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=-11.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 5E877C433E1 for ; Mon, 20 Jul 2020 07:40:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3A40220773 for ; Mon, 20 Jul 2020 07:40:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726853AbgGTHkw (ORCPT ); Mon, 20 Jul 2020 03:40:52 -0400 Received: from mga04.intel.com ([192.55.52.120]:37388 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726109AbgGTHkw (ORCPT ); Mon, 20 Jul 2020 03:40:52 -0400 IronPort-SDR: ZOcKE1l2L5QxAIyfrvx45+4eMEveSbbMKolgkIS1+EkT717c+Kmde9jXY9A3E7qLVC6rdOpU7P PdVlyitKHQxw== X-IronPort-AV: E=McAfee;i="6000,8403,9687"; a="147367459" X-IronPort-AV: E=Sophos;i="5.75,374,1589266800"; d="scan'208";a="147367459" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Jul 2020 00:40:51 -0700 IronPort-SDR: r3apDs/M39y8U9qBqfznT76nBN59T7vgMnEp2Hgn/vsSE549zA+3c4uipxC7uEpVe9OlSlcM0P 7Z6nwkPCwFpw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.75,374,1589266800"; d="scan'208";a="361945020" Received: from lingshan-mobl5.ccr.corp.intel.com (HELO [10.255.29.73]) ([10.255.29.73]) by orsmga001.jf.intel.com with ESMTP; 20 Jul 2020 00:40:47 -0700 Subject: Re: [PATCH V2 2/6] kvm: detect assigned device via irqbypass manager To: Jason Wang , mst@redhat.com, alex.williamson@redhat.com, pbonzini@redhat.com, sean.j.christopherson@intel.com, wanpengli@tencent.com Cc: virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, kvm@vger.kernel.org References: <1594898629-18790-1-git-send-email-lingshan.zhu@intel.com> <1594898629-18790-3-git-send-email-lingshan.zhu@intel.com> From: "Zhu, Lingshan" Message-ID: Date: Mon, 20 Jul 2020 15:40:46 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.8.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 7/17/2020 12:01 PM, Jason Wang wrote: > > On 2020/7/16 下午7:23, Zhu Lingshan wrote: >> vDPA devices has dedicated backed hardware like >> passthrough-ed devices. Then it is possible to setup irq >> offloading to vCPU for vDPA devices. Thus this patch tries to >> manipulated assigned device counters via irqbypass manager. > > > This part needs some tweak, e.g why assigned device could be detected > through this way. > > >> >> We will increase/decrease the assigned device counter in kvm/x86. > > > And you need explain why we don't need similar thing in other arch. > > Thanks OK Thanks! > > >> Both vDPA and VFIO would go through this code path. >> >> This code path only affect x86 for now. >> >> Signed-off-by: Zhu Lingshan >> Suggested-by: Jason Wang >> --- >>   arch/x86/kvm/x86.c | 10 ++++++++-- >>   1 file changed, 8 insertions(+), 2 deletions(-) >> >> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c >> index 00c88c2..20c07d3 100644 >> --- a/arch/x86/kvm/x86.c >> +++ b/arch/x86/kvm/x86.c >> @@ -10624,11 +10624,17 @@ int kvm_arch_irq_bypass_add_producer(struct >> irq_bypass_consumer *cons, >>   { >>       struct kvm_kernel_irqfd *irqfd = >>           container_of(cons, struct kvm_kernel_irqfd, consumer); >> +    int ret; >>         irqfd->producer = prod; >> +    kvm_arch_start_assignment(irqfd->kvm); >> +    ret = kvm_x86_ops.update_pi_irte(irqfd->kvm, >> +                     prod->irq, irqfd->gsi, 1); >> + >> +    if (ret) >> +        kvm_arch_end_assignment(irqfd->kvm); >>   -    return kvm_x86_ops.update_pi_irte(irqfd->kvm, >> -                       prod->irq, irqfd->gsi, 1); >> +    return ret; >>   } >>     void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer >> *cons, >