docs(ins): additional information qga

Author: bene2k1

pages/instances/reference-content/understanding-qemu-guest-agent.mdx

@@ -15,6 +15,12 @@ This page provides essential insights into this mechanism.
   This documentation page does not apply to Instances running the Microsoft Windows operating system.
 </Message>
 
+## What is the QGA?
+
+The QEMU Guest Agent (QGA) is a daemon intended to be run within virtual machines, facilitating communication between the guest OS and the QEMU hypervisor for tasks like system configuration and resource monitoring.
+
+The source code for QGA is publicly available and located in the [QEMU repository on GitLab](https://gitlab.com/qemu-project/qemu/-/blob/master/docs/interop/qemu-ga.rst).
+
 ## What are the features provided by QGA?
 
 Running the QEMU Guest Agent (QGA) on your Instance currently enables the following feature:
@@ -23,6 +29,11 @@ Running the QEMU Guest Agent (QGA) on your Instance currently enables the follow
 
 Additional features may be added in the future.
 
+## What are the performance impacts of running the QGA inside my VM?
+
+The performance impact of running the QGA are negligible. The agent consumes very low amounts of RAM (<5 MB RAM) and CPU (<0.1% CPU) and there is no measurable I/O or network overhead while being idle.
+The only operation performed by the agent is reading/writing a file **in the VM** each time a public IP is attached/detached to the VM.
+
 ## Checking QGA's status
 
 Since March 1st, 2024, all Scaleway-provided GNU/Linux and InstantApp images for Instances come with QGA pre-installed and enabled by default.