./emulators/qemu, CPU emulator using dynamic translation

[ CVSweb ] [ Homepage ] [ RSS ] [ Required by ] [ Add to tracker ]


Branch: CURRENT, Version: 2.6.0nb1, Package name: qemu-2.6.0nb1, Maintainer: pkgsrc-users

QEMU is a FAST! processor emulator using dynamic translation to achieve
good emulation speed, QEMU has two operating modes:

* Full system emulation. In this mode, QEMU emulates a full system
(for example a PC), including a processor and various peripherals.
It can be used to launch different Operating Systems without rebooting
the PC or to debug system code.
* User mode emulation (Linux host only). In this mode, QEMU can launch
Linux processes compiled for one CPU on another CPU. It can be used
to launch the Wine Windows API emulator or to ease cross-compilation
and cross-debugging.


Required to run:
[security/libgcrypt] [devel/glib2] [devel/SDL] [devel/ncurses] [x11/pixman] [lang/python27]

Required to build:
[textproc/texi2html] [pkgtools/x11-links] [x11/glproto] [x11/renderproto] [x11/xproto] [x11/xf86vidmodeproto] [x11/xf86driproto] [x11/damageproto] [x11/inputproto] [x11/xextproto] [x11/randrproto] [x11/dri2proto] [x11/fixesproto4]

Package options: sdl

Master sites:

SHA1: d558a11d681dd095b1d7cb03c5b723c9d3045020
RMD160: 97e41fab12ad15ba05e63229bf57a51a1564bd32
Filesize: 25151.628 KB

Version history: (Expand)


CVS history: (Expand)


   2016-05-31 07:25:12 by Paul Goyette | Files touched by this commit (1)
Log message:
Mark x86_64 emulator as not safe for MPROTECT

XXX Other platform emulators may be similarly affected, but I can't test
XXX the adequately.
   2016-05-15 03:25:15 by Ryo ONODERA | Files touched by this commit (10) | Package updated
Log message:
Update to 2.6.0

Changelog:
System emulation
Incompatible changes

    The aio=native option to "-drive" now requires the cache=none \ 
option, instead of silently disabling itself for other cache modes. The newly \ 
invalid combination had been warning since QEMU 2.3.
    Specifying block device parameter aio=native is now an error on POSIX \ 
systems if qemu is compiled without libaio support. The newly invalid \ 
combination had been warning since QEMU 2.3.
    The experimental x-drive option for the sdhci-pci device has been removed. \ 
Instead of passing a drive directly to the SD controller device you now must \ 
create an SD card object (which will automatically be plugged into the SD \ 
controller), so "-device sdhci-pci,x-drive=mydrive -drive \ 
id=mydrive,[...]" becomes "-device sdhci-pci -device \ 
sd-card,drive=mydrive -drive id=mydrive,[...]".
    The s390-virtio machine has been removed.
    Machine types pc-q35-1.4, pc-q35-1.5, pc-q35-1.6, pc-q35-1.7, pc-q35-2.0, \ 
pc-q35-2.1, pc-q35-2.2 and pc-q35-2.3 have been removed.
    The "virt" machine type's flash device has changed when TrustZone \ 
is active ("-machine virt,secure=on"). The first flash device is only \ 
available in secure memory, while the second is available in non-secure memory \ 
too.

Future incompatible changes

    Three options are using different names on the command line and in \ 
configuration file. In particular:
        The "acpi" configuration file section matches command-line \ 
option "acpitable";
        The "boot-opts" configuration file section matches \ 
command-line option "boot";
        The "smp-opts" configuration file section matches command-line \ 
option "smp".

    -readconfig will standardize on the name for the command line option.

    Behavior of automatic calculation of SMP topology when some SMP topology \ 
options for -smp are omitted (sockets, cores, threads) will change in the \ 
future. If guest ABI needs to be preserved on upgrades while using the SMP \ 
topology options, users should either set set all options explicitly (sockets, \ 
cores, threads), or omit all of them.
    The original qcow2 image encryption is fatally flawed, and support for it \ 
will be disabled entirely from the system emulators. It'll remain available only \ 
in command line tools qemu-img, qemu-io, qemu-nbd to facilitate data liberation. \ 
It is recommended to use 'qemu-img convert' to convert qcow2 encrypted images to \ 
uncrypted ones. The new LUKS encryption driver can provide a secure replacement \ 
if raw files are acceptable, while a future release will integrate luks into \ 
qcow2 natively.
    A few devices will be configured with explicit properties instead of \ 
implicitly. Unlikely to affect users; for the full list, see the 2.3 ChangeLog.
    QMP command blockdev-add is still a work in progress. It doesn't support all \ 
block drivers, it lacks a matching blockdev-del, and more. It might change \ 
incompatibly.

