project release . As an emulator, QEMU allows the execution of programs compiled for one hardware platform on a system with a completely different architecture, for example, running an ARM application on an x86-compatible PC. In virtualization mode, QEMU's code execution performance in an isolated environment is close to that of a native system due to direct instruction execution on the CPU and the involvement of the Xen hypervisor or KVM module.
The project was originally created by Fabrice Bellard to enable the execution of Linux executables compiled for the x86 platform on architectures other than x86. Over the years of development, support has been added for full emulation for 14 hardware architectures, with the number of emulated hardware devices exceeding 400. More than 2800 changes from 232 developers were made in preparing version 5.0.
Key , added in QEMU 5.0:
- The ability to pass parts of the host environment's file system to the guest system using . The guest system can mount a directory marked for export on the host system, significantly simplifying the organization of shared access to directories in virtualization systems. Unlike using network filesystems such as NFS and virtio-9P, virtiofs allows for performance close to that of a local file system;
- live migration of data from external processes using the QEMU D-Bus;
- The ability to use to provide the main RAM of the guest system. The backend is specified using the "-machine memory-backend" option;
- A new "compress" filter that can be used to create compressed backups of images;
- The command "qemu-img measure" can now work with LUKS images, and the command "qemu-img convert" has a new option "—target-is-zero" to skip zeroing the target image;
- Experimental support has been added for the qemu-storage-daemon process, providing access to the QEMU block level and QMP commands, including operations with block devices and an embedded NBD server, without the need to start a full virtual machine;
- The ARM architecture emulator has added the ability to emulate the Cortex-M7 CPU and support for tacoma-bmc, Netduino Plus 2, and Orangepi PC boards. The 'virt' emulated machines now support vTPM and virtio-iommu devices. The ability to use AArch32 host systems to run KVM guest environments has been deprecated. Emulation support has been implemented for the following architectural features:
- ARMv8.1: VHE, VMID16, PAN, PMU
- ARMv8.2: UAO, DCPoP, ATS1E1, TTCNP
- ARMv8.3: RCPC, CCIDX
- ARMv8.4: PMU, RCPC
- The HPPA architecture emulator has added support for graphical console using the HP Artist graphics device;
- The MIPS architecture emulator has added support for the GINVT (Global Invalidation TLB) instruction;
- The PowerPC architecture emulator for 'powernv' machines has added emulation of KVM hardware acceleration for running guest systems.
KVM with a classic TCG (Tiny Code Generator). Support for file-backed NVDIMM has been added for emulating persistent memory. For 'pseries' machines, the need for a reboot to synchronize the operation of XIVE/XICS interrupt controllers in 'ic-mode=dual' has been removed; - The RISC-V architecture emulator for 'virt' and 'sifive_u' boards has implemented support for standard syscon drivers in Linux for power management and reboot. For the 'virt' board, Goldfish RTC support has been added. An experimental implementation of hypervisor extensions has been introduced;
- The s390 architecture emulator has added support for AIS (Adapter Interrupt Suppression) when operating in KVM mode.
Source: opennet.ru
