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 7A00E2E0412 for ; Mon, 27 Apr 2026 18:37:37 +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=1777315058; cv=none; b=FIPuPL8iEFOEMocXxOwz6Z9qvoMSyHnDprSoxKrWWv27SO42ZcFIvtndL0M2UlAVAZkotNTZa8zWz2qlMEZb35+3dCAycTQ9g6XOR9pBVRbfrjdllqqbIagf+YhSsUqx6b5Qct+eqMSJdnMuch6ErDKdncz4a+8h7U1XxtE3nFY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777315058; c=relaxed/simple; bh=m4T08v0n5rer/Aid8hTieHs817vXp7AqH3Xfx4disSs=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=e03PRU23bi9iOp+RUdWvpZQL9HIS8CKIMJftVsARg0fQ3A3DMcEJXOd5MF+w/AT7Faj5mm8Rh174yHPyypINLK1PWJEBCN22O1zKry6PJr76Zw2mPatpmrgEFRX4t3mLzJ15ZMwDmRnH7zBsAoc7L84xkDv1l/6HVi+ie+Fc/Fk= 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=ZvcX0Usr; 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="ZvcX0Usr" Received: by mail-pf1-f201.google.com with SMTP id d2e1a72fcca58-82f74bcfb86so12687458b3a.0 for ; Mon, 27 Apr 2026 11:37:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1777315057; x=1777919857; 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=B8V0U2CiNzZ5dcx3AMXIw7uJIsqfRpaxOOQdxJ3Zu/s=; b=ZvcX0UsrWCBd0MC9tyUXzk7gDtSJk68TUVwDCiq0/cHWKZDzkZ4LG9yCvRIQagqYBh q8+45Zk5NdEfJJW1/zktk1+sduu5FQhlOuF+bHY+EzJNA/Rqu14qXVwp/7X49QP2LzMK E6AGwFyQOWH4hdGqxINttgzrWW37eNgEMdwfkw82rbU+fuWOfeSN8KWgif4lNdQoNY59 uE5UPR1wC1UTcI+G9zAs9C8xPI89H79oESlRyvaDkuZKOXwDQBh2QXikHaI8wAbRIAA0 WBQfujnJQsGHJB7O79RwrPH3WjjO7hq0tA5Dm584Hv7nDUUkTS0qKwJL+fdLJ7UQmArq BVgQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1777315057; x=1777919857; 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=B8V0U2CiNzZ5dcx3AMXIw7uJIsqfRpaxOOQdxJ3Zu/s=; b=Nh/soyCCigeXlssDpe88R89hNzkK8zazZed5Zk6C342Ka3jTxjpY8t4mUcywAkLyv6 8v5L+E99j18nn3hscf5ncTKP/WUDsbecq4rp5ZnJIt4+NrDeHeu+jlvm+TQtcX+ml1KP vX2QAW3Yo9eeJYIk30KNauUJPiZy9XIQV5AWF/eO3PWXRRonJDpeLIyXFgVDPIT5NPu7 Tnz7AQ1+mhHnoE8GfqkLmu8Hlv1Q9+MT8U+8yDBTCZAH8ZZ/ops2NHW8n6E/mWbWVRxE lNvUXAZljd3RtRj7CgYesqLDY4t4u4HKskwB7i0YbnDL9xDbTj/4hHqCYHoRsml7FT+Z VSGw== X-Forwarded-Encrypted: i=1; AFNElJ8UFZInqd4oQFKDnYqyLiFPh4m6i6E9jQBKThFQ48FlTVaeRwNHYzjf/loCMKHG2pFUy5E=@vger.kernel.org X-Gm-Message-State: AOJu0Yy6gLyFn/UrUG2lPL+j+coOUhFrOdIyqNBfzPqDEiFBqE0wcSt5 Mbbs6F0+dx7IGLxBFxMo0zmmGRt1Ew3X1nFiue0JjoyJb7LH93lqisEpbKxgNzIDnLIqorDBIFb c5TGHkQ== X-Received: from pfbfc25.prod.google.com ([2002:a05:6a00:2e19:b0:82f:98cb:c2a9]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a00:3407:b0:82f:6e39:d90f with SMTP id d2e1a72fcca58-834dc283f7cmr149172b3a.39.1777315056743; Mon, 27 Apr 2026 11:37:36 -0700 (PDT) Date: Mon, 27 Apr 2026 11:37:35 -0700 In-Reply-To: Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: Message-ID: Subject: Re: [PATCH] KVM: x86: enrich kvm_fast_mmio trace event fields From: Sean Christopherson To: zhanghao <76824143@qq.com> Cc: Paolo Bonzini , kvm@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="us-ascii" On Fri, Apr 24, 2026, zhanghao wrote: > kvm_fast_mmio currently logs only the GPA, which makes fast-MMIO traces > less useful when diagnosing access patterns. What's the overall use case / motivation? Fast MMIO doesn't consume the value, length, or type. Why trace something that KVM ignores by design?