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 X-Spam-Level: X-Spam-Status: No, score=-7.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 018F5C47082 for ; Tue, 8 Jun 2021 17:41:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D6B1761360 for ; Tue, 8 Jun 2021 17:40:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233184AbhFHRmv (ORCPT ); Tue, 8 Jun 2021 13:42:51 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:56208 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232376AbhFHRmu (ORCPT ); Tue, 8 Jun 2021 13:42:50 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1623174056; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=uuTEXUh2y4+eVpi9BE2NLF0/TYZeOk1VrPvZH9w4Lo0=; b=caqhqDjdM4brGLMnQ8lduf+VnfYCCJ8K7t5auFexx9AD63HP7GeHEQVcj55Hj7OwzhBkdV K7Y7W1A+602INe2GntPMzm/eZg1S5bGPpXksnqXuaSqsptZt9le2sU8nrRu6JHcyUF81GN 1vVAmQtxGT8mYkXfE2YUDyZ5GFJs/yw= Received: from mail-wr1-f69.google.com (mail-wr1-f69.google.com [209.85.221.69]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-62-MI4Zwb8INmOvBBF2KMhdlQ-1; Tue, 08 Jun 2021 13:40:55 -0400 X-MC-Unique: MI4Zwb8INmOvBBF2KMhdlQ-1 Received: by mail-wr1-f69.google.com with SMTP id q15-20020adfc50f0000b0290111f48b865cso9721008wrf.4 for ; Tue, 08 Jun 2021 10:40:55 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=uuTEXUh2y4+eVpi9BE2NLF0/TYZeOk1VrPvZH9w4Lo0=; b=t3pWkH1EApApm9HMzJGprwbCd/EB6pgknCqGxTU9Q5KV51aZGTgEMRREOvD+ousNJp trgpxF8hVN5cMmiDsi6cx8G5Jh5hmIADzhDvIwdscR5k2tVkH4w4z6JfwX4pKV4MOUmV 6dZgdcRo3duECwetpt9hT2gwg/1J8TY2Qaw/X9ExXrTdOc1RpNFVWn1VqAmk3lSslLJY ox4/h+M7wAP8IlYNkDAr7U6WaiglzUO+xe1lGfaEPdbbfHj1U1tSktlhKAkdU1rfL8Xk WjhKO6nlEMMNTPF7VJPtZqqo2VTujl8MEko5mTPWP20ntZRzdsy0FQ1/k9EiSX7/pxiU LLbg== X-Gm-Message-State: AOAM532T2KVjrGbA+7qrZs4sN7ecZR7QuslhPea2JcM7t0ZgJMpJ/0Qs 2CtyA5B3027dHAkzqO2r6XQdBdmpOzwJua8HQp7lZ93eq2mKZZIWHlgSU5l0P78J2KynX39YFb0 7N/Yp1ghl9HOk X-Received: by 2002:a1c:9804:: with SMTP id a4mr23765708wme.34.1623174054279; Tue, 08 Jun 2021 10:40:54 -0700 (PDT) X-Google-Smtp-Source: ABdhPJxCg/4Dg2XjHEakG0Gnd75nQyKD/Y6nxzDDphWNa3SRKmaQxg54dFAsRxFHIsqIoOwPd/74gA== X-Received: by 2002:a1c:9804:: with SMTP id a4mr23765690wme.34.1623174054086; Tue, 08 Jun 2021 10:40:54 -0700 (PDT) Received: from ?IPv6:2001:b07:6468:f312:c8dd:75d4:99ab:290a? ([2001:b07:6468:f312:c8dd:75d4:99ab:290a]) by smtp.gmail.com with ESMTPSA id o26sm7824493wms.27.2021.06.08.10.40.53 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 08 Jun 2021 10:40:53 -0700 (PDT) Subject: Re: [PATCH v2 3/3] KVM: X86: Let's harden the ipi fastpath condition edge-trigger mode To: Sean Christopherson , Wanpeng Li Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel References: <1623050385-100988-1-git-send-email-wanpengli@tencent.com> <1623050385-100988-3-git-send-email-wanpengli@tencent.com> From: Paolo Bonzini Message-ID: <2a643f94-d159-c1ac-6bd2-cc6b45372630@redhat.com> Date: Tue, 8 Jun 2021 19:40:52 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.10.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On 08/06/21 18:35, Sean Christopherson wrote: > Related side topic, anyone happen to know if KVM (and Qemu's) emulation of IPIs > intentionally follows AMD instead of Intel? I suspect it's unintentional, > especially since KVM's initial xAPIC emulation came from Intel. Not that it's > likely to matter, but allowing level-triggered IPIs is bizarre, e.g. getting an > EOI sent to the right I/O APIC at the right time via a level-triggered IPI seems > extremely convoluted. QEMU traditionally followed AMD a bit more than Intel for historical reasons. Probably the code went QEMU->Xen->KVM even though it was contributed by Intel. Paolo