In this case, load the module with the modprobe command:. There are different ways to add the repository through yum , dnf , and apt-get ; describing them all is beyond the scope of this article. To make it simple, this example will use apt-get , but the idea is similar for the other options. You can also add pattern match to your regular expression to filter further.
Add the repository to the repolist, which should be specified in the driver guide. Run the lscpi command as above to check that the driver was installed successfully. This article was originally published on Opensource. Bryant Jimin Son is a Consultant at Red Hat, a technology company known for its Linux server and opensource contributions.
More about me. Relive our April event with demos, keynotes, and technical sessions from experts, all available on demand. Enable Sysadmin. How to install a device driver on Linux. Learn how Linux drivers work and how to use them. Two approaches to finding drivers 1.
User interfaces If you are new to Linux and coming from the Windows or MacOS world, you'll be glad to know that Linux offers ways to see whether a driver is available through wizard-like programs. Command line What if you can't find a driver through your nice user interface application? By using yum , dnf , apt-get , etc. Download, compile, and build it yourself This usually involves downloading a package directly from a website or using the wget command and running the configuration file and Makefile to install it.
This is beyond the scope of this article, but you should be able to find online guides if you choose to go this route. Check if a driver is already installed Before jumping further into installing a driver in Linux, let's look at some commands that will determine whether the driver is already available on your system. Add the repository and install There are different ways to add the repository through yum , dnf , and apt-get ; describing them all is beyond the scope of this article.
Delete the existing repository, if it exists. It is installed and enabled by default. The SPICE agent supports multiple monitors and is responsible for client-mouse-mode support to provide a better user experience and improved responsiveness than the QEMU emulation. Cursor capture is not needed in client-mouse-mode. The SPICE agent reduces bandwidth usage when used over a wide area network by reducing the display level, including color depth, disabling wallpaper, font smoothing, and animation.
The SPICE agent enables clipboard support allowing cut and paste operations for both text and images between client and virtual machine, and automatic guest display setting according to client-side settings.
To install the guest agents, tools, and drivers on a Windows virtual machine, complete the following steps:. On the Manager machine, install the virtio-win package:. For example, to run the installation when virtio-win-gt-x After installation completes, the guest agents and drivers pass usage information to the Red Hat Virtualization Manager and enable you to access USB devices and other functionality. When installing virtio-win-gt-x Other values are listed in the following tables.
Controls the amount of memory a virtual machine actually accesses. Table 3. Supports multiple monitors, responsible for client-mouse-mode support, reduces bandwidth usage, enables clipboard support between client and virtual machine, provide a better user experience and improved responsiveness. The following command installs only the Spice Agent and its required corresponding drivers:. Installing guest agents and drivers. As an example of the first case, a bit can acknowledge if the device supports SR-IOV or what memory mode can be used.
An example of the second case can be the different offloads it can perform, like checksumming or scatter-gather If the device is a network interface. After the device initialization exposed in the previous section, the former reads the feature bits the device offers, and sends back the subset that it can handle.
If they agree on them, the driver will allocate and inform about the virtqueues to the device, and all other configuration needed. Devices and drivers must notify that they have information to communicate using a notification. While the semantic of these is specified in the standard, the implementation of these are transport specific, like a PCI interruption or to write to a specific memory location. The device and the driver needs to expose at least one notification method.
We will expand on this later in future sections. The current memory layout of a virtqueue implementation is a circular ring, so it is often called the virtring or vring. They will be the main topic of the next section, Virtqueues and virtio ring, so at this moment is enough with that definition. The virtio driver is the software part in the virtual environment that talks with the virtio device using the relevant parts of the virtio spec.
In this section we are going to locate each virtio networking element device, driver, and how the communication works in three different architectures, to provide both a common frame to start explaining the virtio data plane and to show how adaptive it is. We have already presented these elements in past posts, so you can skip this section if you are a virtio-net series reader.
On the other hand, if you have not read them, you can use them as a reference to understand this part better. QEMU can access virtqueue information using the shared memory. Please note the implications of the virtio rings shared memory concept: The memory the driver and the device access is the same page in RAM, they are not two different regions that follow a protocol to synchronize.
In that context, QEMU initiates the device using the virtio dataplane, and then forwards the virtio device status to vhost-net, delegating the data plane to it. In this scenario, KVM will use an event file descriptor eventfd to communicate the device interruptions, and expose another one to receive CPU interruptions. The guest does not need to be aware of this change, it will operate as the previous scenario. Also, in order to increase the performance, we created an in-kernel virtio-net device called vhost-net to offload the data plane directly to the kernel, where packet forwarding takes place:.
Later on, we moved the virtio device from the kernel to an userspace process in the host covered in the post " A journey to the vhost-users realm " that can run a packet forwarding framework like DPDK. The protocol to set all this up is called virtio-user. In this case, virtio names driver the process that is managing the memory and the virtqueues, not the kernel code that runs in the guest.
Lastly, we can directly do a virtio device passthrough with the proper hardware. If a hardware NIC wants to go this way, the easiest approach is to build its driver on top of vDPA , also explained in earlier posts of this series.
We will explain what happens inside of the dataplane communication in the rest of the posts. Thanks to the deep investment in standardization, the virtio data plane is the same in whatever way we use across these scenarios, and whatever transport protocol we use. The format of the exchanged messages are the same, and different devices or drivers can negotiate different capabilities or features based on its characteristics using the feature bits, previously mentioned. This way, the virtqueues only act as a common thin layer of device-driver communication that allows to reduce the investment of development and deployment.
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