From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from szxga08-in.huawei.com (szxga08-in.huawei.com [45.249.212.255]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 94F0621505D; Wed, 26 Feb 2025 11:41:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.255 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740570109; cv=none; b=uogbsB89HMoA0iEu/DdNGTMCZzP3+2Mu4twN5bmmM+YMGzdALx7IxDnzfDxp5JtWAPjMks+H74QgTnvkWRVhBPzbRdRl7YuSxY4dP0Z2MxVyKjGLcl6uq3jedcz2Lc3mfl4coEAlzQjmHfsd1Xp+biz56zicdnm9C5ofGCaUcdc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740570109; c=relaxed/simple; bh=KSwNl3A1mC+3ZEdgjSHwOe3ThOAVyqdt0JrcLju1qg8=; h=Subject:To:CC:References:From:Message-ID:Date:MIME-Version: In-Reply-To:Content-Type; b=Liv4B1LTWfgdrz8cW3SfWl831v+ibAYLnLpyj1pIctN8hBasJxfbdn5oknwCjWlW6pl2k0PsvzsG/8XCYxoPEgqjunCYMNBRJjSK2iqSQ++gIpz8MZhUYfc9ljGXFJ4Fsqu75YCcg5QWEmX3acFCNiyIiFJ1G+RECPbEhedZf/E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=45.249.212.255 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.19.163.174]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4Z2srN2P2Xz1GDh5; Wed, 26 Feb 2025 19:36:52 +0800 (CST) Received: from kwepemg500006.china.huawei.com (unknown [7.202.181.43]) by mail.maildlp.com (Postfix) with ESMTPS id 7B5821402C4; Wed, 26 Feb 2025 19:41:37 +0800 (CST) Received: from [10.67.121.110] (10.67.121.110) by kwepemg500006.china.huawei.com (7.202.181.43) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Wed, 26 Feb 2025 19:41:36 +0800 Subject: Re: [PATCH v4 1/5] hisi_acc_vfio_pci: fix XQE dma address error To: Shameerali Kolothum Thodi , Alex Williamson CC: "jgg@nvidia.com" , Jonathan Cameron , "kvm@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linuxarm@openeuler.org" References: <20250225062757.19692-1-liulongfang@huawei.com> <20250225062757.19692-2-liulongfang@huawei.com> <20250225170941.46b0ede5.alex.williamson@redhat.com> <024fd8e2334141b688150650728699ba@huawei.com> From: liulongfang Message-ID: <2dd0cd4a-0b64-aa21-d82b-f1d506d42631@huawei.com> Date: Wed, 26 Feb 2025 19:41:36 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 In-Reply-To: <024fd8e2334141b688150650728699ba@huawei.com> Content-Type: text/plain; charset="gbk" Content-Transfer-Encoding: 7bit X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To kwepemg500006.china.huawei.com (7.202.181.43) On 2025/2/26 16:11, Shameerali Kolothum Thodi wrote: > > >> -----Original Message----- >> From: Alex Williamson >> Sent: Wednesday, February 26, 2025 12:10 AM >> To: liulongfang >> Cc: jgg@nvidia.com; Shameerali Kolothum Thodi >> ; Jonathan Cameron >> ; kvm@vger.kernel.org; linux- >> kernel@vger.kernel.org; linuxarm@openeuler.org >> Subject: Re: [PATCH v4 1/5] hisi_acc_vfio_pci: fix XQE dma address error >> >> On Tue, 25 Feb 2025 14:27:53 +0800 >> Longfang Liu wrote: >> >>> The dma addresses of EQE and AEQE are wrong after migration and >>> results in guest kernel-mode encryption services failure. >>> Comparing the definition of hardware registers, we found that >>> there was an error when the data read from the register was >>> combined into an address. Therefore, the address combination >>> sequence needs to be corrected. >>> >>> Even after fixing the above problem, we still have an issue >>> where the Guest from an old kernel can get migrated to >>> new kernel and may result in wrong data. >>> >>> In order to ensure that the address is correct after migration, >>> if an old magic number is detected, the dma address needs to be >>> updated. >>> >>> Fixes: b0eed085903e ("hisi_acc_vfio_pci: Add support for VFIO live >> migration") >>> Signed-off-by: Longfang Liu >>> --- >>> .../vfio/pci/hisilicon/hisi_acc_vfio_pci.c | 40 ++++++++++++++++--- >>> .../vfio/pci/hisilicon/hisi_acc_vfio_pci.h | 14 ++++++- >>> 2 files changed, 46 insertions(+), 8 