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 9D24E19F12A for ; Wed, 10 Dec 2025 14:20:19 +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=1765376421; cv=none; b=q+9UW0hmxZDZiv7tOPg0RMvq/XjjSpKxwlsijMjcUts8ph+xy+Y2C7rYypwmR7zGPcF7LwFrXljW/hPooCAuMhxpGjAYfqsMuXXG1d+JPQNeiPPgCcdz7mdGbXIih/awSDlGS8hgpuq6FDBx47mLaF3AnWT1gZbd+Bi53s/4kT0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765376421; c=relaxed/simple; bh=73ZN5gVruYdPb08Z7qWkjqs7M3VqgYcIbZtj6Xjrz9c=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=qC4RAp2VWNeLirTnGBYJNaXI+VShulsw0asjungXN/bxb9lnW5YLXMzRtrWekIlQtg/930SlGTz9vjc7BPKX3yKux/I1GZHTQeQggz8whdvZjB+OLnPXzbXask5cTVa75YPqjMYFptknmreL3Gf1l+BZQyHEtaosAY6jIS9TdhY= 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=PNVCihDA; 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="PNVCihDA" Received: by mail-pj1-f74.google.com with SMTP id 98e67ed59e1d1-34188ba5990so15868223a91.0 for ; Wed, 10 Dec 2025 06:20:19 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1765376419; x=1765981219; darn=lists.linux.dev; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=bR+OZ7ucbAcjgpsdh1BcVHBHgTugKNJ+Rip2j8+KG6Q=; b=PNVCihDAWKRZelBSLTeVF2KGMjbNMoXfRtmyTDRRAVp96s7cgojCkF3qWGGnRY3f/O rd9wF0Bxo7xmsG7k2BWdKUlPNinAncYrDJ9gdVDB8x0jSkJWRk0sAtGbJJdCZrWV5WXs BCC+0EVSI7T0xUK2tn2lzOoY8I1ApPbee5WvpzoBp+kAFUKFn7hOst5S8/QGDFoY3CIg e6HWDDM1q5PxDkLMQDXjpjvLFh0A/q1dHVSz0pOGJ6UscmtdXVLf3nQkYwoKyzNsKnf3 BjFwLxMMpvW6+G5i+d02Jrv+qNzDSuG8nompsQQc5BeP1JlsRa5Mfjv34Aq5aLkcyGTm ipzQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1765376419; x=1765981219; 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=bR+OZ7ucbAcjgpsdh1BcVHBHgTugKNJ+Rip2j8+KG6Q=; b=PkRxiJkaAFe8Z/Kisx/fY1dtn710BvWaqxU7PokHeSWLGubRW9r05Wl8SjD0iL5ngz A+FDyqorqTUdLQkeq2CpelW6fGXxpRjNO4J95b74vZqO+CnZyfToINbfLnCNpjHIY75i 1FABkOOjWF1QCWc5G6ZHY3id0J4kj/lVj8W0s0hii14V9sAM5q6E3DdzMaO5S2tuTbfc JsOsZlwzYXWVI3i1hLU9oneODEZXwXl8H99IORFMURx3IY6En0SWFgJsjo88FIIA5uYi GSMAvlqJFgymXyt6GssbBeyhtR4F4loqXStGd1lKo8O9kLrjFIYvSJgCEtpc9VtB0T9C ww4Q== X-Forwarded-Encrypted: i=1; AJvYcCWOQfYpZcumZY0EjpezKZDtifaQHEblRDZvbBedqMwgHdVgOZVA71VOquS72iEUGitzBAh4rI422O3+@lists.linux.dev X-Gm-Message-State: AOJu0Yw3MGJYfu33CrlKb747j2elvW1fdxRGcluZySveI9XfqvXazZzO TFe7w2Ltfmp9T1461xU8cMWZmn8jcO+P5cycxzESuz1bTHb6GQmDDhBoa+alhb4TGdZZaG5PeA3 M1WP+8Q== X-Google-Smtp-Source: AGHT+IFgCI8qg86hbIJn6V9eCwSFHSrGKpYXFjELjD+yHzAQieQGee8BswD5GlPKq6wLYBeFr1bky6qissw= X-Received: from pjbqc8.prod.google.com ([2002:a17:90b:2888:b0:342:8ef1:9719]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:38c1:b0:32d:a0f7:fa19 with SMTP id 98e67ed59e1d1-34a7285c31fmr2992980a91.17.1765376418861; Wed, 10 Dec 2025 06:20:18 -0800 (PST) Date: Wed, 10 Dec 2025 06:20:17 -0800 In-Reply-To: <6939242dcfff1_20cb5100c3@dwillia2-mobl4.notmuch> Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20251206011054.494190-1-seanjc@google.com> <20251206011054.494190-3-seanjc@google.com> <69352b2239a33_1b2e100d2@dwillia2-mobl4.notmuch> <6939242dcfff1_20cb5100c3@dwillia2-mobl4.notmuch> Message-ID: Subject: Re: [PATCH v2 2/7] KVM: x86: Extract VMXON and EFER.SVME enablement to kernel From: Sean Christopherson To: dan.j.williams@intel.com Cc: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, Kiryl Shutsemau , Paolo Bonzini , linux-kernel@vger.kernel.org, linux-coco@lists.linux.dev, kvm@vger.kernel.org, Chao Gao Content-Type: text/plain; charset="us-ascii" On Wed, Dec 10, 2025, dan.j.williams@intel.com wrote: > Sean Christopherson wrote: > > On Sat, Dec 06, 2025, dan.j.williams@intel.com wrote: > > I don't think we need anything at this time. INTEL_TDX_HOST depends on KVM_INTEL, > > and so without a user that needs VMXON without KVM_INTEL, I think we're good as-is. > > > > config INTEL_TDX_HOST > > bool "Intel Trust Domain Extensions (TDX) host support" > > depends on CPU_SUP_INTEL > > depends on X86_64 > > depends on KVM_INTEL > > ...but INTEL_TDX_HOST, it turns out, does not have any functional > dependencies on KVM_INTEL. At least, not since I last checked. Yes, it > would be silly and result in dead code today to do a build with: > > CONFIG_INTEL_TDX_HOST=y > CONFIG_KVM_INTEL=n > > However, when the TDX Connect support arrives you could have: > > CONFIG_INTEL_TDX_HOST=y > CONFIG_KVM_INTEL=n > CONFIG_TDX_HOST_SERVICES=y > > Where "TDX Host Services" is a driver for PCIe Link Encryption and TDX > Module update. Whether such configuration freedom has any practical > value is a separate question. > > I am ok if the answer is, "wait until someone shows up who really wants > PCIe Link Encryption without KVM". Ya, that's my answer. At the very least, wait until TDX_HOST_SERVICES comes along.