On Fri, May 11, 2018 at 03:29:43PM +0100, Andre Przywara wrote: > Hi Jan, > > On 04/05/18 17:31, Jan Glauber wrote: > > On Fri, May 04, 2018 at 04:17:40PM +0100, Andre Przywara wrote: > >> Hi Jan, > >> > >> can you please test this patch with your setup, to see if it still > >> screams? That converts two forgotten irq_lock's over to be irqsafe, > >> plus lets lpi_list_lock join them (which you already did, IIUC). > >> That should appease lockdep, hopefully. > > > > Hit send too soon, on halting the guest I get: > > So I managed to finally wrap my head around this one. > I sent out a series [1], and failed Cc:ing you under the assumption that > Reported-by: would be picked up by git send-email. Apologies for that, > but you should be able to pick it from one of the lists. > > Can you please confirm that the last two patches fix the splat below for > you? Sorry for the late response, I was offline. With all 4 patches applied both the locking and the RCU warnings are gone. Thanks for fixing this! Grüße, Jan > Thanks for testing and reporting! > Andre. > > [1] > http://lists.infradead.org/pipermail/linux-arm-kernel/2018-May/577054.html > > > > > [ 1025.694857] ============================= > > [ 1025.694862] WARNING: suspicious RCU usage > > [ 1025.694868] 4.17.0-rc3-jang+ #73 Not tainted > > [ 1025.694873] ----------------------------- > > [ 1025.694880] ./include/linux/kvm_host.h:575 suspicious rcu_dereference_check() usage! > > [ 1025.694884] > > other info that might help us debug this: > > > > [ 1025.694890] > > rcu_scheduler_active = 2, debug_locks = 1 > > [ 1025.694896] 18 locks held by qemu-system-aar/5540: > > [ 1025.694901] #0: 000000005e03488a (&kvm->lock){+.+.}, at: vgic_its_set_attr+0x230/0x388 > > [ 1025.694937] #1: 000000004b1a3bb5 (&its->its_lock){+.+.}, at: vgic_its_set_attr+0x23c/0x388 > > [ 1025.694965] #2: 000000003ca8213c (&vcpu->mutex){+.+.}, at: lock_all_vcpus+0x64/0xc0 > > [ 1025.694993] #3: 00000000adb6ae51 (&vcpu->mutex){+.+.}, at: lock_all_vcpus+0x64/0xc0 > > [ 1025.695021] #4: 0000000000563df7 (&vcpu->mutex){+.+.}, at: lock_all_vcpus+0x64/0xc0 > > [ 1025.695048] #5: 00000000da16277a (&vcpu->mutex){+.+.}, at: lock_all_vcpus+0x64/0xc0 > > [ 1025.695076] #6: 00000000bf36d9aa (&vcpu->mutex){+.+.}, at: lock_all_vcpus+0x64/0xc0 > > [ 1025.695103] #7: 00000000607eaa4f (&vcpu->mutex){+.+.}, at: lock_all_vcpus+0x64/0xc0 > > [ 1025.695130] #8: 0000000046dadf65 (&vcpu->mutex){+.+.}, at: lock_all_vcpus+0x64/0xc0 > > [ 1025.695157] #9: 00000000197747b2 (&vcpu->mutex){+.+.}, at: lock_all_vcpus+0x64/0xc0 > > [ 1025.695184] #10: 00000000e4f1282c (&vcpu->mutex){+.+.}, at: lock_all_vcpus+0x64/0xc0 > > [ 1025.695211] #11: 000000007471b896 (&vcpu->mutex){+.+.}, at: lock_all_vcpus+0x64/0xc0 > > [ 1025.695239] #12: 000000005be54486 (&vcpu->mutex){+.+.}, at: lock_all_vcpus+0x64/0xc0 > > [ 1025.695266] #13: 000000000f1fa184 (&vcpu->mutex){+.+.}, at: lock_all_vcpus+0x64/0xc0 > > [ 1025.695293] #14: 0000000093fdb28b (&vcpu->mutex){+.+.}, at: lock_all_vcpus+0x64/0xc0 > > [ 1025.695396] #15: 0000000097cc103c (&vcpu->mutex){+.+.}, at: lock_all_vcpus+0x64/0xc0 > > [ 1025.695426] #16: 00000000d24dd32e (&vcpu->mutex){+.+.}, at: lock_all_vcpus+0x64/0xc0 > > [ 1025.695453] #17: 000000002606c3a7 (&vcpu->mutex){+.+.}, at: lock_all_vcpus+0x64/0xc0 > > [ 1025.695482] > > stack backtrace: > > [ 1025.695489] CPU: 29 PID: 5540 Comm: qemu-system-aar Not tainted 4.17.0-rc3-jang+ #73 > > [ 1025.695494] Hardware name: To be filled by O.E.M. Saber/To be filled by O.E.M., BIOS 0ACKL018 03/30/2018 > > [ 1025.695499] Call trace: > > [ 1025.695505] dump_backtrace+0x0/0x160 > > [ 1025.695510] show_stack+0x24/0x30 > > [ 1025.695517] dump_stack+0x9c/0xd4 > > [ 1025.695524] lockdep_rcu_suspicious+0xcc/0x118 > > [ 1025.695537] gfn_to_memslot+0x174/0x190 > > [ 1025.695546] kvm_read_guest+0x50/0xb0 > > [ 1025.695553] vgic_its_check_id.isra.0+0x114/0x148 > > [ 1025.695560] vgic_its_save_tables_v0+0x1a0/0x320 > > [ 1025.695567] vgic_its_set_attr+0x330/0x388 > > [ 1025.695573] kvm_device_ioctl_attr+0x9c/0xd8 > > [ 1025.695579] kvm_device_ioctl+0x8c/0xf8 > > [ 1025.695587] do_vfs_ioctl+0xc4/0x938 > > [ 1025.695594] ksys_ioctl+0x8c/0x98 > > [ 1025.695601] sys_ioctl+0x34/0x48 > > [ 1025.695609] el0_svc_naked+0x44/0x48 > > > > --Jan > > _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
