...contains block layer and storage features that have been proposed. These features may not be in active development and questions about them should be address
== Core block layer ==
1 KB (196 words) - 10:51, 11 November 2020
Supporting asynchronous I/O in the NBD block device and qemu-nbd server makes it easier to use high-performance remote s
...for using remote storage within QEMU. NBD can also be coupled with other features such as streaming or copy-on-read. However, the NBD implementation in QEMU
932 bytes (132 words) - 14:56, 11 October 2016
..., Ceph). On Linux the cgroups blkio-controller supports I/O throttling on block devices but is a relatively recent feature. More importantly, there is no
The disk I/O limits feature introduces QEMU block layer I/O limits together with command-line and QMP interfaces for configur
1 KB (211 words) - 14:54, 11 October 2016
=== Removed features and incompatible changes ===
...[https://qemu-project.gitlab.io/qemu/about/removed-features.html 'Removed features'] page for details of suggested replacement functionality.
2 KB (229 words) - 17:13, 25 April 2024
...scales to several hundreds nodes, and supports advanced volume management features such as snapshot, cloning, and thin provisioning.
...no central node such as a meta-data server. This design enables following features.
2 KB (247 words) - 14:55, 11 October 2016
'''ICH9 block diagram'''
'''Intel Edison block diagram'''
2 KB (269 words) - 14:56, 9 July 2020
...arushi Mehta is working on the project for Outreachy. Project status is [[Features/IOUring|here]].
* Extending block/file-posix.c to use io_uring
2 KB (365 words) - 15:12, 17 May 2019
Block jobs, and other QAPI operations, may modify and impact the
operations safely, we need a mechanism to block and gate operations,
4 KB (709 words) - 18:15, 14 September 2016
| '''1 - Extend block/file-posix.c to use io_uring.'''
| '''6 - Add a fast path when QEMU block layer features are not in use .'''
2 KB (234 words) - 18:17, 23 May 2019
...out how much coverage of library functions you are doing. As QEMU's basic block boundaries are naturally at branch points you could do all of this pretty e
* See [[Features/TCGPlugins]]
891 bytes (140 words) - 22:19, 17 February 2021
==== Block devices ====
...and can be used by firmware directly. This will in the future enable new features without modifications of all firmware components (SeaBIOS, OVMF, CoreBoot)
4 KB (563 words) - 11:31, 10 December 2013
* Both to be solved by block-queue
...when the old one is full - and that one we don't even read, but write, so block-queue will help
4 KB (552 words) - 08:57, 12 October 2016
..., and the bit is 1 if the block is in the FVD image. The default size of a block is 64KB, same as the cluster size of QCOW2. To represent the state of a 1TB
=Important Features=
4 KB (688 words) - 14:45, 11 October 2016
...ts/qemu-iotests/. It contains test for disk image formats and block layer features.
...lative to the build directory) is the script to run tests. Tests exercise block I/O operations using qemu-img(1), qemu-io(1), and sometimes by running QEMU
2 KB (298 words) - 10:00, 12 October 2016
* Various minor bugfixes; no new features in this release.
=== Block devices ===
4 KB (589 words) - 12:24, 19 February 2013
| [[Planning/SoftFeatureFreeze|Soft feature freeze]]. All features
should have patches on the list by this date; major features should
4 KB (636 words) - 08:31, 12 October 2016
...or Mode Execution Prevention) and SMAP (Supervisor Mode Access Prevention) features of newer x86 processors.
...se, bmi1, hle, avx2, smep, bmi2, erms, invpcid, rtm) and "Opteron_G5" (new features: tbm, f16c, fma)
6 KB (951 words) - 16:38, 15 January 2013
* snowridge cpu name/features
* coverity issue in block/nvme
3 KB (488 words) - 20:51, 5 November 2019
To record and replay block operations the drive must be configured
==Features to add==
4 KB (568 words) - 08:17, 2 March 2017
...l future writes will be redirected into a separate location. The previous block device has a consistent state whereas it represents a point-in-time snapsho
The merge_disk command will copy the allocated block content into the backing file and once the image is empty, reopen the backi
4 KB (663 words) - 14:43, 11 October 2016
...different patch series posted on the mailing list sparked a discussion on block device operations
One is Jeff Cody's multiple-device snapshot series, documented [[Features/SnapshotsMultipleDevices|here]].
5 KB (591 words) - 08:39, 12 October 2016
* the new block-copy feature can assert on unaligned images [https://lists.gnu.org/archive/
== Targeted Features ==
3 KB (468 words) - 08:45, 20 August 2020
features that change the format in an incompatible way, so that older
increase in order to introduce some incompatible features, however it's
9 KB (1,281 words) - 10:12, 9 September 2016
=== New deprecated options and features ===
* Parsing of key,value pair filenames for the RBD block device
7 KB (1,028 words) - 16:56, 21 February 2019
...QAPI/GuestAgent Guest Agent]. Please check the guest [http://wiki.qemu.org/Features/QAPI/GuestAgent Guest Agent] page for design and implementation details.
