v38.0 This release has been tracked in our [roadmap project](https://github.com/orgs/cloud-hypervisor/projects/6) as iteration v38.0. The following user visible changes have been made: Group Rate Limiter on Block Devices ----------------------------------- Users now can throttle a group of block devices with the new `--rate-limiter-group` option. Details can be found from the [I/O Throttling documentation](docs/io_throttling.md) CPU Pinning Support for Block Device Worker Thread -------------------------------------------------- Users now have the option to pin virt-queue threads for block devices to specific host cpus. Optimized Boot Time with Parallel Memory Prefault ------------------------------------------------- The boot time with `prefault` option enabled is optimized via parallel memory prefault. New 'debug-console' Device -------------------------- A 'debug-console' device is added to provide a user-configurable debug port for logging guest information. Details can be found from the [Debug IO Ports documentation](docs/debug-port.md). Improved VFIO Device Support ---------------------------- All non-emulated MMIO regions of VFIO devices are now mapped to the VFIO container, allowing PCIe P2P between all VFIO devices on the same VM. This is required for a wide variety of multi-GPU workloads involving GPUDirect P2P (DMA between two GPUs), GPUDirect RDMA (DMA between a GPU and an IB device). Extended CPU Affinity Support ----------------------------- Users now can set the vcpu affinity to a host CPU with index larger than 255. Notable Bug Fixes ----------------- * Enable HTT flag to avoid crashing cpu topology enumeration software such as hwloc in the guest (#6146) * Fix several security advisories from dependencies (#6134, #6141) * Handle non-power-of-two CPU topology properly (#6062) * Various bug fixes around `virtio-vsock`(#6080, #6091, #6095) * Enable nested virtualization on AMD if supported (#6106) * Align VFIO devices PCI BARs naturally (#6196) Contributors ------------ Many thanks to everyone who has contributed to our release: * Alyssa Ross <hi@alyssa.is> * Bo Chen <chen.bo@intel.com> * Daniel Farina <daniel@ubicloud.com> * Jinank Jain <jinankjain@microsoft.com> * Muminul Islam <muislam@microsoft.com> * Peteris Rudzusiks <rye@stripe.com> * Philipp Schuster <philipp.schuster@cyberus-technology.de> * Ravi kumar Veeramally <ravikumar.veeramally@intel.com> * Rob Bradford <rbradford@rivosinc.com> * Ruslan Mstoi <ruslan.mstoi@intel.com> * Sean Banko <sbanko@crusoeenergy.com> * Thomas Barrett <tbarrett@crusoeenergy.com> * Wei Liu <liuwe@microsoft.com> * Yi Wang <foxywang@tencent.com> * acarp <acarp@crusoeenergy.com>