Il 30/01/2013 21:02, Michael S. Tsirkin ha scritto: > On Wed, Jan 30, 2013 at 05:41:22PM +0100, Paolo Bonzini wrote: >> Ok, so here is my attempt at a vhost-scsi device. I'm creating an >> entirely separate device, with the common parts of virtio-scsi and >> vhost-scsi (actually little more than the initialization) grouped into >> a VirtIOSCSICommon type. The device is used simply like "-device >> vhost-scsi-pci,wwpn=WWPN", with all configuration done in configfs >> beforehand. >> >> As expected, using a separate device finds a snag: vhost-scsi is passing >> force=false to vhost_dev_init, and the BIOS does not use MSI-X so it >> will actually use the non-vhost implementation which is wrong. I fixed >> this by passing force=true; I'm not sure what that would break, but I >> figured "not much" since the BIOS polls and does not rely on interrupts. >> >> That makes vhost start, but it still doesn't work for me with a 3.7.2 >> kernel on the host. Even Nick's patches hang the guest as soon as vhost >> starts, and I get the same behavior with mine. (Of course with my >> patches the BIOS hangs and you never reach Linux; but try a BIOS without >> virtio-scsi support, and you'll see Linux hanging in the same way). >> >> Here is my configuration: >> >> cd /sys/kernel/config/target >> mkdir -p core/fileio_0/fileio >> echo 'fd_dev_name=/home/pbonzini/test.img,fd_dev_size=5905580032' > >> core/fileio_0/fileio/control >> echo 1 > core/fileio_0/fileio/enable >> mkdir -p vhost/naa.600140554cf3a18e/tpgt_0/lun/lun_0 >> cd vhost/naa.600140554cf3a18e/tpgt_0 >> ln -sf ../../../../../core/fileio_0/fileio/ lun/lun_0/virtual_scsi_port >> echo naa.60014053226f0388 > nexus >> >> Nick's patches are run with "-vhost-scsi >> id=vs,tpgt=0,wwpn=naa.600140554cf3a18e >> -device virtio-scsi-pci,vhost-scsi=vs". Perhaps I'm doing something wrong. >> >> Another small bug I found is an ordering problem between >> VHOST_SET_VRING_KICK and VHOST_SCSI_SET_ENDPOINT. Starting the vq >> causes a "vhost_scsi_handle_vq endpoint not set" error in dmesg. > > Hmm but why? What causes a kick? Any idea?
I haven't checked yet, but I don't plan to keep the patches. I want to fix it in the kernel by relaxing VHOST_SCSI_*_ENDPOINT. Paolo
