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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B15D3C433FE for ; Mon, 25 Oct 2021 16:01:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8DE2860E75 for ; Mon, 25 Oct 2021 16:01:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233791AbhJYQDY (ORCPT ); Mon, 25 Oct 2021 12:03:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33486 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233774AbhJYQDX (ORCPT ); Mon, 25 Oct 2021 12:03:23 -0400 Received: from mail-pg1-x530.google.com (mail-pg1-x530.google.com [IPv6:2607:f8b0:4864:20::530]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6219CC061243 for ; Mon, 25 Oct 2021 09:01:01 -0700 (PDT) Received: by mail-pg1-x530.google.com with SMTP id q187so11392317pgq.2 for ; Mon, 25 Oct 2021 09:01:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=x6eNl6O1fSvFYqdMcRuePT95mvtM6NDjKvqXNkc5pYY=; b=W66VdzQAiFa1xER7EM1CT10+Eh4wcd9TMpOSeNztU9mQ/b+ICWh6L1ynZPC3b8cWCA wuqZ3JuK0JGehSxVwtqEbTHwrBlvK53p1U6E/+mtZAETvvOLRtbYFjLFwI5UloPxv8BN XlYir//YmeaaWdnkVyW1uxNuSu55EoKM4Sw+NhmN68wnM6lSDD7jC6Cq+yKsA+BDT9S7 LYFfhy6YQg08/t+jqQY9xY27FLq7qZME+IYTw4bo6b7p4vRP0wxorg/00RAZqr4kWqI+ VviR3lssvu74tKK3FhhWMgst1k6Zz5l/r1ahbN8uJfV8tyf6Q1Oq93E9u1/e6tuuAmnW 0NsA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=x6eNl6O1fSvFYqdMcRuePT95mvtM6NDjKvqXNkc5pYY=; b=WUkOMK6ep0HSR2vS4d5I6ofGVRs9j+c56YeyBsjbyIl6cFbUSSsxmtj6cqyoRh8hNy 4jbvdltHIGCM2kQkAbWnUEXITCU4APXLZe7ZWdbWFm8BowSnBR/SzdZmeQe4setgZ3L+ wzl/iuEJ9jIeWxbpmU+pICpiirwNfPAddT1eluMgaINAOfje5Ee50VqQdPW/bAP6PmYC 6RbmRqQxR2aHtu+SJ5kvec84s0vdB6rg1CCKxyj4hus7Mj+qgj1BRgAh9oeeU/4EpgUh IHX0TnGfqie/HYa9AKpML3By74aDM6aaq+4h+i+JFCV/Sluap8i313Ak/I0TZfsw/vVC 9g9g== X-Gm-Message-State: AOAM531CzTXafXQGL+CIjMxFau1ChnNPJ0GyVi7MWtuJW+QvzYGY91EA MfMFNI/Fvuav1fR+rQe9SGeC7Q== X-Google-Smtp-Source: ABdhPJxfd0U6TdkD95vRyewvEnv+pkmAbt8gRM1KdKD5w9N0+9AMKZEnnSCWoZvj6xIN71v2dvngIg== X-Received: by 2002:a63:e613:: with SMTP id g19mr14679139pgh.12.1635177660627; Mon, 25 Oct 2021 09:01:00 -0700 (PDT) Received: from google.com (157.214.185.35.bc.googleusercontent.com. [35.185.214.157]) by smtp.gmail.com with ESMTPSA id a124sm2589630pgc.15.2021.10.25.09.00.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 25 Oct 2021 09:01:00 -0700 (PDT) Date: Mon, 25 Oct 2021 16:00:56 +0000 From: Sean Christopherson To: Paolo Bonzini Cc: Marc Zyngier , Huacai Chen , Aleksandar Markovic , Paul Mackerras , Anup Patel , Paul Walmsley , Palmer Dabbelt , Albert Ou , Christian Borntraeger , Janosch Frank , James Morse , Alexandru Elisei , Suzuki K Poulose , Atish Patra , David Hildenbrand , Cornelia Huck , Claudio Imbrenda , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-mips@vger.kernel.org, kvm@vger.kernel.org, kvm-ppc@vger.kernel.org, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, David Matlack , Oliver Upton , Jing Zhang Subject: Re: [PATCH v2 37/43] KVM: SVM: Unconditionally mark AVIC as running on vCPU load (with APICv) Message-ID: References: <20211009021236.4122790-1-seanjc@google.com> <20211009021236.4122790-38-seanjc@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org On Mon, Oct 25, 2021, Paolo Bonzini wrote: > On 25/10/21 17:48, Sean Christopherson wrote: > > On Mon, Oct 25, 2021, Paolo Bonzini wrote: > > > On 09/10/21 04:12, Sean Christopherson wrote: > > > > + /* TODO: Document why the unblocking path checks for updates. */ > > > > > > Is that a riddle or what? :) > > > > Yes? I haven't been able to figure out why the unblocking path explicitly > > checks and handles an APICv update. > > > > Challenge accepted. In the original code, it was because without it > avic_vcpu_load would do nothing, and nothing would update the IS_RUNNING > flag. > > It shouldn't be necessary anymore since commit df7e4827c549 ("KVM: SVM: call > avic_vcpu_load/avic_vcpu_put when enabling/disabling AVIC", 2021-08-20), > where svm_refresh_apicv_exec_ctrl takes care of the avic_vcpu_load on the > next VMRUN. Aha! Thanks, I'll work in a removal for the next version.