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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DD471C433EF for ; Thu, 14 Jul 2022 14:55:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238854AbiGNOzC (ORCPT ); Thu, 14 Jul 2022 10:55:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60936 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229986AbiGNOzB (ORCPT ); Thu, 14 Jul 2022 10:55:01 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8BF1D2BB2B; Thu, 14 Jul 2022 07:55:00 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 471A3B826C0; Thu, 14 Jul 2022 14:54:59 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 36310C3411C; Thu, 14 Jul 2022 14:54:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1657810497; bh=nZAl/M9yCCjXCxofy9D8zOlauT5qfrQNarNo+cTtzGY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=07sPYhnSnpZo6EAb/64UVfYDTjvqGLlXqViVTZBCM2gCnJ94OKqEMX7Q0Gugc2x+W liJtqJedq+KKCnZT/NMUQ7gzXoh2HprkZvQFBngXaTf5XR+w5j9NA9CSi+FIr8aeMA Xr2ffmhwMK7nO+pQXAnFnsTVe9ItUJxZXQoz484s= Date: Thu, 14 Jul 2022 16:54:54 +0200 From: Greg Kroah-Hartman To: Sebastian Ene Cc: Rob Herring , Arnd Bergmann , Dragan Cvetic , linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, maz@kernel.org, will@kernel.org, vdonnefort@google.com, Guenter Roeck Subject: Re: [PATCH v12 0/2] Detect stalls on guest vCPUS Message-ID: References: <20220711081720.2870509-1-sebastianene@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220711081720.2870509-1-sebastianene@google.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jul 11, 2022 at 08:17:18AM +0000, Sebastian Ene wrote: > Minor change from v11 which cleans up the Kconfig option selection. > > This adds a mechanism to detect stalls on the guest vCPUS by creating a > per CPU hrtimer which periodically 'pets' the host backend driver. > On a conventional watchdog-core driver, the userspace is responsible for > delivering the 'pet' events by writing to the particular /dev/watchdogN node. > In this case we require a strong thread affinity to be able to > account for lost time on a per vCPU basis. > > This device driver acts as a soft lockup detector by relying on the host > backend driver to measure the elapesed time between subsequent 'pet' events. > If the elapsed time doesn't match an expected value, the backend driver > decides that the guest vCPU is locked and resets the guest. The host > backend driver takes into account the time that the guest is not > running. The communication with the backend driver is done through MMIO > and the register layout of the virtual watchdog is described as part of > the backend driver changes. > > The host backend driver is implemented as part of: > https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/3548817 > > Changelog v12: > - don't select LOCKUP_DETECTOR from Kconfig when VCPU_STALL_DETECTOR is > compiled in as suggested by Greg > - add the review-by tag received from Guenter Thanks for sticking with this, now applied to my tree! greg k-h