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[Qemu-devel] [PATCH 3/3] qga: Prevent qemu-ga exit if serial doesn't exi
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From: |
Sameeh Jubran |
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Subject: |
[Qemu-devel] [PATCH 3/3] qga: Prevent qemu-ga exit if serial doesn't exist |
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Date: |
Sun, 13 Aug 2017 18:58:49 +0300 |
From: Sameeh Jubran <address@hidden>
Currently whenever the qemu-ga's service doesn't find the virtio-serial
it terminates. This commit addresses this issue by listening to the serial
events
by registering for notifications for the chosen serial and it handles channel
initialization accordingily.
A list of possible scenarios of which could lead to this behavour:
* qemu-ga's service is started while the virtio-serial driver hasn't been
installed yet
* hotplug/ unplug of the virtio-serial device
* upgrading the virtio-serial driver
Note: This problem is much more common on Windows as the virtio-serial
driver should be installed by the user and isn't shipped with the Windows OS.
Signed-off-by: Sameeh Jubran <address@hidden>
---
Makefile | 4 +
qga/main.c | 240 ++++++++++++++++++++++++++++++++++++++++++++++++++--
qga/service-win32.h | 4 +
3 files changed, 239 insertions(+), 9 deletions(-)
diff --git a/Makefile b/Makefile
index ef72148..82f26d5 100644
--- a/Makefile
+++ b/Makefile
@@ -203,6 +203,10 @@ $(call set-vpath, $(SRC_PATH))
LIBS+=-lz $(LIBS_TOOLS)
+ifndef CONFIG_WIN32
+LIBS_QGA+=-ludev
+endif
+
HELPERS-$(CONFIG_LINUX) = qemu-bridge-helper$(EXESUF)
ifdef BUILD_DOCS
diff --git a/qga/main.c b/qga/main.c
index cf312b9..d727880 100644
--- a/qga/main.c
+++ b/qga/main.c
@@ -16,6 +16,8 @@
#ifndef _WIN32
#include <syslog.h>
#include <sys/wait.h>
+#include <libudev.h>
+#include <sys/types.h>
#endif
#include "qapi/qmp/json-streamer.h"
#include "qapi/qmp/json-parser.h"
@@ -30,6 +32,7 @@
#include "qemu/sockets.h"
#include "qemu/systemd.h"
#ifdef _WIN32
+#include <dbt.h>
#include "qga/service-win32.h"
#include "qga/vss-win32.h"
#endif
@@ -74,6 +77,10 @@ struct GAState {
GLogLevelFlags log_level;
FILE *log_file;
bool logging_enabled;
+ bool serial_connected;
+#ifndef _WIN32
+ struct udev_monitor *udev_monitor;
+#endif
#ifdef _WIN32
GAService service;
#endif
@@ -130,9 +137,15 @@ static const char *ga_freeze_whitelist[] = {
#ifdef _WIN32
DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
LPVOID ctx);
+DWORD WINAPI handle_serial_device_events(DWORD type, LPVOID data);
VOID WINAPI service_main(DWORD argc, TCHAR *argv[]);
#endif
+static bool get_channel_method(GAChannelMethod *channel_method,
+ const gchar *method, GAState *s);
+static gboolean channel_init(GAState *s, const gchar *method, const gchar
*path,
+ int listen_fd, bool *serial_connected);
+
static void
init_dfl_pathnames(void)
{
@@ -186,6 +199,136 @@ static void quit_handler(int sig)
}
#ifndef _WIN32
+static int get_method_udev_subsystem(const char **serial_subsystem)
+{
+ if (strcmp(ga_config->method, "virtio-serial") == 0) {
