[RFC V1 0/7] Live update: vdpa

[Steve Sistare]

Support vdpa devices with the cpr-exec live migration mode.  
This series depends on the QEMU series 
  Live update: cpr-exec
  
https://lore.kernel.org/qemu-devel/1719776434-435013-1-git-send-email-steven.sistare@oracle.com/

and depends on the kernel series:
  vdpa live update
  
https://lore.kernel.org/virtualization/1720790333-456232-1-git-send-email-steven.sistare@oracle.com/

Preserve the device descriptor across exec, which in turn preserves the
locks on pages which are pinned in memory for DMA.  Suppress the DMA
unmap calls which are normally triggerred when a vdpa device is suspended.
After exec, call VHOST_NEW_OWNER to inform the device that a new process
is in charge.

If the device advertises the VHOST_BACKEND_F_IOTLB_REMAP capability, then
send VHOST_IOTLB_REMAP messages to update the userland address for each
DMA mapping.  Devices that do not advertise this cap have already translated
the userland addresses to physical when the DMA was initially mapped,
and do not require any update.

The cpr-exec mode leverages the vdpa live migration code path for the rest 
of the update, but is faster than live migration because it does not unlock
and relock pages in memory for DMA.

This series does not add any user-visible interfaces.

Steve Sistare (7):
  migration: cpr_needed_for_reuse
  migration: skip dirty memory tracking for cpr
  vdpa/cpr: preserve device fd
  vdpa/cpr: kernel interfaces
  vdpa/cpr: use VHOST_NEW_OWNER
  vdpa/cpr: pass shadow parameter to dma functions
  vdpa/cpr: preserve dma mappings

 hw/virtio/trace-events                       |  5 +-
 hw/virtio/vhost-vdpa.c                       | 71 +++++++++++++++-----
 include/hw/virtio/vhost-vdpa.h               |  7 +-
 include/hw/virtio/vhost.h                    |  1 +
 include/migration/cpr.h                      |  1 +
 include/standard-headers/linux/vhost_types.h |  7 ++
 linux-headers/linux/vhost.h                  |  9 +++
 migration/cpr.c                              |  5 ++
 net/vhost-vdpa.c                             | 29 +++++---
 scripts/tracetool/__init__.py                |  2 +-
 system/memory.c                              | 11 +++
 11 files changed, 120 insertions(+), 28 deletions(-)

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2.39.3