From mboxrd@z Thu Jan 1 00:00:00 1970 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 50732C001DE for ; Mon, 31 Jul 2023 17:43:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229758AbjGaRnt (ORCPT ); Mon, 31 Jul 2023 13:43:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57562 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229712AbjGaRns (ORCPT ); Mon, 31 Jul 2023 13:43:48 -0400 X-Greylist: delayed 363 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Mon, 31 Jul 2023 10:43:47 PDT Received: from out-67.mta0.migadu.com (out-67.mta0.migadu.com [91.218.175.67]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 75F7D10B for ; Mon, 31 Jul 2023 10:43:47 -0700 (PDT) Date: Mon, 31 Jul 2023 17:37:37 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1690825062; 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=8YdaDmAxh2tQ04c65R6HIInMSDgiFElU1rQyABOujGA=; b=EX5P5RrbAyGLiUihHg1zPC7oGWSKDM/ElBWxcBqxOnEfqsICZbH2/AKd3VVoNKwHnOFruh 7NElv6WY+11J1OOCKqt98Yd2d6vWX/LMv7f7kzf3/02EtNU3neXRdqSxXfp5KfexlS5rP8 7iRednQbNTf1lNnkOTSMwB1k8yGXoT8= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Oliver Upton To: Sean Christopherson Cc: Marc Zyngier , Huacai Chen , Anup Patel , Paul Walmsley , Palmer Dabbelt , Albert Ou , Paolo Bonzini , linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-mips@vger.kernel.org, kvm@vger.kernel.org, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, Yu Zhao Subject: Re: [PATCH] KVM: Wrap kvm_{gfn,hva}_range.pte in a per-action union Message-ID: References: <20230729004144.1054885-1-seanjc@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230729004144.1054885-1-seanjc@google.com> X-Migadu-Flow: FLOW_OUT Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org On Fri, Jul 28, 2023 at 05:41:44PM -0700, Sean Christopherson wrote: > Wrap kvm_{gfn,hva}_range.pte in a union so that future notifier events can > pass event specific information up and down the stack without needing to > constantly expand and churn the APIs. Lockless aging of SPTEs will pass > around a bitmap, and support for memory attributes will pass around the > new attributes for the range. > > Add a "KVM_NO_ARG" placeholder to simplify handling events without an > argument (creating a dummy union variable is midly annoying). > > Opportunstically drop explicit zero-initialization of the "pte" field, as > omitting the field (now a union) has the same effect. > > Cc: Yu Zhao > Link: https://lore.kernel.org/all/CAOUHufagkd2Jk3_HrVoFFptRXM=hX2CV8f+M-dka-hJU4bP8kw@mail.gmail.com > Signed-off-by: Sean Christopherson Looks good, and I don't think it'll conflict with anything on the arm64 side. Reviewed-by: Oliver Upton > --- > > If this looks good, my thought is to squeeze it into 6.6 so that the MGLRU > and guest_memfd() series can build on it. Or those series could just > include it? Eh, I'm not a huge fan of having two series independently reposting a common base. It can be a bit annoying when the two authors have slightly different interpretations on how to improve it... > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c > index dfbaafbe3a00..f84ef9399aee 100644 > --- a/virt/kvm/kvm_main.c > +++ b/virt/kvm/kvm_main.c > @@ -526,7 +526,7 @@ typedef void (*on_unlock_fn_t)(struct kvm *kvm); > struct kvm_hva_range { > unsigned long start; > unsigned long end; > - pte_t pte; > + union kvm_mmu_notifier_arg arg; > hva_handler_t handler; > on_lock_fn_t on_lock; > on_unlock_fn_t on_unlock; > @@ -547,6 +547,8 @@ static void kvm_null_fn(void) > } > #define IS_KVM_NULL_FN(fn) ((fn) == (void *)kvm_null_fn) > > +static const union kvm_mmu_notifier_arg KVM_NO_ARG; > + I'm guessing you were trying to keep this short, but it might be nice to use MMU_NOTIFIER_ (or similar) as the prefix to make the scope immediately obvious. -- Thanks, Oliver