On Tue, 2013-04-09 at 12:24 +0800, Asias He wrote: > On Mon, Apr 08, 2013 at 09:09:54PM -0700, Nicholas A. Bellinger wrote: > > Ping. > > > > Any ideas on this one..? It seems like this bug would be effecting > > non vhost-scsi-pci code as well.. > > Nicholas, where is the latest v3 code. Can you push it to your tree. > Sure. Just pushed to: http://git.kernel.org/cgit/virt/kvm/nab/qemu-kvm.git/log/?h=vhost-scsi-for-1.4 and should be appearing momentarily. --nab > > --nab > > > > On Thu, 2013-04-04 at 19:59 -0700, Nicholas A. Bellinger wrote: > > > Hi Paolo & Co, > > > > > > So I've been running into another bug with SeaBIOS w/ virtio-scsi + > > > vhost-scsi-pci code.. > > > > > > During the last weeks debugging on the QEMU vhost memory re-mapping bug, > > > my seabios builds have been using a smaller target ID (16) for scanning > > > than the default hard coded value of 256 in init_virtio_scsi(). > > > > > > After bumping this value back to 256 recently, a bogus out_num value > > > from vhost_get_vq_desc() start appearing on the tcm_vhost side: > > > > > > [17348.044031] Invalid buffer layout out: 0 in: 2 > > > > > > After adding more debug output to SeaBIOS, the vring->num value appears > > > to be reset from the expected MAX_QUEUE_NUM=128, then incremented each > > > time after vring_more_used() is called to poll for completion.. > > > > > > init virtio-scsi > > > found virtio-scsi at 0:4 > > > vring_init Setting vr->num: 128 > > > Calling virtio_scsi_scan_target for target: 0 > > > Searching bootorder for: /pci@i0cf8/*@4/*@0/*@0,0 > > > virtio_scsi_cmd, using vring_add_buf for out_num: 1 in_num: 2 > > > virtio_scsi_cmd, using vring_add_buf vr: 0x000ed404 vr->num: 128 > > > vring_add_buf, vr: 0x000ed404 vr->num: 128 > > > vring_add_buf, head: 0, index: 0 > > > vring_add_buf, setting desc[prev=2].flags > > > vring_add_buf, setting free_head: 3 > > > vring_add_buf, setting q->vdata[head=0] > > > vring_add_buf, setting q->ring[av=0] > > > virtio_scsi_cmd, after vring_add_buf vr: 0x000ed404 vr->num: 128 > > > virtio_scsi_cmd, after vring_kick vr: 0x000ed404 vr->num: 128 > > > virtio_scsi_cmd, after vring_more_used #4 vr: 0x000ed404 vr->num: 1 > > > ^^^^^^^^^^^^^^^^^^^^^^^^^ > > > > > > Reset from 128 to 1 immediate after first vring_more_used()..? > > > > > > vring_get_buf last_used_idx: 0 vr: 0x000ed404 vr->num: 1 > > > vring_get_buf checking &used->ring[0] > > > vring_get_buf, using new last_unsed: 0 >>>>>>>>>>>>>>>>>> > > > vring_get_buf using id: 0 from elem->id: 0x000ed004 > > > vring_detach: vq->free_head: 3 > > > vring_detach: Setting new vq->free_head: 0 > > > virtio_scsi_cmd, after vring_get_buf #5 vr: 0x000ed404 vr->num: 1 > > > Calling virtio_scsi_scan_target for target: 1 > > > Searching bootorder for: /pci@i0cf8/*@4/*@0/*@1,0 > > > virtio_scsi_cmd, using vring_add_buf for out_num: 1 in_num: 2 > > > virtio_scsi_cmd, using vring_add_buf vr: 0x000ed404 vr->num: 1 > > > vring_add_buf, vr: 0x000ed404 vr->num: 1 > > > vring_add_buf, head: 0, index: 0 > > > vring_add_buf, setting desc[prev=2].flags > > > vring_add_buf, setting free_head: 3 > > > vring_add_buf, setting q->vdata[head=0] > > > vring_add_buf, setting q->ring[av=0] > > > virtio_scsi_cmd, after vring_add_buf vr: 0x000ed404 vr->num: 1 > > > virtio_scsi_cmd, after vring_kick vr: 0x000ed404 vr->num: 1 > > > virtio_scsi_cmd, after vring_more_used #4 vr: 0x000ed404 vr->num: 2 > > > ^^^^^^^^^^^^^^^^^^^^^^^^^ > > > > > > Incremented from 1 to 2 after second vring_more_used()..? > > > > > > vring_get_buf last_used_idx: 1 vr: 0x000ed404 vr->num: 2 > > > vring_get_buf checking &used->ring[1] > > > vring_get_buf, using new last_unsed: 1 >>>>>>>>>>>>>>>>>> > > > vring_get_buf using id: 0 from elem->id: 0x000ed00c > > > vring_detach: vq->free_head: 3 > > > vring_detach: Setting new vq->free_head: 0 > > > virtio_scsi_cmd, after vring_get_buf #5 vr: 0x000ed404 vr->num: 2 > > > virtio-scsi vendor='LIO-ORG' product='RAMDISK-MCP' rev='4.0' type=0 removable=0 > > > virtio_scsi_cmd, using vring_add_buf for out_num: 1 in_num: 1 > > > virtio_scsi_cmd, using vring_add_buf vr: 0x000ed404 vr->num: 2 > > > vring_add_buf, vr: 0x000ed404 vr->num: 2 > > > vring_add_buf, head: 0, index: 0 > > > vring_add_buf, setting desc[prev=1].flags > > > vring_add_buf, setting free_head: 2 > > > vring_add_buf, setting q->vdata[head=0] > > > vring_add_buf, setting q->ring[av=0] > > > virtio_scsi_cmd, after vring_add_buf vr: 