ARM

    Support for a separate EL3 address space
    System mode supports BE8 and BE32. Note that qemu-system-arm can emulate \ 
both big-endian and little-endian guests (unlike user-mode emulation which has \ 
separate qemu-arm and qemu-armeb binaries).
    Support for the SETEND instruction, used most notably on Raspbian through \ 
the arm-mem library (previously known as libcofi).
    Faster boot thanks to DMA support in fw_cfg
    The "virt" machine type supports a virtual power button and the \ 
"system_powerdown" monitor command
    The "virt" machine type supports configuring network cards with \ 
-nic in addition to -netdev
    The RAM limit for the "virt" machine type is now 255GB
    The "xlnz-zynqmp" machine type now includes SPI controllers
    The "xlnx-ep108" machine type now supports SPI flash
    New partial Raspberry Pi 2 emulation with "raspi2" machine type. \ 
For now, it can boot older releases of Windows and Raspbian, but lacks a number \ 
of devices including USB.
    New palmetto-bmc machine type using the new, partial ASPEED AST2400 SoC \ 
implementation

KVM

    Support for guest debugging (software and hardware breakpoints, single step) \ 
on AArch64

MIPS

    Support for FPU and MSA in KVM guests
    Support for R6 Virtual Processors
    Initial support for Cluster Power Controller and Global Configuration \ 
Registers allowing the guest to control the start of Virtual Processors
    Support for Inter-Thread Communication Unit
    Support for MAAR registers in P5600 CPU

PowerPC

    Improved support for migration of g3beige and mac99 machines
    Fix serial ports for g3beige and mac99 machines (OpenBIOS)
    The gdb stub supports the VSX instruction set extensions

pSeries

    pSeries machine types starting at pseries-2.6 use XHCI as the USB host \ 
controller instead of OHCI
    Support for more hypercalls (H_SET_SPRG0, H_SET_DABR, H_SET_XDABR and \ 
H_PAGE_INIT)
    Support for EEH on assigned PCI devices can use the normal \ 
spapr-pci-host-bridge instead of the special spapr-pci-vfio-host-bridge.

s390

    Fixes and improvements in s390x PCI support
    Support for hotplug of s390x cpus via cpu-add
    Support for booting from virtio-scsi devices in the s390-ccw bios

SH
SPARC

    sun4m: Fix for ldstub instruction resolves several 32-bit Solaris bugs \ 
(MUTEX_HELD hang, libC error, Java WebStart segfault)
    sun4u: FreeBSD 10.3+ can now run under qemu-system-sparc64 in -nographic mode

TileGX
Tricore

    Support for context management, illegal opcode and opd traps
    Support for FPU instructions

x86
TCG

    Support for the XSAVE/XSAVEOPT, MPX, FSGSBASE and PKE features

KVM

    Support for "split irqchip". In this mode, QEMU emulates the \ 
IOAPIC, PIC (i8259) and PIT (i8254) devices while leaving the local APIC \ 
emulation to the kernel. This mode reduces the attack surface of KVM.
    Support for the new PKU feature found in some Skylake processors
    Support for migrating the TSC rate

Xen
Q35

    Support resume (S3)
    Support for legacy Windows guests (XP/2003)

Device emulation and assignment

    New IPMI emulation subsystem. QEMU can now emulate an internal BMC or attach \ 
to an external BMC simulator such as OpenIPMI's lanserv. IPMI however is not yet \ 
exposed in SMBIOS and ACPI tables (do we want to docume?)
    FIXME: what's the state of nvdimm?

ACPI

    The floppy disk controller's characteristics are now exposed in the ACPI \ 
tables, which makes it possible to use floppies on Windows together with UEFI \ 
firmware.

Block devices

    The floppy disk consk or an empty disk to a 2.88 MB disk
    Improved compatibility of the SD device model with various operating systems \ 
and firmwares
    The NVMe device supports the "bootindex" property.
    The SDHCI device supports reset.

