From patchwork Mon Dec 5 22:23:27 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Llu=C3=ADs_Vilanova?= X-Patchwork-Id: 129455 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [140.186.70.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 957771007D4 for ; Tue, 6 Dec 2011 09:23:49 +1100 (EST) Received: from localhost ([::1]:39642 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RXgws-0007ti-M7 for incoming@patchwork.ozlabs.org; Mon, 05 Dec 2011 17:23:46 -0500 Received: from eggs.gnu.org ([140.186.70.92]:36611) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RXgwl-0007lC-92 for qemu-devel@nongnu.org; Mon, 05 Dec 2011 17:23:40 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1RXgwj-0001OZ-O0 for qemu-devel@nongnu.org; Mon, 05 Dec 2011 17:23:39 -0500 Received: from gw.ac.upc.edu ([147.83.30.3]:47483) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RXgwj-0001OV-A3 for qemu-devel@nongnu.org; Mon, 05 Dec 2011 17:23:37 -0500 Received: from localhost (unknown [84.88.53.92]) by gw.ac.upc.edu (Postfix) with ESMTP id F22CE6B01CA; Mon, 5 Dec 2011 23:23:35 +0100 (CET) To: qemu-devel@nongnu.org From: =?utf-8?b?TGx1w61z?= Vilanova Date: Mon, 05 Dec 2011 23:23:27 +0100 Message-ID: <20111205222327.31271.64834.stgit@ginnungagap.bsc.es> In-Reply-To: <20111205222208.31271.65662.stgit@ginnungagap.bsc.es> References: <20111205222208.31271.65662.stgit@ginnungagap.bsc.es> User-Agent: StGit/0.15 MIME-Version: 1.0 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6 (newer, 3) X-Received-From: 147.83.30.3 Cc: Blue Swirl , Zhi Yong Wu Subject: [Qemu-devel] [PATCH v2 5/5] backdoor: Add guest-side library X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Guest applications can link against "libqemu-backdoor-guest.a" to use the backdoor communication channel. Signed-off-by: Lluís Vilanova --- backdoor/guest/Makefile | 18 ++++ backdoor/guest/common.c | 205 ++++++++++++++++++++++++++++++++++++++++ backdoor/guest/qemu-backdoor.h | 59 ++++++++++++ backdoor/qemu/user.c | 2 configure | 2 5 files changed, 285 insertions(+), 1 deletions(-) create mode 100644 backdoor/guest/Makefile create mode 100644 backdoor/guest/common.c create mode 100644 backdoor/guest/qemu-backdoor.h diff --git a/backdoor/guest/Makefile b/backdoor/guest/Makefile new file mode 100644 index 0000000..200ee3b --- /dev/null +++ b/backdoor/guest/Makefile @@ -0,0 +1,18 @@ +include ../../../config-host.mak +include ../../config-target.mak +include $(SRC_PATH)/rules.mak + +vpath % $(SRC_PATH)/backdoor/guest + +QEMU_CFLAGS += $(GLIB_CFLAGS) +QEMU_CFLAGS += -I../../../ +QEMU_CFLAGS += -I../../ + +obj-y = common.o + +libqemu-backdoor-guest.a: $(obj-y) + +all: libqemu-backdoor-guest.a + +clean: + rm -f $(obj-y) libqemu-backdoor-guest.a diff --git a/backdoor/guest/common.c b/backdoor/guest/common.c new file mode 100644 index 0000000..2238dfa --- /dev/null +++ b/backdoor/guest/common.c @@ -0,0 +1,205 @@ +/* + * Guest-side management of backdoor channels. + * + * Copyright (C) 2011 Lluís Vilanova + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + */ + +#include "qemu-backdoor.h" + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "config-target.h" +#include "hw/pci_ids.h" +#include "hw/pci.h" + + +static char *data_path = NULL; +static char *control_path = NULL; +static int data_fd = -1; +static int control_fd = -1; + +static void *data_addr = NULL; +static void *control_addr = NULL; + + +static int init_channel_file(const char *base, const char *suffix, size_t size, + char ** path, int *fd, void **addr) +{ + *path = malloc(strlen(base) + strlen(suffix) + 1); + sprintf(*path, "%s%s", base, suffix); + + *fd = open(*path, O_RDWR); + if (*fd == -1) { + return -1; + } + + *addr = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, *fd, 0); + if (*addr == MAP_FAILED) { + return -1; + } + return 0; +} + +#if !defined(CONFIG_USER_ONLY) && defined(__linux__) +static int check_device_id (const char *base, const char *name, uint64_t value) +{ + char tmp[1024]; + sprintf(tmp, "%s/%s", base, name); + + int fd = open(tmp, O_RDONLY); + if (fd < 0) { + return -1; + } + + char v[1024]; + ssize_t s = read(fd, v, sizeof(v)); + if (s < 0) { + close(fd); + return -1; + } + v[s] = '\0'; + + char *end; + uint64_t vv = strtoull(v, &end, 16); + if (*end == '\n' && vv == value) { + return 0; + } + else { + return -1; + } +} + +static char* find_device(void) +{ + static char tmp[1024]; + char *res = NULL; + + glob_t g; + if (glob("/sys/devices/pci*/*", GLOB_NOSORT, NULL, &g) != 