From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f69.google.com (mail-pj1-f69.google.com [209.85.216.69]) (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 E01A33B95E9 for ; Wed, 16 Sep 2026 23:57:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.69 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789603078; cv=none; b=E1RRysf6T3W2qPanKtPj1d+7Cup1MRJ4Gm8zJv5aPbpw2LZlE0/kJ3u3dclb/CB238SBwZ3MRWobUmYKqA7rDCM02MajeeQsKoSyn38s9Uw5vnKk+uHVN/Ro+VYyMryQL4d/1KzEqooEFbgbjm4UED18qnwyV6eZepFIjdrH+PY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789603078; c=relaxed/simple; bh=rXMgegBfOhfeytGkgRNDEJriW8nCixKGipVpwv/Yb0U=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=l6YHjaZet8WEWL9UtSjFM53oPrQpJtPLqEvhJQ3eHDLTrS8ZO0TNfG0bID7WF2NOWMz9YRhNPJsaKBN0kDYuPpuEFa9a+63DcuW2CSkAsSXEo1qFwbxBacdKPJPFADP/W83U6/NyqpGAVLC6GUIVWx6EGe/BjxjjOaRQ/5CRPB8= 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=Qe0MNFI1; arc=none smtp.client-ip=209.85.216.69 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="Qe0MNFI1" Received: by mail-pj1-f69.google.com with SMTP id 98e67ed59e1d1-39533bb224cso422471a91.3 for ; Wed, 16 Sep 2026 16:57:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1789603076; x=1790207876; darn=vger.kernel.org; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:from:to:cc:subject:date:message-id:reply-to :content-type; bh=E1lScqubr1yoj5tPRxggQdvm+qpOPiHCADjlZtOkPnU=; b=Qe0MNFI1Ea1lFqndDjR6NqoX7x//SOmMolYJ2hky+j+bvZxcHfpt1VN0yFj1wgMNSL 9mZNQ8f79eDdZwSB4KpgEZE4TrX9B/QPJlrlpNebQmrKc1KbqhIhCNTLaD9qlcONAJqV fnbK1bCrq6A9U1t5NNwxM3XWh3URDJPR6W5sapbufbRyIvjKPsE0X/hpC4y1GCP9ZHrw c6dw6OitjgnmM3pkyvItDvJUpa37+W72/KnVSsEqrOH2vm3kYAVzq29rkSMEwk+04zkW wdwuXnM2GqVg4Hn02yA21htG8YNor/AyyWJxVoo4mmrn/0PSH2K+VO7b9nQRKnUA0cR8 uTew== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1789603076; x=1790207876; h=content-type: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:content-type; bh=E1lScqubr1yoj5tPRxggQdvm+qpOPiHCADjlZtOkPnU=; b=rknm+K6qRSc6wZWhR7UhZceSsvwhrr29vraIDTGOfUwMbA7uvvjLmfYcP1Hk7AdoML 3sOplQa12QUC62RZUmxz6d91CFUkCpejuMddBgf2FeM9Mu1buUmcNO0nSA8AFu5H2zyF acvZ797fHiYhpzDOwkg8QzcpLob7MxoYTbM50ZgAShF9wwBwGQsearIPhcdTgrnO6eiT Ezgx/NSRcpFyUzNagjMhUt50Bw54kIYAK6+FOOEt6WKgo3Kf/aB12ecJ4RtBBg+VtAqr 2oBBYOrlkyzxGcKlRldQ+BrV9cKzEyV2Rxe1mZ8suk9evkWhedWgvzYr8ExXDIf93nrb 0ZCw== X-Forwarded-Encrypted: i=1; AKwUvBz3x3lwEyUMdKte/NatiP1jec5BTV2E+Oli4PBbflPQ9gwhj4DoThCvVbS3qjQEkd8xugs=@vger.kernel.org X-Gm-Message-State: AFuF++mVV+tAg03ZnbbY3ctmFm96y6xN26PUOpTtia8bVG7h1/5uiOp2 2DJP3/bWYRmzKrU5g90qOoO2eM5EOSOi28HbrGeUr/gvrhIhooOdI7qZSdiUBuHQwxzj3O7Vdmx DZjYuFg== X-Received: from pjk3.prod.google.com ([2002:a17:90b:5583:b0:39e:3716:7aca]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:2f06:b0:39e:252:ae4d with SMTP id 98e67ed59e1d1-39e1e4d3fe8mr10125165a91.17.1789603075980; Wed, 16 Sep 2026 16:57:55 -0700 (PDT) Date: Wed, 16 Sep 2026 16:57:49 -0700 In-Reply-To: Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <24a751d16ba0dc37aa7774df5739f39734cf9aca.camel@intel.com> <736a9315f3cc3d8ef7079b784bfcc7b014386bd8.camel@intel.com> Message-ID: Subject: Re: TDG quote analysis From: Sean Christopherson To: Peter Fang Cc: Rick P Edgecombe , Yilun Xu , Elena Reshetova , Binbin Wu , Dave Hansen , "kas@kernel.org" , Vishal Annapurve , "pbonzini@redhat.com" , "kvm@vger.kernel.org" Content-Type: text/plain; charset="us-ascii" On Wed, Sep 16, 2026, Peter Fang wrote: > On Wed, Sep 16, 2026 at 03:31:50PM -0700, Edgecombe, Rick P wrote: > > On Wed, 2026-09-16 at 12:27 -0700, Sean Christopherson wrote: > > > > If you are thinking the implementation could punt on how to handle the guest > > > > interrupts for now, that seems reasonable. I'd think exiting to handle the > > > > host interrupts could not be skipped though. > > > > > > I'm just trying to understand the scope of the problem we're trying to solve. > > > E.g. I don't think any design will save us if generating a quote requires a > > > CPU to be spinning for multiple milliseconds. > > > > Elena, any updated estimates on CPU based quote generation and HW based? > > The current estimate is 10s of milliseconds for HW based, and > milliseconds or less for CPU based. I am beyond confused. What is "HW based" versus "CPU based"? At this point, I don't care about the gory details, I just want to understand the basics: - Does generating a quote require the CPU to actively execute instructions? - If not, how does software know when a quote is ready? I tried peeking at TDX Module source code, but I can't find anything relevant even in the latest TDX 2.0 drop.