Re: [PATCH v3 1/2] KVM: x86/xen: Initialize Xen timer only once

[Paolo Bonzini]

On 8/9/22 02:32, Sean Christopherson wrote:
> On Mon, Aug 08, 2022, Coleman Dietsch wrote:
> > Add a check for existing xen timers before initializing a new one.
> >
> > Currently kvm_xen_init_timer() is called on every
> > KVM_XEN_VCPU_ATTR_TYPE_TIMER, which is causing the following ODEBUG
> > crash when vcpu->arch.xen.timer is already set.
> >
> > ODEBUG: init active (active state 0)
> > object type: hrtimer hint: xen_timer_callbac0
> > RIP: 0010:debug_print_object+0x16e/0x250 lib/debugobjects.c:502
> > Call Trace:
> > __debug_object_init
> > debug_hrtimer_init
> > debug_init
> > hrtimer_init
> > kvm_xen_init_timer
> > kvm_xen_vcpu_set_attr
> > kvm_arch_vcpu_ioctl
> > kvm_vcpu_ioctl
> > vfs_ioctl
> >
> > Fixes: 536395260582 ("KVM: x86/xen: handle PV timers oneshot mode")
> > Cc: stable@xxxxxxxxxxxxxxx
> > Link: https://syzkaller.appspot.com/bug?id=8234a9dfd3aafbf092cc5a7cd9842e3ebc45fc42
> > Reported-by: syzbot+e54f930ed78eb0f85281@xxxxxxxxxxxxxxxxxxxxxxxxx
> > Signed-off-by: Coleman Dietsch <dietschc@xxxxxxx>
> > ---
>
> Reviewed-by: Sean Christopherson <seanjc@xxxxxxxxxx>

Queued both (pending resolution of David's question), thanks.

Paolo