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dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:50106 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1l5Tb8-0001sk-EV for qemu-devel@archiver.kernel.org; Fri, 29 Jan 2021 08:14:02 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:57098) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1l5TYT-0000YM-UC for qemu-devel@nongnu.org; Fri, 29 Jan 2021 08:11:18 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:46805) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1l5TYL-00030Y-1i for qemu-devel@nongnu.org; Fri, 29 Jan 2021 08:11:17 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1611925865; 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=a0n2iAz7qZVW82Meqto8Hz6DydlTWNUsMON8L3R8h70=; b=buGrmOvbHvMH/M9TANwRNlYSrLs6VA/vJdEF4j0Mq44FW591cyKMfp+QhaICZbpzq/JMAn NolqlNpmkJx/7CXNeGbsddDy0LBBEu9IequjBWSFooaupDT9uC8T8hNKOGml9w3yj1eIuu KpTuaxI0BTIDK3c5oFqDKhaFrJ99xo4= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-79-tHs3kU-RPhKpf3hiodCbUw-1; Fri, 29 Jan 2021 08:11:03 -0500 X-MC-Unique: tHs3kU-RPhKpf3hiodCbUw-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 4332C107ACE3; Fri, 29 Jan 2021 13:11:02 +0000 (UTC) Received: from [10.36.114.62] (ovpn-114-62.ams2.redhat.com [10.36.114.62]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 25DBD620D7; Fri, 29 Jan 2021 13:10:59 +0000 (UTC) Subject: Re: [PATCH] hw/arm/smmuv3: Fix addr_mask for range-based invalidation To: Zenghui Yu , qemu-devel@nongnu.org, qemu-arm@nongnu.org, peter.maydell@linaro.org References: <20201225095015.609-1-yuzenghui@huawei.com> <4e114709-e5c2-1860-c760-c05aa3ed5388@redhat.com> <45f3334d-f0b4-9a40-1bd1-78bd04735eaf@redhat.com> From: Auger Eric Message-ID: Date: Fri, 29 Jan 2021 14:10:58 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.5.0 MIME-Version: 1.0 In-Reply-To: X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=eric.auger@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=216.205.24.124; envelope-from=eric.auger@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -29 X-Spam_score: -3.0 X-Spam_bar: --- X-Spam_report: (-3.0 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.249, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, NICE_REPLY_A=-0.001, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: wanghaibin.wang@huawei.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Hi Zenghui, On 1/29/21 1:15 PM, Zenghui Yu wrote: > Hi Eric, > > On 2021/1/29 5:30, Auger Eric wrote: >> Hi Zenghui, >> >> On 1/28/21 9:25 AM, Auger Eric wrote: >>> Hi Zenghui, >>> >>> On 12/25/20 10:50 AM, Zenghui Yu wrote: >>>> When performing range-based IOTLB invalidation, we should decode the TG >>>> field into the corresponding translation granule size so that we can >>>> pass >>>> the correct invalidation range to backend. Set @granule to (tg * 2 + >>>> 10) to >>>> properly emulate the architecture. >>>> >>>> Fixes: d52915616c05 ("hw/arm/smmuv3: Get prepared for range >>>> invalidation") >>>> Signed-off-by: Zenghui Yu >>> >>> Good catch! I tested with older guest kernels though. I wonder how I did >>> not face the bug? >> Please ignore this wrong comment as this corresponds to recent kernels >> instead. Still puzzled anyway ;-) > > I noticed this when looking through your nested SMMU series and I didn't > have much clue about the impact on the real setups. > > I guess we may receive some unexpected fault events with this bug. But I > think we may miss it for some reasons: > >  - the stale TLB entries happen to be evicted due to heavy traffic >  - some form of over-invalidation is performed by your implementation >  - ... Yep I will further trace things. Anyway thank you for spotting it. > >>>> --- >>>>   hw/arm/smmuv3.c | 4 +++- >>>>   1 file changed, 3 insertions(+), 1 deletion(-) >>>> >>>> diff --git a/hw/arm/smmuv3.c b/hw/arm/smmuv3.c >>>> index bbca0e9f20..65231c7d52 100644 >>>> --- a/hw/arm/smmuv3.c >>>> +++ b/hw/arm/smmuv3.c >>>> @@ -801,7 +801,7 @@ static void smmuv3_notify_iova(IOMMUMemoryRegion >>>> *mr, >>>>   { >>>>       SMMUDevice *sdev = container_of(mr, SMMUDevice, iommu); >>>>       IOMMUTLBEvent event; >>>> -    uint8_t granule = tg; >>>> +    uint8_t granule; >>>>         if (!tg) { >>>>           SMMUEventInfo event = {.inval_ste_allowed = true}; >>>> @@ -821,6 +821,8 @@ static void smmuv3_notify_iova(IOMMUMemoryRegion >>>> *mr, >>>>               return; >>>>           } >>>>           granule = tt->granule_sz; >>>> +    } else { >>>> +        guanule = tg * 2 + 10; >>> maybe just init granule to this value above while fixing the typo. > > My intention is to initialize @granule to this value explicitly for the > range-based invalidation case. But I'm okay with either way. same for me ;-) Eric > > > Thanks, > Zenghui >