The two main guest agent features of interest to live snapshots are:
21 KB (3,274 words) - 14:58, 11 October 2016
...ing to I/O errors; patch proposed: https://lists.gnu.org/archive/html/qemu-block/2022-08/msg00375.html
== Targeted Features ==
2 KB (273 words) - 13:20, 22 August 2022
...host-user-blk device backend although the QEMU block layer has a number of features that make QEMU desirable as a software-defined storage appliance in its own
2 KB (342 words) - 07:49, 11 March 2019
uint64_t features; /* format feature bits */
/* if (features & QED_F_BACKING_FILE) */
9 KB (1,374 words) - 14:45, 11 October 2016
...It should integrate into the existing build system. Currently, we allow features to be specified in for inclusion in a boolean fashion (either 'y' or 'n' to
...mechanism to support third party extensions to QEMU or out of tree drivers/features
9 KB (1,464 words) - 19:33, 11 August 2016
* The "autoload" parameter of the "block-dirty-bitmap-add" QMP command has been removed (it's no longer needed).
=== New deprecated options and features ===
11 KB (1,631 words) - 11:24, 3 December 2019
Future qemu is expected to support these features (some already implemented):
= Live features =
21 KB (3,397 words) - 15:04, 11 October 2016
* mps3-an524: Fix MPC setting for SRAM block
== Targeted Features ==
4 KB (610 words) - 14:09, 19 October 2021
...s without a native code generator can use the TCG interpreter (TCI). See [[Features/TCI]] for more information.
== Block devices (disks) ==
6 KB (908 words) - 20:51, 17 February 2012
...cpu-add QMP command. More details [[Features/CPUHotplug#cpu-add_interface|Features/CPUHotplug]].
...ltered-features" to allow introspection of supported and not supported CPU features.
7 KB (1,120 words) - 18:28, 27 May 2013
...registers mean we can boot more recent Linux kernels that probe for these features
* Removed dependency on external kernel headers, all supported KVM features are now built into the binary
8 KB (1,151 words) - 06:40, 13 October 2011
...[https://qemu-project.gitlab.io/qemu/about/removed-features.html 'Removed features' ] page for details of suggested replacement functionality
=== New deprecated options and features ===
8 KB (1,060 words) - 18:28, 9 December 2021
* Fixed block load instructions regression happened in 1.0 release.
...g a pflash drive. This feature is not supported when KVM is enabled. See [[Features/PC System Flash]] for more information.
8 KB (1,276 words) - 05:38, 3 June 2012
== Block subsystem ==
* Tested all 9p file system ( security models, features like mmap, locking, posixacl, zerocopy) using the basic fs tests, I/O and s
7 KB (1,052 words) - 16:41, 29 November 2011
* Host floppy device pass-through (block driver “host_floppy”) has been removed; it is still possible to use the
* Block device parameter aio=native has no effect without cache.direct=on. It will
13 KB (2,001 words) - 11:33, 17 December 2015
...size configurations, with the logical block size smaller than the physical block size, are rejected.
...eprecated Features"] appendix for the full list of historically deprecated features/options.
10 KB (1,457 words) - 01:21, 12 June 2018
=== New deprecated options and features ===
...eprecated Features"] appendix for the full list of historically deprecated features/options.
12 KB (1,748 words) - 09:55, 28 April 2019
...ockdev setup). Fix is on the list: https://lists.gnu.org/archive/html/qemu-block/2018-11/msg00759.html
== Targeted Features ==
3 KB (531 words) - 15:15, 4 September 2019
easy to understand and implement. The fine-grained features are marked
Requests that exceed the current limit must be queued since block I/O is
4 KB (631 words) - 15:41, 11 October 2016
...MODEL'',enforce", of course as long as TCG or KVM support the CPU's set of features. Previously, a few CPUs included extraneous CPUID flags that cause "-cpu ''
=== Block devices in system emulation ===
7 KB (980 words) - 15:30, 14 December 2014
=== [[Features/VNC_Tight_PNG|Tight PNG]] ===
...the queue will be threaded and (hopefully) send_framebuffer_update() won't block the guest execution anymore.
4 KB (662 words) - 07:54, 13 October 2016
...[https://qemu-project.gitlab.io/qemu/about/removed-features.html 'Removed features'] page for details of suggested replacement functionality.
==== Other removed features ====
11 KB (1,553 words) - 14:27, 3 February 2023
[[Features/QED | QED]] is another new QEMU image format. Below is the FVD developer’
.../ext4, reiserFS, Reiser4, XFS, JFS, VMFS, ZFS, etc) provide many different features and are optimized for different objectives (flash wear leveling, seek dista
8 KB (1,278 words) - 14:45, 11 October 2016
* A thin layer sits between device emulation and net/block layer
|Storage replication QEMU's block migration or others
4 KB (636 words) - 14:45, 11 October 2016
=== New deprecated options and features ===
...System Emulation User's Guide for the full list of historically deprecated features/options.
14 KB (2,072 words) - 20:38, 28 April 2020
=== New deprecated options and features ===
...eprecated Features"] appendix for the full list of historically deprecated features/options.
11 KB (1,707 words) - 08:58, 24 October 2019
