From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f201.google.com (mail-pf1-f201.google.com [209.85.210.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F0BFB4A15 for ; Wed, 12 Jun 2024 02:04:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718157851; cv=none; b=udkFuwZjMDnNoMwAH/zrEtceciWf1/VOV1JYagGc2H+id8jZ/RzqwKtXH+Zz6A8hxzqmmD+hUANr0sxDA0HytQs4/Rvb+O/kV1UMvHXWfwv+qxsSCruNWUQn7OMtk+nq+xbSSMetJsNirPNhWimgal64fF7onUYYr0PWFdd1hfk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718157851; c=relaxed/simple; bh=0DPlTkS07FZrwdnRXWDEH1hCjKNYS7C/USz49ifWufw=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=ufrCtFQtzcDJDsjv0EJp4YS2N9B8xcSenucMnmlJ0H5hqUoolARQmueQRcCPC/+qi9geGWXldRZhrOmDECIkeNJNpJNoLiQrOffp/05D48DvOwyev0BsTLRx1TVsGgaYJU7THFh8/BeCKu6eaDt39MGnGz5Ms/7nO9Gea7KU/yY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=1VN+IPK4; arc=none smtp.client-ip=209.85.210.201 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="1VN+IPK4" Received: by mail-pf1-f201.google.com with SMTP id d2e1a72fcca58-7043008f4beso2965172b3a.2 for ; Tue, 11 Jun 2024 19:04:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1718157849; x=1718762649; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=oXnVrUTMJFYjzKddbINiNlPIUhxMFsXMcMylDIRfeC0=; b=1VN+IPK4SWyWCHxYzxVIMbHepOdXcD2qs1POOX8yM9F7sZ+BNvjn9IqFeAZyMNbRZS UN3bkqQ3uzBWrMfJ5+y2MeKAXGvcfPzWumKx4pjhP3d5bbv/ZzQIX98Z0C/ocAaL4ci4 3ySa3GeUPqIB0YlsAfubpcltMz1Q3zogmTnI9TDc2/0voGn2h5EkkUh0lExbimOkQY2y NcgO9oxAWgQ9FoaOZFrLJhk9bsf8R4OtjGC9z8hiM6VYpMRf685mzdx2WFRQjUnovD+y BqsNIhg4sCjvCuziJAHnx20hbeIYSvSkbEffsswitq1SS2rtzxGYDBxNYd8SorZC/hkX nlAw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1718157849; x=1718762649; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=oXnVrUTMJFYjzKddbINiNlPIUhxMFsXMcMylDIRfeC0=; b=vC2lmowttpZDqA8TyN1dMxBE67CGknmz+0g+d24xDJcpeZwh7x7G27RU2rAPx1o2UB g5nrQWJrb7IfYPjGg3ckZ+6vfoqleUIymlqxjK6RO3a31Ek+ceuZAUWntEImmd3Xrlzp FNNn7zM3U6WnXzHaSAfS1KITQ72Kx5mu+GV78wNDFqjkfpIjXhZU5g5x1p/GEHA0i5oT zzHThxi9G+obcxLud+KMQVkSYqE/964/4j2kdBIpaHs3/nLl4yCEJmLozlWHmo6kiL51 I8WauIBsk0CTPgl4j77GwFrfYGnQM0wOXUIJrnDpaWhT0ARXT2bzGw+pzPxm027j274K WT8A== X-Forwarded-Encrypted: i=1; AJvYcCVfUFSbjc6MOplEjgNOyNxnFoB9jYUjS9qDWBwjNxaS5shQpm8fHqM9NCzWCfrbyG1+AJwXhiP0PUKBBzr/bgsYreoTryB44C5YhojX3JMhHA== X-Gm-Message-State: AOJu0YwzOytFrsPNP1wRkXh//aR7bWiMkxqOS8XCxHzg/m8+4RNiexO+ sD/zCCoZIabdPNl7M6cuhaZGutg/VHX6n0aU0J5MBbsL706zmrKMed114nXZee/g51pVKeSQp0K cnw== X-Google-Smtp-Source: AGHT+IH5FPrTorAscjXfc3OIIcg+n+F0jZHwu145CjOfyG5FYTz/Hz/lXRHCxgY6Vs4mMXVQCOdjphJn6FU= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a05:6a00:895:b0:6f6:7c6a:2c02 with SMTP id d2e1a72fcca58-705bcecea17mr67040b3a.3.1718157849088; Tue, 11 Jun 2024 19:04:09 -0700 (PDT) Date: Tue, 11 Jun 2024 19:04:07 -0700 In-Reply-To: <20240611165457.156364-1-jacob.jun.pan@linux.intel.com> Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20240611165457.156364-1-jacob.jun.pan@linux.intel.com> Message-ID: Subject: Re: From: Sean Christopherson To: Jacob Pan Cc: X86 Kernel , LKML , Thomas Gleixner , Dave Hansen , "H. Peter Anvin" , Ingo Molnar , Borislav Petkov , linux-perf-users@vger.kernel.org, Peter Zijlstra , Andi Kleen , Xin Li Content-Type: text/plain; charset="us-ascii" On Tue, Jun 11, 2024, Jacob Pan wrote: > To tackle these challenges, Intel introduced NMI source reporting as a part > of the FRED specification (detailed in Chapter 9). Chapter 9 of the linked spec is "VMX Interactions with FRED Transitions". I spent a minute or so poking around the spec and didn't find anything that describes how "NMI source reporting" works. > 1. Performance monitoring. > 2. Inter-Processor Interrupts (IPIs) for functions like CPU backtrace, > machine check, Kernel GNU Debugger (KGDB), reboot, panic stop, and > self-test. > > Other NMI sources will continue to be handled as previously when the NMI > source is not utilized or remains unidentified. > > Next steps: > 1. KVM support I can't tell for sure since I can't find the relevant spec info, but doesn't KVM support need to land before this gets enabled? Otherwise the source would get lost if the NMI arrived while the CPU was in non-root mode, no? E.g. I don't see any changes to fred_entry_from_kvm() in this series.