Changelog for VirtualBox 5.1

This page lists all changes of the VirtualBox 5.1 releases.
All branches: 5.2 · 5.1 · 5.0 · 4.3 · 4.2 · 4.1 · 4.0

VirtualBox 5.1.38 (released May 09 2018)

This is a maintenance release. The following items were fixed and/or added:

• Linux hosts: support Linux 4.17 changes. Thank you Larry Finger
• Linux guests: support Linux 4.16 and EL 7.5 kernels (bugs #17676 and #17678)
• Linux guests: 3D fixes for recent guests (bug #17623)

VirtualBox 5.1.36 (released April 17 2018)

This is a maintenance release. The following items were fixed and/or added:

• VMM: Fixed missing NULL pointer check in MMIO code.
• Network: fixed VERR_INTNET_FLT_IF_NOT_FOUND when bridging to some adapters on Windows hosts (possibly related bugs #15294, #15060, #13481)

VirtualBox 5.1.34 (released February 27 2018)

This is a maintenance release. The following items were fixed and/or added:

• VMM: Added support for FSGSBASE, PCID, INVPCID CPU features for guests
• VMM: Fixed EMM386 issue with detecting suitable page frame base (bug #10022)
• Front end: switched to https downloads
• Serial: fixed an issue where the serial port parameters in the emulation and host serial port got out of sync (bug #17116)
• Storage: fixed handling VMDK images created by Amazon EC2 VM export
• Audio: various fixes for HDA emulation
• 3D: add environment variable to configure presenting 3D content on main thread (see bug #13653)
• Windows hosts: fixed indiscriminate binding of NDIS5 bridged driver, that caused PPPOE malfunction (bugs #16407, #17489)
• Linux guests: Linux 4.15 support (bugs #17311, #17320, #17282)
• Linux guests: fixed black screen when 3D enabled in guests (bug #17463, 5.2.6 regression)
• Linux guests: suppress setuid and setgid in shared folders

VirtualBox 5.1.32 (released January 15 2018)

This is a maintenance release. The following items were fixed and/or added:

• GUI: fixed occasional screen corruption when host screen resolution is changed
• User interface: increase proposed disk size when creating new VMs for Windows 7 and newer
• Serial: fixed broken communication with certain devices on Linux hosts
• VMM: Fixed problems using 256MB VRAM in raw-mode VMs
• Audio: added HDA support for more exotic guests (e.g. Haiku)
• Audio: fixed playback with ALSA backend (5.1.28 regression)
• USB/OHCI: fixed a problem where OHCI emulation might sporadically drop data transfers
• Windows hosts: VirtualBoxManager in the Python API no longer calls CoUninitialize when destroyed
• Linux hosts: fixed VBoxNetFlt kernel module compilation failure with Linux kernel 4.14
• Linux guests: fixed kernel module compilation and other problems with Linux kernel 4.14

VirtualBox 5.1.30 (released October 16 2017)

This is a maintenance release. The following items were fixed and/or added:

• GUI: translation updates
• GUI: fixed double mouse cursor when using mouse integration without Guest Additions, actually a Qt 5.6 bug fixed with QT 5.6.3 (Mac OS X hosts only; bug #15610)
• Solaris hosts: allow increasing MTU size for host-only adapter to 9706 bytes to support jumbo frames
• Linux hosts: glibc 2.26 compile fix
• Windows Additions: 3D related crash fix (bugs #17082, #17092)

VirtualBox 5.1.28 (released September 13 2017)

This is a maintenance release. The following items were fixed and/or added:

• GUI: mouse events did not reach host windows behind the transparent VM window (Mac OS X hosts only; bug #16246)
• Audio: fixed accidental crashes when using the AC'97 sound emulation (bug #16959)
• Audio: fixed crash when default input or output devices have changed (bugs #16968, #16969, #17004)
• Audio: fixed recording when using the ALSA backend
• Audio: fixed handle leak when using the OSS backend
• E1000: fixed a crash related to VLAN traffic over internal network (5.1.26 regression; bug #16960)
• NAT: apply --natbindip1 to TCP connections (bug #16478)
• OVF: when importing an appliance with XHCI controller, don't add an OHCI controller
• Mac OS X hosts: fixed a GUI crash if Spotlight is used from file dialogs (5.1.20 regression; bugs #16935, #16953)
• Linux hosts: fixed creating fixed sized VDI images (bug #17010)
• Linux hosts / guests: fixes for Linux 4.4 of openSUSE Leap 42.3 (bug #16966)
• Bridged networking: align outgoing packet at word boundary, preventing Windows host crash in MsLbfoProvider
• Linux Additions: kernel drm driver support for custom EL7 Linux 3.10 kernel
• Solaris Additions: hide an informational message on the bootup console

