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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 DF99CC43331 for ; Mon, 30 Mar 2020 09:27:05 +0000 (UTC) Received: from hemlock.osuosl.org (smtp2.osuosl.org [140.211.166.133]) (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 B2010206E6 for ; Mon, 30 Mar 2020 09:27:05 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B2010206E6 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by hemlock.osuosl.org (Postfix) with ESMTP id 8462B8843B; Mon, 30 Mar 2020 09:27:05 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from hemlock.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 14SW0ZCPsICI; Mon, 30 Mar 2020 09:27:04 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by hemlock.osuosl.org (Postfix) with ESMTP id A521C88146; Mon, 30 Mar 2020 09:27:04 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 99220C1AE8; Mon, 30 Mar 2020 09:27:04 +0000 (UTC) Received: from silver.osuosl.org (smtp3.osuosl.org [140.211.166.136]) by lists.linuxfoundation.org (Postfix) with ESMTP id 52A81C07FF for ; Mon, 30 Mar 2020 09:27:03 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by silver.osuosl.org (Postfix) with ESMTP id 4969F22D22 for ; Mon, 30 Mar 2020 09:27:03 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from silver.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id qRYXgJBLGwVP for ; Mon, 30 Mar 2020 09:27:00 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by silver.osuosl.org (Postfix) with ESMTPS id 4B5F722CC6 for ; Mon, 30 Mar 2020 09:27:00 +0000 (UTC) IronPort-SDR: mHnzoBP8i0Jc/zA1cYVUEcMLk5y9uhPT3k9g+d1jvrdwmFbOpM7Vz4/flyGE6CnMMWsN+ZwAny 6O8SKV5/8i0Q== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Mar 2020 02:26:58 -0700 IronPort-SDR: 94phFjaHxIasgNLV5x9F/Y59NUW+TEzHZGsZZBXmxT5JANcvNFzRqoyYNuhAXXiFkCJJGqav4r teAmesN35kBw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.72,323,1580803200"; d="scan'208";a="421871454" Received: from fmsmsx108.amr.corp.intel.com ([10.18.124.206]) by orsmga005.jf.intel.com with ESMTP; 30 Mar 2020 02:26:57 -0700 Received: from fmsmsx113.amr.corp.intel.com (10.18.116.7) by FMSMSX108.amr.corp.intel.com (10.18.124.206) with Microsoft SMTP Server (TLS) id 14.3.439.0; Mon, 30 Mar 2020 02:26:56 -0700 Received: from shsmsx153.ccr.corp.intel.com (10.239.6.53) by FMSMSX113.amr.corp.intel.com (10.18.116.7) with Microsoft SMTP Server (TLS) id 14.3.439.0; Mon, 30 Mar 2020 02:26:56 -0700 Received: from shsmsx104.ccr.corp.intel.com ([169.254.5.225]) by SHSMSX153.ccr.corp.intel.com ([169.254.12.89]) with mapi id 14.03.0439.000; Mon, 30 Mar 2020 17:26:52 +0800 From: "Liu, Yi L" To: "Tian, Kevin" , "alex.williamson@redhat.com" , "eric.auger@redhat.com" Subject: RE: [PATCH v1 2/8] vfio/type1: Add vfio_iommu_type1 parameter for quota tuning Thread-Topic: [PATCH v1 2/8] vfio/type1: Add vfio_iommu_type1 parameter for quota tuning Thread-Index: AQHWAEUbHl/tnnhWl0eaKvrwJMb1AqhgVzOAgACGb+D//4RdgIAAh3wg Date: Mon, 30 Mar 2020 09:26:51 +0000 Message-ID: References: <1584880325-10561-1-git-send-email-yi.l.liu@intel.com> <1584880325-10561-3-git-send-email-yi.l.liu@intel.com> In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: dlp-product: dlpe-windows dlp-version: 11.2.0.6 dlp-reaction: no-action x-originating-ip: [10.239.127.40] MIME-Version: 1.0 Cc: "jean-philippe@linaro.org" , "Raj, Ashok" , "kvm@vger.kernel.org" , "Tian, Jun J" , "iommu@lists.linux-foundation.org" , "linux-kernel@vger.kernel.org" , "Sun, Yi