ChangeLog/2.3

System emulation

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".

Starting with QEMU xyz.jkl, -readconfig will standardize on the name for the command line option.

ARM

• When semihosting mode is active, the exit code is passed to the operating system.
• New option -semihosting-config that supersedes -semihosting. A new suboption target=native forces QEMU to execute semihosting operations even when running under GDB. This helps for targets that do not implement semihosting calls in GDB.
• The virt machine now has a fw_cfg device. It allows use of the boot order options, as well as supporting -kernel/-initrd/-append even when you're using a firmware (-bios/-pflash) and not booting directly to the kernel.

MIPS

• Support for 5KEc and 5KEf MIPS64r2 processors.
• Support for M14K and M14Kc MIPS32r2 microMIPS processors.
• qemu-mips64 uses the 5KEf processor.
• Many fixes.

TriCore

• More complete emulation

x86

• New CPU model IvyBridge.

KVM

• Support for running under valgrind with KVM enabled.
• Support for the XSAVES feature. The feature is not yet available in any predefined CPU model, but can be enabled with "-cpu host" or "-cpu ...,+xsaves".

Block devices in system emulation

• Support for SD cards on PCI systems, through the new device "sdhci-pci".
• QEMU will restrict writes to the first sector when an image is autodetected as a raw image, so that the next time the VM is started it will not be autodetected e.g. as qcow2. To avoid this restriction, start QEMU with an explicit "format=raw" option.

Known issues

• NVMe guest ABI changed from 2.2 to 2.3.
• Broken -usb.