From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f74.google.com (mail-pj1-f74.google.com [209.85.216.74]) (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 5494F297A78 for ; Mon, 12 May 2025 19:37:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.74 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747078643; cv=none; b=rf6Ik+mHjm8R99mwSY4IoBFmd9vTG27s/RAvT2mzi66rIyKmjlC0b9pov8RD4vd9bB3dj005i9+54KQzTO/As9wyzjxn9S0xxTqdnwQyO9SrwF3oQlGq5a5T9TQ0ViSNQCkudsodu38NLhvaRjzERTsXov4R9lbwKzixrbeyek4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747078643; c=relaxed/simple; bh=QWiCLP8D2rUi6TG/MoWMjJzDeskVuP36w/zPOMjGcws=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=JChkJE6Log1WAzmFeWevDIr3ebuNAOJZSh0adGIBChKnlQcBqju1uNxhbcW4Cj6c3otX883zuTyrrDD/1m477Nl6x1DQ6sqNFv1ODUbZTlJv/SV5W+vAU1NHl3WFjkhKhprPbbDqxFpR/F8YG3A7LHSDSYlCY9SIPqIB7IWRJmI= 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=4kLthsVE; arc=none smtp.client-ip=209.85.216.74 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="4kLthsVE" Received: by mail-pj1-f74.google.com with SMTP id 98e67ed59e1d1-30c8c9070d2so3051036a91.0 for ; Mon, 12 May 2025 12:37:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1747078641; x=1747683441; 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=38HKQiklWepPU3qbWvVj4j0NVLrqbA0sO4nv2WaJHSU=; b=4kLthsVEzqD663f3iK1mlng4rS1zzIOSA/ICh91vJrJyQf3lfklRG2GvrvMc0fKl+H 9K1D43ebiCJ1n5TwVrWHxjZpWxc17q0CnMnOTfS231STmRbd8i+WUZF64zxBjHfcvXsJ ApR2Yn0BIsC1PhgombGFK8LsxgOKDCYmpOWPvgS+pGLTIOLAQe07nxItH8bmwkHJhByX a6Ksu5rsH8sWSO06ej5WmqTyoBU/KZQhOpof9lbJLYFPacQIB/K1KVxK8MGA1B8QGXQv ans453i4U1+6qkdjv+zqVVeNMnm7V6nx1iy0wF88lWGLsv0I6f2y01lAYW7HeIGP+OxB XxdA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1747078641; x=1747683441; 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=38HKQiklWepPU3qbWvVj4j0NVLrqbA0sO4nv2WaJHSU=; b=OOX4BvD+AJ/FWbQhLs4L7zFQWat1RTM+9Fa1+WT7RnTbhHzXLaBaEaZru5Y+kO/qUr T/j92dVCqBils8DkhP2GDL6oFlZoKa75juz6uSsiIvXpEIoECsREebwjaGI7VjOs2izz qZoJ16mQwf4jgmHoTQuYukw0NN8CJk/faprQkAs+LCCix9pTh8SsINkXR1GWkOqlAkL3 t1RVGCuBV60uOYQ2ODuQgyJmN/c17mmVhf6EA1FRZkmMZ4ot/VUh35JiSlEAp4JNwIAL wE8jkA03l6O7Sbad28eh8/TwF7sFnwpN+JNY4nYtS5yJrVEBm7wK++jqlaTvaH3ZMI9k X93Q== X-Forwarded-Encrypted: i=1; AJvYcCUsMqDo63o5H3y22wxJYS3ukorFLKiGB8+3C5shc2n3Eexaw37PsydCwCK4y7EqbCHCCTw=@vger.kernel.org X-Gm-Message-State: AOJu0Yxj7b74H3GNuFW6Z4WaJfmxhX1BqLA4KpRYU/fNA8EhM6ioRDIU wFnhM1HnrGG+hbGuAEFOLdBrLECFWLv/j6Ss+di/iCSxm0uSOmieHTjYn0rawQfJE9FVzFzkkUE 9Gg== X-Google-Smtp-Source: AGHT+IEH/vApxszPhZUNxCOdgc1rPPj0HCQHT2dwioZc2EGArIqaGYNc0uWa7Ib8OiwC6GxFHUvbjJ13Q9w= X-Received: from pjbpb18.prod.google.com ([2002:a17:90b:3c12:b0:30a:953d:af9a]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:380f:b0:2ff:64a0:4a58 with SMTP id 98e67ed59e1d1-30c3d628b6emr19141945a91.22.1747078641552; Mon, 12 May 2025 12:37:21 -0700 (PDT) Date: Mon, 12 May 2025 12:37:19 -0700 In-Reply-To: <20250313203702.575156-14-jon@nutanix.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250313203702.575156-1-jon@nutanix.com> <20250313203702.575156-14-jon@nutanix.com> Message-ID: Subject: Re: [RFC PATCH 13/18] KVM: x86/mmu: Adjust SPTE_MMIO_ALLOWED_MASK to understand MBEC From: Sean Christopherson To: Jon Kohler Cc: pbonzini@redhat.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="us-ascii" Please be more precise with the shortlogs. "Understand MBEC" is extremely vague. On Thu, Mar 13, 2025, Jon Kohler wrote: > Adjust the SPTE_MMIO_ALLOWED_MASK and associated values to make these > masks aware of PTE Bit 10, to be used by Intel MBEC. Same thing here. "aware of PTE bit 10" doesn't describe the change in a way that allows for quick review of the patch. E.g. KVM: x86/mmu: Exclude EPT MBEC's user-executable bit from the MMIO generation The changelogs also need to explain *why*. If you actually tried to write out justification for why KVM can't use bit 10 for the MMIO generation, then unless you start making stuff up (or Chao and I are missing something), you'll come to same conclusion that Chao and I came to: this patch is unnecessary.