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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 36130C2D0DB for ; Wed, 29 Jan 2020 23:56:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F1F47205ED for ; Wed, 29 Jan 2020 23:56:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="TfuynleX" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726921AbgA2X4q (ORCPT ); Wed, 29 Jan 2020 18:56:46 -0500 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:34768 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726750AbgA2X4p (ORCPT ); Wed, 29 Jan 2020 18:56:45 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1580342205; 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=/FlUx/0EoEDOcXXUzpcXpnQOxR5qtEH6XDuKSHdNwAQ=; b=TfuynleXNs2ck5VXo9w6ZatE0dXFOAF/eNbqFuDYGC+OCsFPKUqjKattABi+ZTeauofMCT TiIvHp4MH1Sg41MTdgLNCWwaYQG+0sJFhYphj2OsJ3dBBfOO9vqfAQpMnqSPthu5o6ki51 9XTYXDvkbo9m40g7HmAisFoY85PSLXs= 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-327-Bc17NHRPPPGl2sn0Hbfd7g-1; Wed, 29 Jan 2020 18:56:42 -0500 X-MC-Unique: Bc17NHRPPPGl2sn0Hbfd7g-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id BDD621800D41; Wed, 29 Jan 2020 23:56:40 +0000 (UTC) Received: from w520.home (ovpn-116-28.phx2.redhat.com [10.3.116.28]) by smtp.corp.redhat.com (Postfix) with ESMTP id 777451001B05; Wed, 29 Jan 2020 23:56:32 +0000 (UTC) Date: Wed, 29 Jan 2020 16:56:32 -0700 From: Alex Williamson To: "Liu, Yi L" Cc: eric.auger@redhat.com, kevin.tian@intel.com, jacob.jun.pan@linux.intel.com, joro@8bytes.org, ashok.raj@intel.com, jun.j.tian@intel.com, yi.y.sun@intel.com, jean-philippe.brucker@arm.com, peterx@redhat.com, iommu@lists.linux-foundation.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [RFC v3 2/8] vfio/type1: Make per-application (VM) PASID quota tunable Message-ID: <20200129165632.5f69b949@w520.home> In-Reply-To: <1580299912-86084-3-git-send-email-yi.l.liu@intel.com> References: <1580299912-86084-1-git-send-email-yi.l.liu@intel.com> <1580299912-86084-3-git-send-email-yi.l.liu@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Wed, 29 Jan 2020 04:11:46 -0800 "Liu, Yi L" wrote: > From: Liu Yi L > > The PASID quota is per-application (VM) according to vfio's PASID > management rule. For better flexibility, quota shall be user tunable > . This patch provides a VFIO based user interface for which quota can > be adjusted. However, quota cannot be adjusted downward below the > number of outstanding PASIDs. > > This patch only makes the per-VM PASID quota tunable. While for the > way to tune the default PASID quota, it may require a new vfio module > option or other way. This may be another patchset in future. If we give an unprivileged user the ability to increase their quota, why do we even have a quota at all? I figured we were going to have a module option tunable so its under the control of the system admin. Thanks, Alex > > 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_iommu_type1.c | 33 +++++++++++++++++++++++++++++++++ > include/uapi/linux/vfio.h | 22 ++++++++++++++++++++++ > 2 files changed, 55 insertions(+) > > diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c > index e836d04..1cf75f5 100644 > --- a/drivers/vfio/vfio_iommu_type1.c > +++ b/drivers/vfio/vfio_iommu_type1.c > @@ -2243,6 +2243,27 @@ static int vfio_iommu_type1_pasid_free(struct vfio_iommu *iommu, > return ret; > } > > +static int vfio_iommu_type1_set_pasid_quota(struct vfio_iommu *iommu, > + u32 quota) > +{ > + struct vfio_mm *vmm = iommu->vmm; > + int ret = 0; > + > + mutex_lock(&iommu->lock); > + mutex_lock(&vmm->pasid_lock); > + if (vmm->pasid_count > quota) { > + ret = -EINVAL; > + goto out_unlock; > + } > + vmm->pasid_quota = quota; > + ret = quota; > + > +out_unlock: > + mutex_unlock(&vmm->pasid_lock); > + mutex_unlock(&iommu->lock); > + return ret; > +} > + > static long vfio_iommu_type1_ioctl(void *iommu_data, > unsigned int cmd, unsigned long arg) > { > @@ -2389,6 +2410,18 @@ static long vfio_iommu_type1_ioctl(void *iommu_data, > default: > return -EINVAL; > } > + } else if (cmd == VFIO_IOMMU_SET_PASID_QUOTA) { > + struct vfio_iommu_type1_pasid_quota quota; > + > + minsz = offsetofend(struct vfio_iommu_type1_pasid_quota, > + quota); > + > + if (copy_from_user("a, (void __user *)arg, minsz)) > + return -EFAULT; > + > + if (quota.argsz < minsz) > + return -EINVAL; > + return vfio_iommu_type1_set_pasid_quota(iommu, quota.quota); > } > > return -ENOTTY; > diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h > index 298ac80..d4bf415 100644 > --- a/include/uapi/linux/vfio.h > +++ b/include/uapi/linux/vfio.h > @@ -835,6 +835,28 @@ struct vfio_iommu_type1_pasid_request { > */ > #define VFIO_IOMMU_PASID_REQUEST _IO(VFIO_TYPE, VFIO_BASE + 22) > > +/** > + * @quota: the new pasid quota which a userspace application (e.g. VM) > + * is configured. > + */ > +struct vfio_iommu_type1_pasid_quota { > + __u32 argsz; > + __u32 flags; > + __u32 quota; > +}; > + > +/** > + * VFIO_IOMMU_SET_PASID_QUOTA - _IOW(VFIO_TYPE, VFIO_BASE + 23, > + * struct vfio_iommu_type1_pasid_quota) > + * > + * Availability of this feature depends on PASID support in the device, > + * its bus, the underlying IOMMU and the CPU architecture. In VFIO, it > + * is available after VFIO_SET_IOMMU. > + * > + * returns: latest quota on success, -errno on failure. > + */ > +#define VFIO_IOMMU_SET_PASID_QUOTA _IO(VFIO_TYPE, VFIO_BASE + 23) > + > /* -------- Additional API for SPAPR TCE (Server POWERPC) IOMMU -------- */ > > /*