| Message ID | 20210928035755.11684-2-wangyanan55@huawei.com |
|---|---|
| State | New |
| Headers | show |
| Series | machine: smp parsing fixes and improvement | expand |
On Tue, Sep 28, 2021 at 11:57:42AM +0800, Yanan Wang wrote: > In the SMP configuration, we should either provide a topology > parameter with a reasonable value (greater than zero) or just > omit it and QEMU will compute the missing value. > > The users shouldn't provide a configuration with any parameter > of it specified as zero (e.g. -smp 8,sockets=0) which could > possibly cause unexpected results in the -smp parsing. So we > deprecate this kind of configurations since 6.2 by adding the > explicit sanity check. > > Signed-off-by: Yanan Wang <wangyanan55@huawei.com> > Reviewed-by: Cornelia Huck <cohuck@redhat.com> > --- > docs/about/deprecated.rst | 15 +++++++++++++++ > hw/core/machine.c | 14 ++++++++++++++ > qapi/machine.json | 2 +- > qemu-options.hx | 12 +++++++----- > 4 files changed, 37 insertions(+), 6 deletions(-) > > diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst > index 3c2be84d80..97415dbecd 100644 > --- a/docs/about/deprecated.rst > +++ b/docs/about/deprecated.rst > @@ -160,6 +160,21 @@ Use ``-display sdl`` instead. > > Use ``-display curses`` instead. > > +``-smp`` ("parameter=0" SMP configurations) (since 6.2) > +''''''''''''''''''''''''''''''''''''''''''''''''''''''' > + > +Specified CPU topology parameters must be greater than zero. > + > +In the SMP configuration, users should either provide a CPU topology > +parameter with a reasonable value (greater than zero) or just omit it > +and QEMU will compute the missing value. > + > +However, historically it was implicitly allowed for users to provide > +a parameter with zero value, which is meaningless and could also possibly > +cause unexpected results in the -smp parsing. So support for this kind of > +configurations (e.g. -smp 8,sockets=0) is deprecated since 6.2 and will > +be removed in the near future, users have to ensure that all the topology > +members described with -smp are greater than zero. > > Plugin argument passing through ``arg=<string>`` (since 6.1) > '''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' > diff --git a/hw/core/machine.c b/hw/core/machine.c > index 067f42b528..711e83db54 100644 > --- a/hw/core/machine.c > +++ b/hw/core/machine.c > @@ -835,6 +835,20 @@ static void machine_set_smp(Object *obj, Visitor *v, const char *name, > return; > } > > + /* > + * Specified CPU topology parameters must be greater than zero, > + * explicit configuration like "cpus=0" is not allowed. > + */ > + if ((config->has_cpus && config->cpus == 0) || > + (config->has_sockets && config->sockets == 0) || > + (config->has_dies && config->dies == 0) || > + (config->has_cores && config->cores == 0) || > + (config->has_threads && config->threads == 0) || > + (config->has_maxcpus && config->maxcpus == 0)) { > + warn_report("Invalid CPU topology deprecated: " > + "CPU topology parameters must be greater than zero"); > + } > + > mc->smp_parse(ms, config, errp); > if (*errp) { > goto out_free; > diff --git a/qapi/machine.json b/qapi/machine.json > index 32d47f4e35..227e75d8af 100644 > --- a/qapi/machine.json > +++ b/qapi/machine.json > @@ -1331,7 +1331,7 @@ > # > # @dies: number of dies per socket in the CPU topology > # > -# @cores: number of cores per thread in the CPU topology > +# @cores: number of cores per die in the CPU topology > # > # @threads: number of threads per core in the CPU topology > # This change is unrelated to the rest of this commit. It just looks like a simple bug fix and should just be spun out into its own patch. > diff --git a/qemu-options.hx b/qemu-options.hx > index 8f603cc7e6..91d859aa29 100644 > --- a/qemu-options.hx > +++ b/qemu-options.hx > @@ -227,11 +227,13 @@ SRST > of computing the CPU maximum count. > > Either the initial CPU count, or at least one of the topology parameters > - must be specified. Values for any omitted parameters will be computed > - from those which are given. Historically preference was given to the > - coarsest topology parameters when computing missing values (ie sockets > - preferred over cores, which were preferred over threads), however, this > - behaviour is considered liable to change. > + must be specified. The specified parameters must be greater than zero, > + explicit configuration like "cpus=0" is not allowed. Values for any > + omitted parameters will be computed from those which are given. > + Historically preference was given to the coarsest topology parameters > + when computing missing values (ie sockets preferred over cores, which > + were preferred over threads), however, this behaviour is considered > + liable to change. > ERST > > DEF("numa", HAS_ARG, QEMU_OPTION_numa, If you split the docs fix out into its own patch then you can add Reviewed-by: Daniel P. Berrangé <berrange@redhat.com> to both this patch and the new patch. Regards, Daniel
