public inbox for kvm@vger.kernel.org
 help / color / mirror / Atom feed
From: Jason Gunthorpe <jgg@nvidia.com>
To: "Liu, Yi L" <yi.l.liu@intel.com>
Cc: Alex Williamson <alex.williamson@redhat.com>,
	"Tian, Kevin" <kevin.tian@intel.com>,
	"joro@8bytes.org" <joro@8bytes.org>,
	"robin.murphy@arm.com" <robin.murphy@arm.com>,
	"cohuck@redhat.com" <cohuck@redhat.com>,
	"eric.auger@redhat.com" <eric.auger@redhat.com>,
	"nicolinc@nvidia.com" <nicolinc@nvidia.com>,
	"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
	"mjrosato@linux.ibm.com" <mjrosato@linux.ibm.com>,
	"chao.p.peng@linux.intel.com" <chao.p.peng@linux.intel.com>,
	"yi.y.sun@linux.intel.com" <yi.y.sun@linux.intel.com>,
	"peterx@redhat.com" <peterx@redhat.com>,
	"jasowang@redhat.com" <jasowang@redhat.com>,
	"shameerali.kolothum.thodi@huawei.com" 
	<shameerali.kolothum.thodi@huawei.com>,
	"lulu@redhat.com" <lulu@redhat.com>,
	"suravee.suthikulpanit@amd.com" <suravee.suthikulpanit@amd.com>,
	"intel-gvt-dev@lists.freedesktop.org" 
	<intel-gvt-dev@lists.freedesktop.org>,
	"intel-gfx@lists.freedesktop.org"
	<intel-gfx@lists.freedesktop.org>,
	"linux-s390@vger.kernel.org" <linux-s390@vger.kernel.org>,
	"Hao, Xudong" <xudong.hao@intel.com>,
	"Zhao, Yan Y" <yan.y.zhao@intel.com>,
	"Xu, Terrence" <terrence.xu@intel.com>,
	"Jiang, Yanting" <yanting.jiang@intel.com>,
	"Duan, Zhenzhong" <zhenzhong.duan@intel.com>,
	"clegoate@redhat.com" <clegoate@redhat.com>
Subject: Re: [PATCH v11 20/23] vfio: Add VFIO_DEVICE_[AT|DE]TACH_IOMMUFD_PT
Date: Tue, 6 Jun 2023 11:42:59 -0300	[thread overview]
Message-ID: <ZH9F8zFtD7pPeUE8@nvidia.com> (raw)
In-Reply-To: <DS0PR11MB7529407F01EE55AE4A0A9F1FC3469@DS0PR11MB7529.namprd11.prod.outlook.com>

On Thu, May 25, 2023 at 03:03:54AM +0000, Liu, Yi L wrote:

> vIOMMU may introduce some performance deduction if there
> are frequent map/unmap. 

DPDK doesn't do that.

And once you turn on the HW IOMMU you negate alot of the micro
performance wins of bypassing. Maybe there is still some argument
about giant/huge pages or something.

> without vIOMMU is supposed to be more robust. But I'm not
> sure if the noiommu userspace will adapt to cdev noiommu.
> Perhaps yes if group may be deprecated in future.

I think that is more a distro question, and we don't have to answer it
fully now.
 
Jason

  parent reply	other threads:[~2023-06-06 14:46 UTC|newest]

