mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: "Naveen N Rao (AMD)" <naveen@kernel.org>
To: Borislav Petkov <bp@alien8.de>,
	Dave Hansen <dave.hansen@linux.intel.com>
Cc: <linux-kernel@vger.kernel.org>, <x86@kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Bharata B Rao <bharata@amd.com>,
	Manali Shukla <manali.shukla@amd.com>,
	Nikunj A Dadhania <nikunj@amd.com>,
	"H. Peter Anvin" <hpa@zytor.com>
Subject: [PATCH RESEND v4 0/3] x86/apic: Add support for additional AMD EILVT registers
Date: Thu,  3 Sep 2026 14:58:38 +0530	[thread overview]
Message-ID: <cover.1788425679.git.naveen@kernel.org> (raw)

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@kernel.org

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


             reply	other threads:[~2026-09-03  9:37 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-09-03  9:28 Naveen N Rao (AMD) [this message]
2026-09-03  9:28 ` [PATCH RESEND v4 1/3] perf/amd/ibs: Limit the max EILVT register count for AMD family 0x10 Naveen N Rao (AMD)
2026-09-03  9:28 ` [PATCH RESEND v4 2/3] x86/apic: Introduce a variable to track the number of EILVT registers Naveen N Rao (AMD)
2026-09-03  9:28 ` [PATCH RESEND v4 3/3] x86/apic: Drop APIC_EILVT_NR_MAX Naveen N Rao (AMD)

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=cover.1788425679.git.naveen@kernel.org \
    --to=naveen@kernel.org \
    --cc=bharata@amd.com \
    --cc=bp@alien8.de \
    --cc=dave.hansen@linux.intel.com \
    --cc=hpa@zytor.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=manali.shukla@amd.com \
    --cc=mingo@redhat.com \
    --cc=nikunj@amd.com \
    --cc=tglx@linutronix.de \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox

all inboxes | Powered by JetHome®