Re: kvm: GPF in kvm_lapic_latched_init

[Dmitry Vyukov]

On Wed, Jun 22, 2016 at 10:36 AM, Paolo Bonzini <pbonzini@xxxxxxxxxx> wrote:
>
>
> On 22/06/2016 10:20, Dmitry Vyukov wrote:
>>>> >> All crashes suggest that apic is NULL.
>>>> >>
>>>> >> On commit b06f3a168cdcd80026276898fd1fee443ef25743 (Jan 6).
>>
>> Ping. Just hit it again on 67016f6cdfd079e632bbc49e33178b2d558c120a (Jun 20):
>
> This might have been the same bug you reported yesterday in kvm_set_cr8.
>  I've sent a patch to fix static keys.

Then it is probably the same as the following one as well?

WARNING: CPU: 3 PID: 23379 at kernel/sched/core.c:2583[<      none
 >] preempt_notifier_register+0x2b/0x120 kernel/sched/core.c:2583
registering preempt_notifier while notifiers disabled
Modules linked in:
CPU: 3 PID: 23379 Comm: syz-executor Not tainted 4.7.0-rc4+ #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
 ffffffff880b58e0 ffff88003a79fa60 ffffffff82cc62cf ffffffff81495e98
 fffffbfff1016b1c ffff88003a79fad8 0000000000000000 ffffffff86ca0220
 ffffffff813ed78b 0000000000000009 ffff88003a79faa8 ffffffff8136d27f
Call Trace:
 [<     inline     >] __dump_stack lib/dump_stack.c:15
 [<ffffffff82cc62cf>] dump_stack+0x12e/0x18f lib/dump_stack.c:51
 [<ffffffff8136d27f>] __warn+0x19f/0x1e0 kernel/panic.c:516
 [<ffffffff8136d36c>] warn_slowpath_fmt+0xac/0xd0 kernel/panic.c:531
 [<ffffffff813ed78b>] preempt_notifier_register+0x2b/0x120
kernel/sched/core.c:2583
 [<ffffffff81067d96>] vcpu_load+0x46/0x70
arch/x86/kvm/../../../virt/kvm/kvm_main.c:146
 [<ffffffff810b933f>] kvm_arch_vcpu_setup+0x1f/0x60 arch/x86/kvm/x86.c:7390
 [<     inline     >] kvm_vm_ioctl_create_vcpu
arch/x86/kvm/../../../virt/kvm/kvm_main.c:2355
 [<ffffffff8106b9f2>] kvm_vm_ioctl+0x582/0x10d0
arch/x86/kvm/../../../virt/kvm/kvm_main.c:2839
 [<     inline     >] vfs_ioctl fs/ioctl.c:43
 [<ffffffff818510bc>] do_vfs_ioctl+0x18c/0xff0 fs/ioctl.c:674
 [<     inline     >] SYSC_ioctl fs/ioctl.c:689
 [<ffffffff81851faf>] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:680
 [<ffffffff86a97000>] entry_SYSCALL_64_fastpath+0x23/0xc1
arch/x86/entry/entry_64.S:207
---[ end trace c0e5c1ad551a4947 ]---