bug: l2 el2 opt?

BUG: scheduling while atomic: qemu-system-aar/10754/0x00000002
BUG: scheduling while atomic: qemu-system-aar/10754/0x00000000
BUG: scheduling while atomic: qemu-system-aar/10759/0x00000002
BUG: scheduling while atomic: qemu-system-aar/10759/0x00000000
BUG: scheduling while atomic: qemu-system-aar/10754/0x00000002
BUG: scheduling while atomic: qemu-system-aar/10754/0x00000000
BUG: scheduling while atomic: qemu-system-aar/10759/0x00000002
BUG: scheduling while atomic: qemu-system-aar/10759/0x00000000
Unable to handle kernel NULL pointer dereference at virtual address 00000078
pgd = ffff800fb2179000
[00000078] *pgd=0000004fb21ff003, *pud=0000004fb4642003, *pmd=0000000000000000
Internal error: Oops: 96000006 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 10759 Comm: qemu-system-aar Tainted: G        W       4.6.0-rc1+ #399
Hardware name: HP ProLiant m400 Server Cartridge (DT)
task: ffff800fafc88000 ti: ffff800f6eb58000 task.ti: ffff800f6eb58000
PC is at pick_next_task_fair+0x19c/0x4ac
LR is at pick_next_task_fair+0x198/0x4ac
pc : [] lr : [] pstate: 600001c5
sp : ffff800f6eb5b970
x29: ffff800f6eb5b970 x28: ffff000008887000
x27: ffff800fb7968000 x26: 0000000000000000
x25: ffff0000088a5000 x24: ffff800fafc88c00
x23: 0000000000000000 x22: 0000000000000000
x21: ffff800ffff2d068 x20: ffff800ffff2d000
x19: 0000000000000000 x18: 0000ffffed1b5e50
x17: 0000ffffadcc6410 x16: ffff0000081bacf4
x15: 003b9aca00000000 x14: 2b3163722d302e36
x13: 2e34202020202020 x12: 0000000000000028
x11: 0000000000000002 x10: 0000000000000001
x9 : 00000000000001d4 x8 : ffff800ffff19068
x7 : ffff800ffff19090 x6 : ffff000008658e60
x5 : 0000000000000001 x4 : 00000000002a3933
x3 : ffff000008909280 x2 : 0000000000000000
x1 : 00000000000003d2 x0 : 00000002f5ac7a04

Process qemu-system-aar (pid: 10759, stack limit = 0xffff800f6eb58020)
Stack: (0xffff800f6eb5b970 to 0xffff800f6eb5c000)
b960:                                   ffff800f6eb5ba00 ffff00000863b958
b980: ffff800ffff2d000 ffff800fafc88550 ffff800fafc88000 ffff0000088a6000
b9a0: ffff000008887000 ffff00000863be2c 0000000000000000 0000000000000001
b9c0: ffff800fb7968000 ffff0000089052c8 ffff800f6eb5b9e0 ffff800fafc88c80
b9e0: ffff000008887000 ffff800fafc88000 ffff800ffff2d000 ffff0000088a6000
ba00: ffff800f6eb5ba50 ffff00000863be2c ffff800f6eb58000 ffff800faf968098
ba20: 0000000000000001 0000284c13048422 0000000000000000 ffff0000088b3000
ba40: ffff800f6eb5bb90 ffff00000809a664 ffff800f6eb5ba70 ffff00000809a740
ba60: ffff800faf968000 0000000000000001 ffff800f6eb5bac0 ffff0000080a76d8
ba80: ffff800faf968000 ffff800fb7968000 0000000000000001 ffff800faf969000
baa0: ffff800fb7968000 ffff800fafc88000 ffff800f6eb5bab0 ffff800f6eb5bab0
bac0: ffff800f6eb5bae0 ffff0000080a7780 ffff800faf968000 ffff800f080a95c0
