[PATCH-SERIES qemu-server v3 00/18] fix #7066: api: allow live snapshot (remove) of qcow2 TPM drive with snapshot-as-volume-chain

Fiona Ebner
2026-04-23T09:38:20Z

Changes in v3:
* Rebase on latest master (adapt to change from new perltidy version).

Changes in v2:
* Rebase on latest master (many modified functions moved to
VolumeChain.pm).
* get_node_name_below_throttle(): also die after else branch if no
top node can be found.

The QMP commands for snapshot operations can just be passed to the
qemu-storage-daemon for the FUSE-exported TPM state and it will handle
it just the same as the main QEMU instance.

There is a single limitation remaining. That limitation is removing
the top-most snapshot live when the current image is exported via
FUSE, because exporting unshares the 'resize' permission, which would
be required by both 'block-commit' and 'block-stream', for example:

> QEMU storage daemon 100 qsd command 'block-commit' failed - Permission
> conflict on node '#block017': permissions 'resize' are both required
> by node 'drive-tpmstate0' (uses node '#block017' as 'file' child) and
> unshared by commit job 'commit-drive-tpmstate0' (uses node '#block017'
> as 'main node' child).

Most of the work is preparing the code interacting with the block
layer to support different QMP peers.

The first two commits are independent from the goal of the series, but
tangentially related.

Since this touches quite a bit of code, more testing would be very
appreciated!

qemu-server:

Fiona Ebner (18):
block job: fix variable name in documentation
qmp client: add default timeouts for more block commands
drive: introduce drive_uses_qsd_fuse() helper
monitor: add vm_qmp_peer() helper
monitor: add qsd_peer() helper
blockdev: rename variable in get_node_name_below_throttle() for
readability
blockdev: switch get_node_name_below_throttle() to use QMP peer
blockdev: switch detach() to use QMP peer
blockdev: switch blockdev_replace() to use QMP peer
blockdev: switch blockdev_external_snapshot() to use QMP peer
block job: switch qemu_handle_concluded_blockjob() to use QMP peer
block job: switch qemu_blockjobs_cancel() to use QMP peer
block job: switch qemu_drive_mirror_monitor() to use QMP peer
blockdev: switch blockdev_delete() to use QMP peer
blockdev: switch blockdev_stream() to use QMP peer
blockdev: switch blockdev_commit() to use QMP peer
snapshot: support live snapshot (remove) of qcow2 TPM drive on storage
with snapshot-as-volume-chain
fix #7066: api: allow live snapshot (remove) of qcow2 TPM drive with
snapshot-as-volume-chain

src/PVE/API2/Qemu.pm | 45 ++++++--------
src/PVE/QMPClient.pm | 7 +++
src/PVE/QemuMigrate.pm | 6 +-
src/PVE/QemuServer.pm | 65 +++++++++++---------
src/PVE/QemuServer/BlockJob.pm | 62 +++++++++++--------
src/PVE/QemuServer/Blockdev.pm | 59 +++++++++---------
src/PVE/QemuServer/Drive.pm | 20 +++++++
src/PVE/QemuServer/Monitor.pm | 19 +++++-
src/PVE/QemuServer/QSD.pm | 11 ++--
src/PVE/QemuServer/VolumeChain.pm | 73 ++++++++++++++---------
src/PVE/VZDump/QemuServer.pm | 6 +-
src/test/MigrationTest/QemuMigrateMock.pm | 2 +-
12 files changed, 222 insertions(+), 153 deletions(-)

Summary over all repositories:
12 files changed, 222 insertions(+), 153 deletions(-)

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