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=-4.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, 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 BBC7BC4338F for ; Mon, 2 Aug 2021 12:56:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A62D460E09 for ; Mon, 2 Aug 2021 12:56:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233791AbhHBM45 (ORCPT ); Mon, 2 Aug 2021 08:56:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53710 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233703AbhHBM4z (ORCPT ); Mon, 2 Aug 2021 08:56:55 -0400 Received: from mail-pj1-x1029.google.com (mail-pj1-x1029.google.com [IPv6:2607:f8b0:4864:20::1029]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 21D4BC061760; Mon, 2 Aug 2021 05:56:46 -0700 (PDT) Received: by mail-pj1-x1029.google.com with SMTP id pj14-20020a17090b4f4eb029017786cf98f9so13938206pjb.2; Mon, 02 Aug 2021 05:56:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=/GYPS7X+85wR6YC8425aJSok3ZXyi4U2bTyYNUsfO5w=; b=pyQkhPeDqOZN1lKQvpgjaZhDuqcfBH++qI9Yz80iquDkO6oGt+tBuSPtyV0nMGVBJ1 M2E5aA/XAnoteOyDQT8M+x5AliZKopkoGnInKwL3m2QqBiWDu36W26gL/YPC8K/KeYlr lKiZUAf6XKEOBg70NsE3K9fU4mOPUUIoCYKqtgQQ2HjvRH1Q+CjUYFOowxeVCbfkbnu7 GXswmjuYPprsxcXIE4NienyvsAMjibDdMeps+gxmOrpMJQUHeDF7e/9b+DgNRmsrf0dj R82WDqtlRqQuveuh5cTGWXuurfZKwGo+CrnXy7KJkYXeft1AWFi82RFU5cJODZER7tHh HwOA== 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=/GYPS7X+85wR6YC8425aJSok3ZXyi4U2bTyYNUsfO5w=; b=rrQnvroREh2lzghJkvH2U/ojYO3L0NmRV7JJFuYQUXDTIqPGYR6Rcij7ihjFmzgNJQ mkdaOkLN1jYbe5o32gpwVSeeujdufvy3hKZaUXkRTqNpIskdgh5zN/Ndwyay3hZvIyrL n+Dn7iGXruIGy5LNhbFluSoNHOfha6Oj+Mw0pYbERbZ5Mcoo8rza+5NER0XsnryI+w40 C7g+fONcn788RhZd0MEVV4pHdjPTzWDrGP83kg6BsdzLptgypFvOG/dmNOyDR0l/vUWu HZhI+snNNzdulBGXoHqTsp1ZGxsVowjZ2IlTPvalbDHT7/XJRUnncPksy0YflbysJYI5 TU7Q== X-Gm-Message-State: AOAM533ThRRBnRAPRb96QhFcxQ0mzS4Ya2ROpZpS1VCxA/Mpof/3bP/V qap4wV5zVSIH2t8/CssSYe0= X-Google-Smtp-Source: ABdhPJyLDEEPYFYa8bCYhczgLUorbl2lwmF46SVfXQIXh/rESGtdQ+84YDRl3Rg46/KGbl2xu2SCOw== X-Received: by 2002:a17:902:b48b:b029:12c:59b:dc44 with SMTP id y11-20020a170902b48bb029012c059bdc44mr14086944plr.47.1627909005643; Mon, 02 Aug 2021 05:56:45 -0700 (PDT) Received: from ?IPv6:2404:f801:0:5:8000::4b1? ([2404:f801:9000:1a:efea::4b1]) by smtp.gmail.com with ESMTPSA id g7sm6679837pfv.66.2021.08.02.05.56.32 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 02 Aug 2021 05:56:45 -0700 (PDT) Subject: Re: [PATCH 04/13] HV: Mark vmbus ring buffer visible to host in Isolation VM To: Joerg Roedel Cc: kys@microsoft.com, haiyangz@microsoft.com, sthemmin@microsoft.com, wei.liu@kernel.org, decui@microsoft.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org, hpa@zytor.com, dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org, konrad.wilk@oracle.com, boris.ostrovsky@oracle.com, jgross@suse.com, sstabellini@kernel.org, will@kernel.org, davem@davemloft.net, kuba@kernel.org, jejb@linux.ibm.com, martin.petersen@oracle.com, arnd@arndb.de, hch@lst.de, m.szyprowski@samsung.com, robin.murphy@arm.com, thomas.lendacky@amd.com, brijesh.singh@amd.com, ardb@kernel.org, Tianyu.Lan@microsoft.com, rientjes@google.com, martin.b.radev@gmail.com, akpm@linux-foundation.org, rppt@kernel.org, kirill.shutemov@linux.intel.com, aneesh.kumar@linux.ibm.com, krish.sadhukhan@oracle.com, saravanand@fb.com, xen-devel@lists.xenproject.org, pgonda@google.com, david@redhat.com, keescook@chromium.org, hannes@cmpxchg.org, sfr@canb.auug.org.au, michael.h.kelley@microsoft.com, iommu@lists.linux-foundation.org, linux-arch@vger.kernel.org, linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org, netdev@vger.kernel.org, vkuznets@redhat.com, anparri@microsoft.com