bae0: ffff800f6eb5bb10 ffff0000080a1ccc ffff800faf968000 ffff800f6eb58000
bb00: ffff80086eb5b81b ffff0000080a95c0 ffff800f6eb5bba0 ffff00000809cc8c
bb20: ffff800faf968000 ffff800fb7502d00 0000000000000000 ffff800fb1efbf00
bb40: 0000000000000000 000000000000ae80 000000000000011e 000000000000001d
bb60: ffff00000864b000 ffff800f6eb58000 ffff800faf968000 ffff0000089052e0
bb80: fffffffe7ffbfeff ffff800fb75cc28c ffff000008887000 0000000000000001
bba0: ffff800f6eb5be00 ffff0000081ba9f0 ffff800fb1efbf00 0000000000000000
bbc0: ffff800fb7c06bf8 0000000000000013 0000000000000000 0000000000000000
bbe0: 0000000000000001 000000000000ae80 ffff000008887000 00000000000001c0
bc00: ffff0000088a6ce0 0000000000000000 ffff800f6eb5bc20 ffff0000080dd9e0
bc20: ffff800f6eb5bc90 ffff0000080ddbd8 ffff800fb2341c78 ffff800fb2341c90
bc40: 0000000000000001 0000000000000000 0000000000000003 0000000000000001
bc60: 0000000000000000 0000000000000040 ffff00000864b000 0000000000000003
bc80: ffff800f6eb5bcb0 0000000000000003 ffff800f6eb5bca0 ffff0000081bba08
bca0: ffff800f6eb5bce0 ffff0000080eef68 ffff800f6eb5bd30 0000000000000000
bcc0: ffff800fb75cbc00 ffff0000080ddbc8 0000000000000000 0000000000000000
bce0: ffff800f6eb5bd30 ffff0000080eefdc ffff800fb2341c88 ffff800fb2341c80
bd00: ffff800f6eb58000 ffff800f6eb5bd88 0000000000000008 0000000000000015
bd20: 000000000000011e 00000000000005f8 ffff800f6eb5bd40 ffff0000081eb830
bd40: ffff800f6eb5bdb0 ffff0000081a88e0 ffff800fb457bc00 ffff800f6eb5bec8
bd60: ffff800f6eb5bec8 00000000008b2f50 0000000080000000 0000000000000062
bd80: ffff800f6eb5be30 ffff0000081a9860 ffff800fb457bc00 0000000000000008
bda0: ffff800fb7c06bf8 0000000000000002 ffff800fb457bc10 0000000000000015
bdc0: 000000000000011e 0000000000000040 ffff00000864b000 ffff800f6eb58000
bde0: 0000000000000008 ffff800fb457bc00 ffff800f6eb5be30 ffff0000081a9844
be00: ffff800f6eb5be90 ffff0000081bb100 ffff800fb1efbf01 0000000000000000
be20: ffff800fb1efbf00 0000000000000013 0000000000000000 ffff0000081aab04
5be90 ffff0000081bb0bc
be60: ffff800fb1efbf01 0000000000f1cac0 ffff800fb1efbf00 0000000000000013
be80: 0000000000000000 ffff0000081bb0a0 0000000000000000 ffff000008085e70
bea0: 0000000000000000 0000000000f1cac0 ffffffffffffffff 0000ffff78ef448c
bec0: 0000000060000000 0000000000000015 0000000000000013 000000000000ae80
bee0: 0000000000000000 00000000ffffff80 0000ffff7520f4f0 0000000000000001
bf00: 0000000000000002 0000000000000000 000000000000001d 0000000000940000
bf20: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
bf40: 0000000000000000 0000ffff78f79590 00000000008d73d0 0000ffff78ef4480
bf60: 0000ffffcfde8350 0000000000940000 0000000000f1cac0 0000000000000000
bf80: 00000000009985f8 0000000000000001 0000000000f24ac0 0000ffff7520f6e0
