QEMU Making Progress With Legacy-Free Display Support - Avoids Old VGA Code

As part of QEMU's emulated display support they have long had a lot of old VGA/SVGA support code around. But as that code is overly complex, has been prone to security issues, and less used these days with modern interfaces, the developers behind this important piece of the open-source virtualization stack have been working on eliminating the legacy display support.

With the current QEMU 3.0 release they introduced the new Bochs-Display device that doesn't depend upon VGA compatibility, is implemented from scratch, OVMF supports it for UEFI support, is compatible with the Bochs DRM/KMS Linux driver, and is all around in good shape for UEFI guests compared to the standard VGA (stdvga) display code.

The last bit of work they are pursuing on the Bochs Display device front in QEMU is for text mode support such as when dealing with SeaBIOS and Linux boot-loaders. For taking care of text mode support they are working on changing the initialization code to use the Bochs DISPI interface for presenting boot messages on the Bochs display frame-buffer. That bit of code should be in good shape for the next stable release, QEMU 3.1.

Worrying about VGA isn't over yet in the virtual space.

The old VGA display code isn't being dropped off at this point in QEMU, but hopefully it will in time with the Bochs Display support coming together. More details on the legacy display support in QEMU and the new Bochs-Display device can be found via this interesting blog post by developer Gerd Hoffmann.

QEMU 3.1 is tentatively planned for release in December while the soft feature freeze is set for next week followed by several weeks of release candidates.