VirtualBox 5.1.26 (released July 27 2017)

This is a maintenance release. The following items were fixed and/or added:

• VMM: reset the TSC on VM reset to work around a Windows bug (bug #16643)
• Audio: fixed memory leak when enabled with VRDP connections (5.1.24 regression; bug #16928)
• Audio: fixed creation of too many sound sinks on Linux hosts when using the PulseAudio backend (bug #16938)
• Audio: implemented record gain registers for AC'97 emulation; those are needed for newer Ubuntu guests which rely on those when controlling gain and muting the recording (capturing) levels
• Storage: fixed hang when using the emulated NVMe controller with the SPDK (bug #16945)
• Mouse: double click was not working with a precision touchpad (bug #14632)
• Linux hosts: properly bring up host-only network interfaces with iproute (5.1.24 regression; bug #16911)
• Linux hosts: provide Python 3 libraries for deb/rpm packages
• Windows hosts: make it possible to use host-only networking without having bridged networking installed
• Windows guests: fixed automatic logons for Vista and newer Windows guests (5.1.24 regression; bug #16921)

VirtualBox 5.1.24 (released July 18 2017)

This is a maintenance release. The following items were fixed and/or added:

• VMM: mask the VME CPUID capability on AMD Ryzen processors for now to make certain guests works, for example Windows XP
• VMM: emulate more SSE2 instructions
• VMM: properly clear the TF and AC flags when dispatching real-mode interrupts
• GUI: fixes to make the mini-toolbar work with recent versions of KDE / Plasma (bug #16325)
• GUI: fixed a potential crash when a VM with multiple screens is running in full screen / seamless mode and a host screen is removed, for example when connecting to the host via RDP
• GUI: fixed initial size hints for guests which set intermediate sizes before responding (bug #16593)
• GUI: prevent stopped screen updates or black screen on reboot in a multi-screen setup under certain conditions
• Audio: many improvements for Windows 10 guests (bugs #15189, #15925, #16170, #16682, #16794 and others)
• Storage: fixed possible crash when using Intels SPDK
• API: use the correct file name of the VM machine state if the VM settings directory is renamed, for example during grouping / ungrouping a VM (bugs #16074 and #16745)
• API: return the correct error code if powering up a VM fails
• API: video recording did not automatically start at VM start when enabled in the VM settings (bug #16803)
• API: when relocating a medium, check that the target path is fully qualified
• EFI: fix for VMs with more than 3504MB RAM (bug #11103)
• Host-only adapter: correctly determine IPv4 netmasks on Windows hosts (bug #16826)
• NAT network: properly do the refcounting for starting / stopping the NAT / DHCP services if the NAT network is changed while the adapter network connection type is anything else but NAT network
• VBoxManage: fixed controlvm videocapfile (bug #16779)
• Windows hosts: another fix for Windows insider builds (bug #16892)
• Windows hosts: fixed crashes if driver verifier is enabled (bug #15741)
• Linux / Mac OS X hosts: more fixes for loading shared libraries (5.1.20 regression; bugs #16778, #16693)
• Linux hosts / guests: Linux 4.12 fixes (bugs #16725, #16800)
• Linux hosts / guests: reduce the kernel stack consumption for Linux kernels with CONFIG_CPUMASK_OFFSTACK defined
• Linux hosts / guests: fixes for kernel modules built with gcc-7 (bug #16772)
• Linux hosts / guests: Linux 4.13 fix (bug #16887)
• Linux hosts: don't depend on net-tools on newer distributions as this package is deprecated in favour of iproute (bug #16764)
• Linux hosts: make 2D video acceleration available for older Linux distributions (5.1 regression; bug #16858)
• Linux Additions: fix for dynamic resizing with Oracle Linux 6 with UEK4
• Linux Additions: make Fedora 25 and 26 Alpha work when 3D pass-through is enabled
• Linux Additions: no longer recommend removing distribution- installed Additions if they are updated to our guidelines

