Re: [PATCH v7 0/2] Remove EPYC mode apicid decode and use generic decode

[Michael S. Tsirkin]

On Tue, Sep 01, 2020 at 10:57:20AM -0500, Babu Moger wrote:
> To support some of the complex topology, we introduced EPYC mode apicid 
> decode.
> But, EPYC mode decode is running into problems. Also it can become quite a
> maintenance problem in the future. So, it was decided to remove that code and
> use the generic decode which works for majority of the topology. Most of the
> SPECed configuration would work just fine. With some non-SPECed user inputs,
> it will create some sub-optimal configuration.
> 
> Here is the discussion thread.
> https://lore.kernel.org/qemu-devel/c0bcc1a6-1d84-a6e7-e468-d5b437c1b254@amd.com/
> https://lore.kernel.org/qemu-devel/20200826143849.59f6970b@redhat.com/
> 
> This series removes all the EPYC mode specific apicid changes and use the 
> generic
> apicid decode.

PC, x86 changes:

Acked-by: Michael S. Tsirkin <mst@redhat.com>

Feel free to merge.

> ---
> v7:
>  Eduardo has already queued 1-8 from the v6. Sending rest of the patches.
>  Fixed CPUID 800000ld based on Igor's comment and few text changes.
>  
> v6:
>  
> https://lore.kernel.org/qemu-devel/159889924378.21294.16494070903874534542.stgit@naples-babu.amd.com/
>  Found out that numa configuration is not mandatory for all the EPYC model 
> topology.
>  We can use the generic decode which works pretty well. Also noticed that
>  cpuid does not changes when the numa nodes change(NPS- Nodes per socket).
>  Took care of couple comments from Igor and Eduardo.
>  Thank you Igor, Daniel, David, Eduardo for your feedback.  
> 
> v5:
>  
> https://lore.kernel.org/qemu-devel/159804762216.39954.15502128500494116468.stgit@naples-babu.amd.com/
>  Revert EPYC specific decode.
>  Simplify CPUID_8000_001E
> 
> v4:
>   
> https://lore.kernel.org/qemu-devel/159744083536.39197.13827776633866601278.stgit@naples-babu.amd.com/
>   Not much of a change. Just added few text changes.
>   Error out configuration instead of warning if dies are not configured in 
> EPYC.
>   Few other text changes to clarify the removal of node_id, nr_nodes and 
> nodes_per_pkg.
> 
> v3:
>   
> https://lore.kernel.org/qemu-devel/159681772267.9679.1334429994189974662.stgit@naples-babu.amd.com/#r
>   Added a new check to pass the dies for EPYC numa configuration.
>   Added Simplify CPUID_8000_001E patch with some changes suggested by Igor.
>   Dropped the patch to build the topology from CpuInstanceProperties.
>   TODO: Not sure if we still need the Autonuma changes Igor mentioned.
>   Needs more clarity on that.
> 
> v2:
>   
> https://lore.kernel.org/qemu-devel/159362436285.36204.986406297373871949.stgit@naples-babu.amd.com/
>   Used the numa information from CpuInstanceProperties for building
>   the apic_id suggested by Igor.
>   Also did some minor code re-aarangement to take care of changes.
>   Dropped the patch "Simplify CPUID_8000_001E" from v1. Will send
>   it later.
> 
> v1:
>  
> https://lore.kernel.org/qemu-devel/159164739269.20543.3074052993891532749.stgit@naples-babu.amd.com
> 
> Babu Moger (2):
>       i386: Simplify CPUID_8000_001d for AMD
>       i386: Simplify CPUID_8000_001E for AMD
> 
> 
>  target/i386/cpu.c |  226 
> ++++++++++++++---------------------------------------
>  1 file changed, 61 insertions(+), 165 deletions(-)
> 
> --