[PATCH RESEND v4 0/3] x86/apic: Add support for additional AMD EILVT registers

[Naveen N Rao (AMD)]

Add support for additional APIC EILVT registers being introduced in 
future AMD processors:
https://docs.amd.com/v/u/en-US/69205_1.00_AMD64_IBS_PUB)

This is a resend of v4, rebased on tip/master. Previous posting:
http://lore.kernel.org/r/cover.1784785046.git.naveen@xxxxxxxxxx

Since then:
- I have retained the macro name 'APIC_EILVT_NR_AMD_10H' since I felt it 
  is accurate, and didn't hear a preference for anything else. Happy to 
  change if needed (Ingo)
- I have gone through Sashiko's findings on the previous versions, and 
  none of those justified a change. Other than the pre-existing issues
  reported by Sashiko, there have been 3 findings:
  1. Sashiko seems to be confusing the Max LVT Register index field in 
     APIC Version Register, with the EILVT Count in EFEAT. The former is 
     the maximum index, while the latter is the count.
  2. Secure AVIC driver handling of EILVTs: that is not impacted by this 
     change since the driver never consults the hypervisor value today. 
     The driver will require separate changes regardless.
  3. Need to clamp the maximum EILVT register count to prevent incorrect 
     MMIO accesses: this is not an issue since all offsets being 
     programmed are appropriately clamped at the source.


- Naveen



Naveen N Rao (AMD) (3):
  perf/amd/ibs: Limit the max EILVT register count for AMD family 0x10
  x86/apic: Introduce a variable to track the number of EILVT registers
  x86/apic: Drop APIC_EILVT_NR_MAX

 arch/x86/include/asm/apic.h    |  2 ++
 arch/x86/include/asm/apicdef.h |  2 +-
 arch/x86/events/amd/ibs.c      |  4 ++--
 arch/x86/kernel/apic/apic.c    | 17 +++++++++++++++--
 4 files changed, 20 insertions(+), 5 deletions(-)


base-commit: 461735aa6e8e357fb90d2cf827d2b15ce78a1bc7
-- 
2.55.0