The QEMU 7.2 project release has been presented. As an emulator, QEMU allows you to run software 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 physical system due to direct instruction execution on the CPU and the involvement of the Xen hypervisor or KVM module.
Initially, the project was 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 for full emulation for 14 hardware architectures has been added, and the number of emulated hardware devices has exceeded 400. More than 1,800 changes have been made by 205 developers in preparation for version 7.2.
Key improvements added in QEMU 7.2:
- In the x86 architecture emulator, support for AVX, AVX2, F16C, FMA3, and VAES instructions has been added in the classic TCG code generator, along with performance optimizations related to the use of SSE instructions. For KVM support for the mechanism for tracking virtual machine exits ('notify vmexit') has been added, which allows bypassing CPU errors that can lead to hangs.
- In the ARM emulator, support has been implemented for the Cortex-A35 CPU and the ETS (Enhanced Translation Synchronization), PMUv3p5 (PMU Extensions 3.5), GTG (Guest Translation Granule 4KB, 16KB, 64KB), HAFDBS (hardware access flag and dirty state management), and E0PD (prevention of EL0 access to split address maps) processor extensions.
- In the LoongArch emulator, support for fw_cfg DMA, hot-plugging memory, and emulation of TPM (Trusted Platform Module) devices has been added.
- In the OpenRISC architecture emulator, the 'virt' platform has been implemented for device testing and use in continuous integration systems. Support for multi-threaded execution of the classic TCG (Tiny Code Generator) has been implemented.
- In the RISC-V architecture emulator, the 'virt' emulated machines have implemented the ability to load firmware from pflash in S-mode. Device tree handling has been improved.
- The 390x architecture emulator provides support for the MSA5 extension (Message-Security-Assist Extension 5 with the PRNO instruction for generating pseudo-random numbers), the KIMD/KLM instructions (SHA-512 implementation), and enhanced zPCI interpretation for guest systems based on the KVM hypervisor.
- In the backends for memory management, pre-allocation is provided considering the NUMA architecture.
- Strengthened checks for headers of encrypted LUKS block devices, with the addition of the capability to create LUKS images on macOS.
- In the 9pfs backend, which allows a Plan 9 network file system for one virtual machine to access another, a transition to using the GHashTable hash in the identifier table has been made, resulting in a performance increase of 6 to 12 times in certain situations.
- New netdev backends stream and dgram have been added.
- Support for FreeBSD has been added in the agent for guest systems based on the ARM architecture.
- In the GUI builds for macOS, the ability to include Cocoa and SDL/GTK-based interfaces into a single executable file has been provided.
- The built-in submodule 'slirp' has been removed, with a recommendation to use the system library libslirp instead.
- Due to the inability to test, support for host systems with 32-bit MIPS processors using 'Big endian' byte order has been declared deprecated.
Source: opennet.ru
