From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pg1-f202.google.com (mail-pg1-f202.google.com [209.85.215.202]) (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 263083F9E8 for ; Tue, 7 May 2024 17:11:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.215.202 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715101921; cv=none; b=ujjV2j0he7NfxnZgorv3TgSumsVBhPMhyiBGfbMLiSVcJXh9GrsLu1PTPN/kGIjx4yB8xWV8/79LG9UPS4nN8cQgFmLNSzGfla3LFLhhPt8z5jZIqx+UUVjiZw5q1ThynN9QALPGOJKxzjmpoOLZJZnzwCkHqE3ql6I8xoXK8uw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715101921; c=relaxed/simple; bh=7OSkgP5+kPRPnXz92hms6Q0kbyy8WDX+cILm9CSvN1M=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=GzJ26BAmQl+nE+97fX8XeenZFEYiz44CnOJAPCEjJ1e5o26uD2SZinOGoSpYjk2EhdP0pd1kpGckx3jGbndKyUdTYvc8R2TT3r6yynD5BNxSjJN1Aj8rKsugexXRnb91lx5gvZtjDIskW7RagONeKg40O6qG6DaUfdkUs77evy8= 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=O8T3i7rc; arc=none smtp.client-ip=209.85.215.202 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="O8T3i7rc" Received: by mail-pg1-f202.google.com with SMTP id 41be03b00d2f7-6292562bac4so2428186a12.1 for ; Tue, 07 May 2024 10:11:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1715101919; x=1715706719; darn=vger.kernel.org; h=content-transfer-encoding:cc:to:from:subject:message-id:references :mime-version:in-reply-to:date:from:to:cc:subject:date:message-id :reply-to; bh=jNWTjRHNzguG/ECX3sxXEdtUovfHpdLwJgS1SRLByzU=; b=O8T3i7rc+RkWnSrCk9mcubuP5KVcymafCfpjL9wB9fVo2xZUtppD1OoH4gLp0OhTWR F6920V715+PLHJRNsnFP/QtSEwlP+q4UGoUHnKSwLWdQcSZDFZHNVOaPc2wk4AbPHsIe 1NnLCMZ8PDrKClv7fYa85u2d66KbnMmpN++J9V1A/G+gBeWWQENaiJxWj+xqUvN+rCdC 0DZImk2eBk65/vwqdYl4Yvp3BOvPy3rY7owIRle3YUpr67eEeZA73brIFfcMw1YJQw00 zEMrgYIIQk5syCcCr0XDmeHUvqDIuZeI7UK8nzbtQHKVu4C6aIDlJw3cnZZfD5KXV/Lh vXSA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1715101919; x=1715706719; h=content-transfer-encoding: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=jNWTjRHNzguG/ECX3sxXEdtUovfHpdLwJgS1SRLByzU=; b=fW8rW9UZMauXsqvak7fseCp10Z3y5XDbArYmebfHJcOxr24nCYPV8J7E/3H5ZNaYcZ c7I0x/uzvVGojRiC1IHhBt3S+UPPPlEJveg4Wy49a81ABr25vKGyvcR9gU1s2l2Ozihf CA0hOd0udtTgv2HISYlklv/DCmhgYfpx3pYEc4hNKVnEi3j3OAGaIA2MwGS26I9I7Mio S15O3dd+XT614GBMQ8BocQ9s35lKCkKX4zsyZ1j4CVVSq0/uJ/kkoYk902olee51oayt /TBT6834q8wjhvhRv4xmRbFWvNL20BNKvyRgSr1y2End0H2xx2DGh9r5MXkFpjh0k5p9 2lkA== X-Forwarded-Encrypted: i=1; AJvYcCUPPpraKYPLaf2y/WmIuY/XbiTLDpzekCU6f4XYbF5oxuadysZKdnHUjEpiw8oumFHtBXF9U2pesx57/vveVDIw/Eqw X-Gm-Message-State: AOJu0YyOYPf6IngVFUw6G91ZioZFN65Du2BhWfMV72n65vsgLlV5lJmc QcbEVGqMaC8L1TOHI1pyzZh56NHqMPGdNrnFK+5kWQomycwALv38W/IT74SIsoPkzlHtQmkwzhD nkw== X-Google-Smtp-Source: AGHT+IGXYTNhE4o6Jz4a9tofzokKuMCJots4ro+a/npTiGMlkU1K2gSt900bsifAeL/u4yulw2hSE1dwe40= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a65:6d0c:0:b0:5f7:651b:fed8 with SMTP id 41be03b00d2f7-62f295deabemr1389a12.12.1715101919434; Tue, 07 May 2024 10:11:59 -0700 (PDT) Date: Tue, 7 May 2024 10:11:57 -0700 In-Reply-To: <6e0dc5f2-169e-4277-b7fe-e69234ccc1fd@intel.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <6e0dc5f2-169e-4277-b7fe-e69234ccc1fd@intel.com> Message-ID: Subject: Re: [RFC] TDX module configurability of 0x80000008 From: Sean Christopherson To: Xiaoyao Li Cc: Rick P Edgecombe , "kvm@vger.kernel.org" , "pbonzini@redhat.com" Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable On Wed, May 08, 2024, Xiaoyao Li wrote: > On 4/25/2024 12:55 AM, Edgecombe, Rick P wrote: > > One of the TDX module features is called MAXPA_VIRT. In short, it is si= milar to > > KVM=E2=80=99s allow_smaller_maxphyaddr. It requires an explicit opt-in = by the VMM, and > > allows a TD=E2=80=99s 0x80000008.EAX[7:0] to be configured by the VMM. = Accesses to > > physical addresses above the specified value by the TD will cause the T= DX module > > to inject a mostly correct #PF with the RSVD error code set. It has to = deal with > > the same problems as allow_smaller_maxphyaddr for correctly setting the= RSVD > > bit. I wasn=E2=80=99t thinking to push this feature for KVM due the mov= ement away from > > allow_smaller_maxphyaddr and towards 0x80000008.EAX[23:16]. > >=20 >=20 > I would like to get your opinion of the MAXPA_VIRT feature of TDX. What i= s > likely the KVM's decision on it? Won't support it due to it has the same > limitation of allow_smaller_maxphyaddr? Not supporting MAXPA_VIRT has my vote. I'm of the opinion that allow_small= er_maxphyaddr should die a horrible, fiery death :-)