bfa0: 0000ffff77b096f0 0000000000800000 0000ffff78fa8000 0000ffff7520f3f0
bfc0: 000000000045c9e8 0000ffff7520f3f0 0000ffff78ef448c 0000000060000000
bfe0: 0000000000000013 000000000000001d 0000000000000000 0000000000000000
Call trace:
Exception stack(0xffff800f6eb5b7b0 to 0xffff800f6eb5b8d0)
b7a0:                                   0000000000000000 ffff800ffff2d000
b7c0: ffff800f6eb5b970 ffff0000080e9be0 ffff800fafc88000 0000000000000000
b7e0: ffff000008082000 0000000000000000 ffff0000080826a0 ffff000008775ab0
b800: ffff800fb7968000 ffff0000089052c8 ffff000008910080 ffff00000863be2c
b820: 0000000000000000 0000000000000000 ffff000008775ab0 00000000089052c8
b840: ffff800f6eb5b940 ffff800f6eb5b940 00000002f5ac7a04 00000000000003d2
b860: 0000000000000000 ffff000008909280 00000000002a3933 0000000000000001
b880: ffff000008658e60 ffff800ffff19090 ffff800ffff19068 00000000000001d4
b8a0: 0000000000000001 0000000000000002 0000000000000028 2e34202020202020
b8c0: 2b3163722d302e36 003b9aca00000000
[] pick_next_task_fair+0x19c/0x4ac
[] __schedule+0xe0/0x578
[] schedule+0x3c/0xa0
[] kvm_vcpu_block+0x94/0x170
[] kvm_handle_wfx+0x44/0x98
[] handle_exit+0x54/0x14c
[] kvm_arch_vcpu_ioctl_run+0x410/0x5e4
[] kvm_vcpu_ioctl+0x358/0x6cc
[] do_vfs_ioctl+0xac/0x738
[] SyS_ioctl+0x84/0x98
[] el0_svc_naked+0x24/0x28
Code: aa1503e0 aa1303e1 97fff79e f9403a73 (f9403f40)
---[ end trace 11fa7317f90ca366 ]---
note: qemu-system-aar[10759] exited with preempt_count 2
INFO: rcu_preempt self-detected stall on CPU
	2-...: (1 ticks this GP) idle=1d9/1/0 softirq=315517/315517 fqs=1
	 (t=5655 jiffies g=110692 c=110691 q=21)
rcu_preempt kthread starved for 5638 jiffies! g110692 c110691 f0x0 RCU_GP_WAIT_FQS(3) ->state=0x1
rcu_preempt     S ffff000008086c04     0     7      2 0x00000000
Call trace:
[] __switch_to+0xb4/0xdc
[] __schedule+0x1b0/0x578
[] schedule+0x3c/0xa0
[] schedule_timeout+0x104/0x1a0
[] rcu_gp_kthread+0x4b8/0x830
[] kthread+0xd4/0xe8
[] ret_from_fork+0x10/0x40
Task dump for CPU 2:
swapper/2       R  running task        0     0      1 0x00000000
Call trace:
[] dump_backtrace+0x0/0x1ac
[] show_stack+0x14/0x1c
[] sched_show_task+0xa8/0xf4
[] dump_cpu_task+0x40/0x4c
[] rcu_dump_cpu_stacks+0x98/0xe4
[] rcu_check_callbacks+0x4c4/0x95c
[] update_process_times+0x3c/0x68
[] tick_sched_handle.isra.15+0x3c/0x4c
[] tick_sched_timer+0x44/0x7c
[] __hrtimer_run_queues+0xe8/0x14c
[] hrtimer_interrupt+0x9c/0x1e0
[] arch_timer_handler_phys+0x2c/0x38
[] handle_percpu_devid_irq+0x78/0x98
[] generic_handle_irq+0x24/0x38
[] __handle_domain_irq+0x60/0xac
[] gic_handle_irq+0x5c/0xb0
Exception stack(0xffff800fb80cfe30 to 0xffff800fb80cff50)
fe20:                                   0000000000000000 0000000000000000
fe40: ffff800ffff3cab8 ffff800ffff3cac4 0100000000000000 000002045a88930f
