Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9F92AC433EF for ; Thu, 25 Nov 2021 21:13:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1357225AbhKYVQ6 (ORCPT ); Thu, 25 Nov 2021 16:16:58 -0500 Received: from Galois.linutronix.de ([193.142.43.55]:54874 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1357074AbhKYVO5 (ORCPT ); Thu, 25 Nov 2021 16:14:57 -0500 From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1637874704; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=Ei6BbjfXmiegGIxn055IaCo1HunjXkDEFUAK/rZBh+s=; b=qmRj7ZHqJt9kjsiKoHAU2q7qkuyptXUW9/viq1tuDnZ+OLsMtLYos2M7ykQ+F1F1BvMxsz sBxVHNj2Q6GXMnsXvG+M5EmjHTmyHXhJ2HexnNaVejA1HBw2nKsUrU1j8UUHs2FsuO1l5B 9QqOcRmP0BRZHzlwxHOAhF1kw37y9kWjdrhtebllpV4bWbDMzsMJ/MLPdtrovX6Bky305D Bm78L6y3z0/0VfKBoqfCGuk1j6TxSDyd8XPrsxYNgqYO98MDMNCXGyVY3APBhGoK0o7DQK t5VuNtoaC1JIyQbq1b5ANQD+9rChs3b8ZtX94zIJW8wa+iOIFI/uasB+Q+t/OA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1637874704; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=Ei6BbjfXmiegGIxn055IaCo1HunjXkDEFUAK/rZBh+s=; b=+LWDPfJHUUZ+SyomF1JSF094i7WZfugEzLom/j2USfZswmkfp222rQU/Ued8bCkGYAzPOO TM2sq8EqRe7fyXDQ== To: Paolo Bonzini , isaku.yamahata@intel.com, Ingo Molnar , Borislav Petkov , "H . Peter Anvin" , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , erdemaktas@google.com, Connor Kuehl , Sean Christopherson , linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: isaku.yamahata@gmail.com, Sean Christopherson Subject: Re: [RFC PATCH v3 26/59] KVM: x86: Introduce vm_teardown() hook in kvm_arch_vm_destroy() In-Reply-To: <21e8d65c-62bd-b410-1260-1ff4b0e0c251@redhat.com> References: <1fa2d0db387a99352d44247728c5b8ae5f5cab4d.1637799475.git.isaku.yamahata@intel.com> <87a6hsj9wd.ffs@tglx> <21e8d65c-62bd-b410-1260-1ff4b0e0c251@redhat.com> Date: Thu, 25 Nov 2021 22:11:43 +0100 Message-ID: <8735nkhre8.ffs@tglx> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Nov 25 2021 at 21:54, Paolo Bonzini wrote: > On 11/25/21 20:46, Thomas Gleixner wrote: >> On Wed, Nov 24 2021 at 16:20, isaku yamahata wrote: >>> Add a second kvm_x86_ops hook in kvm_arch_vm_destroy() to support TDX's >>> destruction path, which needs to first put the VM into a teardown state, >>> then free per-vCPU resource, and finally free per-VM resources. >>> >>> Note, this knowingly creates a discrepancy in nomenclature for SVM as >>> svm_vm_teardown() invokes avic_vm_destroy() and sev_vm_destroy(). >>> Moving the now-misnamed functions or renaming them is left to a future >>> patch so as not to introduce a functional change for SVM. >> That's just the wrong way around. Fixup SVM first and then add the TDX >> muck on top. Stop this 'left to a future patch' nonsense. I know for >> sure that those future patches never materialize. > > Or just keep vm_destroy for the "early" destruction, and give a new name > to the new hook. It is used to give back the TDCS memory, so perhaps > you can call it vm_free? Up to you, but the current approach is bogus. I rather go for a fully symmetric interface and let the various incarnations opt in at the right place. Similar to what cpu hotplug states are implementing. Thanks, tglx