Re: [PATCH 3/6] ch: start a new thread for handling ch events

Use a FIFO(named pipe) for --event-monitor option in CH. Introduce a new thread, `virCHEventHandlerLoop`, to continuously monitor and handle events from cloud-hypervisor. Signed-off-by: Purna Pavan Chandra Aekkaladevi <paekkaladevi(a)linux.microsoft.com&gt; Co-authored-by: Vineeth Pillai <viremana(a)linux.microsoft.com&gt; --- po/POTFILES | 1 + src/ch/ch_events.c | 96 +++++++++++++++++++++++++++++++++++++++++++++ src/ch/ch_events.h | 26 ++++++++++++ src/ch/ch_monitor.c | 28 +++++++++++++ src/ch/ch_monitor.h | 3 ++ src/ch/meson.build | 2 + 6 files changed, 156 insertions(+) create mode 100644 src/ch/ch_events.c create mode 100644 src/ch/ch_events.h diff --git a/po/POTFILES b/po/POTFILES index 1ed4086d2c..d53307cec4 100644 --- a/po/POTFILES +++ b/po/POTFILES @@ -21,6 +21,7 @@ src/bhyve/bhyve_process.c src/ch/ch_conf.c src/ch/ch_domain.c src/ch/ch_driver.c +src/ch/ch_events.c src/ch/ch_interface.c src/ch/ch_monitor.c src/ch/ch_process.c diff --git a/src/ch/ch_events.c b/src/ch/ch_events.c new file mode 100644 index 0000000000..851fbc9f26 --- /dev/null +++ b/src/ch/ch_events.c @@ -0,0 +1,96 @@ +/* + * Copyright Microsoft Corp. 2024 + * + * ch_events.h: Handle Cloud-Hypervisor events + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library. If not, see + * <http://www.gnu.org/licenses/>;. + */ + +#include <config.h> + +#include <fcntl.h> + +#include "ch_events.h" +#include "virfile.h" +#include "virlog.h" + +VIR_LOG_INIT("ch.ch_events"); + +static void virCHEventHandlerLoop(void *data) +{ + virCHMonitor *mon = data; + virDomainObj *vm = NULL; + int event_monitor_fd; + + VIR_DEBUG("Event handler loop thread starting"); + + while ((event_monitor_fd = open(mon->eventmonitorpath, O_RDONLY)) < 0) { + if (errno == EINTR) { + g_usleep(100000); // 100 milli seconds + continue; + } + /* + * Any other error should be a BUG(kernel/libc/libvirtd) + * (ENOMEM can happen on exceeding per-user limits) + */ + VIR_ERROR(_("Failed to open the event monitor FIFO(%1$s) read end!"), + mon->eventmonitorpath); + abort(); + } + VIR_DEBUG("Opened the event monitor FIFO(%s)", mon->eventmonitorpath); + + /* + * We would need to wait until VM is initialized. + */ + while (!(vm = virObjectRef(mon->vm))) + g_usleep(100000); // 100 milli seconds + + while (g_atomic_int_get(&mon->event_handler_stop) == 0) { + VIR_DEBUG("Reading events from event monitor file..."); + /* Read and process events here */ + } + + VIR_FORCE_CLOSE(event_monitor_fd); + virObjectUnref(vm); + + VIR_DEBUG("Event handler loop thread exiting"); + return; +} + +int virCHStartEventHandler(virCHMonitor *mon) +{ + g_autofree char *name = NULL; + name = g_strdup_printf("event-handler-%d", mon->pid); + + virObjectRef(mon); + if (virThreadCreateFull(&mon->event_handler_thread, + false, + virCHEventHandlerLoop, + name, + false, + mon) < 0) { + virObjectUnref(mon); + return -1; + } + virObjectUnref(mon); + + g_atomic_int_set(&mon->event_handler_stop, 0); + return 0; +} + +void virCHStopEventHandler(virCHMonitor *mon) +{ + g_atomic_int_set(&mon->event_handler_stop, 1); +} diff --git a/src/ch/ch_events.h b/src/ch/ch_events.h new file mode 100644 index 0000000000..4c8a48231d --- /dev/null +++ b/src/ch/ch_events.h @@ -0,0 +1,26 @@ +/* + * Copyright Microsoft Corp. 2024 + * + * ch_events.h: header file for handling Cloud-Hypervisor events + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library. If not, see + * <http://www.gnu.org/licenses/>;. + */ + +#pragma once + +#include "ch_monitor.h" + +int virCHStartEventHandler(virCHMonitor *mon); +void virCHStopEventHandler(virCHMonitor *mon); diff --git a/src/ch/ch_monitor.c b/src/ch/ch_monitor.c index 8c99fe1019..5e43bf9ef8 100644 --- a/src/ch/ch_monitor.c +++ b/src/ch/ch_monitor.c @@ -26,6 +26,7 @@ #include "datatypes.h" #include "ch_conf.h" +#include "ch_events.h" #include "ch_interface.h" #include "ch_monitor.h" #include "domain_interface.h" @@ -572,6 +573,28 @@ virCHMonitorNew(virDomainObj *vm, virCHDriverConfig *cfg) return NULL; } + /* Event monitor file to listen for VM state changes */ + mon->eventmonitorpath = g_strdup_printf("%s/%s-event-monitor-fifo", + cfg->stateDir, vm->def->name); + if (virFileExists(mon->eventmonitorpath) && + !virFileIsNamedPipe(mon->eventmonitorpath)) { + VIR_WARN("Monitor file (%s) is not a FIFO, trying to delete!", + mon->eventmonitorpath); + if (virFileRemove(mon->eventmonitorpath, -1, -1) < 0) { + virReportError(VIR_ERR_INTERNAL_ERROR, + _("Failed to remove the file: %1$s"), + mon->eventmonitorpath); + return NULL; + } + } + + if (mkfifo(mon->eventmonitorpath, S_IWUSR | S_IRUSR) < 0 && + errno != EEXIST) { + virReportSystemError(errno, "%s", + _("Cannot create monitor FIFO")); + return NULL; + }

+ cmd = virCommandNew(vm->def->emulator); virCommandSetUmask(cmd, 0x002); socket_fd = chMonitorCreateSocket(mon->socketpath); @@ -593,6 +616,9 @@ virCHMonitorNew(virDomainObj *vm, virCHDriverConfig *cfg) if (virCommandRunAsync(cmd, &mon->pid) < 0) return NULL; + if (virCHStartEventHandler(mon) < 0) + return NULL; + /* get a curl handle */ mon->handle = curl_easy_init(); @@ -641,6 +667,8 @@ void virCHMonitorClose(virCHMonitor *mon) g_free(mon->eventmonitorpath); } + virCHStopEventHandler(mon); + virObjectUnref(mon); } diff --git a/src/ch/ch_monitor.h b/src/ch/ch_monitor.h index 2ef8706b99..878a185f29 100644 --- a/src/ch/ch_monitor.h +++ b/src/ch/ch_monitor.h @@ -97,6 +97,9 @@ struct _virCHMonitor { char *eventmonitorpath; + virThread event_handler_thread; + int event_handler_stop; + pid_t pid; virDomainObj *vm; diff --git a/src/ch/meson.build b/src/ch/meson.build index 633966aac7..684beac1f2 100644 --- a/src/ch/meson.build +++ b/src/ch/meson.build @@ -7,6 +7,8 @@ ch_driver_sources = [ 'ch_domain.h', 'ch_driver.c', 'ch_driver.h', + 'ch_events.c', + 'ch_driver.h', 'ch_interface.c', 'ch_interface.h', 'ch_monitor.c',