diff options
| author |   RajithaY <rajithax.yerrumsetty@intel.com> | 2017-04-25 03:31:15 -0700 |
|---|---|---|
| committer | Rajitha Yerrumchetty <rajithax.yerrumsetty@intel.com> | 2017-05-22 06:48:08 +0000 |
| commit | bb756eebdac6fd24e8919e2c43f7d2c8c4091f59 (patch) | |
| tree | ca11e03542edf2d8f631efeca5e1626d211107e3 /qemu/docs/virtio-migration.txt | |
| parent | a14b48d18a9ed03ec191cf16b162206998a895ce (diff) | |
Adding qemu as a submodule of KVMFORNFV
This Patch includes the changes to add qemu as a submodule to
kvmfornfv repo and make use of the updated latest qemu for the
execution of all testcase
Change-Id: I1280af507a857675c7f81d30c95255635667bdd7
Signed-off-by:RajithaY<rajithax.yerrumsetty@intel.com>
Diffstat (limited to 'qemu/docs/virtio-migration.txt')
| -rw-r--r-- | qemu/docs/virtio-migration.txt | 106 |
1 files changed, 0 insertions, 106 deletions
diff --git a/qemu/docs/virtio-migration.txt b/qemu/docs/virtio-migration.txt deleted file mode 100644 index cf66458b9..000000000 --- a/qemu/docs/virtio-migration.txt +++ /dev/null @@ -1,106 +0,0 @@ -Virtio devices and migration -============================ - -Copyright 2015 IBM Corp. - -This work is licensed under the terms of the GNU GPL, version 2 or later. See -the COPYING file in the top-level directory. - -Saving and restoring the state of virtio devices is a bit of a twisty maze, -for several reasons: -- state is distributed between several parts: - - virtio core, for common fields like features, number of queues, ... - - virtio transport (pci, ccw, ...), for the different proxy devices and - transport specific state (msix vectors, indicators, ...) - - virtio device (net, blk, ...), for the different device types and their - state (mac address, request queue, ...) -- most fields are saved via the stream interface; subsequently, subsections - have been added to make cross-version migration possible - -This file attempts to document the current procedure and point out some -caveats. - - -Save state procedure -==================== - -virtio core virtio transport virtio device ------------ ---------------- ------------- - - save() function registered - via register_savevm() -virtio_save() <---------- - ------> save_config() - - save proxy device - - save transport-specific - device fields -- save common device - fields -- save common virtqueue - fields - ------> save_queue() - - save transport-specific - virtqueue fields - ------> save_device() - - save device-specific - fields -- save subsections - - device endianness, - if changed from - default endianness - - 64 bit features, if - any high feature bit - is set - - virtio-1 virtqueue - fields, if VERSION_1 - is set - - -Load state procedure -==================== - -virtio core virtio transport virtio device ------------ ---------------- ------------- - - load() function registered - via register_savevm() -virtio_load() <---------- - ------> load_config() - - load proxy device - - load transport-specific - device fields -- load common device - fields -- load common virtqueue - fields - ------> load_queue() - - load transport-specific - virtqueue fields -- notify guest - ------> load_device() - - load device-specific - fields -- load subsections - - device endianness - - 64 bit features - - virtio-1 virtqueue - fields -- sanitize endianness -- sanitize features -- virtqueue index sanity - check - - feature-dependent setup - - -Implications of this setup -========================== - -Devices need to be careful in their state processing during load: The -load_device() procedure is invoked by the core before subsections have -been loaded. Any code that depends on information transmitted in subsections -therefore has to be invoked in the device's load() function _after_ -virtio_load() returned (like e.g. code depending on features). - -Any extension of the state being migrated should be done in subsections -added to the core for compatibility reasons. If transport or device specific -state is added, core needs to invoke a callback from the new subsection. |