From owner-svn-src-head@FreeBSD.ORG Mon Mar 30 07:09:09 2015 Return-Path: Delivered-To: svn-src-head@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 5FCE4B85; Mon, 30 Mar 2015 07:09:09 +0000 (UTC) Received: from svn.freebsd.org (svn.freebsd.org [IPv6:2001:1900:2254:2068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 40399E52; Mon, 30 Mar 2015 07:09:09 +0000 (UTC) Received: from svn.freebsd.org ([127.0.1.70]) by svn.freebsd.org (8.14.9/8.14.9) with ESMTP id t2U799JU015693; Mon, 30 Mar 2015 07:09:09 GMT (envelope-from royger@FreeBSD.org) Received: (from royger@localhost) by svn.freebsd.org (8.14.9/8.14.9/Submit) id t2U798fS015691; Mon, 30 Mar 2015 07:09:08 GMT (envelope-from royger@FreeBSD.org) Message-Id: <201503300709.t2U798fS015691@svn.freebsd.org> X-Authentication-Warning: svn.freebsd.org: royger set sender to royger@FreeBSD.org using -f From: Roger Pau Monné Date: Mon, 30 Mar 2015 07:09:08 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r280838 - in head/sys: conf dev/xen/debug X-SVN-Group: head MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 30 Mar 2015 07:09:09 -0000 Author: royger Date: Mon Mar 30 07:09:07 2015 New Revision: 280838 URL: https://svnweb.freebsd.org/changeset/base/280838 Log: xen: add a handler for the debug interrupt Handle the VIRQ_DEBUG signal and print a stack trace of each vCPU on the Xen console. This is only used for debug purposes and is triggered by the administrator of the Xen host. Sponsored by: Citrix Systems R&D MFC after: 1 week Added: head/sys/dev/xen/debug/ head/sys/dev/xen/debug/debug.c (contents, props changed) Modified: head/sys/conf/files Modified: head/sys/conf/files ============================================================================== --- head/sys/conf/files Mon Mar 30 04:06:36 2015 (r280837) +++ head/sys/conf/files Mon Mar 30 07:09:07 2015 (r280838) @@ -2702,6 +2702,7 @@ dev/xen/xenstore/xenstore_dev.c optional dev/xen/xenstore/xenstored_dev.c optional xen | xenhvm dev/xen/evtchn/evtchn_dev.c optional xen | xenhvm dev/xen/privcmd/privcmd.c optional xen | xenhvm +dev/xen/debug/debug.c optional xen | xenhvm dev/xl/if_xl.c optional xl pci dev/xl/xlphy.c optional xl pci fs/autofs/autofs.c optional autofs Added: head/sys/dev/xen/debug/debug.c ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ head/sys/dev/xen/debug/debug.c Mon Mar 30 07:09:07 2015 (r280838) @@ -0,0 +1,157 @@ +/* + * Copyright (c) 2015 Roger Pau Monné + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include +__FBSDID("$FreeBSD$"); + +#include "opt_stack.h" +#include "opt_ddb.h" + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include + +/* + * Xen debug device + * + * Handles the VIRQ_DEBUG interrupt and prints the backtrace of each + * vCPU on the Xen console. + */ + +DPCPU_DEFINE(xen_intr_handle_t, xendebug_handler); +static struct mtx lock; +static struct sbuf *buf; + +static int +xendebug_drain(void *arg, const char *str, int len) +{ + + HYPERVISOR_console_write(__DECONST(char *, str), len); + return (len); +} + +extern void +stack_capture(struct stack *st, register_t rbp); + +static int +xendebug_filter(void *arg) +{ +#if defined(STACK) && defined(DDB) + struct stack st; + struct trapframe *frame; + + frame = arg; + stack_zero(&st); + stack_save(&st); + + mtx_lock_spin(&lock); + sbuf_clear(buf); + xc_printf("Printing stack trace vCPU%d\n", PCPU_GET(vcpu_id)); + stack_sbuf_print_ddb(buf, &st); + sbuf_finish(buf); + mtx_unlock_spin(&lock); +#endif + + return (FILTER_HANDLED); +} + +static void +xendebug_identify(driver_t *driver, device_t parent) +{ + + KASSERT(xen_domain(), + ("Trying to add Xen debug device to non-xen guest")); + + if (xen_hvm_domain() && !xen_vector_callback_enabled) + return; + + if (BUS_ADD_CHILD(parent, 0, "debug", 0) == NULL) + panic("Unable to add Xen debug device."); +} + +static int +xendebug_probe(device_t dev) +{ + + device_set_desc(dev, "Xen debug handler"); + return (BUS_PROBE_NOWILDCARD); +} + +static int +xendebug_attach(device_t dev) +{ + int i, error; + + mtx_init(&lock, "xen-dbg", NULL, MTX_SPIN); + buf = sbuf_new(NULL, NULL, 1024, SBUF_FIXEDLEN); + if (buf == NULL) + panic("Unable to create sbuf for stack dump"); + sbuf_set_drain(buf, xendebug_drain, NULL); + + /* Bind an event channel to a VIRQ on each VCPU. */ + CPU_FOREACH(i) { + error = xen_intr_bind_virq(dev, VIRQ_DEBUG, i, xendebug_filter, + NULL, NULL, INTR_TYPE_TTY, + DPCPU_ID_PTR(i, xendebug_handler)); + if (error != 0) { + printf("Failed to bind VIRQ_DEBUG to vCPU %d: %d", + i, error); + continue; + } + xen_intr_describe(DPCPU_ID_GET(i, xendebug_handler), "d%d", i); + } + + return (0); +} + +static device_method_t xendebug_methods[] = { + DEVMETHOD(device_identify, xendebug_identify), + DEVMETHOD(device_probe, xendebug_probe), + DEVMETHOD(device_attach, xendebug_attach), + + DEVMETHOD_END +}; + +static driver_t xendebug_driver = { + "debug", + xendebug_methods, + 0, +}; + +devclass_t xendebug_devclass; + +DRIVER_MODULE(xendebug, xenpv, xendebug_driver, xendebug_devclass, 0, 0); +MODULE_DEPEND(xendebug, xenpv, 1, 1, 1);