From: Thomas Gleixner <tglx@kernel.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Binbin Wu <binbin.wu@linux.intel.com>,
"Verma, Vishal L" <vishal.l.verma@intel.com>,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
"Edgecombe, Rick P" <rick.p.edgecombe@intel.com>,
"Wu, Binbin" <binbin.wu@intel.com>,
"x86@kernel.org" <x86@kernel.org>
Subject: Re: CPU Lockups in KVM with deferred hrtimer rearming
Date: Tue, 21 Apr 2026 18:30:43 +0200 [thread overview]
Message-ID: <87jyu0b7ik.ffs@tglx> (raw)
In-Reply-To: <20260421113212.GI3126523@noisy.programming.kicks-ass.net>
On Tue, Apr 21 2026 at 13:32, Peter Zijlstra wrote:
> On Tue, Apr 21, 2026 at 01:18:58PM +0200, Peter Zijlstra wrote:
>> > /*
>> > + * This is sadly required due to KVM, which invokes regular
>> > + * interrupt handlers with interrupt disabled state in @regs.
>> > + */
>> > + instrumentation_begin();
>> > + hrtimer_rearm_deferred();
>> > + instrumentation_end();
>> > +
>> > + /*
>> > * IRQ flags state is correct already. Just tell RCU if it
>> > * was not watching on entry.
>> > */
>
> Ohhh, wait. What happens if you take a page-fault from NMI context? Does
> this then not result in trying to program the timer from NMI context?
Uuuurgh, yes.
next prev parent reply other threads:[~2026-04-21 16:30 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-04-16 20:50 CPU Lockups in KVM with deferred hrtimer rearming Verma, Vishal L
2026-04-20 15:00 ` Thomas Gleixner
2026-04-20 15:22 ` Thomas Gleixner
2026-04-20 20:57 ` Verma, Vishal L
2026-04-20 22:19 ` Thomas Gleixner
2026-04-20 22:24 ` Verma, Vishal L
2026-04-21 6:29 ` Thomas Gleixner
2026-04-21 4:51 ` Binbin Wu
2026-04-21 7:39 ` Thomas Gleixner
2026-04-21 11:18 ` Peter Zijlstra
2026-04-21 11:32 ` Peter Zijlstra
2026-04-21 11:34 ` Peter Zijlstra
2026-04-21 11:49 ` Peter Zijlstra
2026-04-21 12:05 ` Peter Zijlstra
2026-04-21 13:19 ` Peter Zijlstra
2026-04-21 13:29 ` Peter Zijlstra
2026-04-21 16:36 ` Thomas Gleixner
2026-04-21 18:11 ` Verma, Vishal L
2026-04-21 17:11 ` Thomas Gleixner
2026-04-21 17:20 ` Jim Mattson
2026-04-21 18:29 ` Thomas Gleixner
2026-04-21 18:55 ` Sean Christopherson
2026-04-21 20:06 ` Peter Zijlstra
2026-04-21 20:46 ` Peter Zijlstra
2026-04-21 20:57 ` Sean Christopherson
2026-04-21 21:02 ` Peter Zijlstra
2026-04-21 21:42 ` Sean Christopherson
2026-04-22 6:55 ` Peter Zijlstra
2026-04-21 20:39 ` Paolo Bonzini
2026-04-21 21:02 ` Sean Christopherson
2026-04-21 22:48 ` Thomas Gleixner
2026-04-21 23:15 ` Paolo Bonzini
2026-04-21 23:34 ` Jim Mattson
2026-04-21 23:37 ` Paolo Bonzini
2026-04-22 2:10 ` Thomas Gleixner
2026-04-21 21:49 ` Thomas Gleixner
2026-04-21 22:07 ` Sean Christopherson
2026-04-21 22:24 ` Paolo Bonzini
2026-04-21 19:18 ` Verma, Vishal L
2026-04-21 16:30 ` Thomas Gleixner [this message]
2026-04-21 16:11 ` Verma, Vishal L
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