From: Kirti Wankhede <kwankhede@nvidia.com>
To: Alex Williamson <alex.williamson@redhat.com>,
"Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Yan Zhao <yan.y.zhao@intel.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: Fri, 29 May 2020 23:27:53 +0530 [thread overview]
Message-ID: <b6d78fd3-d2d7-91c9-5f5d-a76ebe5a7a5e@nvidia.com> (raw)
In-Reply-To: <20200528165906.7d03f689@x1.home>
On 5/29/2020 4:29 AM, Alex Williamson wrote:
> 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,
>
That's correct.
Thanks,
Kirti
prev parent reply other threads:[~2020-05-29 17:58 UTC|newest]
Thread overview: 40+ 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 ` [PATCH Kernel v22 1/8] vfio: UAPI for migration interface for device state 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 ` [PATCH Kernel v22 3/8] vfio iommu: Cache pgsize_bitmap in struct vfio_iommu Kirti Wankhede
2020-05-20 10:08 ` Cornelia Huck
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 ` [PATCH Kernel v22 5/8] vfio iommu: Implementation of ioctl " Kirti Wankhede
2020-05-18 21:53 ` Alex Williamson
2020-05-19 7:11 ` 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
2020-05-19 6:54 ` Kirti Wankhede
2020-05-20 10:27 ` Cornelia Huck
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
2020-05-20 10:42 ` Cornelia Huck
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
2020-05-19 6:54 ` Kirti Wankhede
2020-05-19 16:58 ` [PATCH Kernel v22 0/8] Add UAPIs to support migration for VFIO devices Alex Williamson
2020-05-20 2:55 ` Yan Zhao
2020-05-20 13:40 ` Kirti Wankhede
2020-05-20 16:46 ` Alex Williamson
2020-05-21 5:08 ` Yan Zhao
2020-05-21 7:09 ` Kirti Wankhede
2020-05-21 7:04 ` Yan Zhao
2020-05-21 7:28 ` Kirti Wankhede
2020-05-21 7:32 ` Kirti Wankhede
2020-05-25 6:59 ` Yan Zhao
2020-05-25 13:20 ` Kirti Wankhede
2020-05-26 20:19 ` Alex Williamson
2020-05-27 6:23 ` Yan Zhao
2020-05-27 8:48 ` Dr. David Alan Gilbert
2020-05-28 8:01 ` Yan Zhao
2020-05-28 22:53 ` Alex Williamson
2020-05-29 11:12 ` Dr. David Alan Gilbert
2020-05-28 22:59 ` Alex Williamson
2020-05-29 4:15 ` Yan Zhao
2020-05-29 17:57 ` Kirti Wankhede [this message]
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