| Message ID | 1369309901-418-1-git-send-email-borntraeger@de.ibm.com |
|---|---|
| State | New |
| Headers | show |
Am 23.05.2013 13:51, schrieb Christian Borntraeger: > With the ccw ipl code sometimes an error message like > "virtio: trying to map MMIO memory" or > "Guest moved used index from %u to %u" appeared. Turns out > that the ccw bios did not zero out the vring, which might > cause stale values in avail->idx and friends, especially > on reboot. > > Lets zero out the relevant fields. To activate the patch we > need to rebuild s390-ccw.img as well. > > Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Tested-by: Andreas Färber <afaerber@suse.de> Indeed no such errors any more, but I'm still seeing other issues with rebooting some initrds (BNC#812983). Andreas
Applied. Thanks. Regards, Anthony Liguori
diff --git a/pc-bios/s390-ccw/virtio.c b/pc-bios/s390-ccw/virtio.c index 5b9e1dc..f438af1 100644 --- a/pc-bios/s390-ccw/virtio.c +++ b/pc-bios/s390-ccw/virtio.c @@ -114,8 +114,13 @@ static void vring_init(struct vring *vr, unsigned int num, void *p, vr->used = (void *)(((unsigned long)&vr->avail->ring[num] + align-1) & ~(align - 1)); + /* Zero out all relevant field */ + vr->avail->flags = 0; + vr->avail->idx = 0; + /* We're running with interrupts off anyways, so don't bother */ vr->used->flags = VRING_USED_F_NO_NOTIFY; + vr->used->idx = 0; debug_print_addr("init vr", vr); }
With the ccw ipl code sometimes an error message like "virtio: trying to map MMIO memory" or "Guest moved used index from %u to %u" appeared. Turns out that the ccw bios did not zero out the vring, which might cause stale values in avail->idx and friends, especially on reboot. Lets zero out the relevant fields. To activate the patch we need to rebuild s390-ccw.img as well. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> --- pc-bios/s390-ccw/virtio.c | 5 +++++ 1 file changed, 5 insertions(+)