0x000ed404 vr->num: 2 > > > virtio_scsi_cmd, after vring_kick vr: 0x000ed404 vr->num: 2 > > > virtio_scsi_cmd, after vring_more_used #4 vr: 0x000ed404 vr->num: 3 > > > ^^^^^^^^^^^^^^^^^^^^^^^^^ > > > > > > Incremented from 2 to 3, and so on.. > > > > > > and this keeps happening until vr->num begins to exceed > > > MAX_QUEUE_NUM around scanning of target ID 127: > > > > > > virtio_scsi_cmd, after vring_add_buf vr: 0x000ed404 vr->num: 128 > > > virtio_scsi_cmd, after vring_kick vr: 0x000ed404 vr->num: 128 > > > virtio_scsi_cmd, after vring_more_used #4 vr: 0x000ed404 vr->num: 129 > > > vring_get_buf last_used_idx: 128 vr: 0x000ed404 vr->num: 129 > > > vring_get_buf checking &used->ring[128] > > > vring_get_buf, using new last_unsed: 128 >>>>>>>>>>>>>>>>>> > > > vring_get_buf using id: 129 from elem->id: 0x000ed404 > > > vring_detach: vq->free_head: 3 > > > vring_detach: Setting new vq->free_head: 129 > > > virtio_scsi_cmd, after vring_get_buf #5 vr: 0x000ed404 vr->num: 129 > > > Calling virtio_scsi_scan_target for target: 127 > > > Searching bootorder for: /pci@i0cf8/*@4/*@0/*@127,0 > > > virtio_scsi_cmd, using vring_add_buf for out_num: 1 in_num: 2 > > > virtio_scsi_cmd, using vring_add_buf vr: 0x000ed404 vr->num: 129 > > > vring_add_buf, vr: 0x000ed404 vr->num: 129 > > > vring_add_buf, head: 129, index: 0 > > > vring_add_buf, setting desc[prev=4].flags > > > vring_add_buf, setting free_head: 5 > > > vring_add_buf, setting q->vdata[head=0] > > > vring_add_buf, setting q->ring[av=129] > > > virtio_scsi_cmd, after vring_add_buf vr: 0x000ed404 vr->num: 129 > > > virtio_scsi_cmd, after vring_kick vr: 0x000ed404 vr->num: 129 > > > virtio_scsi_cmd, after vring_more_used #4 vr: 0x000ed404 vr->num: 130 > > > vring_get_buf last_used_idx: 129 vr: 0x000ed404 vr->num: 130 > > > vring_get_buf checking &used->ring[129] > > > vring_get_buf, using new last_unsed: 129 >>>>>>>>>>>>>>>>>> > > > vring_get_buf using id: 968704 from elem->id: 0x000ed40c > > > vring_detach: vq->free_head: 5 > > > vring_detach: Setting new vq->free_head: 968704 > > > virtio_scsi_cmd, after vring_get_buf #5 vr: 0x000ed404 vr->num: 130 > > > Calling virtio_scsi_scan_target for target: 128 > > > Searching bootorder for: /pci@i0cf8/*@4/*@0/*@128,0 > > > virtio_scsi_cmd, using vring_add_buf for out_num: 1 in_num: 2 > > > virtio_scsi_cmd, using vring_add_buf vr: 0x000ed404 vr->num: 130 > > > vring_add_buf, vr: 0x000ed404 vr->num: 130 > > > vring_add_buf, head: 51200, index: 0 > > > vring_add_buf, setting desc[prev=1].flags > > > vring_add_buf, setting free_head: 2 > > > vring_add_buf, setting q->vdata[head=0] > > > vring_add_buf, setting q->ring[av=51200] > > > > > > until '[17348.044031] Invalid buffer layout out: 0 in: 2' appears on the > > > vhost. > > > > > > So it's clear this definitely is not supposed to be happening, but I've > > > not yet been able to ascertain why it's suddenly being triggered now..? > > > I don't recall Asias running into a similar issue during his earlier > > > testing, but this bug is happening after every I/O in SeaBIOS with the > > > most recent vhost-scsi-pci code. > > Ah, I did not see this before. If we disable SeaBIOS and only use guest > kernel to access tcm_vhost disk, do you see this. > > > > I'm using the following to work-around this issue for the moment, and > > > would like some input from virtio / SeaBIOS folks.. > > > > > > WDYT..? > > > > > > --nab > > > > > > diff --git a/src/virtio-ring.c b/src/virtio-ring.c > > > index bddb090..e046141 100644 > > > --- a/src/virtio-ring.c > > > +++ b/src/virtio-ring.c > > > @@ -35,10 +35,16 @@ > > > > > > int vring_more_used(struct vring_virtqueue *vq) > > > { > > > + struct vring *vr = &vq->vring; > > > struct vring_used *used = GET_LOWFLAT(vq->vring.used); > > > int more = GET_LOWFLAT(vq->last_used_idx) != GET_LOWFLAT(used->idx); > > > /* Make sure ring reads are done after idx read above. */ > > > smp_rmb(); > > > + > > > + /* Huh..? vr->num is somehow changing from below us..? */ > > Pretty strange. > > > > + if (GET_LOWFLAT(vr->num) != MAX_QUEUE_NUM) { > > > + SET_LOWFLAT(vr->num, MAX_QUEUE_NUM); > > > + } > > > return more; > > > } > > > > > > -- > > > To unsubscribe from this list: send the line "unsubscribe target-devel" in > > > the body of a message to majordomo@xxxxxxxxxxxxxxx > > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > > > > _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization