Hi guys, We found a qemu core in our testing environment, the assertion 'assert(bus->irq_count[i] == 0)' in pcibus_reset() was triggered and the bus->irq_count[i] is '-1'.
Through analysis, it was happened after VM migration and we think it was caused by the following sequence: *Migration Source* 1. save bus pci.0 state, including irq_count[x] ( =0 , old ) 2. save E1000: e1000_pre_save e1000_mit_timer set_interrupt_cause pci_set_irq --> update pci_dev->irq_state to 1 and update bus->irq_count[x] to 1 ( new ) the irq_state sent to dest. *Migration Dest* 1. Receive the irq_count[x] of pci.0 is 0 , but the irq_state of e1000 is 1. 2. If the e1000 need change irqline , it would call to pci_irq_handler(), the irq_state maybe change to 0 and bus->irq_count[x] will become -1 in this situation. 3. do VM reboot then the assertion will be triggered. We also found some guys faced the similar problem: [1] https://lists.gnu.org/archive/html/qemu-devel/2016-11/msg02525.html [2] https://bugs.launchpad.net/qemu/+bug/1702621 Is there some patches to fix this problem ? Can we save pcibus state after all the pci devs are saved ? Thanks, Longpeng(Mike)