Messages in this thread | | | From | Thomas Gleixner <> | Subject | Re: [patch V4 part 1 12/36] x86/kvm: Sanitize kvm_async_pf_task_wait() | Date | Tue, 05 May 2020 23:50:33 +0200 |
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"Paul E. McKenney" <paulmck@kernel.org> writes: > On Tue, May 05, 2020 at 03:16:14PM +0200, Thomas Gleixner wrote: >> RCU is watching for: >> >> #1 The vCPU exited and current is definitely not the idle task >> >> #2a The #PF entry code on the guest went through enter_from_user_mode() >> which reactivates RCU > > I have to double-check... The NO_HZ_FULL case transitioning to/from > userspace is entirely non-preemptible, correct? (After rcu_user_enter() > and before rcu_user_exit(), respectively.)
Yes. It runs with interrupts disabled down to the actual return (sysret, iret).
Thanks,
tglx
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