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Re: [Qemu-devel] [PATCH V3 0/4] vfio: Introduce Live migration capabilit
From: |
Zhang, Yulei |
Subject: |
Re: [Qemu-devel] [PATCH V3 0/4] vfio: Introduce Live migration capability to vfio_mdev device |
Date: |
Tue, 6 Mar 2018 13:34:37 +0000 |
Hi Kirti,
Yes, that is the plan and we will address it in the coming versions.
In this version we just rebase the code and looking for more inputs.
Thanks,
Yulei
> -----Original Message-----
> From: Kirti Wankhede [mailto:address@hidden
> Sent: Monday, March 5, 2018 9:03 PM
> To: Zhang, Yulei <address@hidden>; address@hidden
> Cc: Tian, Kevin <address@hidden>; address@hidden;
> address@hidden
> Subject: Re: [PATCH V3 0/4] vfio: Introduce Live migration capability to
> vfio_mdev device
>
> Hi Yulei Zhang,
>
> This series is same as the previous version, that is, there is no pre-copy
> phase. This only takes care of stop-and-copy phase.
> As per we discussed in KVM Forum 2017 in October, there should be
> provision of pre-copy phase.
>
> Thanks,
> Kirti
>
> On 3/5/2018 11:30 AM, Yulei Zhang wrote:
> > Summary
> >
> > This series RFC would like to resume the discussion about how to
> > introduce the live migration capability to vfio mdev device.
> >
> > By adding a new vfio subtype region
> VFIO_REGION_SUBTYPE_DEVICE_STATE,
> > the mdev device will be set to migratable if the new region exist
> > during the initialization.
> >
> > The intention to add the new region is using it for mdev device status
> > save and restore during the migration. The access to this region will
> > be trapped and forward to the mdev device driver, it also uses the
> > first byte in the new region to control the running state of mdev
> > device, so during the migration after stop the mdev driver, qemu could
> > retrieve the specific device status from this region and transfer to
> > the target VM side for the mdev device restore.
> >
> > In addition, we add one new ioctl VFIO_IOMMU_GET_DIRTY_BITMAP to
> help
> > do the mdev device dirty page synchronization during the migration,
> > currently it is just for static copy, in the future we would like to
> > add new interface for the pre-copy.
> >
> > Below is the vfio_mdev device migration sequence Source VM side:
> > start migration
> > |
> > V
> > get the cpu state change callback, write to the
> > subregion's first byte to stop the mdev device
> > |
> > V
> > quary the dirty page bitmap from iommu container
> > and add into qemu dirty list for synchronization
> > |
> > V
> > save the deivce status into Qemufile which is
> > read from the vfio device subregion
> >
> > Target VM side:
> > restore the mdev device after get the
> > saved status context from Qemufile
> > |
> > V
> > get the cpu state change callback
> > write to subregion's first byte to
> > start the mdev device to put it in
> > running status
> > |
> > V
> > finish migration
> >
> > V3->V2:
> > 1. rebase the patch to Qemu stable 2.10 branch.
> > 2. use a common name for the subregion instead of specific for
> > intel IGD.
> >
> > V1->V2:
> > Per Alex's suggestion:
> > 1. use device subtype region instead of VFIO PCI fixed region.
> > 2. remove unnecessary ioctl, use the first byte of subregion to
> > control the running state of mdev device.
> > 3. for dirty page synchronization, implement the interface with
> > VFIOContainer instead of vfio pci device.
> >
> > Yulei Zhang (4):
> > vfio: introduce a new VFIO subregion for mdev device migration support
> > vfio: Add vm status change callback to stop/restart the mdev device
> > vfio: Add struct vfio_vmstate_info to introduce put/get callback
> > funtion for vfio device status save/restore
> > vifo: introduce new VFIO ioctl VFIO_IOMMU_GET_DIRTY_BITMAP
> >
> > hw/vfio/common.c | 34 +++++++++
> > hw/vfio/pci.c | 171
> +++++++++++++++++++++++++++++++++++++++++-
> > hw/vfio/pci.h | 1 +
> > include/hw/vfio/vfio-common.h | 1 +
> > linux-headers/linux/vfio.h | 29 ++++++-
> > 5 files changed, 232 insertions(+), 4 deletions(-)
> >
- [Qemu-devel] [PATCH V3 2/4] vfio: Add vm status change callback to stop/restart the mdev device, (continued)
- [Qemu-devel] [PATCH V3 2/4] vfio: Add vm status change callback to stop/restart the mdev device, Yulei Zhang, 2018/03/05
- [Qemu-devel] [PATCH V3 1/4] vfio: introduce a new VFIO subregion for mdev device migration support, Yulei Zhang, 2018/03/05
- [Qemu-devel] [PATCH V3 3/4] vfio: Add struct vfio_vmstate_info to introduce put/get callback funtion for vfio device status save/restore, Yulei Zhang, 2018/03/05
- [Qemu-devel] [PATCH V3 4/4] vifo: introduce new VFIO ioctl VFIO_IOMMU_GET_DIRTY_BITMAP, Yulei Zhang, 2018/03/05
- Re: [Qemu-devel] [PATCH V3 0/4] vfio: Introduce Live migration capability to vfio_mdev device, no-reply, 2018/03/05
- Re: [Qemu-devel] [PATCH V3 0/4] vfio: Introduce Live migration capability to vfio_mdev device, Kirti Wankhede, 2018/03/05
- Re: [Qemu-devel] [PATCH V3 0/4] vfio: Introduce Live migration capability to vfio_mdev device,
Zhang, Yulei <=
- Re: [Qemu-devel] [PATCH V3 0/4] vfio: Introduce Live migration capability to vfio_mdev device, Alex Williamson, 2018/03/12