 ivshmem

    No longer available on hosts lacking eventfd(2), because inter-vm interrupts \ 
don't work there
    New devices ivshmem-plain and ivshmem-doorbell, fully backwards compatible \ 
for guests, notable differences to ivshmem:
        PCI revision is 1 instead of 0
        ivshmem role=master becomes master=on, role=peer becomes master=off
        ivshmem x-memdev=ID becomes ivshmem-plain memdev=ID
        ivshmem shm=NAME,size=SZ becomes ivshmem-plain memdev=ID, with -object \ 
memory-backend-file,id=ID,mem-path=/dev/mem/NAME,size=SZ,share
        ivshmem chardev=ID becomes ivshmem-doorbell,chardev=ID
        Property ioeventfd defaults to on instead of off
        ivshmem-plain never has MSI-X capability, and ivshmem-doorbell always \ 
has MSI-X capability
    Device ivshmem is deprecated, and its experimental property x-memdev is gone
    Interrupting a peer that reuses an unplugged peer's ID works again (broken \ 
in v1.2.0)
    Unplug no longer destroys the character device, for consistency with other \ 
devices
    The funny "no shared memory, yet" state is no longer \ 
guest-visible, and can no longer fail or mess up migration
        Guests may require PCI revision 1 to make sure they're not exposed to \ 
the funny state
    docs/specs/ivshmem-spec.txt rewritten for completeness and accuracy.

SCSI

    Support for the LSI SAS1068 HBA (also known as "MPT Fusion"). Note \ 
that some operating systems will not recognize disks attached to this adapter, \ 
unless the disks are assigned a world-wide name (WWN).

PCI/PCIe

    PCIe Multi-root support (using the new pxb-pcie root-compex)

USB

    MTP: initial support for events

VFIO

    Support for AMD XGBE platform passthrough
    New sysfsdev property provides a more general way to specify the device to \ 
attach to.
    Provided PCI option ROMs are fixed to include the same vendor and device id \ 
as the device exposed to the guest. This facilitates changing the ids of the \ 
devices.

virtio

    Performance improvements via optimized vring accesses
    The balloon driver statistics now include the amount of available memory \ 
(corresponding to "Available" in /proc/meminfo for Linux guests).

Character devices

    The socket character device backend can now enable TLS over TCP connections, \ 
acting either as a TLS server:

$QEMU -object tls-creds-x509,id=tls0,dir=$HOME/.pki/qemutls,endpoint=server \
      -chardev socket,id=s0,host=127.0.0.1,port=9000,tls-creds=tls0,server \
      -device isa-serial,chardev=s0 \
      ...other args...

or a TLS client:

$QEMU -object tls-creds-x509,id=tls0,dir=$HOME/.pki/qemutls,endpoint=client \
      -chardev socket,id=s0,host=127.0.0.1,port=9000,tls-creds=tls0 \
      -device isa-serial,chardev=s0 \
      ...other args...

If operating in server mode, the same set of TLS credentials can be used for \ 
both character devices and the VNC server

    All character devices can have their output logged to a plain file

$QEMU -chardev stdio,id=mon0,logfile=monitor.log \
      -mon chardev=mon0 \
      ...other args...

will result in logging of all output on the HMP monitor. The logappend parameter \ 
controls whether the file is truncated at startup, defaulting to append.
GUI

    SDL2 and SPICE now support OpenGL and virgl. For SPICE, Unix sockets are the \ 
only usable transport when OpenGL is enabled.
    The "-vnc" and "-display vnc" options support ipv4=off \ 
and ipv6=off. Previously, only "ipv4" and "ipv6" were \ 
available.
    Support getting input events directly from linux evdev devices, using \ 
"-object input-linux,id=$name,evdev=/dev/input/event$nr"
    Support for ncurses on Windows.

Monitor

    Support for a new "detach" option to \ 
"dump-guest-memory". The option dumps memory in the background. \ 
Progress can be queried using the new commands "info dump" (human \ 
monitor) and "query-dump" (QMP), as well as through the QMP event \ 
DUMP_COMPLETED.
    Support for a new command "input-send-event" replacing the \ 
previous experimental command "x-input-send-event".
    The human monitor command "drive_add -n" allows creating block \ 
devices that do not have a BlockBackend (similar to QMP blockdev-add).

Migration

    Postcopy is not experimental anymore; the x-postcopy-ram capability was \ 
renamed to postcopy-ram.

Network

    SLIRP now supports IPv6 for ICMP, UDP, TCP and TFTP.
    mirror filter which can mirror traffic from netdev to socket chardev, vice versa.
    redirector filter which can redirect traffic from netdev to socket chardev, \ 
vice versa.

Secret passing system

There is a new standard mechanism for securely passing secret credentials to \ 
QEMU, which will be used in combination with other subsystems. For example, \ 
network block device passwords, block device decryption passphrases, or TLS \ 
private key passwords can all use the same mechanism.

