What is vhost user?

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The vhost user protocol consists of a control path and a data path. All control information is exchanged via a Unix socket. This includes information for exchanging memory mappings for direct memory access, as well as kicking / interrupting the other side if data is put into the virtio queue.

What is vhost in openstack?

Neutron Open vSwitch vhost-user support¶ The OVS agent detects the capability of the underlying Open vSwitch installation and passes that information over RPC via the agent ‘configurations’ dictionary. The ML2 driver uses this information to select the proper VIF type and binding details.

What is DPDK vhost?

Vhost-user uses Unix domain sockets for passing messages. This means the DPDK vhost-user implementation has two options: DPDK vhost-user acts as the server. DPDK will create a Unix domain socket server file and listen for connections from the frontend. Note, this is the default mode, and the only mode before DPDK v16.

What is vhost-net?

vhost-net is a character device that can be used to reduce the number of system calls involved in virtio networking. vhost-net moves network packets between the guest and the host system using the Linux kernel, bypassing QEMU.

What is vhost protocol?

The vhost protocol is a set of messages and mechanisms designed to offload the virtio datapath processing from QEMU (the primary, that wants to offload packet processing) to an external element (the handler, that configures the virtio rings and does the actual packet processing.).

What is vhost in QEMU?

Vhost-net has silently become the default traffic offloading mechanism for qemu-kvm based virtual environments leveraging the standard virtio networking interface. This mechanism allows the network processing to be performed in a kernel module freeing the qemu process and improving the overall network performance.

How vhost user came into being?

In the vhost-net/virtio-net architecture the data plane communication was straightforward from the guest OS point of view: simply add the virtio drivers to the guest kernel and the guest user space applications automatically gets a standard Linux networking interface to work with.

What is vhost kernel?

The Linux* Kernel vhost-net module was developed as an offload mechanism for virtio-net. The vhost-net module enables KVM (QEMU) to offload the servicing of virtio-net devices to the vhost-net kernel module, reducing the context switching and packet copies in the virtual dataplane.

What is Virtio user?

The virtual device, virtio-user, with unmodified vhost-user backend, is designed for high performance user space container networking or inter-process communication (IPC).

What is vhost KVM?

KVM – kernel based virtual machine that allows Linux to function as a hypervisor so a host machine can run multiple isolated virtual environments called guests. KVM basically provides Linux with hypervisor capabilities. This means that the hypervisor components such as memory manager, scheduler, network stack, etc.

What is the vhost user protocol?

What is vhostuser-client?

vhostuser-client – qemu is the server, the software switch is the client vhost user is based on the vhost architecture and implements all features in user space. When a qemu instance boots, it will allocate all of the instance memory as shared hugepages.

How do I run a website on two different vhosts?

The Web Help > apache > run each vhost as different user This is needed when you want apache to be able to handle the site files that might belong to another user (site ftp maybe), OR when you want to have different user on each site runnning on your server (for better security).

How does vhost_user_set_Mem_table work?

The master sends a list of vhost memory regions to the slave using the VHOST_USER_SET_MEM_TABLE message. Each region has two base addresses: a guest address and a user address. Messages contain guest addresses and/or user addresses to reference locations within the shared memory.