References: <20210728145232.285861-1-ltykernel@gmail.com> <20210728145232.285861-5-ltykernel@gmail.com> From: Tianyu Lan Message-ID: <173823d1-280c-d34e-be2c-157b55bb6bc3@gmail.com> Date: Mon, 2 Aug 2021 20:56:29 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.12.0 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: linux-kernel@vger.kernel.org On 8/2/2021 8:07 PM, Joerg Roedel wrote: > On Wed, Jul 28, 2021 at 10:52:19AM -0400, Tianyu Lan wrote: >> + if (type == HV_GPADL_BUFFER) >> + index = 0; >> + else >> + index = channel->gpadl_range[1].gpadlhandle ? 2 : 1; > > Hmm... This doesn't look very robust. Can you set fixed indexes for > different buffer types? HV_GPADL_BUFFER already has fixed index 0. But > as it is implemented here you risk that index 2 gets overwritten by > subsequent calls. Both second and third are HV_GPADL_RING type. One is send ring and the other is receive ring. The driver keeps the order to allocate rx and tx buffer. You are right this is not robust and will add a mutex to keep the order. 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=-2.0 required=3.0 tests=BAYES_00,DKIM_ADSP_CUSTOM_MED, DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,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 8E4ADC4338F for ; Mon, 2 Aug 2021 12:56:50 +0000 (UTC) Received: from smtp4.osuosl.org (smtp4.osuosl.org [140.211.166.137]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 34E9060F6D for ; Mon, 2 Aug 2021 12:56:50 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 34E9060F6D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by smtp4.osuosl.org (Postfix) with ESMTP id 00DAE4039B; Mon, 2 Aug 2021 12:56:50 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp4.osuosl.org ([127.0.0.1]) by localhost (smtp4.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 8vsv7fiaJ2Dw; Mon, 2 Aug 2021 12:56:49 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [IPv6:2605:bc80:3010:104::8cd3:938]) by smtp4.osuosl.org (Postfix) with ESMTPS id DA4E44014F; Mon, 2 Aug 2021 12:56:48 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 73B5FC001B; Mon, 2 Aug 2021 12:56:48 +0000 (UTC) Received: from smtp1.osuosl.org (smtp1.osuosl.org [140.211.166.138]) by lists.linuxfoundation.org (Postfix) with ESMTP id CFD6CC000E for ; Mon, 2 Aug 2021 12:56:46 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp1.osuosl.org (Postfix) with ESMTP id B0B9A83A85 for ; Mon, 2 Aug 2021 12:56:46 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Authentication-Results: smtp1.osuosl.org (amavisd-new); dkim=pass (2048-bit key) header.d=gmail.com Received: from smtp1.osuosl.org ([127.0.0.1]) by localhost (smtp1.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id V-CJT-NnAztJ for ; Mon, 2 Aug 2021 12:56:46 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.8.0 Received: from mail-pj1-x102d.google.com (mail-pj1-x102d.google.com [IPv6:2607:f8b0:4864:20::102d]) by smtp1.osuosl.org (Postfix) with ESMTPS id 3AD7183A5B for ; Mon, 2 Aug 2021 12:56:46 +0000 (UTC) Received: by mail-pj1-x102d.google.com with SMTP id o44-20020a17090a0a2fb0290176ca3e5a2fso24566170pjo.1 for ; Mon, 02 Aug 2021 05:56:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=/GYPS7X+85wR6YC8425aJSok3ZXyi4U2bTyYNUsfO5w=; b=pyQkhPeDqOZN1lKQvpgjaZhDuqcfBH++qI9Yz80iquDkO6oGt+tBuSPtyV0nMGVBJ1 M2E5aA/XAnoteOyDQT8M+x5AliZKopkoGnInKwL3m2QqBiWDu36W26gL/YPC8K/KeYlr lKiZUAf6XKEOBg70NsE3K9fU4mOPUUIoCYKqtgQQ2HjvRH1Q+CjUYFOowxeVCbfkbnu7 