    Passing credentials inline (insecure, only for developer testing)

$QEMU -object secret,id=sec0,data=letmein

    Passing credentials via a plain file

$QEMU -object secret,id=sec0,file=mypassword.txt

    Passing credentials via a base64 encoded file

$QEMU -object secret,id=sec0,file=mypassword.txt,format=base64

    Passing credentials inline, encrypted with a master key (recommended for \ 
management apps)

 $QEMU -object secret,id=master0,file=mykey.b64,format=base64 \
       -object secret,id=sec0,data=[base64 ciphertext],\
               keyid=master0,iv=[base64 IV],format=base64

TLS credential handling

It is now possible to use encrypted TLS private keys with credentials for TLS \ 
servers/clients in QEMU. The password for unlocking the private key is provided \ 
by a secret object whose id is specified via the passwordid' property

$QEMU -object secret,id=tlskey0,file=mypassword.txt \
      -object \ 
tls-creds-x509,id=tls0,dir=$HOME/.pki/qemutls,endpoint=server,passwordid=tlskey0 \ 
\
      ...other args...

Block devices

    Block device throttling now support specifying a burst length as well. While \ 
previously the burst could only be specified as a total number of IOPS (e.g. \ 
10000 IOPS), more complex specifications such as "10000 IOPS for 10 \ 
seconds" are now possible. Note that, because of the implementation of the \ 
algorithm, a guest that is allowed "10000 IOPS for 10 seconds" will \ 
also be allowed to perform for example 5000 IOPS for 20 seconds.
    The curl block device driver now supports HTTP authentication and HTTP proxy \ 
authentication via the new properties 'username', 'password-secret', \ 
'proxy-username' and 'proxy-password-secret'.

$QEMU -object secret,id=sec0,file=password.txt \
      -object secret,id=sec1,file=proxy-password.txt \
      -drive \ 
driver=http,host=localhost,port=443,username=fred,password-secret=sec0,proxy-username=bob,proxy-password-secret=sec1 \ 
\
      ...other args...

    The RBD block device driver can now use the secret object type to securely \ 
receive the authentication password without exposing it in the command line args

$QEMU -object secret,id=sec0,file=password.b64,format=base64 \
      -drive \ 
driver=rbd,filename=rbd:pool/image:id=myname:auth_supported=cephx,password-secret=sec0 \ 
\
      ...other args...

    The iSCSI block device driver can now use the secret object type to securely \ 
receive the authentication password without exposing it in the command line args

$QEMU -object secret,id=sec0,file=password.txt \
      -iscsi user=fred,password-secret=sec0 \
      -drive \ 
file=iscsi://192.168.122.1:3260/iqn.2013-12.com.example%3Aiscsi-chap-netpool/1

NB this syntax requires that all iSCSI backed drives use the same password

    The qemu-io tool gained support for new '--object' and '--image-opts' \ 
arguments. The --object argument allows 'secret' and 'tls-creds-x509' objects to \ 
be defined for use in association with a block device backend. The \ 
'--image-opts' argument instructs qemu-io to parse the image string as a set of \ 
image options, instead of a plain filename. For example, to connect qemu-io to \ 
an NBD server using TLS

qemu-io -c "read 0 512" \
        --object tls-creds-x509,id=tls0,dir=$HOME/.pki/qemutls,endpoint=client \
        --image-opts driver=nbd,host=localhost,port=10809,tls-creds=tls0

    The qemu-nbd tool gained support for new '--object' and '--image-opts' \ 
arguments. The --object argument allows 'secret' and 'tls-creds-x509' objects to \ 
be defined for use in association with a block device backend or the NBD server. \ 
The '--image-opts' argument instructs qemu-io to parse the image string as a set \ 
of image options, instead of a plain filename. For example, to connect qemu-nbd \ 
to an HTTP server with authentication and export it over NBD using TLS

qemu-nbd --readonly \
         --object secret,id=sec0,file=passwd.txt \
         --object tls-creds-x509,id=tls0,dir=$HOME/.pki/qemutls,endpoint=server \
         --image-opts \ 
driver=http,url=http://some.random.host/some/image,username=fred,password-secret=sec0

    The qemu-img tool gained support for new '--object' and '--image-opts' \ 
arguments. The --object argument allows 'secret' and 'tls-creds-x509' objects to \ 
be defined for use in association with a block device backend or the NBD server. \ 
The '--image-opts' argument instructs qemu-io to parse the image string as a set \ 
of image options, instead of a plain filename. For example, to a remote HTTP \ 
server with authentication

qemu-img info --object secret,id=sec0,file=passwd.txt \
              --image-opts \ 
driver=http,url=http://some.random.host/some/image,username=fred,password-secret=sec0