0) { + return NULL; + } + + + int i; + for (i = 0; i < g.gl_pathc; i++) { + char *path = g.gl_pathv[i]; + + if (check_device_id(path, "vendor", PCI_VENDOR_ID_REDHAT_QUMRANET) < 0) { + continue; + } + if (check_device_id(path, "device", PCI_DEVICE_ID_BACKDOOR) < 0) { + continue; + } + + sprintf(tmp, "%s", path); + res = tmp; + break; + } + + globfree(&g); + + return res; +} +#endif + +int qemu_backdoor_init(const char *base) +{ +#if defined(CONFIG_USER_ONLY) + const char *control_suff = "-control"; + const size_t control_size = getpagesize() * 2; + const char *data_suff = "-data"; +#elif defined(__linux__) + const char *control_suff = "/resource0"; + const size_t control_size = getpagesize(); + const char *data_suff = "/resource1"; +#else +#error Unsupported OS +#endif + +#if !defined(CONFIG_USER_ONLY) + if (base == NULL) { + /* try to guess the base path */ + base = find_device(); + if (base == NULL) { + return -1; + } + } +#endif + + int res; + res = init_channel_file(base, control_suff, control_size, + &control_path, &control_fd, &control_addr); + if (res != 0) { + return res; + } + + res = init_channel_file(base, data_suff, qemu_backdoor_data_size(), + &data_path, &data_fd, &data_addr); + if (res != 0) { + return res; + } + return 0; +} + + +static int fini_channel(int *fd, char **path) +{ + if (*fd != -1) { + if (close(*fd) == -1) { + return -1; + } + *fd = -1; + } + if (*path != NULL) { + free(*path); + *path = NULL; + } + return 0; +} + +int qemu_backdoor_fini(void) +{ + if (fini_channel(&data_fd, &data_path) != 0) { + return -1; + } + if (fini_channel(&control_fd, &control_path) != 0) { + return -1; + } + return 0; +} + + +uint64_t qemu_backdoor_data_size(void) +{ + return *(uint64_t*)control_addr; +} + +void *qemu_backdoor_data(void) +{ + return data_addr; +} + +void qemu_backdoor (uint64_t cmd) +{ + uint64_t *ctrl; + ctrl = control_addr; + ctrl[1] = cmd; +#if defined(CONFIG_USER_ONLY) + /* QEMU in 'user' mode uses two faulting pages to detect invocations */ + ctrl = control_addr + getpagesize(); + ctrl[1] = cmd; +#endif +} diff --git a/backdoor/guest/qemu-backdoor.h b/backdoor/guest/qemu-backdoor.h new file mode 100644 index 0000000..0e34dc9 --- /dev/null +++ b/backdoor/guest/qemu-backdoor.h @@ -0,0 +1,59 @@ +/* + * Guest-side management of backdoor channels. + * + * Copyright (C) 2011 Lluís Vilanova + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + */ + +#include +#include + + +/** + * Initialize the backdoor channel. + * + * The base path to the backdoor channel is dependant on the type of QEMU + * target: + * + * - User (single-application) + * The base path provided when starting QEMU ("-backdoor" commandline option). + * + * - Softmmu (full-system); OS-dependant + * - Linux: The base path to the backdoor channel virtual device (on a default + * device setup for x86 this is "/sys/devices/pci0000:00/0000:00:04.0"). If + * NULL is provided, the first backdoor device to be found will be used. + * + * @param base Base path to the backdoor channel. + * @return Zero on success. + */ +int qemu_backdoor_init(const char *base); + +/** + * Deinitialize the backdoor channel. + * + * @return Zero on success. + */ +int qemu_backdoor_fini(void); + +/** + * The amount of data that can be passed through the data channel. + */ +uint64_t qemu_backdoor_data_size(void); + +/** + * Pointer to the start of the data channel. + */ +void *qemu_backdoor_data(void); + +/** + * Invoke the control channel. + * + * The command in the control channel can be used to, e.g., differentiate + * between multiple users of the backdoor channel without resorting to the data + * channel for deambiguation. + * + * @param cmd Integral number passed out-of-band w.r.t the data channel. + */ +void qemu_backdoor(uint64_t cmd); diff --git a/backdoor/qemu/user.c b/backdoor/qemu/user.c index 6e178cc..54d797f 100644 --- a/backdoor/qemu/user.c +++ b/backdoor/qemu/user.c @@ -114,7 +114,7 @@ static void fini_channel(int *fd, char **path) *fd = -1; } if (*path != NULL) { - g_free(path); + g_free(*path); *path = NULL; } } diff --git a/configure b/configure index 8af8313..67d4c9a 100755 --- a/configure +++ b/configure @@ -3374,6 +3374,8 @@ if test -n "$backdoor"; then mkdir -p $target_dir/libbackdoor symlink $backdoor/Makefile $target_dir/libbackdoor/Makefile mkdir -p $target_dir/backdoor/qemu + mkdir -p $target_dir/backdoor/guest + symlink $source_path/backdoor/guest/Makefile $target_dir/backdoor/guest/Makefile fi