Okay, so I need to classify this bug report as either user-mode or system-mode. Let me start by understanding the problem. The issue is about using sed -i on a file mounted via 9p virtfs under MacOS in QEMU version 7.0.0-rc1. The error message says "Protocol not supported" when trying to preserve permissions. Looking at the strace output, there are several system calls related to file attributes and xattr. Hmm, the error occurs during fsetxattr, which is a system call used for setting extended file attributes. Extended attributes are part of the filesystem metadata and typically require kernel-level handling. So when QEMU handles this over 9p virtfs, it's dealing with how filesystem operations are translated between host and guest. Since the problem involves file permissions and xattrs, which are lower-level filesystem features, it probably relates to how the 9p protocol or thevirtfs implementation in QEMU is handling these attributes. The error suggests that the operation isn't supported by the underlying protocol or filesystem driver. I think this falls under system-mode because it's about how the virtualization layer interacts with the host's filesystem at a lower level, involving kernel operations and file metadata rather than user applications. system