+ *serial_subsystem = SUBSYSTEM_VIRTIO_SERIAL;
+ } else if (strcmp(ga_config->method, "isa-serial") == 0) {
+ /* try the default path for the serial port - COM1 */
+ *serial_subsystem = SUBSYSTEM_ISA_SERIAL;
+ } else {
+ serial_subsystem = NULL;
+ return -1;
+ }
+ return 0;
+}
+
+static gboolean serial_event_callback(GIOChannel *source,
+ GIOCondition condition, gpointer data)
+{
+ struct udev_monitor *mon = ga_state->udev_monitor;
+ const char *serial_subsystem = NULL;
+ struct udev_device *dev;
+
+ if (get_method_udev_subsystem(&serial_subsystem) == -1) {
+ return false;
+ }
+ dev = udev_monitor_receive_device(mon);
+
+ if (dev && serial_subsystem && strcmp(udev_device_get_subsystem(dev),
+ serial_subsystem) == 0) {
+
+ GAChannelMethod channel_method;
+ get_channel_method(&channel_method, ga_config->method, ga_state);
+ if (ga_channel_was_serial_attached(channel_method,
+ ga_config->channel_path, ga_state->serial_connected)) {
+ ga_state->serial_connected = true;
+ if (!channel_init(ga_state,
+ ga_config->method, ga_config->channel_path,
+ ga_socket_activation ? FIRST_SOCKET_ACTIVATION_FD : -1,
+ &ga_state->serial_connected)) {
+ g_critical("failed to initialize guest agent channel");
+ }
+ }
+
+ if (ga_channel_was_serial_detached(channel_method,
+ ga_config->channel_path, ga_state->serial_connected)) {
+ ga_state->serial_connected = false;
+ ga_channel_free(ga_state->channel);
+ }
+ udev_device_unref(dev);
+ }
+ return true;
+}
+
+static int monitor_serial_events(void)
+{
+ int ret = 0;
+ const char *serial_subsystem = NULL;
+ struct udev *udev = NULL;
+ ga_state->udev_monitor = NULL;
+ GIOChannel *channel = NULL;
+ GSource *watch_source = NULL;
+ if (get_method_udev_subsystem(&serial_subsystem) == -1) {
+ ret = -1;
+ goto out;
+ }
+
+ udev = udev_new();
+ if (!udev) {
+ g_error("Couldn't create udev\n");
+ ret = -1;
+ goto out;
+ }
+
+ ga_state->udev_monitor =
+ udev_monitor_new_from_netlink(udev, "udev");
+ if (!ga_state->udev_monitor) {
+ ret = -1;
+ goto out;
+ } else {
+ /* We don't want the udev_monitor to be freed on out, so increase
+ * ref count
+ */
+ udev_monitor_ref(ga_state->udev_monitor);
+ }
+
+ if (udev_monitor_filter_add_match_subsystem_devtype(ga_state->udev_monitor,
+ serial_subsystem, NULL) < 0 ||
+ udev_monitor_enable_receiving(ga_state->udev_monitor) < 0) {
+ ret = -1;
+ goto out;
+ }
+
+ channel =
+ g_io_channel_unix_new(udev_monitor_get_fd(ga_state->udev_monitor));
+ if (!channel) {
+ ret = -1;
+ goto out;
+ }
+ watch_source = g_io_create_watch(channel, G_IO_IN);
+ if (!watch_source) {
+ ret = -1;
+ goto out;
+ }
+ g_source_set_callback(watch_source, (GSourceFunc)serial_event_callback,
+ ga_state->udev_monitor, NULL);
+ g_source_attach(watch_source,
g_main_loop_get_context(ga_state->main_loop));
+
+out:
+ if (udev) {
+ udev_unref(udev);
+ }
+ if (ga_state->udev_monitor) {
+ udev_monitor_unref(ga_state->udev_monitor);
+ }
+ if (channel) {
+ g_io_channel_unref(channel);
+ }
+ if (watch_source) {
+ g_source_unref(watch_source);
+ }
+
+ return ret;
+}
