All of lore.kernel.org
 help / color / mirror / Atom feed
From: Alex Williamson <alex.williamson@redhat.com>
To: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Yan Zhao <yan.y.zhao@intel.com>,
	Kirti Wankhede <kwankhede@nvidia.com>,
	cjia@nvidia.com, kevin.tian@intel.com, ziye.yang@intel.com,
	changpeng.liu@intel.com, yi.l.liu@intel.com, mlevitsk@redhat.com,
	eskultet@redhat.com, cohuck@redhat.com,
	jonathan.davies@nutanix.com, eauger@redhat.com, aik@ozlabs.ru,
	pasic@linux.ibm.com, felipe@nutanix.com,
	Zhengxiao.zx@alibaba-inc.com, shuangtai.tst@alibaba-inc.com,
	Ken.Xue@amd.com, zhi.a.wang@intel.com, qemu-devel@nongnu.org,
	kvm@vger.kernel.org
Subject: Re: [PATCH Kernel v22 0/8] Add UAPIs to support migration for VFIO devices
Date: Thu, 28 May 2020 16:59:06 -0600	[thread overview]
Message-ID: <20200528165906.7d03f689@x1.home> (raw)
In-Reply-To: <20200527084822.GC3001@work-vm>

On Wed, 27 May 2020 09:48:22 +0100
"Dr. David Alan Gilbert" <dgilbert@redhat.com> wrote:
> * Yan Zhao (yan.y.zhao@intel.com) wrote:
> > BTW, for viommu, the downtime data is as below. under the same network
> > condition and guest memory size, and no running dirty data/memory produced
> > by device.
> > (1) viommu off
> > single-round dirty query: downtime ~100ms   
> 
> Fine.
> 
> > (2) viommu on
> > single-round dirty query: downtime 58s   
> 
> Youch.

Double Youch!  But we believe this is because we're getting the dirty
bitmap one IOMMU leaf page at a time, right?  We've enable the kernel
to get a dirty bitmap across multiple mappings, but QEMU isn't yet
taking advantage of it.  Do I have this correct?  Thanks,

Alex


WARNING: multiple messages have this Message-ID (diff)
From: Alex Williamson <alex.williamson@redhat.com>
To: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Zhengxiao.zx@alibaba-inc.com, kevin.tian@intel.com,
	yi.l.liu@intel.com, cjia@nvidia.com, kvm@vger.kernel.org,
	eskultet@redhat.com, ziye.yang@intel.com, cohuck@redhat.com,
	shuangtai.tst@alibaba-inc.com, qemu-devel@nongnu.org,
	zhi.a.wang@intel.com, mlevitsk@redhat.com, pasic@linux.ibm.com,
	aik@ozlabs.ru, Kirti Wankhede <kwankhede@nvidia.com>,
	eauger@redhat.com, felipe@nutanix.com,
	jonathan.davies@nutanix.com, Yan Zhao <yan.y.zhao@intel.com>,
	changpeng.liu@intel.com, Ken.Xue@amd.com
Subject: Re: [PATCH Kernel v22 0/8] Add UAPIs to support migration for VFIO devices
Date: Thu, 28 May 2020 16:59:06 -0600	[thread overview]
Message-ID: <20200528165906.7d03f689@x1.home> (raw)
In-Reply-To: <20200527084822.GC3001@work-vm>

On Wed, 27 May 2020 09:48:22 +0100
"Dr. David Alan Gilbert" <dgilbert@redhat.com> wrote:
> * Yan Zhao (yan.y.zhao@intel.com) wrote:
> > BTW, for viommu, the downtime data is as below. under the same network
> > condition and guest memory size, and no running dirty data/memory produced
> > by device.
> > (1) viommu off
> > single-round dirty query: downtime ~100ms   
> 
> Fine.
> 
> > (2) viommu on
> > single-round dirty query: downtime 58s   
> 
> Youch.

Double Youch!  But we believe this is because we're getting the dirty
bitmap one IOMMU leaf page at a time, right?  We've enable the kernel
to get a dirty bitmap across multiple mappings, but QEMU isn't yet
taking advantage of it.  Do I have this correct?  Thanks,

Alex



  parent reply	other threads:[~2020-05-28 22:59 UTC|newest]

