[Qemu-devel] [PATCH v3 0/9] Introduce cpu die topology and enable CPUID.1F for i386

[Like Xu <like.xu@linux.intel.com>]

Multi-chip packaging technology allows integration of multi-cores in one die
and multi-dies in one single package, for example Intel CLX-AP or AMD EPYC.

This patch series extend the CPU topology to the socket/dies/core/thread model,
allowing the setting of dies number per one socket on -smp qemu command. For
i386, it upgrades APIC_IDs generation and reversion functions with a new exposed
leaf called CPUID.1F, which is a preferred superset to leaf 0BH. The CPUID.1F
spec is on https://software.intel.com/en-us/articles/intel-sdm, 3-190 Vol 2A.

E.g. we use -smp 4,dies=2,cores=2,threads=1 to run a multi-dies guest and
check raw cpuid data and the expected output from guest is following:
0x0000001f 0x00: eax=0x00000000 ebx=0x00000001 ecx=0x00000100 edx=0x00000002
0x0000001f 0x01: eax=0x00000001 ebx=0x00000002 ecx=0x00000201 edx=0x00000001
0x0000001f 0x02: eax=0x00000002 ebx=0x00000004 ecx=0x00000502 edx=0x00000003
0x0000001f 0x03: eax=0x00000000 ebx=0x00000000 ecx=0x00000003 edx=0x00000001

Guest system could discover multi-die/package topology through CPUID.1F.
and its benefit is primarily for _reporting_ of the (virtual) CPU topology.
The guest kernel with multi-die/package support have no impact on its 
cache topology, NUMA topology, Linux scheduler, or system performance. 

==changelog==

v3:

- add a MachineClass::smp_parse function pointer
- place the PC-specific function inside hw/i386/pc.c
- introduce die_id in a separate patch with default value 0
- set env->nr_dies in pc_new_cpu() and pc_cpu_pre_plug()
- fix a circular dependency between target/i386/cpu.c and hw/i386/pc.c
- fix cpu->die_id check in pc_cpu_pre_plug()
- Based on "[PATCH v3 00/10] Refactor cpu topo into machine properties"
- Rebase to commit 219dca61ebf41625831d4f96a720852baf44b762

v2: https://patchwork.kernel.org/cover/10953191/

- Enable cpu die-level topolgy only for PCMachine and X86CPU
- Minimize cpuid.0.eax to the setting value actually used by guest
- Update cmd line -smps docs for die-level configurations
- Refactoring topo-bit tests for x86_apicid_from_cpu_idx() with nr_dies
- Based on "[PATCH v3 00/10] Refactor cpu topo into machine properties"
- Rebase to commit 2259637b95bef3116cc262459271de08e038cc66

v1: https://patchwork.kernel.org/cover/10876667/

Like Xu (9):
  i386: Add die-level cpu topology to x86CPU on PCMachine
  hw/i386: Adjust nr_dies with configured smp_dies for PCMachine
  i386/cpu: Consolidate die-id validity in smp context
  i386: Update new x86_apicid parsing rules with die_offset support
  tests/x86-cpuid: Update testcases in test_topo_bits() with multiple dies
  i386/cpu: Add CPUID.1F generation support for multi-dies PCMachine
  target/i386: Support multi-dies when host doesn't support CPUID.1F
  machine: Refactor smp_parse() in vl.c as MachineClass::smp_parse()
  vl.c: Add -smp, dies=* command line support and update doc

 hmp.c                      |   3 +
 hw/core/machine.c          |  89 ++++++++++++++++++++++
 hw/i386/pc.c               | 148 ++++++++++++++++++++++++++++++++-----
 include/hw/boards.h        |   5 ++
 include/hw/i386/pc.h       |   3 +
 include/hw/i386/topology.h |  76 +++++++++++++------
 qapi/misc.json             |   6 +-
 qemu-options.hx            |  17 +++--
 target/i386/cpu.c          |  53 +++++++++++--
 target/i386/cpu.h          |   7 ++
 target/i386/kvm.c          |  36 ++++++++-
 tests/test-x86-cpuid.c     |  84 +++++++++++----------
 vl.c                       |  78 ++-----------------
 13 files changed, 438 insertions(+), 167 deletions(-)

-- 
2.21.0