This is a note to let you know that I've just added the patch titled
KVM: x86/xen: Initialize Xen timer only once
to the 5.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
kvm-x86-xen-initialize-xen-timer-only-once.patch
and it can be found in the queue-5.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From af735db31285fa699384c649be72a9f32ecbb665 Mon Sep 17 00:00:00 2001
From: Coleman Dietsch <dietschc@xxxxxxx>
Date: Mon, 8 Aug 2022 14:06:06 -0500
Subject: KVM: x86/xen: Initialize Xen timer only once
From: Coleman Dietsch <dietschc@xxxxxxx>
commit af735db31285fa699384c649be72a9f32ecbb665 upstream.
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>
Message-Id: <20220808190607.323899-2-dietschc@xxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/kvm/xen.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
--- a/arch/x86/kvm/xen.c
+++ b/arch/x86/kvm/xen.c
@@ -713,7 +713,9 @@ int kvm_xen_vcpu_set_attr(struct kvm_vcp
break;
}
vcpu->arch.xen.timer_virq = data->u.timer.port;
- kvm_xen_init_timer(vcpu);
+
+ if (!vcpu->arch.xen.timer.function)
+ kvm_xen_init_timer(vcpu);
/* Restart the timer if it's set */
if (data->u.timer.expires_ns)
Patches currently in stable-queue which might be from dietschc@xxxxxxx are
queue-5.19/kvm-x86-xen-initialize-xen-timer-only-once.patch
queue-5.19/kvm-x86-xen-stop-xen-timer-before-changing-irq.patch
