On Thu, 1 Jun 2023 17:29:52 +0800 Zhao Liu <zhao1....@linux.intel.com> wrote:
> From: Zhao Liu <zhao1....@intel.com> > > From SMBIOS 3.0 specification, core count field means: > > Core Count is the number of cores detected by the BIOS for this > processor socket. [1] > > Before 003f230e37d7 ("machine: Tweak the order of topology members in > struct CpuTopology"), MachineState.smp.cores means "the number of cores > in one package", and it's correct to use smp.cores for core count. > > But 003f230e37d7 changes the smp.cores' meaning to "the number of cores > in one die" and doesn't change the original smp.cores' use in smbios as > well, which makes core count in type4 go wrong. > > Fix this issue with the correct "cores per socket" caculation. see comment on 2/3 patch and do the same for cores. > > [1] SMBIOS 3.0.0, section 7.5.6, Processor Information - Core Count > > Fixes: 003f230e37d7 ("machine: Tweak the order of topology members in struct > CpuTopology") > Signed-off-by: Zhao Liu <zhao1....@intel.com> > --- > Changes since v1: > * Calculate cores_per_socket in a different way from > threads_per_socket. > * Add the sanity check to ensure consistency of results between these 2 > ways. This can help not miss any future change of cpu topology. > --- > hw/smbios/smbios.c | 13 +++++++++++-- > 1 file changed, 11 insertions(+), 2 deletions(-) > > diff --git a/hw/smbios/smbios.c b/hw/smbios/smbios.c > index faf82d4ae646..2b46a51dfcad 100644 > --- a/hw/smbios/smbios.c > +++ b/hw/smbios/smbios.c > @@ -714,6 +714,7 @@ static void smbios_build_type_4_table(MachineState *ms, > unsigned instance) > char sock_str[128]; > size_t tbl_len = SMBIOS_TYPE_4_LEN_V28; > unsigned threads_per_socket; > + unsigned cores_per_socket; > > if (smbios_ep_type == SMBIOS_ENTRY_POINT_TYPE_64) { > tbl_len = SMBIOS_TYPE_4_LEN_V30; > @@ -750,8 +751,16 @@ static void smbios_build_type_4_table(MachineState *ms, > unsigned instance) > > /* smp.max_cpus is the total number of threads for the system. */ > threads_per_socket = ms->smp.max_cpus / ms->smp.sockets; > + cores_per_socket = ms->smp.cores * ms->smp.clusters * ms->smp.dies; > > - t->core_count = (ms->smp.cores > 255) ? 0xFF : ms->smp.cores; > + /* > + * Currently, max_cpus = threads * cores * clusters * dies * sockets. > + * threads_per_socket and cores_per_socket are calculated in 2 ways so > + * that this sanity check ensures we won't miss any topology level. > + */ > + g_assert(cores_per_socket == (threads_per_socket / ms->smp.threads)); > + > + t->core_count = (cores_per_socket > 255) ? 0xFF : cores_per_socket; > t->core_enabled = t->core_count; > > t->thread_count = (threads_per_socket > 255) ? 0xFF : threads_per_socket; > @@ -760,7 +769,7 @@ static void smbios_build_type_4_table(MachineState *ms, > unsigned instance) > t->processor_family2 = cpu_to_le16(0x01); /* Other */ > > if (tbl_len == SMBIOS_TYPE_4_LEN_V30) { > - t->core_count2 = t->core_enabled2 = cpu_to_le16(ms->smp.cores); > + t->core_count2 = t->core_enabled2 = cpu_to_le16(cores_per_socket); > t->thread_count2 = cpu_to_le16(threads_per_socket); > } >