ChangeLog/1.5

General

• The default for log output enabled via the '-d' command line switch is now standard error rather than a file. You can obtain the previous behaviour using the '-D' command line switch to specify a file to send the logging to.
• QEMU now uses poll rather than select, and thus does not have any restriction on the number of open file descriptors.

System emulation

Device emulation

• New support for passing the host's TPM (Trusted Platform Module) to the guest.

USB

• Experimental support for USB 3.0 streams, both in the nec-usb-xhci controller and in the usb-uas USB-attached SCSI device emulation.

ARM

• The Zynq board provides a SD host controller interface.

x86

• TCG supports the SSE4.1, SSE4.2, PCLMULQDQ, AES-NI, BMI and ADX extensions.

Character devices

• Character devices support flow control [...]
• All kinds of character devices can now be hot-plugged. Character device hotplug is also supported from the "human" monitor.

Block devices

• IDE and SCSI disks always have the ability to issue "discard" (aka TRIM or UNMAP) commands. However, by default "discard" commands are silently ignored as they can cause performance degradation and fragmentation. To enable them, the "-drive" option now supports a "discard" suboption; the default value is "ignore" (or its synonym "off"), and the other valid value is "unmap" (or "on").
• Sheepdog drives can also be specified with URIs.
• iSCSI disks support on-line resizing using block_resize. Similar to block devices, the resize has to be done first outside QEMU.

Live Migration

• Further improvements in latency and throughput.
• RDMA Support

User interface

• QEMU now provides a GTK+ interface. The interface uses the VTE library to provide better terminal emulation for serial consoles and the monitor.