    Support for deleting snapshots on Sheepdog devices.
    The NBD client and server now support use of TLS. When enabled, the server \ 
will mandate that the client also enable TLS and drop any client which attempts \ 
to continue in plain text. To run a qemu-nbd server with TLS:

qemu-nbd --object tls-creds-x509,id=tls0,dir=$HOME/.pki/qemutls,endpoint=server \
         --tls-creds tls0 \
         /path/to/disk/image

To connect to a server that requires TLS with qemu-img:

qemu-img info --object \ 
tls-creds-x509,id=tls0,dir=$HOME/.pki/qemutls,endpoint=client \
              --image-opts driver=nbd,host=localhost,port=10809,tls-creds=tls0

To start a VM pointing to the NBD server

$QEMU -object tls-creds-x509,id=tls0,dir=$HOME/.pki/qemutls,endpoint=client \
      -drive driver=nbd,host=localhost,port=10809,tls-creds=tls0 \
      ...other args...

    The NBD server gained support for specifying an export name. When the client \ 
negotiates use of the new style NBD protocol the default export name is \ 
"". The --exportname argument allows this to be customized:

qemu-nbd --exportname myvol  /path/to/myvol.qcow2

    QEMU gained support for volumes formatted with the LUKSv1 data format. To \ 
format a new LUKS volume

qemu-img create -f luks \
                --object secret,id=sec0,file=passphrase.txt \
                -o key-secret=sec0 \
                demo.luks 10G

To boot a guest from a LUKS volume:

$QEMU -object secret,id=sec0,file=passphrase.txt \
      -drive driver=luks,key-secret=sec0,file=demo.luks \
      ...other args...

The LUKS implementation is intended to be compatible with that used by \ 
cryptsetup/dm-crypt, so it should be possible to use disk images interchangeably \ 
between them. The only caveat is that some less common cipher/hash algorithms \ 
are not yet supported by QEMU. It is also not yet possible to manage key-slots \ 
with qemu-img.
TCG

    Record/replay support extended to cover character devices.

Tracing

    The "stderr" tracing backend was replaced by the "log" \ 
tracing backend, which is now the default. This backend prints tracing messages \ 
to the destination specified with the "-D" option.
    In addition to the existing "-trace file=...", tracepoints can be \ 
enabled using "-trace [enable=]...". The new option also supports \ 
globbing, as in "-trace bdrv_aio_*".
    In addition to the existing "-trace file=...", tracepoints can be \ 
enabling using "-d trace:...". This option also supports globbing, as \ 
in "-d trace:bdrv_aio_*".
    When using "-daemonize", the "-D" option also provides \ 
the file to which QEMU's stderr output will be redirected.
    TCG supports a new "-dfilter" option to limit exec, out_asm, op \ 
and op_opt logging to a range of guest physical addresses. ARM also applies the \ 
filter to in_asm logging; this will be extended to other targets in future \ 
releases (FIXME: probably should do it now instead...)
    A "%d" substring in the log file name is replaced with QEMU's pid.

User-mode emulation

    The default CPU for ppc64 and ppc64le is now POWER8
   2016-03-24 16:21:10 by Pierre Pronchery | Files touched by this commit (2)
Log message:
Avoid a "bad substitution" error in the configure script

This fixes building emulators/qemu on netbsd-7 (amd64).
On a related note, it may also make sense to include
security/nettle/buildlink3.mk to the build.
   2016-03-06 20:41:24 by Darrin B. Jewell | Files touched by this commit (2)
Log message:
slightly better shm_open check fix
   2016-03-06 10:55:58 by Darrin B. Jewell | Files touched by this commit (2)
Log message:
tweak check for shm_open.  Fixes build on darwin
   2015-12-23 00:52:00 by Ryo ONODERA | Files touched by this commit (2)
Log message:
Build ivshmem* conditionally, fix broken if conditional
   2015-12-21 13:10:22 by Ryo ONODERA | Files touched by this commit (7)
Log message:
Fix build under NetBSD 6 or other platform that has no shm_open()
Fix PR pkg/50572.
   2015-12-18 23:39:33 by Ryo ONODERA | Files touched by this commit (5) | Package updated
Log message:
Update to 2.5.0

Changelog:
== System emulation ==
* guard pages are now inserted after guest RAM, to guard against guest-triggered \ 
buffer overflow attacks

=== Incompatible changes ===
* The mips32r5-generic CPU was renamed to P5600
* Host floppy device pass-through (block driver "host_floppy") has \ 
been removed; it is still possible to use them just like any other device file, \ 
however, a medium change will no longer be passed through to the guest