VirtualBox 5.1.22 (released April 28 2017)

This is a maintenance release. The following items were fixed and/or added:

• VMM: fixed VERR_IEM_INSTR_NOT_IMPLEMENTED Guru Meditation under certain conditions (5.1 regression; mostly Mac OS X hosts; bugs #15693, #15801, #16274, #16569, #16663)
• VMM: fixed software virtualization on Solaris hosts (5.1.20 regression)
• Storage: fixed a potential hang under rare circumstances (bug #16677)
• Storage: fixed a potential crash under rare circumstances (asynchronous I/O disabled or during maintenance file operations like merging snapshots)
• Linux hosts: make the ALSA backend work again as well as loading the GL libraries on certain hosts (5.1.20 regression; bugs #16667, #16693)
• Linux Additions: fixed mount.vboxsf symlink problem (5.1.20 regression; bug #16670)

VirtualBox 5.1.20 (released April 18 2017)

This is a maintenance release. The following items were fixed and/or added:

• GUI: don't check if the Extension Pack is up-to-date if the user is about to install a new Extension Pack (bug #16317)
• GUI: fixed a possible crash when switching a multi-monitor VM into full-screen or seamless mode
• GUI: fixed non-literal shortcuts if the keyboard is not captured (5.1.10 regression; Windows hosts only)
• GUI: several mini-toolbar fixes in full-screen / seamless mode (X11 hosts only)
• GUI: don't crash on restoring defaults in the appliance import dialog
• Windows Additions: another fix for automatic logins for Windows Vista and newer (bug #15904)
• ICH9: fix for Windows guests with a huge amount (>64G) of guest memory
• BIOS: fixed El Torito hard disk emulation geometry calculation (thanks Dwight Engen)

VirtualBox 5.1.18 (released March 15 2017)

This is a maintenance release. The following items were fixed and/or added:

• Shared Folders: fixed case insensitive filename access (5.1.16 regression; Windows guests only; bug #16549)
• Shared Folders: fixed access to long pathes (5.1.16 regression; Windows guests only; bugs #14651, #16564)
• API: fixed snapshot handling of medium attachments and PCI device attachments (bug #16545)
• API: make 32-bit Windows guests boot again with software virtualization if the ICH9 chipset is used (5.1.16 regression)
• VBoxBugReport: fixed VM log collection issue
• Linux hosts: fixed autostart service script (bug #14955)
• Windows Additions: fixed automatic logins for Windows Vista and newer (5.1.4 regression; bug #15904)

VirtualBox 5.1.16 (released March 08 2017)

This is a maintenance release. The following items were fixed and/or added:

• VMM: don't access the MSR_IA32_SMM_MONITOR_CTL MSR if dual-monitor treatment is not available (KVM workaround, bug #14965)
• VMM: another fix for handling certain MSRs on ancient CPUs without VT-x support for MSR bitmaps
• VMM: fixed VERR_SSM_LOAD_CPUID_MISMATCH errors when restoring a saved state with SMP guests on hosts without the CPUID/HTT bit set (bug #16428)
• VMM: fixed a bug in call gate emulation
• VMM: FWAIT instruction fix
• VMM: fixed a sporadic guest hang under certain conditions
• GUI: hide the mini-toolbar from the taskbar and the pager on certain X11 hosts
• GUI: better error handling on the global settings / network / host-only / DHCP server settings
• GUI: fixes for full-screen with multiple screens
• Host-only Network: fixed host-only adapter creation issue preventing VirtualBox installation on Windows 10 hosts (bug #16379)
• NAT network: fixed two potential crashes in the DHCP server
• ICH9: fixed incorrect initialization of the primary bus for PCI bridges (5.1.14 regression)
• Storage: LsiLogic fix for Windows 10
• USB: fixed not being able to attach certain USB devices having invalid characters in the device strings (5.0.18 regression; bug #15956)
• USB: several fixes for the USB/IP support (bug #16462)
• VBoxSVC: fixed another crash during shutdown under rare circumstances
• VBoxSVC: fixed a stack overflow on (Windows debug builds only; bug #16409)
• OVF: when importing an appliance handle more than 10 network adapters if the OVA was created by VirtualBox (bug #16401)
• OVF: fixes for exporting and importing appliances with many disks (bug #16402)
• VBoxManage: fixed regression with modifyhd --resize (bug #16311)
• rdesktop-vrdp: source code tarball fixes
• Linux Installers: do not rebuild kernel modules unnecessarily (bug #16408)
• Linux hosts: added an action for opening the VM manager window to the .desktop file
• Linux hosts / guests: Linux 4.11 compile fixes (bug #16506)
• Linux Additions: added vboxsf FS modules alias (bug #16404)
• Linux Additions: fix for the shared folders kernel module to compile on Linux 4.10
• Linux Additions: properly install the Linux kernel module override rule on distributions without /etc/depmod.d
• Windows Additions: fixed a crash with recent Windows 10 builds if 3D is disabled (bug #15973)

