On Wed, May 11 2022, Jason Wang <[email protected]> wrote: > On Tue, May 10, 2022 at 7:28 PM Michael S. Tsirkin <[email protected]> wrote: >> >> On Sat, May 07, 2022 at 03:19:51PM +0800, Jason Wang wrote: >> > @@ -1106,6 +1130,7 @@ static void virtio_ccw_int_handler(struct ccw_device >> > *cdev, >> > vcdev->err = -EIO; >> > } >> > virtio_ccw_check_activity(vcdev, activity); >> > + read_lock_irqsave(&vcdev->irq_lock, flags); >> > for_each_set_bit(i, indicators(vcdev), >> > sizeof(*indicators(vcdev)) * BITS_PER_BYTE) { >> > /* The bit clear must happen before the vring kick. */ >> >> Cornelia sent a lockdep trace on this. >> >> Basically I think this gets the irqsave/restore logic wrong. >> It attempts to disable irqs in the handler (which is an interrupt >> anyway). > > The reason I use irqsave/restore is that it can be called from process > context (if I was not wrong), e.g from io_subchannel_quiesce().
io_subchannel_quiesce() should disable interrupts, though? Otherwise, it would be a bug. _______________________________________________ Virtualization mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/virtualization