=== Future incompatible changes ===
* Three options are using different names on the command line and in \ 
configuration file.  In particular:
** The "acpi" configuration file section matches command-line option \ 
"acpitable";
** The "boot-opts" configuration file section matches command-line \ 
option "boot";
** The "smp-opts" configuration file section matches command-line \ 
option "smp".
:-readconfig will standardize on the name for the command line option.
* Behavior of automatic calculation of SMP topology when some SMP topology \ 
options for -smp are omitted (sockets, cores, threads) will change in the \ 
future. If guest ABI needs to be preserved on upgrades while using the SMP \ 
topology options, users should either set set all options explicitly (sockets, \ 
cores, threads), or omit all of them.
* Image encryption is fatally flawed, and will be dropped entirely.  It'll \ 
remain available only in qemu-img, so you can use 'qemu-img convert' to convert \ 
encrypted images to uncrypted ones.
* Block device parameter aio=native has no effect without cache.direct=on.  It \ 
will be made an error.
* Block device parameter aio=native has no effect if qemu is compiled without \ 
libaio support.  It will be made an error.
* A few devices will be configured with explicit properties instead of \ 
implicitly.  Unlikely to affect users; for the full list, see the 2.3 ChangeLog.
* QMP command blockdev-add is still a work in progress.  It doesn't support all \ 
block drivers, it lacks a matching blockdev-del, and more.  It might change \ 
incompatibly.
* The s390-virtio machine has been deprecated for 2.5; it will be removed in \ 
2.6. s390x users should switch to the (default) s390-ccw-virtio machine.
* Changes to device "sdhci-pci" will make migration between old and \ 
new versions impossible.
* We intend to drop support for running QEMU on MacOSX 10.5 hosts in the QEMU \ 
2.6 release, unless somebody who uses it wishes to step forward and help us with \ 
regular testing.

=== Alpha ===
=== ARM ===
* The "virt" machine type supports passing SMBIOS to the firmware.
* Semihosting support on AArch64
* New i.MX31 SoC.
* The ZynqMP and Allwinner A10 platforms support AHCI.
* Support for VGICv3 in KVM
* Support for GICv3 in the ACPI tables.
* The "virt" machine now has a second PCIe MMIO region of 512GB in \ 
size in high memory. Note that older 32-bit ARM Linux kernels built without \ 
CONFIG_LPAE have a bug where the presence of this region in high memory causes \ 
them to refuse to use the PCIe controller at all. In this case you can either \ 
reconfigure your kernel with CONFIG_LPAE=y, or pass QEMU the "-machine \ 
highmem=off" option to disable the use of high memory for PCIe. The kernel \ 
bug is expected to be fixed in Linux kernel release 4.4.
=== MIPS ===
* The mips32r5-generic CPU was renamed to P5600
* Improvements to MIPS R6 emulation

=== PowerPC ===
==== pSeries ====
* Support for memory hotplug
* The shipped version of SLOF includes GPT support.
* Using VFIO doesn't need spapr-pci-vfio-host-bridge anymore.
* virtio-vga now supported on sPAPR guests.
* [[Features/HRandomHypercall | H_RANDOM hypercall]] device for providing good \ 
random data to the guests.
==== Mac99 ====
* Improve ability to boot MacOS 9 (based upon GSoC project "Implement \ 
support for Mac OS 9 in QEMU " by Cormac O'Brien)

=== s390 ===
* Storage keys are migrated.
* New "info skeys" command in HMP to dump the storage key for a given \ 
address.
* Support for virtio 1 in the virtio-ccw devices.
** A maximum virtio-ccw revision can be specified via the \ 
"max_revision" property: max_revision=0 may be used to enforce usage \ 
of legacy virtio mode.
* Support for boot from El Torito iso images on virtio-blk has been added.

=== SH ===
=== SPARC ===

* sun4u: Fix EBus device enumeration under FreeBSD SPARC64 (OpenBIOS)

=== TileGX ===
* New target.
=== x86 ===
* The emulated IOMMU (VT-d) supports devices behind a bridge
* QEMU will warn when using a "-cpu" model that includes unsupported \ 
features. These features are disabled automatically, just like in previous \ 
versions of QEMU
* /machine/icc-bridge was removed from the QOM tree. Software relying on \ 
icc-bridge to find CPU objects should use the "qom_path" field of \ 
"query-cpus" QMP command

==== CPU models and features ====
* Haswell and Broadwell CPU models now include ABM
* Cache information passthrough (which was enabled by default on "-cpu \ 
host") is now disabled by default
* ABM, POPCNT, and SSE4a are not enabled in the default CPU models (qemu64, \ 
qemu32) anymore, as many hosts don't support it
* RDTSCP was removed from AMD CPU models, as current KVM versions can't expose \ 
RDTSCP to guests in AMD hosts
* New Intel memory instructions (clflushopt/clwb/pcommit) are now supported
* TCG now supports Debug Extensions (CR4.DE)

==== KVM ====
* Support for Hyper-V-compatible reporting of crashes.