VirtualBox 5.1.14 (released January 16 2017)

This is a maintenance release. The following items were fixed and/or added:

• VMM: fixed emulation of certain instructions for 64-bit guests on 32-bit hosts
• VMM: properly handle certain MSRs for 64-bit guests on ancient CPUs without VT-x support for MSR bitmaps (bug #13886)
• GUI: fixed a crash with multimonitor setups under certain conditions
• GUI: allow cloning of snapshots when the VM is running
• NVMe: fixed compatibility with the Storage Performance Development Kit (SPDK, bug #16368)
• VBoxSVC: fixed a crash under rare circumstances
• VBoxManage: added a sanity check to modifymedium --resize to prevent users from resizing their hard disk from 1GB to 1PB (bug #16311)
• Windows hosts: another fix for recent Windows 10 hosts
• Linux hosts: Linux 4.10 fixes
• Linux Additions: fixed protocol error during certain operations on shared folders (bug #8463)

VirtualBox 5.1.12 (released December 20 2016)

This is a maintenance release. The following items were fixed and/or added:

• VMM: fixed VERR_IEM_ASPECT_NOT_IMPLEMENTED Guru Meditations with certain Linux guests if KVM paravirtualization is enabled (5.1 regression; bugs #15613 and #16251)
• VMM: fixed VERR_VMX_UNABLE_TO_START_VM Guru Meditations under rare conditions
• GUI: prevent a crash under certain conditions if the VM is terminated very early
• GUI: fixed certain keyboard capture issues (5.1.10 regression; Mac OS X hosts only; bug #16150)
• GUI: fixed dragging guest windows in seamless mode with the keyboard captured (X11 hosts only; bug #15837)
• GUI: fixed a problem where the new version detected dialog was covered by the appliance import dialog (Mac OS X hosts only; bug #16238)
• Storage: fixed NVMe reset processing when doing rmmod nvme; modprobe nvme in a Linux guest (bug #16080)
• Storage: fixed creating a snapshot when the VM is running and an NVMe controller is present
• Storage: fixed a problem with the LsiLogic SCSI controller where requests could be lost with SMP guests
• E1000: fixed "cable disconnected" issue (Mac OS X guests only; 5.1.10 regression; bug #16260)
• E1000: fixed "TX unit hang" issue (Linux guests only; 5.1.10 regression; bug #16221)
• Parallel ports: fixed port enumeration on Windows host (bugs #15872 and #16127)
• API: don't crash when sanitizing certain VM names (bug #16299)
• Linux hosts: automatically disable asynchronous I/O on Linux 2.6.18 kernels as high I/O load may trigger kernel oopses on these kernels if this feature is enabled
• Linux hosts / guests: Linux 2.6.28 compile fix (bug #16267)
• Linux hosts: compile Linux 4.9 compile fix (bug #16286)
• Linux Additions: warn the user about a known bug with older Linux guests (e.g. Debian 7) requiring manual work to get 3D working (bug #15319)
• Linux Additions: fix the graphics driver build with Linux 4.10 and later (bug #16298)
• Windows Additions: fixed a crash in the WDDM driver under certain conditions

VirtualBox 5.1.10 (released November 21 2016)

This is a maintenance release. The following items were fixed and/or added:

• GUI: the USB filter settings dialog should allow to specify the USB revision in hexadecimal format (bug #15400)
• GUI: fixed crash on certain hosts when pressing certain key combinations (Windows hosts only; bug #15719)
• GUI: fixed issue with updating the available-geometry on host-screen work-area resize
• GUI: don't crash / hang on certain environments if accessibility support is enabled
• GUI: fixed various issues in Unscaled HiDPI Output mode (bug #15707)
• GUI: extend the VM Input menu with Print Screen-related actions
• GUI: improved handling of inserting the Guest Additions ISO image by trying all available optical drives rather than only the first one and by not asking the user if he wants to force unmounting (which doesn't work in most cases anyway)
• API: default to RTC using UTC for Solaris 11 guests
• Settings: be less restrictive when reading a VM configuration containing a host-only adapter without an interface name
• Storage: fixed resizing VDI images resulting in an unbootable image under certain circumstances (bug #15983)
• NAT: fixed several 5.1.8 regressions on Mac OS X and Windows hosts (bug #16084)
• Audio: fixed a few 5.1.x regressions by using the audio code from 5.0.x until the audio overhaul is completed
• VBoxManage: fixed documentation of the storagectl command (bug #15971)
• Build system: another fix for building VirtualBox on systems which default to Python 3
• Windows hosts: hardening fix for Windows 10 build 14971 (bug #16202)
• Windows Additions: properly start the VirtualBox guest services even if the guest user name contains special characters (bug #15982)
• Solaris Additions: fixed preemptible mouse notification callback being executed under a spinlock for Solaris guests
• Linux hosts / guests: Linux 4.9 fixes (bugs #16155 and #16064)
• Linux Additions: fixed Linux kernel module override rule (thanks Mark Furneaux)

VirtualBox 5.1.8 (released October 18 2016)

This is a maintenance release. The following items were fixed and/or added:

• GUI: fixed keyboard shortcut handling regressions (Mac OS X hosts only; bugs #15937 and #15938)
• GUI: fixed keyboard handling regression for separate UI (Windows hosts only; bugs #15928)
• NAT: don't exceed the maximum number of "search" suffixes. Patch from bug #15948
• NAT: fixed parsing of port-forwarding rules with a name which contains a slash (bug #16002)
• NAT Network: when the host has only loopback nameserver that cannot be mapped to the guests (e.g. dnsmasq running on 127.0.1.1), make DHCP supply NAT Network DNS proxy as nameserver
• Bridged Network: prevent flooding syslog with packet allocation error messages (bug #15569)
• Audio: now using Audio Queues on Mac OS X hosts
• Audio: fixed recording with the PulseAudio backend (5.1 regression)
• Audio: various bugfixes
• Snapshots: fixed regression in 5.1.4 for deleting snapshots with several disks (bug #15831)
• Snapshots: crash fix and better error reporting when snapshot deletion failed
• Storage: some fixes for the NVMe emulation with Windows guests
• API: fixed initialization of SAS controllers (bug #15972)
• Build system: make it possible to build VBox on systems which default to Python 3
• Windows hosts: detect certain cases of REGDB_E_CLASSNOTREG errors and print a helpful error message
• Windows hosts: adapted to changes in Windows 10 build 14901 (bug #15944)
• Windows hosts: better support for processor groups on Windows 7 and later which is required on certain hosts with many CPUs
• Windows installer / Additions: added option to prevent creating of start menu items (bug #15922)
• Windows Additions / VGA: if the guest's power management turns a virtual screen off, blank the corresponding VM window rather than hide the window
• Windows Additions: fixed a generic bug which could lead to freezing shared folders (bug #15662)
• Linux hosts / guests: fix for kernels with CONFIG_CPUMASK_OFFSTACK set (bug #16020)
• Linux Additions: don't require all virtual consoles be in text mode. This should fix cases when the guest is booted with a graphical boot screen (bug #15683)
• Linux Additions: added depmod overrides for the vboxguest and vboxsf kernel modules to fix conflicts with modules shipped by certain Linux distributions
• X11 Additions: disable 3D on the guest if the host does not provide enough capabilities (bug #15860)

VirtualBox 5.1.6 (released September 12 2016)

This is a maintenance release. The following items were fixed and/or added:

