Hi, The following two patches enables a NetBSD guest running on a Linux KVM to share files with its host over virtio-9p.
https://www.netbsd.org/~ozaki-r/vio9p.diff https://www.netbsd.org/~ozaki-r/mount_9p-cdev.diff The first patch exports a 9p endpoint of virtio-9p via a character device (e.g., /dev/vio9p0) and the second one extends mount_9p (puffs) to talk with a 9p server inside qemu via the character device. [Usage] Export a directory of a host via virtio-9p. The below XML is part of a libvirt domain configuration. It exports "/var/lib/libvirt/export" directory with a tag "test". If it is the first entry, it will have minor number 0 and /dev/vio9p0 is assigned to it typically. <filesystem type='mount' accessmode='mapped'> <source dir='/var/lib/libvirt/export'/> <target dir='test'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/> </filesystem> A boot log of vio9p looks like this: virtio0 at pci0 dev 3 function 0 virtio0: Virtio 9P Transport Device (rev. 0x00) vio9p0 at virtio0: Features: 0x10000000<INDIRECT_DESC> virtio0: allocated 12288 byte for virtqueue 0 for vio9p, size 128 virtio0: using 4096 byte (256 entries) indirect descriptors vio9p0: tagged as test virtio0: interrupting at ioapic0 pin 11 A NetBSD guest can mount the exported directory with mount_9p. mount_9p -cu /dev/vio9p0 /mnt/9p -c tells mount_9p to interpret the first argument as a character device file to talk with. Have fun, ozaki-r
