From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755298AbbAZNmC (ORCPT ); Mon, 26 Jan 2015 08:42:02 -0500 Received: from mx1.redhat.com ([209.132.183.28]:45660 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751910AbbAZNl5 (ORCPT ); Mon, 26 Jan 2015 08:41:57 -0500 From: Vitaly Kuznetsov To: "K. Y. Srinivasan" Cc: devel@linuxdriverproject.org, Haiyang Zhang , linux-kernel@vger.kernel.org Subject: Re: [PATCH 0/3] Drivers: hv: vmbus: fix crashes on hv_vmbus load/unload path References: <1421866929-20167-1-git-send-email-vkuznets@redhat.com> Date: Mon, 26 Jan 2015 14:41:50 +0100 In-Reply-To: <1421866929-20167-1-git-send-email-vkuznets@redhat.com> (Vitaly Kuznetsov's message of "Wed, 21 Jan 2015 20:02:06 +0100") Message-ID: <87y4opek0x.fsf@vitty.brq.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Vitaly Kuznetsov writes: > It is possible (since 93e5bd06a953: "Drivers: hv: Make the vmbus driver > unloadable") to unload hv_vmbus driver if no other devices are connected. > 1aec169673d7: "x86: Hyperv: Cleanup the irq mess" fixed doulble interrupt > gate setup. However, if we try to unload hv_vmbus and then load it back > crashes in different places of vmbus driver occur on both unload and second > load paths. Address those I saw in my testing. It seems that newly introduced clockevent device (Drivers: hv: vmbus: Implement a clockevent device) makes it impossible to unload hv_vmbus module: # rmmod hv_vmbus rmmod hv_vmbus rmmod: ERROR: Module hv_vmbus is in use I'll try investigating before sending v2 without PATCH 2/3. > > Not everything is fixed though. MCE was hit once on Generation2 instance and > I neither understand what caused it nor do I know the way to reproduce it. > Anyway, here is the log: > > [ 204.846255] mce: [Hardware Error]: CPU 0: Machine Check Exception: 4 Bank 0: b2000000c0020001 > [ 204.846675] mce: [Hardware Error]: TSC 6b5cd64bc8 > [ 204.846675] mce: [Hardware Error]: PROCESSOR 0:306e4 TIME 1421944123 SOCKET 0 APIC 0 microcode ffffffff > [ 204.846675] mce: [Hardware Error]: Run the above through 'mcelog --ascii' > [ 204.846675] mce: [Hardware Error]: Machine check: Processor context corrupt > [ 204.846675] Kernel panic - not syncing: Fatal Machine check > [ 204.846675] Kernel Offset: 0x0 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffff9fffffff) > [ 204.846675] Rebooting in 30 seconds.. > [ 204.846675] ACPI MEMORY or I/O RESET_REG. > > Vitaly Kuznetsov (3): > Drivers: hv: vmbus: avoid double kfree for device_obj > Drivers: hv: vmbus: introduce vmbus_acpi_remove > Drivers: hv: vmbus: teardown hv_vmbus_con workqueue and > vmbus_connection pages on shutdown > > drivers/hv/channel_mgmt.c | 1 - > drivers/hv/connection.c | 17 ++++++++++++----- > drivers/hv/hyperv_vmbus.h | 1 + > drivers/hv/vmbus_drv.c | 16 ++++++++++++++++ > 4 files changed, 29 insertions(+), 6 deletions(-) -- Vitaly