From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f202.google.com (mail-pf1-f202.google.com [209.85.210.202]) (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 E2EBC487BE for ; Tue, 30 Jun 2026 00:37:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.202 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782779844; cv=none; b=rG6XotKuii+BdvUG35kVUwnsttb/297Ck8sS3MGJ3KD/OiXKG66BX9yaIj7NetG0jbPc8FWHlSp6Zqhch2OZ1L+eu3BlVEowyoUeHHg7JXfO8gYagELAnZ3nQtWLC5QeU5JREAfIeI25ziJb4M2vAPtkXFB8qMpxNRU/Ch/h4yA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782779844; c=relaxed/simple; bh=dGW4RFk+phOZLtM3wOZBLttvDNqv+AwSk9KuOQKGHa0=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=eIPwUzwZysmR6X5jFBesZW3RCRqj7xm9GjQ3IgNN8LSPtaqcE4DPniJFucERT9p+5f/FV9lXxsK/zUwWoa4c8F7lpXAhWBaMRXlCNufpMuXHtUCDTC9JpuvoqxgJSEnM9Raq0fpARvldmX99YWGI1e8YjTm2FIkJUiSzrZCD9AI= 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=ryDEglHI; arc=none smtp.client-ip=209.85.210.202 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="ryDEglHI" Received: by mail-pf1-f202.google.com with SMTP id d2e1a72fcca58-8479c6c6cbeso421305b3a.0 for ; Mon, 29 Jun 2026 17:37:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1782779842; x=1783384642; 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=BKV7MubbT236XgrwpvmR2un3HfsGFp5e/uG2tY2I0c4=; b=ryDEglHI9LF+P/IRZaDnHV/jvGBE4T7M4omYEuXl9R49WuJdWgKWK5+b35kAa8E91s gK9nPdU0SjNsQiE8FEWAUT43y4fNAzFq0OBYey/qv8o+CJTYTZfOEh6IZ6pMTbPbzcnw LFFUn9mPD/+PhjpE6TyZpAWI74V9aIAUWvSmekxR39U9yluaHZoFMSZFMpFa4qjxFADh sxoOL8Q4NhC/H4FMP06UPi+tOMji53JDFsMlcGYnAWcNGIyAmYe3tw+e/Fcl/Tz4dU+U 8CMQkDa763Cj10EfA6AIBLALCQPhPtcI9jFbELXnnIQp082S3bkwltFlyp/orMyi1Hsq 3xrQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1782779842; x=1783384642; 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=BKV7MubbT236XgrwpvmR2un3HfsGFp5e/uG2tY2I0c4=; b=KLBU9TmwHKVXyVRu/YzHPwJMu3vVr8529nPl+EOM1c/zqKk/3nzCKN6YH5Ms7/njkV MUx4b+fX+D4Nn6ute+I1zdw6HrN+4GiZ39FywQe9iW2YvlLPt0r3pM2sRIp+eG63g6Py 1u0mbazYgHR8jpTJ7aa1EZAZ4EuBPMPApV30X8T4QtVqfPnMQc+SD6rm/LDsb0Kha5rK CHQAVdQ9aQe1g1hlM9V2wxHZF5Ic78tTc5pdf0cdm7D11a0Beb1uMMUliNC7UbdqeEcV qlWg43sWq7rrs+dCbo9yKdEN/WNwC6ON4XzVgULcgBMBBbPiV7IJSYz8gfHRngwHVTCQ /AnQ== X-Forwarded-Encrypted: i=1; AHgh+RqhZ0sKTzUu3s5KEtG8dpFLsuenhq6vDvZ7mJeXZyqPfeSXXwFbXXnjrcMi2UH0u1cUBKvALP6kBGyXfME=@vger.kernel.org X-Gm-Message-State: AOJu0YzCV+YSqWjFzz7bWLQ9ay+y4J+IY3JRS4t+f0S296psYyqUYJBE AWWa93R1smq3wa/mhnBj8FsKyUCuKccKi/oLFnlrOam01MK7VweTav6bU8kQ6JL4pfF58zA56Oy /owNd4Q== X-Received: from pfbfc21.prod.google.com ([2002:a05:6a00:2e15:b0:847:8c62:85d5]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a00:a27:b0:847:80c8:dfdb with SMTP id d2e1a72fcca58-8479f4482a5mr1155351b3a.55.1782779841830; Mon, 29 Jun 2026 17:37:21 -0700 (PDT) Date: Mon, 29 Jun 2026 17:37:21 -0700 In-Reply-To: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260604023314.3907511-1-binbin.wu@linux.intel.com> <20260604023314.3907511-2-binbin.wu@linux.intel.com> Message-ID: Subject: Re: [RFC PATCH v2 1/4] KVM: x86: TDX: Track supported configurable CPUID bits From: Sean Christopherson To: Binbin Wu Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, pbonzini@redhat.com, rick.p.edgecombe@intel.com, xiaoyao.li@intel.com, chao.gao@intel.com, kai.huang@intel.com Content-Type: text/plain; charset="us-ascii" On Mon, Jun 29, 2026, Binbin Wu wrote: > On 6/26/2026 1:04 AM, Sean Christopherson wrote: > > On Thu, Jun 04, 2026, Binbin Wu wrote: > > CPUID.0x1E is a bit different because it's kinda sorta a feature? That one is > > probably worth restricting, but again that's easy to do in a case-statement. > > Only CPUID.0x1E.EAX has TDX directly configurable bits currently, no special > handling needed for the rest of CPUID.0x1E. But isn't the whole point to guard against TDX Modules gaining support for features KVM doesn't know about? What happens if hardware extends into CPUID.0x1E.ECX, and the TDX Module follows suit? I guess that applies to all the feature leaves?