From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 96DB2CCFA03 for ; Mon, 3 Nov 2025 17:08:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type:MIME-Version: References:In-Reply-To:Subject:Cc:To:From:Message-ID:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=KNOX9bC4PnsvZSk/tqDcQzI2znHB7qB+hzfTMmMU2hU=; b=eqdpyUUUVgxeD9H/qXbsWY9izb GYGVza3wst3LHk4wRoHzwxxYxhYj8YTU7sqx6J86D4D2nYLaz5nUyyw+oxaZ5EXvwrb7N1EXoH00o +VcpYGDOgU1F+Pq7d00L2tCXPiorVHofx8pw5ErIdsN8hiJwZ7OFf+1FGgrso2DLrfppHRgSoAmaK 8H/LRAQfB9V7JHqsagaw1VsANKDcvX3VwcoHzeB04v4NnXec1QhQIACGzRTY/JVgmoZVboE321o0C tH30+j8T9JyBUIF7wAX1SQXONfSUjtvicM60gq8idKXX2/LPvF2VRSdbc5jVyBiZED45hfiqrp+So /kGuDkyQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vFy2l-0000000ANiL-2pUU; Mon, 03 Nov 2025 17:08:35 +0000 Received: from tor.source.kernel.org ([2600:3c04:e001:324:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vFy2j-0000000ANiB-2wma for linux-arm-kernel@lists.infradead.org; Mon, 03 Nov 2025 17:08:33 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id D9A7D600AC; Mon, 3 Nov 2025 17:08:32 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8BA28C4CEE7; Mon, 3 Nov 2025 17:08:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1762189712; bh=wE/D5rYtdA0boJDz954m2D45oyFdKQreqvfhxiSLQOA=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=TYcFsJx8VKaS4+k6+vtaAgEH0SSOCBkMQbXseJMEvVtWApzTJyqm9ghkRAgzeWd/c kCw6yzFSgF9z/iigU539QBLtUHTSTsxa/JTfr9vVlx0JGC11z08grKLC8VkoPUKySE OWVQRvneiRx8WoYjuUWPxO1he6gdInKL8zVMnZFjktDs7XAMJQc2omHcyi16ufOJVN GksCQwCwh6OaMKid1dohrsdsemgwYVbRzLnRBjaOUYMkDAUPeP9HOWj5O3NurRAkBv 4KiSU7+3c6u32i/chJvdAJzAY/AMxmz9Ou0NTF4MzFnw4UH+e6phGR8s7RZQnPBmQc 67LDPPu/bF6jg== Received: from sofa.misterjones.org ([185.219.108.64] helo=goblin-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 1vFy2g-000000022Aw-2kRh; Mon, 03 Nov 2025 17:08:30 +0000 Date: Mon, 03 Nov 2025 17:08:30 +0000 Message-ID: <86ldknujqp.wl-maz@kernel.org> From: Marc Zyngier To: Volodymyr Babchuk Cc: "linux-arm-kernel@lists.infradead.org" , Dmytro Terletskyi Subject: Re: KVM: Nested VGIC emulation leads to infinite IRQ exceptions In-Reply-To: <87bjmrprvq.fsf@epam.com> References: <87bjmrprvq.fsf@epam.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) 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: Volodymyr_Babchuk@epam.com, linux-arm-kernel@lists.infradead.org, Dmytro_Terletskyi@epam.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, 30 Sep 2025 22:11:54 +0100, Volodymyr Babchuk wrote: > > > Hi all, > > We are trying to run Xen as KVM nested hypervisor (again!) and we have > encountered strange issue with GIC nested emulation. I am certain that > we'll dig to the root cause, but probably someone on the ML will save us > a couple of days of debugging by providing with some insights. [...] FWIW, I have just posted a (large) series[1] that aims at fixing the issue you have reported. I'd appreciate it if you could give it a go and report whether this helps addressing it. Thanks, M. [1] https://lore.kernel.org/all/20251103165517.2960148-1-maz@kernel.org/ -- Without deviation from the norm, progress is not possible.