Y" , "Wu, Hao" 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-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" > From: Tian, Kevin > Sent: Monday, March 30, 2020 5:20 PM > To: Liu, Yi L ; alex.williamson@redhat.com; > Subject: RE: [PATCH v1 2/8] vfio/type1: Add vfio_iommu_type1 parameter for quota > tuning > > > From: Liu, Yi L > > Sent: Monday, March 30, 2020 4:53 PM > > > > > From: Tian, Kevin > > > Sent: Monday, March 30, 2020 4:41 PM > > > To: Liu, Yi L ; alex.williamson@redhat.com; > > > Subject: RE: [PATCH v1 2/8] vfio/type1: Add vfio_iommu_type1 > > > parameter > > for quota > > > tuning > > > > > > > From: Liu, Yi L > > > > Sent: Sunday, March 22, 2020 8:32 PM > > > > > > > > From: Liu Yi L > > > > > > > > This patch adds a module option to make the PASID quota tunable by > > > > administrator. > > > > > > > > TODO: needs to think more on how to make the tuning to be per-process. > > > > > > > > Previous discussions: > > > > https://patchwork.kernel.org/patch/11209429/ > > > > > > > > Cc: Kevin Tian > > > > CC: Jacob Pan > > > > Cc: Alex Williamson > > > > Cc: Eric Auger > > > > Cc: Jean-Philippe Brucker > > > > Signed-off-by: Liu Yi L > > > > --- > > > > drivers/vfio/vfio.c | 8 +++++++- > > > > drivers/vfio/vfio_iommu_type1.c | 7 ++++++- > > > > include/linux/vfio.h | 3 ++- > > > > 3 files changed, 15 insertions(+), 3 deletions(-) > > > > > > > > diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c index > > > > d13b483..020a792 100644 > > > > --- a/drivers/vfio/vfio.c > > > > +++ b/drivers/vfio/vfio.c > > > > @@ -2217,13 +2217,19 @@ struct vfio_mm > > *vfio_mm_get_from_task(struct > > > > task_struct *task) > > > > } > > > > EXPORT_SYMBOL_GPL(vfio_mm_get_from_task); > > > > > > > > -int vfio_mm_pasid_alloc(struct vfio_mm *vmm, int min, int max) > > > > +int vfio_mm_pasid_alloc(struct vfio_mm *vmm, int quota, int min, > > > > +int > > max) > > > > { > > > > ioasid_t pasid; > > > > int ret = -ENOSPC; > > > > > > > > mutex_lock(&vmm->pasid_lock); > > > > > > > > + /* update quota as it is tunable by admin */ > > > > + if (vmm->pasid_quota != quota) { > > > > + vmm->pasid_quota = quota; > > > > + ioasid_adjust_set(vmm->ioasid_sid, quota); > > > > + } > > > > + > > > > > > It's a bit weird to have quota adjusted in the alloc path, since the > > > latter > > might > > > be initiated by non-privileged users. Why not doing the simple math > > > in > > vfio_ > > > create_mm to set the quota when the ioasid set is created? even in > > > the > > future > > > you may allow per-process quota setting, that should come from > > > separate privileged path instead of thru alloc.. > > > > The reason is the kernel parameter modification has no event which can > > be used to adjust the quota. So I chose to adjust it in pasid_alloc > > path. If it's not good, how about adding one more IOCTL to let user- > > space trigger a quota adjustment event? Then even non-privileged user > > could trigger quota adjustment, the quota is actually controlled by > > privileged user. How about your opinion? > > > > why do you need an event to adjust? As I said, you can set the quota when the set is > created in vfio_create_mm... oh, it's to support runtime adjustments. I guess it may be helpful to let per-VM quota tunable even the VM is running. If just set the quota in vfio_create_mm(), it is not able to adjust at runtime. Regards, Yi Liu _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu