QEMU 7.1 implements improvements with memory transfer in Linux
The launch of the new version of QEMU 7.1, version that presents a series of improvements for the different emulators and of which the changes for ARM, Risc-V stand out, as well as an improvement for linux in relation to memory transfer. In preparation for version 7.1, more than 2800 changes were made by 238 developers.
For those who are new to QEMU, you should know that it allows you to run a program built 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 in QEMU, the performance of code execution in an isolated environment is similar to that of a hardware system due to the direct execution of instructions on the CPU and the use of the Xen hypervisor or KVM module.
Main novelties of QEMU 7.1
In this new version that is presented, for Linux, the zero-copy-send option is implementedWhich enables organize the transfer of memory pages during live migration without intermediate buffering.
Besides that, QMP (QEMU machine protocol) adds the ability to use the block-export-add command to export NBD images with page data in "dirty" state. New 'query-stats' and 'query-stats-schema' commands have also been added to query statistics from various QEMU subsystems.
Another change that stands out in this new version of QEMU is that guest agent improved compatibility with the Solaris platform and added new 'guest-get-diskstats' and 'guest-get-cpustats' commands to display CPU and disk status. Added NVMe SMART information output to 'guest-get-disks' command and NVMe bus type information output to 'guest-get-fsinfo' command.
In addition to this, it is also noted that it was added a new LoongArch emulator to support the 64-bit version of the LoongArch instruction set architecture (LA64). The emulator supports Loongson 3 5000 processors and Loongson 7A1000 Northbridges.
On the other hand, it is also highlighted that the emulator ARM has implemented new types of emulated machines: Aspeed AST1030 SoC, Qualcomm and AST2600/AST1030 (fby35), plus support for Cortex-A76 and Neoverse-N1 CPU emulation, as well as SME (Scalable Matrix Extensions), RAS (Reliability, Availability, Serviceability) processor extensions, and commands to block internal cache leaks during execution of speculative instructions in the CPU.
While the emulator architecture RISC-V has added support for the new Instruction Set Extensions (ISAs) defined in the 1.12.0 specification, as well as added support for the Sdtrig extension and improved support for vector instructions.
Of the other changes that stand out of this new version:
- Improved debugging options.
- Added Trusted Platform Module (TPM) support to the 'virt' emulated machine and added Ibex SPI support to the 'OpenTitan' machine.
- The x86 emulator for KVM has added support for the virtualization of the LBR (Last Branch Record) trace mechanism.
- Implemented GICv4 interrupt handler emulation for 'virt' machines.
- The HPPA architecture emulator offers a new firmware based on SeaBIOS v6 that supports the use of a PS/2 keyboard in the boot menu.
- Improved serial port emulation.
- Added additional STI console fonts.
- The MIPS architecture emulator for Nios2 boards (-machine 10m50-ghrd) implements vector interrupt controller emulation and shadow register set.
- Improved exception handling.
- Added the ability to use up to 4 16550A UART devices in the OpenRISC architecture emulator for the 'or1k-sim' machine.
- The 390x architecture emulator provides support for Vector-Enhancements Facility 2 (VEF 2) extensions. The s390-ccw BIOS has the ability to boot from disks with a sector size other than 512 bytes.
- Added support for lx106 kernels and cache testing object codes to the Xtensa architecture emulator.
Finally if you are interested in knowing more about it of the changes and novelties that are presented in this new version of QEMU 7.1 you can check the details and more in the following link