10.2. QEMU Guest Agent
10.2. QEMU Guest Agent The QEMU guest agent runs inside the guest and allows the host machine to issue commands to the guest operating system using libvirt. The guest operating system then responds to those commands asynchronously. This chapter covers the libvirt commands and options available to the guest agent. Important Note that it is only safe to rely on the guest agent when run by trusted guests. An untrusted guest may maliciously ignore or abuse the guest agent protocol, and although built-in safeguards exist to prevent a denial of service attack on the host, the host requires guest co-operation for operations to run as expected. Note that QEMU guest agent can be used to enable and disable virtual CPUs (vCPUs) while the guest is running, thus adjusting the number of vCPUs without using the hot plug and hot unplug features. Refer to Section 14.13.6, "Configuring Virtual CPU Count" for more information. 10.2.1. Install and Enable the Guest Agent Install qemu-guest-agent on the guest virtual machine with the yum install qemu-guest-agent command and make it run automatically at every boot as a service (qemu-guest-agent.service).