On 2021/9/28 17:58, Daniel P. Berrangé wrote: > On Tue, Sep 28, 2021 at 11:57:42AM +0800, Yanan Wang wrote: >> In the SMP configuration, we should either provide a topology >> parameter with a reasonable value (greater than zero) or just >> omit it and QEMU will compute the missing value. >> >> The users shouldn't provide a configuration with any parameter >> of it specified as zero (e.g. -smp 8,sockets=0) which could >> possibly cause unexpected results in the -smp parsing. So we >> deprecate this kind of configurations since 6.2 by adding the >> explicit sanity check. >> >> Signed-off-by: Yanan Wang <wangyanan55@huawei.com> >> Reviewed-by: Cornelia Huck <cohuck@redhat.com> >> --- >> docs/about/deprecated.rst | 15 +++++++++++++++ >> hw/core/machine.c | 14 ++++++++++++++ >> qapi/machine.json | 2 +- >> qemu-options.hx | 12 +++++++----- >> 4 files changed, 37 insertions(+), 6 deletions(-) >> >> diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst >> index 3c2be84d80..97415dbecd 100644 >> --- a/docs/about/deprecated.rst >> +++ b/docs/about/deprecated.rst >> @@ -160,6 +160,21 @@ Use ``-display sdl`` instead. >> >> Use ``-display curses`` instead. >> >> +``-smp`` ("parameter=0" SMP configurations) (since 6.2) >> +''''''''''''''''''''''''''''''''''''''''''''''''''''''' >> + >> +Specified CPU topology parameters must be greater than zero. >> + >> +In the SMP configuration, users should either provide a CPU topology >> +parameter with a reasonable value (greater than zero) or just omit it >> +and QEMU will compute the missing value. >> + >> +However, historically it was implicitly allowed for users to provide >> +a parameter with zero value, which is meaningless and could also possibly >> +cause unexpected results in the -smp parsing. So support for this kind of >> +configurations (e.g. -smp 8,sockets=0) is deprecated since 6.2 and will >> +be removed in the near future, users have to ensure that all the topology >> +members described with -smp are greater than zero. >> >> Plugin argument passing through ``arg=<string>`` (since 6.1) >> '''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' >> diff --git a/hw/core/machine.c b/hw/core/machine.c >> index 067f42b528..711e83db54 100644 >> --- a/hw/core/machine.c >> +++ b/hw/core/machine.c >> @@ -835,6 +835,20 @@ static void machine_set_smp(Object *obj, Visitor *v, const char *name, >> return; >> } >> >> + /* >> + * Specified CPU topology parameters must be greater than zero, >> + * explicit configuration like "cpus=0" is not allowed. >> + */ >> + if ((config->has_cpus && config->cpus == 0) || >> + (config->has_sockets && config->sockets == 0) || >> + (config->has_dies && config->dies == 0) || >> + (config->has_cores && config->cores == 0) || >> + (config->has_threads && config->threads == 0) || >> + (config->has_maxcpus && config->maxcpus == 0)) { >> + warn_report("Invalid CPU topology deprecated: " >> + "CPU topology parameters must be greater than zero"); >> + } >> + >> mc->smp_parse(ms, config, errp); >> if (*errp) { >> goto out_free; >> diff --git a/qapi/machine.json b/qapi/machine.json >> index 32d47f4e35..227e75d8af 100644 >> --- a/qapi/machine.json >> +++ b/qapi/machine.json >> @@ -1331,7 +1331,7 @@ >> # >> # @dies: number of dies per socket in the CPU topology >> # >> -# @cores: number of cores per thread in the CPU topology >> +# @cores: number of cores per die in the CPU topology >> # >> # @threads: number of threads per core in the CPU topology >> # > This change is unrelated to the rest of this commit. > > It just looks like a simple bug fix and should just be > spun out into its own patch. > >> diff --git a/qemu-options.hx b/qemu-options.hx >> index 8f603cc7e6..91d859aa29 100644 >> --- a/qemu-options.hx >> +++ b/qemu-options.hx >> @@ -227,11 +227,13 @@ SRST >> of computing the CPU maximum count. >> >> Either the initial CPU count, or at least one of the topology parameters >> - must be specified. Values for any omitted parameters will be computed >> - from those which are