==== Xen ====
* Support for passthrough of Intel integrated GPUs.

=== Device emulation and assignment ===
* fw_cfg supports a DMA interface on ARM and x86.  This interface makes \ 
-kernel/-initrd much faster if supported by the firmware. SeaBIOS supports the \ 
DMA interface starting with release 1.9.0 (commit 06316c9d). The UEFI guest fw \ 
for ARM VMs (known as ArmVirtQemu or AAVMF) supports the DMA interface starting \ 
with git commit 953bcbcc / SVN r18545.
==== ACPI ====
==== Audio ====
==== Block devices ====
==== Character devices ====
==== IDE ====
* AHCI ATAPI PIO transfers greater than one sector are fixed. This helps on \ 
OVMF, which utilizes such transfers.
* Zero byte count limits will no longer hang ATAPI drives.
* ATAPI PIO reads, when the byte count limit is set to the ATAPI block size, are \ 
now asynchronous. This should help to prevent hangs due to missing CDROM media \ 
mounted via NFS.

==== Mouse/keyboard ====
==== Network ====
==== SCSI ====
* scsi-generic devices now can be used together with a "readonly=on" \ 
backend.
==== Shared memory device ====
* A sample implementation of the ivshmem client and ivhsmem server is included \ 
with QEMU.
* ivshmem supports a new "x-memdev" property that uses a memory object \ 
for the backend.  This makes it possible to use ivshmem with a hugetlbfs \ 
backend. This property is experimental and may be removed in future release in \ 
favour of an alternative ivshmem device.
* Use kvm irqfd for msi notifications
* Protocol change, native long -> LE int64_t

==== PCI/PCIe ====
* hotplug support added for multifunction devices. To use, add all functions \ 
except function 0 first. Adding function 0 exposes the device to the guest. \ 
Request removal on function 0. On guest acknowledge, all functions are ejected \ 
together.

==== TPM ====
==== VFIO ====
==== virtio ====
* virtio-gpu now supports 3D mode
* vhost-user now supports live migration. client changes are required to enable \ 
this. When used with an old client without migration support, vhost-user will \ 
now block migration (instead of failing silently)
* vhost-user now supports multi-queue. Use queues=# to enable this. client \ 
changes are required to enable this mode.  When used with an old client without \ 
multi-queue support, device will automatically fall back on using a single pair \ 
of queues.
* vhost-user protocol now includes protocol feature negotiation, including \ 
multiple new messages. When used with old clients, all new messages are \ 
automatically disabled.
* vhost-user no longer sents the RESET_OWNER message on device stop. The only \ 
QEMU version that sent it was 2.4, the message is now officially deprecated.
* migration now works when virtio 1 is enabled for virtio-pci
* For virtio-pci, virtio 1 performance on kvm on Intel CPUs has been improved \ 
(on kernel 4.4 and up).
* a new flag modern-pio-notify can be used to enable PIO for notifications in \ 
virtio 1 mode, to improve performance for host kernels older than 4.4, and \ 
processors without EPT support.
* virtio devices can now be placed on the pci express bus
* vhost is no longer disabled when guest does not use MSI-X. The vhostforce flag \ 
is no longer required.
* in virtio 1 mode, scsi passthrough is now disabled for virtio blk
* Please note that for virtio-pci, the modern (virtio 1) interface is still \ 
disabled by default. To enable, set the flag disable-modern=off.

==== VGA ====

=== Character devices ===
=== GUI ===
* New syntax for enabling TLS in the VNC server:
** Equivalent to <tt>-vnc hostname:0,tls</tt>: <tt>-object \ 
tls-creds-anon,id=tls0,endpoint=server -vnc hostname:0,tls-creds=tls0</tt>
** Equivalent to <tt>-vnc hostname:0,tls,x509=/path/to/certs</tt>: \ 
<tt>-object \ 
tls-creds-x509,id=tls0,endpoint=server,dir=/path/to/certs,verify-peer=no -vnc \ 
hostname:0,tls-creds=tls0</tt>
** Equivalent to <tt>-vnc \ 
hostname:0,tls,x509verify=/path/to/certs</tt>: <tt>-object \ 
tls-creds-x509,id=tls0,endpoint=server,dir=/path/to/certs,verify-peer=yes -vnc \ 
hostname:0,tls-creds=tls0</tt>
* The Cocoa GUI does not have show an 'open image file' dialog box anymore even \ 
if QEMU is started without arguments
* Thu curses GUI supports 256 colors and line graphics.

