On 02/11/17 15:50, Gerd Hoffmann wrote:
Queues have 256 entries on kvmtool, support that. Needs more memory for virtqueues now. But with the move to 32bit drivers for virtio this should not be much of an issue any more.
Known problems (probably kvmtool bugs):
- Must bump to 260 entries to make things actually work, otherwise kvmtool segfaults. Oops.
You mean setting MAX_QUEUE_NUM to 256 instead of 260 in seabios causes a kvmtool crash? Do you have any more detail on the segfault?
One problem I can see is kvmtool's handling of used/avail event indexes. net and blk devices call virtio_queue__should_signal which reads event indexes without of checking if VIRTIO_F_EVENT_IDX was negotiated first. Since seabios doesn't use the event indexes, this would lead to missing signals, but not a segfault.
- Linux kernel doesn't find virtio-blk devices after seabios initialized them. virtio device reset not working properly?
No, reset isn't implemented at all... A lot of work is required to properly clear the state and threads of each device.
Thanks, Jean