• GUI: fixed issue with opening '.vbox' files and it's aliases
• GUI: keyboard grabbing fixes (bugs #15771 and #15745)
• GUI: fix for passing through Ctrl + mouse-click (Mac OS X hosts only; bug #15714)
• GUI: fixed automatic deletion of extension pack files (bugs #11352 and #14742)
• USB: fixed showing unknown device instead of the manufacturer or product description under certain circumstances (5.1.0 regression; bug #15764)
• XHCI: another fix for a hanging guest under certain conditions as result of the fix for bug #15747, this time for Windows 7 guests
• Serial: fixed high CPU usage with certain USB to serial converters on Linux hosts (bug #7796)
• Storage: fixed attaching stream optimized VMDK images (bug #14764)
• Storage: reject image variants which are unsupported by the backend (bug #7227)
• Storage: fixed loading saved states created with VirtualBox 5.0.10 and older when using a SCSI controller (bug #15865)
• Storage: fixed broken NVMe emulation if the host I/O cache setting is enabled
• Storage: fixed using multiple NVMe controllers if ICH9 is used
• NVMe: fixed a crash during reset which could happen under certain circumstances
• Audio: fixed microphone input (5.1.2 regression; bugs #14386 and #15802)
• Audio: fixed crashes under certain conditions (5.1.0 regression; bug #15887 and others)
• Audio: fixed recording with the ALSA backend (5.1 regression)
• Audio: fixed stream access mode with OSS backend (5.1 regression, thanks to Jung-uk Kim)
• E1000: do also return masked bits when reading the ICR register, this fixes booting from iPXE (5.1.2 regression; bug #15846)
• BIOS: fixed 4bpp scanline calculation (bug #15787)
• API: relax the check for the version attribute in OVF/OVA appliances (bug #15856)
• Windows hosts: fixed crashes when terminating the VM selector or other VBox COM clients (bug #15726 and others)
• Linux Installer: fixed path to the documentation in .rpm packages (5.1.0 regression)
• Linux Installer: fixed the vboxdrv.sh script to prevent an SELinux complaint (bug #15816)
• Linux hosts: don't use 32-bit legacy capabilities
• Linux Additions: Linux 4.8 fix for the kernel display driver (bugs #15890 and #15896)
• Linux Additions: don't load the kernel modules provided by the Linux distribution but load the kernel modules from the official Guest Additions package instead (bug #15324)
• Linux Additions: fix dynamic resizing problems in recent Linux guests (bug #15875)
• User Manual: fixed error in the VBoxManage chapter for the getextradata enumerate example (bug #15862)

VirtualBox 5.1.4 (released August 16 2016)

This is a maintenance release. The following items were fixed and/or added:

• GUI: show actual VM uptime in the session information window
• Audio: re-enabled speakers for Mac OS X guests (5.1.0 regression; bug #15611)
• Audio: fixed crashes under certain conditions
• USB: fixed a hang under certain conditions
• USB: fixed a hanging guest under certain conditions (bug #15747)
• PIIX4: implemented dummy SMBus controller to prevent annoying Linux kernel warnings about uninitialized SMBus base address (bug #9517)
• NVMe: several fixes to improve stability, fixed a crash while saving a VM state
• VMDK: fixed an issue creating fixed size images with certain sizes and the Split2G option enabled (bug #15748)
• VHDX: fixed cloning images with VBoxManage clonehd (bug #14288)
• Storage: fixed broken bandwidth limitation when the limit is very low (bug #14982)
• EFI: fixed sending debug messages in the EFI firmware if a serial port is enabled (bug #12161)
• OVF: when importing appliances, make sure that the version of the embedded VirtualBox specific settings is processed, to get the default settings handling right
• VBoxManage: Don't try to set the medium type if there is no change (bug #13850)
• Linux installer: fixed some scripting issues (bugs #15701 and #15702)
• Linux installer: fixed a path issue on certain Linux distributions (bug #15717)
• Windows hosts: fixed corrupted mouse pointers with some Linux and Solaris guests (bug #15665)
• Linux Additions: made the video driver work on 32-bit guests with large video memory sizes (bug #15621)
• Linux Additions: made the video driver work on kernel 4.7 and later (bug #15769)
• Linux Additions: converted a failure message to an informational one when drivers could not be stopped during upgrade (bug #15692)
• Linux Additions: made the video driver work around an X server bug which cause screen refresh to stop (bug #15511)
• Windows Additions: auto-resizing fixes for Windows 10 guests (bug #15257)
• Windows Additions: fixed VBoxTray problems with Windows 2000 (bug #15661)

