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 102A637269B for ; Thu, 30 Apr 2026 18:05:01 +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=1777572303; cv=none; b=Cs5l+sBDvcuQ5U3SefIhYqulJQ/XsBklHWNVjkI4QHggCmIM7Xf2LSIrlZGD3Z6aVg/fAgtnxjBEFbQ2M72hIEM2uFlH+lnFYRY3ZeyfaMBmxjljCO+yg4iLi7oIsUr7Mc0wLLxvBUiMeL7IDv5YU3LvOLh8f6hohKpOYzzi+Tk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777572303; c=relaxed/simple; bh=0jyakFSOwcrlsI3bihlbsbMEQRRTZqmFvYR2ZvD0L4o=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=VAo7GIa3XQtsLW3KJLhbwCmzHof6adPuYVCFsUVaiGPCgvwrc8A9iR5lk/6+eJXFYNO76NOPVMJfY87LwLH6kzmKFkVkCFvqlUyht+ntD8im3JBgQA3c+F01Cq6pf1g/qgiif+z+c7iWRwPZwQWRYEMdItrILZtQI5uu18QUrS8= 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=nvT6ZK3O; 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="nvT6ZK3O" Received: by mail-pf1-f201.google.com with SMTP id d2e1a72fcca58-82f9f49e4beso829390b3a.0 for ; Thu, 30 Apr 2026 11:05:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1777572301; x=1778177101; 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=Nh6SF4JLNSjAgzZteQloYKD+0xB5PbyFLeDfh+8tIAo=; b=nvT6ZK3OVlyvrQ8fNWrSypsOMAjiGGJt04U6FyWznMOQWPLSFh9XssI72hF/DO2H4V ybxcOdhMtJVZLS7uEYNSni+tjXO7MdmjKUYE89pctHUThCMg+Q38W8zMkyM3+J8NbtvM d1dxryto3u6aFa07cuquTo2rcVzVLj4wGWS1JjPJ6TlHEAB6E29yYH8nKHRD9OTm4USZ LbU8otvyZG5ZDLRsn57cwJDHCA55MhIGQ6rIhB2J16pfIaYvwxQ6Q8agLwDFhoAmRXRh F2m4d+2wrG8wL7w7NfFD2oPiCKoODypR45hq9DrUcscG99eRBJgzCl2yPxIuXI+j5yE0 bYrQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1777572301; x=1778177101; 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=Nh6SF4JLNSjAgzZteQloYKD+0xB5PbyFLeDfh+8tIAo=; b=J0UWkGILyhkGLJljmtwhuJiMBSUtr7cB5NN6uU86V/Z4ilvZdx2tyzy8CA/AO0IJEJ Q0du3GbmOnmfSTVS6OJISZi4as1hFAOVSspgFH0xZkDJhjegPK0WRLKxyOnAAGMLDNDc 8hTW89D5RO8uB2sMwMkRFNudGq39zELphX4uGu2hvy3dQWy2uvp4WcnzbGvVKNq2/jFF fjN3eu8FHdQiafrkEmXIZbvNbRM7gXCVL/8Fk8eIw0euUoKYFJFvrte9BJIo7QhbQJYV AWEXfoG4SS00Ya0AmhcKi2p1MPiYvUmfyOQnNEd6we/8+on1vZs768uATGgYl2K95nUW /L6w== X-Gm-Message-State: AOJu0YwEhHc1pHYP+BZTg+r8OcV4rKvOqEBdYs4W1WEnnnS9HydEL//D dg5IdQ9qhbQR6qGo12fYkZYkYcVVynNy4bGmfzCnKnfwtOSrpOL/Odn5ugXd1fKAu09ixI4yaqy LLqK8HA== X-Received: from pfbjw26.prod.google.com ([2002:a05:6a00:929a:b0:82f:ba4a:d050]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a00:f8d:b0:82a:7893:e14b with SMTP id d2e1a72fcca58-834fdd3f090mr5019262b3a.38.1777572301059; Thu, 30 Apr 2026 11:05:01 -0700 (PDT) Date: Thu, 30 Apr 2026 11:04:59 -0700 In-Reply-To: <20260430150747.76749-4-pbonzini@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260430150747.76749-1-pbonzini@redhat.com> <20260430150747.76749-4-pbonzini@redhat.com> Message-ID: Subject: Re: [PATCH 03/28] KVM: x86/mmu: free up bit 10 of PTEs in preparation for MBEC From: Sean Christopherson To: Paolo Bonzini Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, d.riley@proxmox.com, jon@nutanix.com, Kai Huang Content-Type: text/plain; charset="us-ascii" On Thu, Apr 30, 2026, Paolo Bonzini wrote: > From: Jon Kohler > > Update SPTE_MMIO_ALLOWED_MASK to allow EPT user executable (bit 10) to > be treated like EPT RWX bit2:0, as when mode-based execute control is > enabled, bit 10 can act like a "present" bit. For posterity, this matters because MMIO SPTEs for TDX need to be RWX=0 in order to generate #VEs on any access (hardware never reflects EPT Misconfigs as #VEs). Arguably we could delay this until the TDX-Module enables MBEC (or maybe that's already in the works?), because even though KVM enables MBEC, that only matters for non-TDX guests. But I don't see any point in delaying the inevitable.