=== Monitor ===
* New "info iothreads" command.
* New "query-qmp-schema" command allows the caller to \ 
[[Features/QMP/Introspection | introspect the QMP schema]] used by QEMU.

=== Migration ===
* [[Features/PostCopyLiveMigration | Postcopy migration]] for migration of \ 
large/busy guests
* A more flexible [[Features/AutoconvergeLiveMigration | auto-converge \ 
mechanism]] (for busy guests)

=== Network ===
* Support for multiqueue in vhost-user.
* Support for network filters.  Currently, the only filter objects are \ 
"filter-buffer", which batches packets every N microseconds, and \ 
"filter-dump", which can be used to log the network traffic in a file. \ 
 Filters are attached to a netdev device using e.g. "-object \ 
filter-buffer,id=filter,netdev=net0,queue=rx,interval=1000" (which creates \ 
a 1ms filter-buffer).
=== Block devices in system emulation ===
=== Command-line options ===
=== TCG ===
* Improved system emulation performance for targets with software TLBs (e.g. SPARC).
* Initial support for [[Features/record-replay | record/replay]].

== Block devices and tools ==
* The HMP "change" command (QMP's \ 
“"lockdev-change-medium") now allows you to change the read-only \ 
mode of the device (e.g. when inserting a read-only floppy disk image into a \ 
previously R/W drive)
* Fine-grained control over a block device's tray with the new QMP commands \ 
"blockdev-open-tray", "blockdev-close-tray", \ 
"x-blockdev-insert-medium", and "x-blockdev-remove-medium" \ 
(the latter two are experimental for now)
* New "reopen" command in qemu-io
* block-dirty-bitmap-add and block-dirty-bitmap-clear transaction actions have \ 
been added to now fully support (transient) incremental bitmap usage and \ 
management.
* QMP transactions now support a "completion-mode" parameter which \ 
controls the completion behavior of jobs launched by transactions, which will \ 
allow them to fail together. See the \ 
[https://github.com/qemu/qemu/blob/master/docs/bitmaps.md bitmaps.md] \ 
documentation for how this affects incremental backups.
* Block I/O accounting can now report average queue depth, min/avg/max latency, \ 
and failed/invalid request counts
* qcow2 learnt a new option ''cache-clean-interval'', which allows to free \ 
unused cache entries after some time.
* An experimental QMP command ''x-blockdev-del'' was added as a completement for \ 
the (also still experimental) ''blockdev-add'' command.
* A new QMP command ''blockdev-snapshot'' that allows creating a snapshot using \ 
as overlay an image previously opened with ''blockdev-add''. This allows opening \ 
the overlay image with arbitrary run-time options, solving one of the \ 
limitations of ''blockdev-snapshot-sync''.
* It is now possible to open an image without its backing file by specifying the \ 
empty string as a backing file reference when opening the image. This is useful \ 
for creating snapshots, since images opened with ''blockdev-add'' are not \ 
supposed to have a backing file before the ''blockdev-snapshot'' operation.
* Host CD-ROM support now works on Mac OS X hosts
* Host floppy support has been removed (it was deprecated in QEMU 2.3)
* The temporary "x-data-plane=on/off" option for virtio-blk device is \ 
removed now, all users are requested to use the canonical "-object \ 
iothread,id=<id> -device virtio-blk,iothread=<id>,..." syntax.

== Audio ==

== Guest agent ==
* Add an optional qemu-ga.conf system configuration
* Support for dumping the configuration current file with --dump-conf
* Win32 support for guest-set-user-password
* New command guest-exec

== User-mode emulation ==
* The configure option --disable-guest-base has been removed.
== Build dependencies ==
* libcacard has been moved to a standalone project, hosted at \ 
git://anongit.freedesktop.org/spice/libcacard.  The libcacard library from QEMU \ 
2.4 can also be used to build QEMU 2.5.
* virtio-gpu 3D support requires virglrenderer.
== Known issues ==
* SDL audio only works with SDL 1.x.
* 64-bit QEMU might crash on Windows (problems with stack unwinding, depends on \ 
build environment, \ 
[http://repo.or.cz/w/qemu/ar7.git/commit/8fa9c07c9a33174905e67589bea6be3e278712cb \ 
possible fix])
* QEMU's configure script fails with pdksh from OpenBSD (see \ 
[https://bugs.launchpad.net/qemu/+bug/1525682 bug #1525682]. Using another shell \ 
with configure should work.