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 02E33C4167B for ; Tue, 5 Apr 2022 21:04:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345651AbiDEVDF (ORCPT ); Tue, 5 Apr 2022 17:03:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46592 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1447329AbiDEPqS (ORCPT ); Tue, 5 Apr 2022 11:46:18 -0400 Received: from mail-wm1-x34a.google.com (mail-wm1-x34a.google.com [IPv6:2a00:1450:4864:20::34a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A018D91565 for ; Tue, 5 Apr 2022 07:21:08 -0700 (PDT) Received: by mail-wm1-x34a.google.com with SMTP id c125-20020a1c3583000000b0038e3f6e871aso4079128wma.8 for ; Tue, 05 Apr 2022 07:21:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:message-id:mime-version:subject:from:to:cc; bh=m3vxItKXnUJTINlJEdj+JcIaXhSRzpBzJXMN0Ho5eps=; b=U/rCu1Z2QfNGh7871ZpZdN4wY/+Lh1Wn/I5Ha6phoPhUI3yRDteIeF+TZGPPbHc3Ai BBQSP1z5sD9b+wklr0ZXpHQDx20253jpVlFYCml1fsblFB2Q243A1smZeVhSbDbYut0u z7IHIiryy2SGXsp58k8lugrnBQWpAfe4UaUoIoiLNUWU6VPrmVSPjgLFVRjjlsnuviJh g2vIiFzGHXI6KSMbAEIY16WttCiHeVwLMIUVeWsgv9R9tws08lP2EReN2yTioJTEcmxr 8dTXpSzd/4Gkzv5UDngHARkRMF8rXO+CxVkuFg6Z/c+C3T3Db9QNzs4r4LR3an7j0BQQ bBuw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=m3vxItKXnUJTINlJEdj+JcIaXhSRzpBzJXMN0Ho5eps=; b=dY+cr4XghiiNDq5E2AFWN39V7i2lWNwXnGfqAVwsLwohr/AdAMIHjCDtVin09lpR4X MTFTjJSmlwa8vC7wDNVPjXfz11j4P4tE9TfqvhodTb6XAajuKY0gp1Bm+C9JjmcTTgdb BboTdjOPdhGS/gUtiAW8FIenJ4SyVYQ1DU6Ens0bti0xtrCg1dvBW1KAxIRnw+Syln4a aGgnZVQQ5ykKJfG/HWjbUCFKTi+vWyAOzQs/tKNNjrmsV2DUIxLVYYWjliF2C0v0txD7 8L1NJoEh/5Ks4swA2PkuQzgKDJqOdvig52XTp9M1BoCZIGjcNcafRku0quDyqMo7YtJD lipg== X-Gm-Message-State: AOAM53120/yRG3VPGfYa7cDuI8ANawVrpoZWTS+dzkl6dZc3F2W+GrCM N38W+URgQ6ORP4AwSxHyV8yLNcyeFwMNIut98mg= X-Google-Smtp-Source: ABdhPJwN5QFMBNAx6z4lJuIDDPZMY0wbemxu/vZ7lASsb58ZkL62PcBPIS8ol+sPOaL6RzriqT4z3Z6RSNAw7S3JJqU= X-Received: from sene.c.googlers.com ([fda3:e722:ac3:cc00:28:9cb1:c0a8:27c4]) (user=sebastianene job=sendgmr) by 2002:a05:600c:4f87:b0:38c:adde:1d99 with SMTP id n7-20020a05600c4f8700b0038cadde1d99mr3320464wmq.16.1649168466877; Tue, 05 Apr 2022 07:21:06 -0700 (PDT) Date: Tue, 5 Apr 2022 14:19:53 +0000 Message-Id: <20220405141954.1489782-1-sebastianene@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.35.1.1094.g7c7d902a7c-goog Subject: [PATCH 0/2] Detect stalls on guest vCPUS From: Sebastian Ene To: Wim Van Sebroeck , Guenter Roeck , Rob Herring Cc: devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-watchdog@vger.kernel.org, will@kernel.org, qperret@google.com, maz@kernel.org, Sebastian Ene Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This adds a mechanism to detect stalls on the guest vCPUS by creating a per CPU hrtimer which periodically 'pets' the host backend driver. 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 Sebastian Ene (2): dt-bindings: watchdog: Add qemu,vm-watchdog compatible watchdog: Add a mechanism to detect stalls on guest vCPUs .../devicetree/bindings/watchdog/vm-wdt.yaml | 44 ++++ drivers/watchdog/Kconfig | 8 + drivers/watchdog/Makefile | 1 + drivers/watchdog/vm-wdt.c | 215 ++++++++++++++++++ 4 files changed, 268 insertions(+) create mode 100644 Documentation/devicetree/bindings/watchdog/vm-wdt.yaml create mode 100644 drivers/watchdog/vm-wdt.c -- 2.35.1.1094.g7c7d902a7c-goog