VirtualBox 5.1.2 (released July 21 2016)

This is a maintenance release. The following items were fixed and/or added:

• VMM: several fixes
• GUI: fixed screenshot if the VM is started in separate mode
• GUI: fixed issue with double-click/opening registered file types (.vbox and .vbox-extpack) on Mac OS X (bug #15648)
• GUI: fixed a bug which made it impossible close some error/warning messages using the close button
• GUI: weakened the control over the VM window behavior allowing to resize it across multiple screens and to use in Snap Assist techniques
• GUI: jump to the second tab of the session information window (5.1.0 regression)
• GUI: fix for Alt-Tab
• Storage: fixed creating fixed size VHD images (bug #15601)
• Storage: fixed a hang during power off if the VM was suspended before and a NVMe controller is configured
• USB: fixed a crash under certain conditions
• Audio: make AC'97 volume control work again (5.1.0 regression; bug #15598)
• Audio: fixed rare VM hangs when using AC'97 emulation
• Audio: SB16 fixes
• EFI: fixed access to devices attached to SATA port 2 and higher (bug #15607)
• OVA: fix for checking certain signatures
• OVA: fixed MAC address generation for appliances created by VirtualBox (5.1.0 regression; bug #15623)
• API: fixed audio settings handling for older config files (bug #15626)
• API: fixed truncation of USB product/vendor IDs on Linux hosts (5.1.0 regression; bug #15644)
• API: fixed VRDP with authentication (bug #15653)
• API: don't crash if there is no graphics controller configured (bug #15628)
• Linux hosts: fixed EL5 builds (bug #15634)
• non-Windows hosts: fixed a crash during shutdown under rare circumstances (bug #15568)
• Linux Additions: fixed SELinux issue which prevented certain Linux guests to work in 3D mode (bug #15574)
• User Manual: updates

VirtualBox 5.1.0 (released July 12 2016)

This is a major update. The following major new features were added:

• VMM: new APIC and I/O APIC implementations that result in significantly improved performance in certain situations (for example with networking, bug #15295)
• VMM: added support for Hyper-V paravirtualized debugging of Windows guests
• VMM: emulate even more MMIO and shadow pagetable exits without going back to user mode
• GUI: overall migration to Qt5 (bug #11775)
• GUI: passive API event listener improving the VM GUI performance and response time
• Audio: added HDA (High Definition Audio) support for newer Linux guests
• Audio: added on-demand timers which should improve the overall performance and reduce the CPU consumption
• Audio: more fine-grained volume control for the AC'97 emulation, which now also takes the master volume control into account
• better support for Python 3

In addition, the following items were fixed and/or added:

• VMM: activate the x2APIC by default for Linux guests
• VMM: many more fixes
• GUI: the Detach UI action is now a part of the VM Machine menu
• GUI: reworked session information window
• GUI: the new VM wizard now allows to choose the VM location for the VM which is being created
• GUI: fixed location of touch events in unscaled HiDPI mode (bugs #14366, #14367)
• GUI: various bugfixes and internal cleanup
• Storage: use fallocate() or similar if present to speed up creating fixed-sized disk images (bug #5967)
• Storage: implemented NVMHCI-compatible storage controller
• Audio: various bugfixes and infrastructure improvements
• E1000: implemented interrupt throttling for performance improvements
• EFI: many improvements, for example allow to boot from USB
• OVF: improved handling of signed manifests
• API: Windows XP guests and Windows 2003 server guests now default to the E1000 T Server network card
• VBoxSVC: fixed several memory leaks when handling .dmg images
• Installers: ship VBoxBugReport
• Windows hosts: reworked COM proxy (e.g. bug #8298)
• Linux installers: no longer rely on DKMS for module rebuilding
• Linux Additions: fix a problem when updating the initramfs after the guest modules are compiled (bug #15579)
• Linux Additions: try to fix a problem where the OpenGL libraries where loaded by the X server when we only support X clients (bug #15574)