Thread overview: 80+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-18  5:56 [PATCH Kernel v22 0/8] Add UAPIs to support migration for VFIO devices Kirti Wankhede
2020-05-18  5:56 ` Kirti Wankhede
2020-05-18  5:56 ` [PATCH Kernel v22 1/8] vfio: UAPI for migration interface for device state Kirti Wankhede
2020-05-18  5:56   ` Kirti Wankhede
2020-05-18  5:56 ` [PATCH Kernel v22 2/8] vfio iommu: Remove atomicity of ref_count of pinned pages Kirti Wankhede
2020-05-18  5:56   ` Kirti Wankhede
2020-05-18  5:56 ` [PATCH Kernel v22 3/8] vfio iommu: Cache pgsize_bitmap in struct vfio_iommu Kirti Wankhede
2020-05-18  5:56   ` Kirti Wankhede
2020-05-20 10:08   ` Cornelia Huck
2020-05-20 10:08     ` Cornelia Huck
2020-05-20 14:46     ` Kirti Wankhede
2020-05-20 14:46       ` Kirti Wankhede
2020-05-18  5:56 ` [PATCH Kernel v22 4/8] vfio iommu: Add ioctl definition for dirty pages tracking Kirti Wankhede
2020-05-18  5:56   ` Kirti Wankhede
2020-05-18  5:56 ` [PATCH Kernel v22 5/8] vfio iommu: Implementation of ioctl " Kirti Wankhede
2020-05-18  5:56   ` Kirti Wankhede
2020-05-18 21:53   ` Alex Williamson
2020-05-18 21:53     ` Alex Williamson
2020-05-19  7:11     ` Kirti Wankhede
2020-05-19  7:11       ` Kirti Wankhede
2020-05-19  6:52       ` Kirti Wankhede
2020-05-19  6:52         ` Kirti Wankhede
2020-05-18  5:56 ` [PATCH Kernel v22 6/8] vfio iommu: Update UNMAP_DMA ioctl to get dirty bitmap before unmap Kirti Wankhede
2020-05-18  5:56   ` Kirti Wankhede
2020-05-19  6:54   ` Kirti Wankhede
2020-05-19  6:54     ` Kirti Wankhede
2020-05-20 10:27     ` Cornelia Huck
2020-05-20 10:27       ` Cornelia Huck
2020-05-20 15:16       ` Kirti Wankhede
2020-05-20 15:16         ` Kirti Wankhede
2020-05-18  5:56 ` [PATCH Kernel v22 7/8] vfio iommu: Add migration capability to report supported features Kirti Wankhede
2020-05-18  5:56   ` Kirti Wankhede
2020-05-20 10:42   ` Cornelia Huck
2020-05-20 10:42     ` Cornelia Huck
2020-05-20 15:23     ` Kirti Wankhede
2020-05-20 15:23       ` Kirti Wankhede
2020-05-18  5:56 ` [PATCH Kernel v22 8/8] vfio: Selective dirty page tracking if IOMMU backed device pins pages Kirti Wankhede
2020-05-18  5:56   ` Kirti Wankhede
2020-05-19  6:54   ` Kirti Wankhede
2020-05-19  6:54     ` Kirti Wankhede
2020-05-19 16:58 ` [PATCH Kernel v22 0/8] Add UAPIs to support migration for VFIO devices Alex Williamson
2020-05-19 16:58   ` Alex Williamson
2020-05-20  2:55   ` Yan Zhao
2020-05-20  2:55     ` Yan Zhao
2020-05-20 13:40     ` Kirti Wankhede
2020-05-20 13:40       ` Kirti Wankhede
2020-05-20 16:46       ` Alex Williamson
2020-05-20 16:46         ` Alex Williamson
2020-05-21  5:08         ` Yan Zhao
2020-05-21  5:08           ` Yan Zhao
2020-05-21  7:09           ` Kirti Wankhede
2020-05-21  7:09             ` Kirti Wankhede
2020-05-21  7:04             ` Yan Zhao
2020-05-21  7:04               ` Yan Zhao
2020-05-21  7:28               ` Kirti Wankhede
2020-05-21  7:28                 ` Kirti Wankhede
2020-05-21  7:32               ` Kirti Wankhede
2020-05-21  7:32                 ` Kirti Wankhede
2020-05-25  6:59   ` Yan Zhao
2020-05-25  6:59     ` Yan Zhao
2020-05-25 13:20     ` Kirti Wankhede
2020-05-25 13:20       ` Kirti Wankhede
2020-05-26 20:19       ` Alex Williamson
2020-05-26 20:19         ` Alex Williamson
2020-05-27  6:23         ` Yan Zhao
2020-05-27  6:23           ` Yan Zhao
2020-05-27  8:48           ` Dr. David Alan Gilbert
2020-05-27  8:48             ` Dr. David Alan Gilbert
2020-05-28  8:01             ` Yan Zhao
2020-05-28  8:01               ` Yan Zhao
2020-05-28 22:53               ` Alex Williamson
2020-05-28 22:53                 ` Alex Williamson
2020-05-29 11:12                 ` Dr. David Alan Gilbert
2020-05-29 11:12                   ` Dr. David Alan Gilbert
2020-05-28 22:59             ` Alex Williamson [this message]
2020-05-28 22:59               ` Alex Williamson
2020-05-29  4:15               ` Yan Zhao
2020-05-29  4:15                 ` Yan Zhao
2020-05-29 17:57               ` Kirti Wankhede
2020-05-29 17:57                 ` Kirti Wankhede

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=20200528165906.7d03f689@x1.home \
    --to=alex.williamson@redhat.com \
    --cc=Ken.Xue@amd.com \
    --cc=Zhengxiao.zx@alibaba-inc.com \
    --cc=aik@ozlabs.ru \
    --cc=changpeng.liu@intel.com \
    --cc=cjia@nvidia.com \
    --cc=cohuck@redhat.com \
    --cc=dgilbert@redhat.com \
    --cc=eauger@redhat.com \
    --cc=eskultet@redhat.com \
    --cc=felipe@nutanix.com \
    --cc=jonathan.davies@nutanix.com \
    --cc=kevin.tian@intel.com \
    --cc=kvm@vger.kernel.org \
    --cc=kwankhede@nvidia.com \
    --cc=mlevitsk@redhat.com \
    --cc=pasic@linux.ibm.com \
    --cc=qemu-devel@nongnu.org \
    --cc=shuangtai.tst@alibaba-inc.com \
    --cc=yan.y.zhao@intel.com \
    --cc=yi.l.liu@intel.com \
    --cc=zhi.a.wang@intel.com \
    --cc=ziye.yang@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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.