From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 18DA61684BE for ; Wed, 22 Apr 2026 06:55:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776840955; cv=none; b=SvVpa/95EfWi1aEWpBO7DhLTzPExZK8BTaDjeATnImjM8z8E0JHvB79xCtU+6DwDIku5ml8VfjXuXBLRIlySsq0VUp/hY9qVEVxvJl95lrOanJxsItI6m52oR7MGlCy1zEvEIomzS7OmnpBq96i1i+FN4gXX2tRs9JiTwvdwZB8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776840955; c=relaxed/simple; bh=2DemsOezg/z3DkZS5H1dvBnCGi3HrYdAoFz5trCrzaM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=itjDZrq/h7TxFExdvNxayklJl7q8RDZQyqs8wb/yBtPh4p2zRPJ//eojXlPhMkEILAwFUTnZKsvFaGs7Y8TDktJt4grVfSE+owdpLQkfaMcArt8PX57Ff59JKnYWnPMP/USn2mogK0GIF/7kdlNQ2AdbJonQSygaGgrltsVBmPw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=pKSUvDwu; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="pKSUvDwu" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=wxqAo6OR7qeLNWMF1zi73AWo6MmC+rCHLnjlPsmqr4I=; b=pKSUvDwuNB44J7t+qn0y48uWwF Wy7qdHh3hGyQBiPgbax11KhxHAnJ6Mk5WuECelZZBruwNtg5Lsq6pfZ6hNJ4rmcmdcHN5VnhfA2ms sEUxAUx9Q/ykyjqeSG9KQlagSj+MX8FoG4MbprMK1qSOSznPNhLCRxl9rWrPeOqYydoqe9Ct6kYOQ zjvdnXxKYNigzEtPe7jFHcmKWjbolXF0sAKa0Euc/mrbwnskuIp93FN/0IZskzFKYrwfplxxFj1I1 YKs0A11KuoRh4equfkSbobk+JrrbVmUbjZpwMhwyrP/QoUkuwPWGmBLgcXoZ+E7OjDd6xrhm9r8rK nzX1F3iw==; Received: from 77-249-17-252.cable.dynamic.v4.ziggo.nl ([77.249.17.252] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.98.2 #2 (Red Hat Linux)) id 1wFRUu-0000000BLb9-0ib5; Wed, 22 Apr 2026 06:55:44 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id A64AA3008E2; Wed, 22 Apr 2026 08:55:42 +0200 (CEST) Date: Wed, 22 Apr 2026 08:55:42 +0200 From: Peter Zijlstra To: Sean Christopherson Cc: Thomas Gleixner , Jim Mattson , Binbin Wu , Vishal L Verma , "kvm@vger.kernel.org" , Rick P Edgecombe , Binbin Wu , "x86@kernel.org" , Paolo Bonzini Subject: Re: CPU Lockups in KVM with deferred hrtimer rearming Message-ID: <20260422065542.GN3126523@noisy.programming.kicks-ass.net> References: <20260421113407.GE3102924@noisy.programming.kicks-ass.net> <20260421114940.GJ3126523@noisy.programming.kicks-ass.net> <87cxzsb5n0.ffs@tglx> <878qagb20x.ffs@tglx> <20260421200620.GK3126523@noisy.programming.kicks-ass.net> <20260421210201.GM3126523@noisy.programming.kicks-ass.net> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Tue, Apr 21, 2026 at 02:42:46PM -0700, Sean Christopherson wrote: > On Tue, Apr 21, 2026, Peter Zijlstra wrote: > > On Tue, Apr 21, 2026 at 08:57:24PM +0000, Sean Christopherson wrote: > > > This as delta? (I had typed this all up before Peter posted a new verison, so > > > dammit I'm sending it!) > > > > :-) > > > > I'll go stare at it in the morning, I'm about to go crash out. > > New delta against your effective v2, builds all of my configs (which isn't _that_ > many, but I think they cover most of the weirder ways to include KVM (or not)). > > I'll start testing the full thing to try and get early signal on the health. Oh, re-reading commit 28d11e4548b7, I think this wrecks NMIs. The patch will also use the FRED NMI path and that's not good when running IDT. I'll go fix that and stick in a few more comments to clarify this magic.