From: "H. Peter Anvin" <hpa@zytor.com>
To: Sohil Mehta <sohil.mehta@intel.com>, Xin Li <xin@zytor.com>,
x86@kernel.org, linux-kernel@vger.kernel.org
Cc: Andy Lutomirski <luto@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
Peter Zijlstra <peterz@infradead.org>,
Sean Christopherson <seanjc@google.com>,
Adrian Hunter <adrian.hunter@intel.com>,
Kan Liang <kan.liang@linux.intel.com>,
Tony Luck <tony.luck@intel.com>, Zhang Rui <rui.zhang@intel.com>,
Steven Rostedt <rostedt@goodmis.org>,
Andrew Cooper <andrew.cooper3@citrix.com>,
"Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
Jacob Pan <jacob.pan@linux.microsoft.com>,
Andi Kleen <ak@linux.intel.com>, Kai Huang <kai.huang@intel.com>,
Sandipan Das <sandipan.das@amd.com>,
linux-perf-users@vger.kernel.org, linux-edac@vger.kernel.org,
kvm@vger.kernel.org, linux-pm@vger.kernel.org,
linux-trace-kernel@vger.kernel.org
Subject: Re: [PATCH v7 02/10] x86/fred: Pass event data to the NMI entry point from KVM
Date: Fri, 20 Jun 2025 15:51:38 -0700 [thread overview]
Message-ID: <7acedeba-9c90-403c-8985-0247981bf2b5@zytor.com> (raw)
In-Reply-To: <39987c98-1f63-4a47-b15e-8c78f632da4e@intel.com>
On 2025-06-19 15:57, Sohil Mehta wrote:
> On 6/19/2025 3:45 PM, Xin Li wrote:
>> On 6/19/2025 3:15 PM, Sohil Mehta wrote:
>>>
>>> I want to say that the event data for IRQ has to be zero until the
>>> architecture changes — Similar to the /* Reserved, must be 0 */ comment
>>> in asm_fred_entry_from_kvm().
>>>
>>
>> FRED spec says:
>>
>> For any other event, the event data are not currently defined and will
>> be zero until they are.
>>
>> So "Event data not defined for IRQ thus 0."
>
> I am fine with this. Not *defined* removes the ambiguity.
>
So I was thinking about this, and wonder: how expensive is it to get the
event data exit information out of VMX? If it is not very expensive, it
would arguably be a good thing to future-proof by fetching that
information, even if it is currently always zero.
-hpa
next prev parent reply other threads:[~2025-06-20 22:53 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-06-12 21:48 [PATCH v7 00/10] x86: Add support for NMI-source reporting with FRED Sohil Mehta
2025-06-12 21:48 ` [PATCH v7 01/10] x86/fred: Provide separate IRQ vs. NMI wrappers for entry from KVM Sohil Mehta
2025-06-19 3:53 ` Xin Li
2025-06-19 21:35 ` Sohil Mehta
2025-06-12 21:48 ` [PATCH v7 02/10] x86/fred: Pass event data to the NMI entry point " Sohil Mehta
2025-06-13 0:18 ` Sean Christopherson
2025-06-13 15:20 ` Sohil Mehta
2025-06-19 5:02 ` Xin Li
2025-06-19 22:15 ` Sohil Mehta
2025-06-19 22:45 ` Xin Li
2025-06-19 22:57 ` Sohil Mehta
2025-06-20 22:51 ` H. Peter Anvin [this message]
2025-06-20 23:18 ` Sean Christopherson
2025-06-20 23:22 ` H. Peter Anvin
2025-06-23 15:39 ` Sean Christopherson
2025-06-23 16:10 ` H. Peter Anvin
2025-06-12 21:48 ` [PATCH v7 03/10] x86/cpufeatures: Add the CPUID feature bit for NMI-source reporting Sohil Mehta
2025-06-19 5:06 ` Xin Li
2025-06-12 21:48 ` [PATCH v7 04/10] x86/nmi: Extend the registration interface to include the NMI-source vector Sohil Mehta
2025-06-12 21:48 ` [PATCH v7 05/10] x86/nmi: Assign and register NMI-source vectors Sohil Mehta
2025-07-07 13:21 ` Zhuo, Qiuxu
2025-07-07 20:00 ` Sohil Mehta
2025-07-08 7:30 ` Zhuo, Qiuxu
2025-07-11 0:32 ` Sohil Mehta
2025-06-12 21:48 ` [PATCH v7 06/10] x86/nmi: Add support to handle NMIs with source information Sohil Mehta
2025-07-07 13:50 ` Zhuo, Qiuxu
2025-07-07 20:32 ` Sohil Mehta
2025-06-12 21:48 ` [PATCH v7 07/10] x86/nmi: Prepare for the new NMI-source vector encoding Sohil Mehta
2025-06-19 7:43 ` Chao Gao
2025-06-19 22:23 ` Sohil Mehta
2025-06-19 22:54 ` Sohil Mehta
2025-06-12 21:48 ` [PATCH v7 08/10] x86/nmi: Enable NMI-source for IPIs delivered as NMIs Sohil Mehta
2025-07-08 18:37 ` Sean Christopherson
2025-07-10 22:04 ` Sohil Mehta
2025-07-10 22:40 ` Sean Christopherson
2025-07-24 22:59 ` Sohil Mehta
2025-06-12 21:48 ` [PATCH v7 09/10] perf/x86: Enable NMI-source reporting for perfmon Sohil Mehta
2025-06-12 21:48 ` [PATCH v7 10/10] x86/nmi: Print source information with the unknown NMI console message Sohil Mehta
2025-06-13 7:06 ` [PATCH v7 00/10] x86: Add support for NMI-source reporting with FRED Peter Zijlstra
2025-06-13 15:21 ` Sohil Mehta
2025-07-07 13:56 ` Zhuo, Qiuxu
2025-07-07 20:33 ` Sohil Mehta
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