From: "Paul E. McKenney" <paulmck@kernel.org>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: LKML <linux-kernel@vger.kernel.org>,
x86@kernel.org, Paolo Bonzini <pbonzini@redhat.com>,
KVM <kvm@vger.kernel.org>
Subject: Re: [patch 2/2] x86/kvm: Sanitize kvm_async_pf_task_wait()
Date: Fri, 6 Mar 2020 19:48:42 -0800 [thread overview]
Message-ID: <20200307034842.GM2935@paulmck-ThinkPad-P72> (raw)
In-Reply-To: <874kv1asf2.fsf@nanos.tec.linutronix.de>
On Sat, Mar 07, 2020 at 02:02:25AM +0100, Thomas Gleixner wrote:
> "Paul E. McKenney" <paulmck@kernel.org> writes:
> >> In #2c RCU is eventually not watching, but as that state cannot schedule
> >> anyway there is no point to worry about it so it has to invoke
> >> rcu_irq_enter() before running that code. This can be optimized, but this
> >> will be done as an extra step in course of the entry code consolidation
> >> work.
> >
> > In other words, any needed rcu_irq_enter() and rcu_irq_exit() are added
> > in one of the entry-code consolidation patches, and patch below depends
> > on that patch, correct?
>
> No. The patch itself is already correct when applied to mainline. It has
> no dependencies.
>
> It invokes rcu_irq_enter()/exit() for the case (#2c) where it is
> relevant. All other case are already RCU safe today.
>
> The fact that the invocation is misplaced is a different story and yes,
> that is part of the entry code cleanup along with some optimization
> which are possible once the entry voodoo is out of ASM and adjustable
> for a particular entry point in C.
The weekend clearly did not come a moment too soon for me, did it? :-/
Thanx, Paul
next prev parent reply other threads:[~2020-03-07 3:48 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-06 23:42 [patch 0/2] x86/kvm: Sanitize async page fault Thomas Gleixner
2020-03-06 23:42 ` [patch 1/2] x86/kvm: Handle async page faults directly through do_page_fault() Thomas Gleixner
2020-03-17 8:47 ` [x86/kvm] aec3011ae9: WARNING:at_arch/x86/kernel/kvm.c:#kvm_guest_init kernel test robot
2020-03-06 23:42 ` [patch 2/2] x86/kvm: Sanitize kvm_async_pf_task_wait() Thomas Gleixner
2020-03-07 0:22 ` Paul E. McKenney
2020-03-07 1:02 ` Thomas Gleixner
2020-03-07 3:48 ` Paul E. McKenney [this message]
2020-03-07 2:18 ` Andy Lutomirski
2020-03-07 10:01 ` Thomas Gleixner
2020-03-07 15:10 ` Andy Lutomirski
2020-03-07 15:51 ` Andy Lutomirski
2020-03-07 19:18 ` Thomas Gleixner
2020-03-07 19:30 ` Andy Lutomirski
2020-03-07 15:52 ` Thomas Gleixner
2020-03-07 16:06 ` Andy Lutomirski
2020-03-07 20:08 ` Thomas Gleixner
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