topoext(cs->nr_cores, cs->nr_threads, errp)) { > > return; > > } > > /* ... */ > > } > > > > -- > > Eduardo
diff --git a/target/i386/cpu.c b/target/i386/cpu.c index 86fb1a4..fc5c66d 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -509,6 +509,20 @@ static void encode_topo_cpuid8000001e(CPUState *cs, X86CPU *cpu, } /* + * Check if we can support this topology + * Fail if number of cores are beyond the supported config + * or nr_threads is more than 2 + */ +static int topology_supports_topoext(int nr_cores, int nr_threads) +{ + if ((nr_cores > (MAX_CORES_IN_NODE * MAX_NODES_PER_SOCKET)) || + (nr_threads > 2)) { + return 0; + } + return 1; +} + +/* * Definitions of the hardcoded cache entries we expose: * These are legacy cache values. If there is a need to change any * of these values please use builtin_x86_defs @@ -4941,6 +4955,19 @@ static void x86_cpu_realizefn(DeviceState *dev, Error **errp) qemu_init_vcpu(cs); + /* On AMD systems, check if we can support topoext feature */ + if (IS_AMD_CPU(env) && + (env->features[FEAT_8000_0001_ECX] & CPUID_EXT3_TOPOEXT)) { + if (!topology_supports_topoext(cs->nr_cores, cs->nr_threads)) { + /* Cannot support topoext */ + error_setg(errp, "CPU model does not support topoext feature " + "with number of cores(%d) and threads(%d). " + "Please configure -smp options properly.", + cs->nr_cores, cs->nr_threads); + return; + } + } + /* Only Intel CPUs support hyperthreading. Even though QEMU fixes this * issue by adjusting CPUID_0000_0001_EBX and CPUID_8000_0008_ECX * based on inputs (sockets,cores,threads), it is still better to gives
topoext feature cannot be supported in certain cases with large number of cores or threads. Add the check. Signed-off-by: Babu Moger <babu.moger@amd.com> --- target/i386/cpu.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+)