fe60: 00000000007ffc66 0000284bb5433b30 ffff800fb80c14a0 ffff800fb80cc000
fe80: 0000000000000840 ffff0000088b93b0 ffff0000088ba580 0000000000000000
fea0: 0000000000000000 0000000000000000 ffff0000080becd0 0000aaaad3f71058
fec0: 0000ffffd680c870 ffff0000088a6b0c 0000000000000e12 ffff0000088a6a78
fee0: ffff800fb80cc000 ffff800fb80cc000 ffff800fb80cc000 ffff0000088ffb31
ff00: 0000000000000001 ffff000008082850 00000000febeba6b ffff800fb80cff50
ff20: ffff00000808677c ffff800fb80cff50 ffff000008086780 0000000060000145
ff40: ffff0000088ffb31 ffff000008117eb4
[] el1_irq+0xa0/0x10c
[] arch_cpu_idle+0x10/0x18
[] default_idle_call+0x18/0x28
[] cpu_startup_entry+0x10c/0x140
[] secondary_start_kernel+0x16c/0x1a0
[<000000400008283c>] 0x400008283c
INFO: rcu_preempt detected stalls on CPUs/tasks:
	(detected by 4, t=6340 jiffies, g=110692, c=110691, q=21)
All QSes seen, last rcu_preempt kthread activity 6323 (4305975437-4305969114), jiffies_till_next_fqs=1, root ->qsmask 0x0
swapper/4       R  running task        0     0      1 0x00000000
Call trace:
[] dump_backtrace+0x0/0x1ac
[] show_stack+0x14/0x1c
[] sched_show_task+0xa8/0xf4
[] rcu_check_callbacks+0x958/0x95c
[] update_process_times+0x3c/0x68
[] tick_sched_handle.isra.15+0x3c/0x4c
[] tick_sched_timer+0x44/0x7c
[] __hrtimer_run_queues+0xe8/0x14c
[] hrtimer_interrupt+0x9c/0x1e0
[] arch_timer_handler_phys+0x2c/0x38
[] handle_percpu_devid_irq+0x78/0x98
[] generic_handle_irq+0x24/0x38
[] __handle_domain_irq+0x60/0xac
[] gic_handle_irq+0x5c/0xb0
Exception stack(0xffff800fb80d7e30 to 0xffff800fb80d7f50)
7e20:                                   0000000000000000 0000000000000000
7e40: ffff800ffff64ab8 ffff800ffff64ac4 0100000000000000 000002045f3e04cf
7e60: 00000000007ffcf0 0000284c13452aa4 ffff800fb80c2ca0 0000000100a7da81
7e80: 0000000000000840 0000000000004bf0 0000000000000000 0000000000200000
7ea0: 000000000000016d 0000000000000000 ffff0000080becd0 0000aaaaba559058
7ec0: 0000ffffef15ae10 ffff0000088a6b0c 0000000000000e12 ffff0000088a6a78
7ee0: ffff800fb80d4000 ffff800fb80d4000 ffff800fb80d4000 ffff0000088ffb31
7f00: 0000000000000001 ffff000008082850 3fefd7fabdef7fb7 ffff800fb80d7f50
7f20: ffff00000808677c ffff800fb80d7f50 ffff000008086780 0000000060000145
7f40: ffff0000088ffb31 ffff000008117eb4
[] el1_irq+0xa0/0x10c
[] arch_cpu_idle+0x10/0x18
[] default_idle_call+0x18/0x28
[] cpu_startup_entry+0x10c/0x140
[] secondary_start_kernel+0x16c/0x1a0
[<000000400008283c>] 0x400008283c
rcu_preempt kthread starved for 6438 jiffies! g110692 c110691 f0x2 RCU_GP_WAIT_FQS(3) ->state=0x100
rcu_preempt     W ffff000008086c04     0     7      2 0x00000000
Call trace:
[] __switch_to+0xb4/0xdc
[] __schedule+0x1b0/0x578
[] schedule+0x3c/0xa0
[] schedule_timeout+0x104/0x1a0
[] rcu_gp_kthread+0x4b8/0x830
[] kthread+0xd4/0xe8
[] ret_from_fork+0x10/0x40