+
+static void free_monitor_resources(void)
+{
+ if (ga_state->udev_monitor) {
+ udev_monitor_unref(ga_state->udev_monitor);
+ }
+}
+
static gboolean register_signal_handlers(void)
{
struct sigaction sigact;
@@ -694,24 +837,38 @@ static gboolean channel_event_cb(GIOCondition condition,
gpointer data)
return true;
}
-static gboolean channel_init(GAState *s, const gchar *method, const gchar
*path,
- int listen_fd)
+static bool get_channel_method(GAChannelMethod *channel_method,
+ const gchar *method, GAState *s)
{
- GAChannelMethod channel_method;
+ assert(channel_method);
+ assert(method);
if (strcmp(method, "virtio-serial") == 0) {
+ assert(s);
s->virtio = true; /* virtio requires special handling in some cases */
- channel_method = GA_CHANNEL_VIRTIO_SERIAL;
+ *channel_method = GA_CHANNEL_VIRTIO_SERIAL;
} else if (strcmp(method, "isa-serial") == 0) {
- channel_method = GA_CHANNEL_ISA_SERIAL;
+ *channel_method = GA_CHANNEL_ISA_SERIAL;
} else if (strcmp(method, "unix-listen") == 0) {
- channel_method = GA_CHANNEL_UNIX_LISTEN;
+ *channel_method = GA_CHANNEL_UNIX_LISTEN;
} else if (strcmp(method, "vsock-listen") == 0) {
- channel_method = GA_CHANNEL_VSOCK_LISTEN;
+ *channel_method = GA_CHANNEL_VSOCK_LISTEN;
} else {
g_critical("unsupported channel method/type: %s", method);
return false;
}
+ return true;
+}
+
+static gboolean channel_init(GAState *s, const gchar *method, const gchar
*path,
+ int listen_fd, bool *serial_connected)
+{
+ assert(serial_connected);
+ GAChannelMethod channel_method;
+ if (!get_channel_method(&channel_method, method, s)) {
+ return false;
+ }
+ *serial_connected = ga_channel_serial_is_present(channel_method, path);
s->channel = ga_channel_new(channel_method, path, listen_fd,
channel_event_cb, s);
@@ -724,6 +881,48 @@ static gboolean channel_init(GAState *s, const gchar
*method, const gchar *path,
}
#ifdef _WIN32
+DWORD WINAPI handle_serial_device_events(DWORD type, LPVOID data)
+{
+ DWORD ret = NO_ERROR;
+ PDEV_BROADCAST_HDR broadcast_header = (PDEV_BROADCAST_HDR)data;
+ GAChannelMethod channel_method;
+
+ if (broadcast_header->dbch_devicetype == DBT_DEVTYP_DEVICEINTERFACE) {
+ get_channel_method(&channel_method, ga_config->method, ga_state);
+ switch (type) {
+ /* Device inserted */
+ case DBT_DEVICEARRIVAL:
+ /* Start QEMU-ga's service */
+ if (ga_channel_was_serial_attached(channel_method,
+ ga_config->channel_path, ga_state->serial_connected)) {
+ if (!channel_init(ga_state,
+ ga_config->method, ga_config->channel_path,
+ ga_socket_activation ? FIRST_SOCKET_ACTIVATION_FD : -1,
+ &ga_state->serial_connected)) {
+ g_critical("failed to initialize guest agent channel");
+ ret = EXIT_FAILURE;
+ }
+ }
+ break;
+ /* Device removed */
+ case DBT_DEVICEQUERYREMOVE:
+ case DBT_DEVICEREMOVEPENDING:
+ case DBT_DEVICEREMOVECOMPLETE:
+
+ /* Stop QEMU-ga's service */
+ if (ga_channel_was_serial_detached(channel_method,
+ ga_config->channel_path, ga_state->serial_connected)) {
+ ga_state->serial_connected = false;
+ ga_channel_free(ga_state->channel);
+ }
+ break;
+ default:
