qemu-e2k/qapi
Vladimir Sementsov-Ogievskiy 1c14eaabdb block: introduce snapshot-access block driver
The new block driver simply utilizes snapshot-access API of underlying
block node.

In further patches we want to use it like this:

[guest]                   [NBD export]
   |                            |
   | root                       | root
   v                 file       v
[copy-before-write]<------[snapshot-access]
   |           |
   | file      | target
   v           v
[active-disk] [temp.img]

This way, NBD client will be able to read snapshotted state of active
disk, when active disk is continued to be written by guest. This is
known as "fleecing", and currently uses another scheme based on qcow2
temporary image which backing file is active-disk. New scheme comes
with benefits - see next commit.

The other possible application is exporting internal snapshots of
qcow2, like this:

[guest]          [NBD export]
   |                  |
   | root             | root
   v       file       v
[qcow2]<---------[snapshot-access]

For this, we'll need to implement snapshot-access API handlers in
qcow2 driver, and improve snapshot-access block driver (and API) to
make it possible to select snapshot by name. Another thing to improve
is size of snapshot. Now for simplicity we just use size of bs->file,
which is OK for backup, but for qcow2 snapshots export we'll need to
imporve snapshot-access API to get size of snapshot.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20220303194349.2304213-12-vsementsov@virtuozzo.com>
[hreitz: Rebased on block GS/IO split]
Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2022-03-07 09:33:31 +01:00
..
acpi.json qapi: Extract ACPI commands to 'acpi.json' 2020-09-29 15:41:36 +02:00
audio.json schemas: add missing vim modeline 2022-01-27 11:20:50 +01:00
authz.json qapi/qom: Add ObjectOptions for authz-* 2021-03-19 10:17:13 +01:00
block-core.json block: introduce snapshot-access block driver 2022-03-07 09:33:31 +01:00
block-export.json qapi/block: Cosmetic change in BlockExportType schema 2022-01-28 16:50:43 -06:00
block.json qapi: Normalize version references x.y.0 to just x.y 2020-12-10 17:16:44 +01:00
char.json ui/dbus: add chardev backend & interface 2021-12-21 10:50:22 +04:00
common.json monitor: introduce HumanReadableText and HMP support 2021-11-02 15:55:13 +00:00
compat.json qapi: Belatedly adjust limitations documentation 2022-02-28 11:39:35 +01:00
control.json monitor: remove 'query-events' QMP command 2021-03-18 09:22:55 +00:00
crypto.json crypto: replace 'des-rfb' cipher with 'des' 2021-07-14 14:15:52 +01:00
dump.json
error.json
introspect.json qapi: Add feature flags to enum members 2021-10-27 17:18:55 +02:00
job.json migration: introduce snapshot-{save, load, delete} QMP commands 2021-02-08 11:19:52 +00:00
machine-target.json qapi: make 'if' condition strings simple identifiers 2021-08-26 13:53:56 +02:00
machine.json qapi: Cleanup SGX related comments and restore @section-size 2022-01-28 11:13:33 +01:00
meson.build qapi: generate trace events by default 2022-01-27 15:17:35 +01:00
migration.json qapi/migration: Fix examples document wrong field name for arguments 2022-02-28 11:39:35 +01:00
misc-target.json qapi: Move RTC_CHANGE back out of target schema 2022-02-28 11:39:35 +01:00
misc.json rtc: Have event RTC_CHANGE identify the RTC by QOM path 2022-02-28 11:39:35 +01:00
net.json netdev: add more commands to preconfig mode 2021-06-11 10:30:13 +08:00
opts-visitor.c qapi, qemu-options: make all parsing visitors parse boolean options the same 2020-11-04 12:00:40 -05:00
pci.json qapi: Normalize version references x.y.0 to just x.y 2020-12-10 17:16:44 +01:00
pragma.json block: Remove monitor command block_passwd 2021-03-23 22:31:56 +01:00
qapi-clone-visitor.c
qapi-dealloc-visitor.c
qapi-forward-visitor.c qapi: Generalize struct member policy checking 2021-10-29 18:23:09 +02:00
qapi-schema.json qemu-options: New -compat to set policy for deprecated interfaces 2021-03-19 15:43:33 +01:00
qapi-type-helpers.c monitor: introduce HumanReadableText and HMP support 2021-11-02 15:55:13 +00:00
qapi-util.c qapi: Fix stale reference to scripts/qapi.py in a comment 2022-02-28 11:39:35 +01:00
qapi-visit-core.c qapi: Factor out compat_policy_input_ok() 2021-10-29 21:27:20 +02:00
qdev.json softmmu: fix device deletion events with -device JSON syntax 2022-01-14 12:03:16 +01:00
qmp-dispatch.c qapi: Factor out compat_policy_input_ok() 2021-10-29 21:27:20 +02:00
qmp-event.c
qmp-registry.c qapi: Generalize command policy checking 2021-10-29 18:24:46 +02:00
qobject-input-visitor.c qapi: Factor out compat_policy_input_ok() 2021-10-29 21:27:20 +02:00
qobject-output-visitor.c qapi: Extend -compat to set policy for unstable interfaces 2021-10-29 21:28:01 +02:00
qom.json qapi/qom,target/i386: sev-guest: Introduce kernel-hashes=on|off option 2021-11-18 11:07:44 +00:00
rdma.json
replay.json schemas: add missing vim modeline 2022-01-27 11:20:50 +01:00
rocker.json
run-state.json runstate: cleanup reboot and panic actions 2021-01-21 13:00:41 +01:00
sockets.json build-sys: add HAVE_IPPROTO_MPTCP 2021-09-30 15:30:25 +02:00
string-input-visitor.c qapi, qemu-options: make all parsing visitors parse boolean options the same 2020-11-04 12:00:40 -05:00
string-output-visitor.c string-output-visitor: Fix to use sufficient precision 2020-12-19 10:37:16 +01:00
tpm.json qapi: Convert simple union TpmTypeOptions to flat one 2021-09-27 08:22:25 +02:00
trace-events qapi: Generalize struct member policy checking 2021-10-29 18:23:09 +02:00
trace.h
trace.json schemas: add missing vim modeline 2022-01-27 11:20:50 +01:00
transaction.json qapi: deprecate drive-backup 2021-11-09 18:21:19 +01:00
ui.json qapi/monitor: allow VNC display id in set/expire_password 2022-03-02 18:12:40 +00:00
yank.json Introduce yank feature 2021-01-13 10:21:17 +01:00