GXswmjuYPprsxcXIE4NienyvsAMjibDdMeps+gxmOrpMJQUHeDF7e/9b+DgNRmsrf0dj R82WDqtlRqQuveuh5cTGWXuurfZKwGo+CrnXy7KJkYXeft1AWFi82RFU5cJODZER7tHh HwOA== 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=/GYPS7X+85wR6YC8425aJSok3ZXyi4U2bTyYNUsfO5w=; b=g6HLTlfMf44nJzMETk+koy/qLx9Xbu+kQRdiDHf2He3SQn8fSTdFc0kwSmogEcQ84z p8PexZK1THmEA1QjuB9220p1EnZhDqLgKbiSAfEUdJ6WXuwdcY3t0w1cIux1Cia/CvIr BTX0Og1Ui0YZlQfh6n2Lv0hm0Q15+kw/bCUH04djDGK8o0Q9zuveI+ccmI9asBsxd5QX QGNRDt1DHV8uhgdtZnL6dyM83KIa0OI0EbO0Tqcn1ZG40Zh0dVRYhwbKyc8u3HPDQ7Qu hB1cV7fhmCEox/tYqccBiv3EjHz4/rQOe0WEFhxpoVcuYk+cUPA0SWIpWqPGNYkgJ+HW vN7Q== X-Gm-Message-State: AOAM532uwvMGdzah13GxGJYYKuDrg/ZrYL1g5v7r761meTvm0E52jOe4 /H0WvGGEdUS0DKLRfkgnSuE= X-Google-Smtp-Source: ABdhPJyLDEEPYFYa8bCYhczgLUorbl2lwmF46SVfXQIXh/rESGtdQ+84YDRl3Rg46/KGbl2xu2SCOw== X-Received: by 2002:a17:902:b48b:b029:12c:59b:dc44 with SMTP id y11-20020a170902b48bb029012c059bdc44mr14086944plr.47.1627909005643; Mon, 02 Aug 2021 05:56:45 -0700 (PDT) Received: from ?IPv6:2404:f801:0:5:8000::4b1? ([2404:f801:9000:1a:efea::4b1]) by smtp.gmail.com with ESMTPSA id g7sm6679837pfv.66.2021.08.02.05.56.32 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 02 Aug 2021 05:56:45 -0700 (PDT) Subject: Re: [PATCH 04/13] HV: Mark vmbus ring buffer visible to host in Isolation VM To: Joerg Roedel References: <20210728145232.285861-1-ltykernel@gmail.com> <20210728145232.285861-5-ltykernel@gmail.com> From: Tianyu Lan Message-ID: <173823d1-280c-d34e-be2c-157b55bb6bc3@gmail.com> Date: Mon, 2 Aug 2021 20:56:29 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.12.0 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US Cc: linux-hyperv@vger.kernel.org, brijesh.singh@amd.com, david@redhat.com, peterz@infradead.org, dave.hansen@linux.intel.com, vkuznets@redhat.com, hpa@zytor.com, anparri@microsoft.com, kys@microsoft.com, will@kernel.org, boris.ostrovsky@oracle.com, linux-arch@vger.kernel.org, sfr@canb.auug.org.au, wei.liu@kernel.org, sstabellini@kernel.org, sthemmin@microsoft.com, xen-devel@lists.xenproject.org, linux-scsi@vger.kernel.org, aneesh.kumar@linux.ibm.com, x86@kernel.org, decui@microsoft.com, hch@lst.de, michael.h.kelley@microsoft.com, mingo@redhat.com, pgonda@google.com, rientjes@google.com, kuba@kernel.org, jejb@linux.ibm.com, martin.b.radev@gmail.com, thomas.lendacky@amd.com, Tianyu.Lan@microsoft.com, keescook@chromium.org, arnd@arndb.de, konrad.wilk@oracle.com, haiyangz@microsoft.com, bp@alien8.de, luto@kernel.org, krish.sadhukhan@oracle.com, tglx@linutronix.de, akpm@linux-foundation.org, jgross@suse.com, martin.petersen@oracle.com, saravanand@fb.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, kirill.shutemov@linux.intel.com, hannes@cmpxchg.org, ardb@kernel.org, robin.murphy@arm.com, davem@davemloft.net, rppt@kernel.org X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" On 8/2/2021 8:07 PM, Joerg Roedel wrote: > On Wed, Jul 28, 2021 at 10:52:19AM -0400, Tianyu Lan wrote: >> + if (type == HV_GPADL_BUFFER) >> + index = 0; >> + else >> + index = channel->gpadl_range[1].gpadlhandle ? 2 : 1; > > Hmm... This doesn't look very robust. Can you set fixed indexes for > different buffer types? HV_GPADL_BUFFER already has fixed index 0. But > as it is implemented here you risk that index 2 gets overwritten by > subsequent calls. Both second and third are HV_GPADL_RING type. One is send ring and the other is receive ring. The driver keeps the order to allocate rx and tx buffer. You are right this is not robust and will add a mutex to keep the order. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu