Re: [Qemu-devel] [PATCH for-2.2] pc: acpi: mark all possible CPUs as enabled in SRAT

[Igor Mammedov]

On Mon, 10 Nov 2014 18:40:12 +0100
Paolo Bonzini <address@hidden> wrote:

> 
> 
> On 10/11/2014 17:20, Igor Mammedov wrote:
> > If QEMU is started with  -numa ... Windows only notices that
> > CPU has been hot-added but it will not online such CPUs.
> > 
> > It's caused by the fact that possible CPUs are flagged as
> > not enabled in SRAT and Windows honoring that information
> > doesn't use corresponding CPU.
> > 
> > ACPI 5.0 Spec regarding to flag says:
> > "
> > Table 5-47 Local APIC Flags
> > ...
> > Enabled: if zero, this processor is unusable, and the operating system
> > support will not attempt to use it.
> > "
> > 
> > Fix QEMU to adhere to spec and mark possible CPUs as enabled
> > in SRAT.
> > 
> > With that Windows onlines hot-added CPUs as expected.
> > 
> > Signed-off-by: Igor Mammedov <address@hidden>
> 
> Does this need to be specific to pc-2.2?
Why not, It's bug fix.
But I don't care if it's merged later.


> 
> Paolo
> 
> > ---
> >  hw/i386/acpi-build.c | 11 +++--------
> >  1 file changed, 3 insertions(+), 8 deletions(-)
> > 
> > diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
> > index 4003b6b..06499da 100644
> > --- a/hw/i386/acpi-build.c
> > +++ b/hw/i386/acpi-build.c
> > @@ -1269,8 +1269,7 @@ acpi_build_srat_memory(AcpiSratMemoryAffinity 
> > *numamem, uint64_t base,
> >  }
> >  
> >  static void
> > -build_srat(GArray *table_data, GArray *linker,
> > -           AcpiCpuInfo *cpu, PcGuestInfo *guest_info)
> > +build_srat(GArray *table_data, GArray *linker, PcGuestInfo *guest_info)
> >  {
> >      AcpiSystemResourceAffinityTable *srat;
> >      AcpiSratProcessorAffinity *core;
> > @@ -1300,11 +1299,7 @@ build_srat(GArray *table_data, GArray *linker,
> >          core->proximity_lo = curnode;
> >          memset(core->proximity_hi, 0, 3);
> >          core->local_sapic_eid = 0;
> > -        if (test_bit(i, cpu->found_cpus)) {
> > -            core->flags = cpu_to_le32(1);
> > -        } else {
> > -            core->flags = cpu_to_le32(0);
> > -        }
> > +        core->flags = cpu_to_le32(1);
> >      }
> >  
> >  
> > @@ -1622,7 +1617,7 @@ void acpi_build(PcGuestInfo *guest_info, 
> > AcpiBuildTables *tables)
> >      }
> >      if (guest_info->numa_nodes) {
> >          acpi_add_table(table_offsets, tables->table_data);
> > -        build_srat(tables->table_data, tables->linker, &cpu, guest_info);
> > +        build_srat(tables->table_data, tables->linker, guest_info);
> >      }
> >      if (acpi_get_mcfg(&mcfg)) {
> >          acpi_add_table(table_offsets, tables->table_data);
> >