Thread overview: 52+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-05-13 13:28 [PATCH v11 00/23] Add vfio_device cdev for iommufd support Yi Liu
2023-05-13 13:28 ` [PATCH v11 01/23] vfio: Allocate per device file structure Yi Liu
2023-05-13 13:28 ` [PATCH v11 02/23] vfio: Refine vfio file kAPIs for KVM Yi Liu
2023-05-13 13:28 ` [PATCH v11 03/23] vfio: Accept vfio device file in the KVM facing kAPI Yi Liu
2023-05-22 19:42   ` Alex Williamson
2023-05-13 13:28 ` [PATCH v11 04/23] kvm/vfio: Rename kvm_vfio_group to prepare for accepting vfio device fd Yi Liu
2023-05-13 13:28 ` [PATCH v11 05/23] kvm/vfio: Accept vfio device file from userspace Yi Liu
2023-05-13 13:28 ` [PATCH v11 06/23] vfio: Pass struct vfio_device_file * to vfio_device_open/close() Yi Liu
2023-05-13 13:28 ` [PATCH v11 07/23] vfio: Block device access via device fd until device is opened Yi Liu
2023-05-13 13:28 ` [PATCH v11 08/23] vfio: Add cdev_device_open_cnt to vfio_group Yi Liu
2023-05-13 13:28 ` [PATCH v11 09/23] vfio: Make vfio_device_open() single open for device cdev path Yi Liu
2023-05-13 13:28 ` [PATCH v11 10/23] vfio-iommufd: Move noiommu compat probe out of vfio_iommufd_bind() Yi Liu
2023-05-22 20:24   ` Alex Williamson
2023-05-23  0:45     ` Liu, Yi L
2023-05-13 13:28 ` [PATCH v11 11/23] vfio-iommufd: Split bind/attach into two steps Yi Liu
2023-05-13 13:28 ` [PATCH v11 12/23] vfio: Record devid in vfio_device_file Yi Liu
2023-05-13 13:28 ` [PATCH v11 13/23] vfio-iommufd: Add detach_ioas support for physical VFIO devices Yi Liu
2023-05-22 20:46   ` Alex Williamson
2023-05-22 20:59     ` Alex Williamson
2023-05-23  1:34       ` Liu, Yi L
2023-05-13 13:28 ` [PATCH v11 14/23] iommufd/device: Add iommufd_access_detach() API Yi Liu
2023-05-13 13:28 ` [PATCH v11 15/23] vfio-iommufd: Add detach_ioas support for emulated VFIO devices Yi Liu
2023-05-13 13:28 ` [PATCH v11 16/23] vfio: Name noiommu vfio_device with "noiommu-" prefix Yi Liu
2023-05-13 13:28 ` [PATCH v11 17/23] vfio: Move vfio_device_group_unregister() to be the first operation in unregister Yi Liu
2023-05-13 13:28 ` [PATCH v11 18/23] vfio: Add cdev for vfio_device Yi Liu
2023-05-13 13:28 ` [PATCH v11 19/23] vfio: Add VFIO_DEVICE_BIND_IOMMUFD Yi Liu
2023-05-22 22:01   ` Alex Williamson
2023-05-23  1:41     ` Liu, Yi L
2023-05-23 15:51       ` Alex Williamson
2023-05-24  2:20         ` Liu, Yi L
2023-05-24  2:39           ` Tian, Kevin
2023-05-24  2:40             ` Liu, Yi L
2023-05-24  8:31               ` Liu, Yi L
2023-05-13 13:28 ` [PATCH v11 20/23] vfio: Add VFIO_DEVICE_[AT|DE]TACH_IOMMUFD_PT Yi Liu
2023-05-22 22:15   ` Alex Williamson
2023-05-23  1:20     ` Liu, Yi L
2023-05-23 15:50       ` Alex Williamson
2023-05-24  2:12         ` Liu, Yi L
2023-05-24 15:31           ` Alex Williamson
2023-05-25  3:03             ` Liu, Yi L
2023-05-25 15:59               ` Alex Williamson
2023-05-26  8:38                 ` Liu, Yi L
2023-06-06 14:42               ` Jason Gunthorpe [this message]
2023-06-06 14:40             ` Jason Gunthorpe
2023-05-13 13:28 ` [PATCH v11 21/23] vfio: Determine noiommu device in __vfio_register_dev() Yi Liu
2023-05-22 23:04   ` Alex Williamson
2023-05-23  2:13     ` Liu, Yi L
2023-05-24  8:14       ` Liu, Yi L
2023-05-13 13:28 ` [PATCH v11 22/23] vfio: Compile vfio_group infrastructure optionally Yi Liu
2023-05-13 13:28 ` [PATCH v11 23/23] docs: vfio: Add vfio device cdev description Yi Liu
2023-05-18  5:39 ` [PATCH v11 00/23] Add vfio_device cdev for iommufd support Xu, Terrence
2023-05-23  7:42 ` Duan, Zhenzhong

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=ZH9F8zFtD7pPeUE8@nvidia.com \
    --to=jgg@nvidia.com \
    --cc=alex.williamson@redhat.com \
    --cc=chao.p.peng@linux.intel.com \
    --cc=clegoate@redhat.com \
    --cc=cohuck@redhat.com \
    --cc=eric.auger@redhat.com \
    --cc=intel-gfx@lists.freedesktop.org \
    --cc=intel-gvt-dev@lists.freedesktop.org \
    --cc=jasowang@redhat.com \
    --cc=joro@8bytes.org \
    --cc=kevin.tian@intel.com \
    --cc=kvm@vger.kernel.org \
    --cc=linux-s390@vger.kernel.org \
    --cc=lulu@redhat.com \
    --cc=mjrosato@linux.ibm.com \
    --cc=nicolinc@nvidia.com \
    --cc=peterx@redhat.com \
    --cc=robin.murphy@arm.com \
    --cc=shameerali.kolothum.thodi@huawei.com \
    --cc=suravee.suthikulpanit@amd.com \
    --cc=terrence.xu@intel.com \
    --cc=xudong.hao@intel.com \
    --cc=yan.y.zhao@intel.com \
    --cc=yanting.jiang@intel.com \
    --cc=yi.l.liu@intel.com \
    --cc=yi.y.sun@linux.intel.com \
    --cc=zhenzhong.duan@intel.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox