From f32ee7f16206334c90d2c92517617c08f436ca97 Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Tue, 16 Jul 2019 13:22:13 +0200 Subject: [PATCH 20/23] vl: add qemu_add_vm_change_state_handler_prio() RH-Author: Stefan Hajnoczi Message-id: <20190716132215.18503-2-stefanha@redhat.com> Patchwork-id: 89536 O-Subject: [RHEL-7.8 RHEL-7.7.z qemu-kvm-rhev PATCH 1/3] vl: add qemu_add_vm_change_state_handler_prio() Bugzilla: 1673546 RH-Acked-by: Paolo Bonzini RH-Acked-by: John Snow RH-Acked-by: Kevin Wolf Add an API for registering vm change state handlers with a well-defined ordering. This is necessary when handlers depend on each other. Small coding style fixes are included to make checkpatch.pl happy. Signed-off-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf (cherry picked from commit 60dbc5a1c5176269669ffc26c081ab2cfb7f12f7) Signed-off-by: Stefan Hajnoczi Signed-off-by: Miroslav Rezanina Conflicts: vl.c The QTAILQ macros require an explicit name for the head type. --- include/sysemu/sysemu.h | 2 ++ vl.c | 61 +++++++++++++++++++++++++++++++++++++++---------- 2 files changed, 51 insertions(+), 12 deletions(-) diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h index 2a6f4a5..723c7a9 100644 --- a/include/sysemu/sysemu.h +++ b/include/sysemu/sysemu.h @@ -29,6 +29,8 @@ typedef void VMChangeStateHandler(void *opaque, int running, RunState state); VMChangeStateEntry *qemu_add_vm_change_state_handler(VMChangeStateHandler *cb, void *opaque); +VMChangeStateEntry *qemu_add_vm_change_state_handler_prio( + VMChangeStateHandler *cb, void *opaque, int priority); void qemu_del_vm_change_state_handler(VMChangeStateEntry *e); void vm_state_notify(int running, RunState state); diff --git a/vl.c b/vl.c index 5b337e1..6529d68 100644 --- a/vl.c +++ b/vl.c @@ -1658,28 +1658,58 @@ static int machine_help_func(QemuOpts *opts, MachineState *machine) struct vm_change_state_entry { VMChangeStateHandler *cb; void *opaque; - QLIST_ENTRY (vm_change_state_entry) entries; + QTAILQ_ENTRY(vm_change_state_entry) entries; + int priority; }; -static QLIST_HEAD(vm_change_state_head, vm_change_state_entry) vm_change_state_head; +static QTAILQ_HEAD(VMChangeStateHead, + vm_change_state_entry) vm_change_state_head; -VMChangeStateEntry *qemu_add_vm_change_state_handler(VMChangeStateHandler *cb, - void *opaque) +/** + * qemu_add_vm_change_state_handler_prio: + * @cb: the callback to invoke + * @opaque: user data passed to the callback + * @priority: low priorities execute first when the vm runs and the reverse is + * true when the vm stops + * + * Register a callback function that is invoked when the vm starts or stops + * running. + * + * Returns: an entry to be freed using qemu_del_vm_change_state_handler() + */ +VMChangeStateEntry *qemu_add_vm_change_state_handler_prio( + VMChangeStateHandler *cb, void *opaque, int priority) { VMChangeStateEntry *e; + VMChangeStateEntry *other; - e = g_malloc0(sizeof (*e)); - + e = g_malloc0(sizeof(*e)); e->cb = cb; e->opaque = opaque; - QLIST_INSERT_HEAD(&vm_change_state_head, e, entries); + e->priority = priority; + + /* Keep list sorted in ascending priority order */ + QTAILQ_FOREACH(other, &vm_change_state_head, entries) { + if (priority < other->priority) { + QTAILQ_INSERT_BEFORE(other, e, entries); + return e; + } + } + + QTAILQ_INSERT_TAIL(&vm_change_state_head, e, entries); return e; } +VMChangeStateEntry *qemu_add_vm_change_state_handler(VMChangeStateHandler *cb, + void *opaque) +{ + return qemu_add_vm_change_state_handler_prio(cb, opaque, 0); +} + void qemu_del_vm_change_state_handler(VMChangeStateEntry *e) { - QLIST_REMOVE (e, entries); - g_free (e); + QTAILQ_REMOVE(&vm_change_state_head, e, entries); + g_free(e); } void vm_state_notify(int running, RunState state) @@ -1688,8 +1718,15 @@ void vm_state_notify(int running, RunState state) trace_vm_state_notify(running, state); - QLIST_FOREACH_SAFE(e, &vm_change_state_head, entries, next) { - e->cb(e->opaque, running, state); + if (running) { + QTAILQ_FOREACH_SAFE(e, &vm_change_state_head, entries, next) { + e->cb(e->opaque, running, state); + } + } else { + QTAILQ_FOREACH_REVERSE_SAFE(e, &vm_change_state_head, + VMChangeStateHead, entries, next) { + e->cb(e->opaque, running, state); + } } } @@ -3194,7 +3231,7 @@ int main(int argc, char **argv, char **envp) } rtc_clock = QEMU_CLOCK_HOST; - QLIST_INIT (&vm_change_state_head); + QTAILQ_INIT(&vm_change_state_head); os_setup_early_signal_handling(); cpu_model = NULL; -- 1.8.3.1