From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750905AbdALOKj (ORCPT ); Thu, 12 Jan 2017 09:10:39 -0500 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:48218 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750791AbdALOKg (ORCPT ); Thu, 12 Jan 2017 09:10:36 -0500 Subject: Re: [PATCH v8 1/1] crypto: add virtio-crypto driver To: "Gonglei (Arei)" , "linux-kernel@vger.kernel.org" , "qemu-devel@nongnu.org" , "virtio-dev@lists.oasis-open.org" , "virtualization@lists.linux-foundation.org" , "linux-crypto@vger.kernel.org" , "davem@davemloft.net" , "herbert@gondor.apana.org.au" References: <1481767396-187748-1-git-send-email-arei.gonglei@huawei.com> <1481767396-187748-2-git-send-email-arei.gonglei@huawei.com> <33183CC9F5247A488A2544077AF19020DA182B83@DGGEMA505-MBX.china.huawei.com> Cc: "Huangweidong (C)" , Claudio Fontana , "mst@redhat.com" , Luonengjun , "Hanweidong (Randy)" , "Xuquan (Quan Xu)" , "Wanzongshun (Vincent)" , "stefanha@redhat.com" , "Zhoujian (jay, Euler)" , longpeng , "arei.gonglei@hotmail.com" , "Wubin (H)" From: Christian Borntraeger Date: Thu, 12 Jan 2017 15:10:25 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.6.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Content-Scanned: Fidelis XPS MAILER x-cbid: 17011214-0008-0000-0000-0000068A3035 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00006420; HX=3.00000240; KW=3.00000007; PH=3.00000004; SC=3.00000199; SDB=6.00806641; UDB=6.00392564; IPR=6.00583972; BA=6.00005051; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00013903; XFM=3.00000011; UTC=2017-01-12 14:10:34 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17011214-0009-0000-0000-00003E93FD48 Message-Id: X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-01-12_10:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1612050000 definitions=main-1701120200 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/10/2017 01:56 PM, Christian Borntraeger wrote: > On 01/10/2017 01:36 PM, Gonglei (Arei) wrote: >> Hi, >> >>> >>> On 12/15/2016 03:03 AM, Gonglei wrote: >>> [...] >>>> + >>>> +static struct crypto_alg virtio_crypto_algs[] = { { >>>> + .cra_name = "cbc(aes)", >>>> + .cra_driver_name = "virtio_crypto_aes_cbc", >>>> + .cra_priority = 501, >>> >>> >>> This is still higher than the hardware-accelerators (like intel aesni or the >>> s390 cpacf functions or the arm hw). aesni and s390/cpacf are supported by the >>> hardware virtualization and available to the guests. I do not see a way how >>> virtio >>> crypto can be faster than that (in the end it might be cpacf/aesni + overhead) >>> instead it will very likely be slower. >>> So we should use a number that is higher than software implementations but >>> lower than the hw ones. >>> >>> Just grepping around, the software ones seem be be around 100 and the >>> hardware >>> ones around 200-400. So why was 150 not enough? >>> >> I didn't find a documentation about how we use the priority, and I assumed >> people use virtio-crypto will configure hardware accelerators in the >> host. So I choosed the number which bigger than aesni's priority. > > Yes, but the aesni driver will only bind if there is HW support in the guest. > And if aesni is available in the guest (or the s390 aes function from cpacf) > it will always be faster than the same in the host via virtio.So your priority > should be smaller. any opinion on this?