From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 6D0763921FF; Sat, 7 Mar 2026 19:10:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772910621; cv=none; b=Xg22kLIP943w09DqdrbHJrkLTv6nOgZ8ypnrihtcBSxBbAsrREPWpBAvRIM6cIP2Ky613oF3nWJpZrhVeabl7Q3AzUoCKKkLGUawLbxaGHMxpVNz8QiTGgzSfsmaq4MAbw9NfzHczcvGrKDBPXJjRt9JZpgCatqoPFc5OCMh9Xo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772910621; c=relaxed/simple; bh=uKa6WLWDHwdq/7UThrztciV8wxtG930MrTaMOemvGkE=; h=Date:Message-ID:From:To:Cc:Subject:In-Reply-To:References: MIME-Version:Content-Type; b=h2BFEPE32oiZRP+VjLYdTlVksg0Us/73/z0+dw+hDnkwK8BgudQXsGxCAt8fyY36Hfex01s94Dk3O8IwGFvBCNmF547tFRwmtjz3RWmhMCSkYlOD8XS1VZ0msFBS+EJ3YQPrSF8F8U9d6w3rMWA0x5DwPyR+4AzmocJpE97+nv0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=D2yF8BIn; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="D2yF8BIn" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 026E4C19422; Sat, 7 Mar 2026 19:10:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772910621; bh=uKa6WLWDHwdq/7UThrztciV8wxtG930MrTaMOemvGkE=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=D2yF8BInsXByWczjZiFjRH3ju0lQH6uX4PxVTlnhqSRbZI9JemF0HyZJn6AI9lMT9 WgFuBECLkplojEs2oCGawoUJxR53rY1iBrwGQDSgjW5WK2xeFswhe1DzUPckUtYc7u xnafL7oNEgE52k6VR3Pr/7lZFQjPc+k9+mZpGiiGu7FpAbEuWxB2Z+1valkrzSvOnW HeXslEVGw5nSGUJJDEDcIV5iK+BxXdw4lbnFAN/4kIJij1FkDDCLNpU1Mb5tyYeivK gmFX7ICTmB/l3lLopNBtKXo+WNxvEHRClSrzpEjROx66dzATM+J1B3V7IIxgNfGf1r wxtgvvldGHD/A== Received: from sofa.misterjones.org ([185.219.108.64] helo=lobster-girl.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.98.2) (envelope-from ) id 1vyx2Y-0000000HDjs-1b7x; Sat, 07 Mar 2026 19:10:18 +0000 Date: Sat, 07 Mar 2026 19:10:17 +0000 Message-ID: <87y0k3cv6u.wl-maz@kernel.org> From: Marc Zyngier To: Valentine Burley Cc: "tabba" , "broonie" , "stable" , "oupton" , "joey.gouly" , "suzuki.poulose" , "yuzenghui" , "catalin.marinas" , "will" , "Sascha.Bischoff" , "sebott" , "linux-arm-kernel" , "kvmarm" , "linux-kernel" Subject: Re: [PATCH] KVM: arm64: Skip interrupts in LRs during EOIcount replay In-Reply-To: <19cc98f6bc6.30a0020a4990004.9101239855762576863@collabora.com> References: <20260307115955.369455-1-valentine.burley@collabora.com> <871phveh17.wl-maz@kernel.org> <19cc98f6bc6.30a0020a4990004.9101239855762576863@collabora.com> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/30.1 (aarch64-unknown-linux-gnu) MULE/6.0 (HANACHIRUSATO) Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: valentine.burley@collabora.com, tabba@google.com, broonie@kernel.org, stable@vger.kernel.org, oupton@kernel.org, joey.gouly@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, catalin.marinas@arm.com, will@kernel.org, Sascha.Bischoff@arm.com, sebott@redhat.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false On Sat, 07 Mar 2026 18:29:05 +0000, Valentine Burley wrote: > > Hi Marc, > > Thanks a lot for your reply. > > On Sat, 07 Mar 2026 17:33:08 +0100 Marc Zyngier wrote > > I can't reproduce it locally, but in a crap integration, where the GIC > > is clocked at a few dozen MHz, this is far more likely to happen. I > > should dig that Lazor out of the bin and put it back in the test rig. > > > > In retrospect, it is obvious. I just couldn't see it until then. Many > > thanks for going the extra mile and pointing out the core issue. > > Appreciate the clarification! > > We also have a few Lazor boards in our CI, and the Trogdors are indeed > legendary for hitting all kinds of edge cases. Right. Time to have a look at SBoyd's u-boot patches from last year! > > > > > Could you please give the hack below a go on your setup? It seems to > > work for me, but given that I never observed the issue the first > > place... > > I've tested this on my sc7180 Trogdor setup, and it completely > resolves the issue. The Cuttlefish VM now boots reliably. > > Tested-by: Valentine Burley Awesome. I have since tweaked the patch a tiny bit to keep the restart pointer per CPU instead of per vcpu, as this doesn't live beyond the load/put sequence. I'll post it formally for you to confirm that the updated version is still correct. Thanks, M. -- Jazz isn't dead. It just smells funny.