On Wed, 2019-02-13 at 09:19 -0500, Frediano Ziglio wrote: > > > > Stream devices assume that all QXL devices are registered with the > > server before we receive any communications from the stream device. > > This > > is due to the fact that QXL display channel IDs are assigned > > directly > > from the QXL device ID, whereas Stream display channels are > > assigned > > channel IDs based on the next free ID. If the stream channel is > > created first, it will find that 0 is the first available display > > ID and > > use that for its channel ID. Then when QXL device #0 is registered, > > it > > will also create a display channel with channel ID 0, and they will > > conflict. > > Interesting, should not be checked somewhere and detected as API > violation? > > Frediano Maybe. Right now qemu always registers QXL devices immediately after qemu starts. And obviously we can't communicate via the stream device until the guest is fully up and running. So I think there's essentially no way for the bug to happen with current code. I think QXL channels will always get created before stream channels. But for completeness it probably would be good to add a check somewhere. The alternative is to disconnect the QXL ID from the channel ID. In other words, QXL display channels would use the next available channel ID (just like the stream channels do) instead of using the qxl->id as the channel_id. But I don't know if such a change would violate any other assumptions in the code. Jonathon _______________________________________________ Spice-devel mailing list Spice-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/spice-devel