Introduce a privileged helper to run persistent reservation commands.
This lets virtual machines send persistent reservations without using
CAP_SYS_RAWIO or out-of-tree patches. The helper uses Unix permissions
and SCM_RIGHTS to restrict access to processes that can access its socket
and prove that they have an open file descriptor for a raw SCSI device.
The next patch will also correct the usage of persistent reservations
with multipath devices.
It would also be possible to support for Linux's IOC_PR_* ioctls in
the future, to support NVMe devices. For now, however, only SCSI is
supported.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Currently, vhost-user does not implement any means for notifying the
backend about guest endianess. This commit introduces a new message
called VHOST_USER_SET_VRING_ENDIAN which is analogous to the ioctl()
called VHOST_SET_VRING_ENDIAN used for kernel vhost backends. Such
message is necessary for backends supporting legacy (pre-1.0) virtio
devices running in big-endian guests.
Signed-off-by: Felipe Franciosi <felipe@nutanix.com>
Signed-off-by: Mike Cui <cui@nutanix.com>
This patch documents (including their QMP invocations) all the four
major kinds of live block operations:
- `block-stream`
- `block-commit`
- `drive-mirror` (& `blockdev-mirror`)
- `drive-backup` (& `blockdev-backup`)
Things considered while writing this document:
- Use reStructuredText as markup language (with the goal of generating
the HTML output using the Sphinx Documentation Generator). It is
gentler on the eye, and can be trivially converted to different
formats. (Another reason: upstream QEMU is considering to switch to
Sphinx, which uses reStructuredText as its markup language.)
- Raw QMP JSON output vs. 'qmp-shell'. I debated with myself whether
to only show raw QMP JSON output (as that is the canonical
representation), or use 'qmp-shell', which takes key-value pairs. I
settled on the approach of: for the first occurrence of a command,
use raw JSON; for subsequent occurrences, use 'qmp-shell', with an
occasional exception.
- Usage of `-blockdev` command-line.
- Usage of 'node-name' vs. file path to refer to disks. While we have
`blockdev-{mirror, backup}` as 'node-name'-alternatives for
`drive-{mirror, backup}`, the `block-commit` command still operates
on file names for parameters 'base' and 'top'. So I added a caveat
at the beginning to that effect.
Refer this related thread that I started (where I learnt
`block-stream` was recently reworked to accept 'node-name' for 'top'
and 'base' parameters):
https://lists.nongnu.org/archive/html/qemu-devel/2017-05/msg06466.html
"[RFC] Making 'block-stream', and 'block-commit' accept node-name"
All commands showed in this document were tested while documenting.
Thanks: Eric Blake for the section: "A note on points-in-time vs file
names". This useful bit was originally articulated by Eric in his
KVMForum 2015 presentation, so I included that specific bit in this
document.
Signed-off-by: Kashyap Chamarthy <kchamart@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20170717105205.32639-3-kchamart@redhat.com
Signed-off-by: Jeff Cody <jcody@redhat.com>
This is part of the on-going effort to convert QEMU upstream
documentation syntax to reStructuredText (rST).
The conversion to rST was done using:
$ pandoc -f markdown -t rst bitmaps.md -o bitmaps.rst
Then, make a couple of small syntactical adjustments. While at it,
reword a statement to avoid ambiguity. Addressing the feedback from
this thread:
https://lists.nongnu.org/archive/html/qemu-devel/2017-06/msg05428.html
Signed-off-by: Kashyap Chamarthy <kchamart@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20170717105205.32639-2-kchamart@redhat.com
Signed-off-by: Jeff Cody <jcody@redhat.com>
A bitmap directory entry is sometimes called a 'bitmap header'. This
patch leaves only one name - 'bitmap directory entry'. The name 'bitmap
header' creates misunderstandings with 'qcow2 header' and 'qcow2 bitmap
header extension' (which is extension of qcow2 header)
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 20170628120530.31251-3-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 20170628120530.31251-2-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
Update the qcow2 specification to describe how the LUKS header is
placed inside a qcow2 file, when using LUKS encryption for the
qcow2 payload instead of the legacy AES-CBC encryption
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 20170623162419.26068-13-berrange@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
This is for the future interoperability & management guide. It includes
the QAPI docs, including the automatically generated ones, other socket
protocols (vhost-user, VNC), and the qcow2 file format.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