+ ret = ERROR_CALL_NOT_IMPLEMENTED;
+ }
+ }
+ return ret;
+}
+
DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
LPVOID ctx)
{
@@ -738,6 +937,9 @@ DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type,
LPVOID data,
service->status.dwCurrentState = SERVICE_STOP_PENDING;
SetServiceStatus(service->status_handle, &service->status);
break;
+ case SERVICE_CONTROL_DEVICEEVENT:
+ handle_serial_device_events(type, data);
+ break;
default:
ret = ERROR_CALL_NOT_IMPLEMENTED;
@@ -764,10 +966,24 @@ VOID WINAPI service_main(DWORD argc, TCHAR *argv[])
service->status.dwServiceSpecificExitCode = NO_ERROR;
service->status.dwCheckPoint = 0;
service->status.dwWaitHint = 0;
+ DEV_BROADCAST_DEVICEINTERFACE notification_filter;
+ ZeroMemory(¬ification_filter, sizeof(notification_filter));
+ notification_filter.dbcc_devicetype = DBT_DEVTYP_DEVICEINTERFACE;
+ notification_filter.dbcc_size = sizeof(DEV_BROADCAST_DEVICEINTERFACE);
+ notification_filter.dbcc_classguid = GUID_VIOSERIAL_PORT;
+
+ service->device_notification_handle =
+ RegisterDeviceNotification(service->status_handle,
+ ¬ification_filter, DEVICE_NOTIFY_SERVICE_HANDLE);
+ if (!service->device_notification_handle) {
+ g_critical("Failed to register device notification handle!\n");
+ return;
+ }
SetServiceStatus(service->status_handle, &service->status);
g_main_loop_run(ga_state->main_loop);
+ UnregisterDeviceNotification(service->device_notification_handle);
service->status.dwCurrentState = SERVICE_STOPPED;
SetServiceStatus(service->status_handle, &service->status);
}
@@ -1330,20 +1546,26 @@ static int run_agent(GAState *s, GAConfig *config, int
socket_activation)
#endif
s->main_loop = g_main_loop_new(NULL, false);
-
if (!channel_init(ga_state, config->method, config->channel_path,
- socket_activation ? FIRST_SOCKET_ACTIVATION_FD : -1)) {
+ socket_activation ? FIRST_SOCKET_ACTIVATION_FD : -1,
+ &ga_state->serial_connected) &&
+ ga_state->serial_connected) {
g_critical("failed to initialize guest agent channel");
return EXIT_FAILURE;
}
#ifndef _WIN32
+ monitor_serial_events();
g_main_loop_run(ga_state->main_loop);
+ free_monitor_resources();
#else
if (config->daemonize) {
SERVICE_TABLE_ENTRY service_table[] = {
{ (char *)QGA_SERVICE_NAME, service_main }, { NULL, NULL } };
StartServiceCtrlDispatcher(service_table);
} else {
+ if (!ga_state->serial_connected) {
+ return EXIT_FAILURE;
+ }
g_main_loop_run(ga_state->main_loop);
}
#endif
diff --git a/qga/service-win32.h b/qga/service-win32.h
index 89e99df..7b16d69 100644
--- a/qga/service-win32.h
+++ b/qga/service-win32.h
@@ -20,9 +20,13 @@
#define QGA_SERVICE_NAME "qemu-ga"
#define QGA_SERVICE_DESCRIPTION "Enables integration with QEMU machine
emulator and virtualizer."
+static const GUID GUID_VIOSERIAL_PORT = { 0x6fde7521, 0x1b65, 0x48ae,
+{ 0xb6, 0x28, 0x80, 0xbe, 0x62, 0x1, 0x60, 0x26 } };
+
typedef struct GAService {
SERVICE_STATUS status;
SERVICE_STATUS_HANDLE status_handle;
+ HDEVNOTIFY device_notification_handle;
} GAService;
int ga_install_service(const char *path, const char *logfile,
--
2.9.4