deletions(-) >>> >>> diff --git a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c >> b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c >>> index 451c639299eb..35316984089b 100644 >>> --- a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c >>> +++ b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c >>> @@ -350,6 +350,31 @@ static int vf_qm_func_stop(struct hisi_qm *qm) >>> return hisi_qm_mb(qm, QM_MB_CMD_PAUSE_QM, 0, 0, 0); >>> } >>> >>> +static int vf_qm_version_check(struct acc_vf_data *vf_data, struct device >> *dev) >>> +{ >>> + switch (vf_data->acc_magic) { >>> + case ACC_DEV_MAGIC_V2: >>> + if (vf_data->major_ver < ACC_DRV_MAJOR_VER || >>> + vf_data->minor_ver < ACC_DRV_MINOR_VER) >>> + dev_info(dev, "migration driver version not >> match!\n"); >>> + return -EINVAL; >>> + break; >> >> What's your major/minor update strategy? >> >> Note that minor_ver is a u16 and ACC_DRV_MINOR_VER is defined as 0, so >> testing less than 0 against an unsigned is useless. >> >> Arguably testing major and minor independently is pretty useless too. >> >> You're defining what a future "old" driver version will accept, which >> is very nearly anything, so any breaking change *again* requires a new >> magic, so we're accomplishing very little here. >> >> Maybe you want to consider a strategy where you'd increment the major >> number for a breaking change and minor for a compatible feature. In >> that case you'd want to verify the major_ver matches >> ACC_DRV_MAJOR_VER >> exactly and minor_ver would be more of a feature level. > > Agree. I think the above check should be just major_ver != ACC_DRV_MAJOR_VER > and we can make use of minor version whenever we need a specific handling for > a feature support. > Well, that's a good way. We only use minor_ver to record important updates of the driver. When there is an important update, minor_ver increases by 1. Major_ver is used to distinguish migration versions. After major_ver is updated, minor_ver returns to 0. Therefore, we can change it to only check major_ver. > Also I think it would be good to print the version info above in case of mismatch. > OK. Thanks. Longfang. >> >>> + case ACC_DEV_MAGIC_V1: >>> + /* Correct dma address */ >>> + vf_data->eqe_dma = vf_data- >>> qm_eqc_dw[QM_XQC_ADDR_HIGH]; >>> + vf_data->eqe_dma <<= QM_XQC_ADDR_OFFSET; >>> + vf_data->eqe_dma |= vf_data- >>> qm_eqc_dw[QM_XQC_ADDR_LOW]; >>> + vf_data->aeqe_dma = vf_data- >>> qm_aeqc_dw[QM_XQC_ADDR_HIGH]; >>> + vf_data->aeqe_dma <<= QM_XQC_ADDR_OFFSET; >>> + vf_data->aeqe_dma |= vf_data- >>> qm_aeqc_dw[QM_XQC_ADDR_LOW]; >>> + break; >>> + default: >>> + return -EINVAL; >>> + } >>> + >>> + return 0; >>> +} >>> + >>> static int vf_qm_check_match(struct hisi_acc_vf_core_device >> *hisi_acc_vdev, >>> struct hisi_acc_vf_migration_file *migf) >>> { >>> @@ -363,7 +388,8 @@ static int vf_qm_check_match(struct >> hisi_acc_vf_core_device *hisi_acc_vdev, >>> if (migf->total_length < QM_MATCH_SIZE || hisi_acc_vdev- >>> match_done) >>> return 0; >>> >>> - if (vf_data->acc_magic != ACC_DEV_MAGIC) { >>> + ret = vf_qm_version_check(vf_data, dev); >>> + if (ret) { >>> dev_err(dev, "failed to match ACC_DEV_MAGIC\n"); >>> return -EINVAL; >>> } >>> @@ -418,7 +444,9 @@ static int vf_qm_get_match_data(struct >> hisi_acc_vf_core_device *hisi_acc_vdev, >>> int vf_id = hisi_acc_vdev->vf_id; >>> int ret; >>> >>> - vf_data->acc_magic = ACC_DEV_MAGIC; >>> + vf_data->acc_magic = ACC_DEV_MAGIC_V2; >>> + vf_data->major_ver = ACC_DRV_MAR; >>> + vf_data->minor_ver = ACC_DRV_MIN; >> >> Where are "MAR" and "MIN" defined? I can't see how this would even >> compile. Thanks, > > Yes. Please make sure to do a compile test and run basic sanity tested even if you > think the changes are minor. Chances are there that you will miss out things like > this. > > Thanks, > Shameer > > . >