On 3/22/23 10:05, Daniel P. Berrangé wrote:
On Wed, Mar 22, 2023 at 06:10:18AM -0300, Daniel Henrique Barboza wrote:
Today, trying to boot a RISC-V Fedora Rawhide image in a RISC-V QEMU domain results in the following error:
==== error: Failed to start domain 'riscv-fedora' error: internal error: process exited while connecting to monitor: 2023-03-20T17:31:02.650862Z qemu-system-riscv64: Some ROM regions are overlapping These ROM regions might have been loaded by direct user request or by default. They could be BIOS/firmware images, a guest kernel, initrd or some other file loaded into guest memory. Check whether you intended to load all this guest code, and whether it has been built to load to the correct addresses. ====
This happens because the default RISC-V QEMU firmware, OpenSBI, is always loaded unless "-bios none" is passed in the command line, and the Fedora Rawhide guest kernel has its own ROM. Other machines such as PPC64 'pseries' shows the same behavior: the default firmware is always loaded unless specified otherwise with the '-bios' option.
What happens when these kernels are used on bare metal ? Presumably bare metal always has firmware, and the kernels successfuly overwrite it ? If so, what makes QEMU special such that it breaks ?
I'm not sure if the OS overwrites the firmware when running bare metal. Usually they provide different OS images for QEMU/libvirt and bare metal systems, probably to account for these differences. Baking the firmware in the kernel like Fedora Rawhide is doing was important a few years ago when RISC-V QEMU wasn't loading the firmware by default, but now it's getting in the way. All this said, having a look at the recently updated Fedora for RISC-V wiki, the instructions for booting with libvirt and QEMU are different. libvirt [1] is using the '-bios none' attribute with 'virt-install' + a Fedora Rawhide image, but QEMU instructions [2] doesn't use '-bios none' and it's using Fedora 37. At first I don't see any particular reason of why this Fedora 37 image would work on QEMU and not on libvirt. So what t I'll do now is do some testings with libvirt and Fedora 37. If it works then this series becomes way less important. Thanks, Daniel [1] https://fedoraproject.org/wiki/Architectures/RISC-V/Installing#Boot_with_lib... [2] https://fedoraproject.org/wiki/Architectures/RISC-V/Installing#Boot_under_QE...
With regards, Daniel