given. Historically preference was given to the >> - coarsest topology parameters when computing missing values (ie sockets >> - preferred over cores, which were preferred over threads), however, this >> - behaviour is considered liable to change. >> + must be specified. The specified parameters must be greater than zero, >> + explicit configuration like "cpus=0" is not allowed. Values for any >> + omitted parameters will be computed from those which are given. >> + Historically preference was given to the coarsest topology parameters >> + when computing missing values (ie sockets preferred over cores, which >> + were preferred over threads), however, this behaviour is considered >> + liable to change. >> ERST >> >> DEF("numa", HAS_ARG, QEMU_OPTION_numa, > If you split the docs fix out into its own patch then you can add Ok, I will split it out. Thanks for the review of this series. Thanks, Yanan > > Reviewed-by: Daniel P. Berrangé <berrange@redhat.com> > > to both this patch and the new patch. > > Regards, > Daniel
diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst index 3c2be84d80..97415dbecd 100644 --- a/docs/about/deprecated.rst +++ b/docs/about/deprecated.rst @@ -160,6 +160,21 @@ Use ``-display sdl`` instead. Use ``-display curses`` instead. +``-smp`` ("parameter=0" SMP configurations) (since 6.2) +''''''''''''''''''''''''''''''''''''''''''''''''''''''' + +Specified CPU topology parameters must be greater than zero. + +In the SMP configuration, users should either provide a CPU topology +parameter with a reasonable value (greater than zero) or just omit it +and QEMU will compute the missing value. + +However, historically it was implicitly allowed for users to provide +a parameter with zero value, which is meaningless and could also possibly +cause unexpected results in the -smp parsing. So support for this kind of +configurations (e.g. -smp 8,sockets=0) is deprecated since 6.2 and will +be removed in the near future, users have to ensure that all the topology +members described with -smp are greater than zero. Plugin argument passing through ``arg=<string>`` (since 6.1) '''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' diff --git a/hw/core/machine.c b/hw/core/machine.c index 067f42b528..711e83db54 100644 --- a/hw/core/machine.c +++ b/hw/core/machine.c @@ -835,6 +835,20 @@ static void machine_set_smp(Object *obj, Visitor *v, const char *name, return; } + /* + * Specified CPU topology parameters must be greater than zero, + * explicit configuration like "cpus=0" is not allowed. + */ + if ((config->has_cpus && config->cpus == 0) || + (config->has_sockets && config->sockets == 0) || + (config->has_dies && config->dies == 0) || + (config->has_cores && config->cores == 0) || + (config->has_threads && config->threads == 0) || + (config->has_maxcpus && config->maxcpus == 0)) { + warn_report("Invalid CPU topology deprecated: " + "CPU topology parameters must be greater than zero"); + } + mc->smp_parse(ms, config, errp); if (*errp) { goto out_free; diff --git a/qapi/machine.json b/qapi/machine.json index 32d47f4e35..227e75d8af 100644 --- a/qapi/machine.json +++ b/qapi/machine.json @@ -1331,7 +1331,7 @@ # # @dies: number of dies per socket in the CPU topology # -# @cores: number of cores per thread in the CPU topology +# @cores: number of cores per die in the CPU topology # # @threads: number of threads per core in the CPU topology # diff --git a/qemu-options.hx b/qemu-options.hx index 8f603cc7e6..91d859aa29 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -227,11 +227,13 @@ SRST of computing the CPU maximum count. Either the initial CPU count, or at least one of the topology parameters - must be specified. Values for any omitted parameters will be computed - from those which are given. Historically preference was given to the - coarsest topology parameters when computing missing values (ie sockets - preferred over cores, which were preferred over threads), however, this - behaviour is considered liable to change. + must be specified. The specified parameters must be greater than zero, + explicit configuration like "cpus=0" is not allowed. Values for any + omitted parameters will be computed from those which are given. + Historically preference was given to the coarsest topology parameters + when computing missing values (ie sockets preferred over cores, which + were preferred over threads), however, this behaviour is considered + liable to change. ERST DEF("numa", HAS_ARG, QEMU_OPTION_numa,