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
next 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)
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