We are about to remove direct calls to individual accelerators for
this information and will need a central point for plugins to hook
into time changes.
From: Alex Bennée <alex.bennee@xxxxxxxxxx>
Reviewed-by: Philippe Mathieu-Daudé <philmd@xxxxxxxxxx>
Signed-off-by: Pierrick Bouvier <pierrick.bouvier@xxxxxxxxxx>
Signed-off-by: Alex Bennée <alex.bennee@xxxxxxxxxx>
Message-Id: <20240530220610.1245424-2-pierrick.bouvier@xxxxxxxxxx>
---
include/sysemu/accel-ops.h | 18 +++++++++++++++++-
include/sysemu/cpu-timers.h | 3 ++-
...et-virtual-clock.c => cpus-virtual-clock.c} | 5 +++++
system/cpus.c | 11 +++++++++++
stubs/meson.build | 2 +-
5 files changed, 36 insertions(+), 3 deletions(-)
rename stubs/{cpus-get-virtual-clock.c => cpus-virtual-clock.c} (68%)
diff --git a/include/sysemu/accel-ops.h b/include/sysemu/accel-ops.h
index ef91fc28bb..a088672230 100644
--- a/include/sysemu/accel-ops.h
+++ b/include/sysemu/accel-ops.h
@@ -20,7 +20,12 @@
typedef struct AccelOpsClass AccelOpsClass;
DECLARE_CLASS_CHECKERS(AccelOpsClass, ACCEL_OPS, TYPE_ACCEL_OPS)
-/* cpus.c operations interface */
+/**
+ * struct AccelOpsClass - accelerator interfaces
+ *
+ * This structure is used to abstract accelerator differences from the
+ * core CPU code. Not all have to be implemented.
+ */
struct AccelOpsClass {
/*< private >*/
ObjectClass parent_class;
@@ -44,7 +49,18 @@ struct AccelOpsClass {
void (*handle_interrupt)(CPUState *cpu, int mask);
+ /**
+ * @get_virtual_clock: fetch virtual clock
+ * @set_virtual_clock: set virtual clock
+ *
+ * These allow the timer subsystem to defer to the accelerator to
+ * fetch time. The set function is needed if the accelerator wants
+ * to track the changes to time as the timer is warped through
+ * various timer events.
+ */
int64_t (*get_virtual_clock)(void);
+ void (*set_virtual_clock)(int64_t time);
+
int64_t (*get_elapsed_ticks)(void);
/* gdbstub hooks */
diff --git a/include/sysemu/cpu-timers.h b/include/sysemu/cpu-timers.h
index d86738a378..7bfa960fbd 100644
--- a/include/sysemu/cpu-timers.h
+++ b/include/sysemu/cpu-timers.h
@@ -96,8 +96,9 @@ int64_t cpu_get_clock(void);
void qemu_timer_notify_cb(void *opaque, QEMUClockType type);
-/* get the VIRTUAL clock and VM elapsed ticks via the cpus accel interface */
+/* get/set VIRTUAL clock and VM elapsed ticks via the cpus accel interface */
int64_t cpus_get_virtual_clock(void);
+void cpus_set_virtual_clock(int64_t new_time);
int64_t cpus_get_elapsed_ticks(void);
#endif /* SYSEMU_CPU_TIMERS_H */
diff --git a/stubs/cpus-get-virtual-clock.c b/stubs/cpus-virtual-clock.c
similarity index 68%
rename from stubs/cpus-get-virtual-clock.c
rename to stubs/cpus-virtual-clock.c
index fd447d53f3..af7c1a1d40 100644
--- a/stubs/cpus-get-virtual-clock.c
+++ b/stubs/cpus-virtual-clock.c
@@ -6,3 +6,8 @@ int64_t cpus_get_virtual_clock(void)
{
return cpu_get_clock();
}
+
+void cpus_set_virtual_clock(int64_t new_time)
+{
+ /* do nothing */
+}
diff --git a/system/cpus.c b/system/cpus.c
index f8fa78f33d..d3640c9503 100644
--- a/system/cpus.c
+++ b/system/cpus.c
@@ -229,6 +229,17 @@ int64_t cpus_get_virtual_clock(void)
return cpu_get_clock();
}
+/*
+ * Signal the new virtual time to the accelerator. This is only needed
+ * by accelerators that need to track the changes as we warp time.
+ */
+void cpus_set_virtual_clock(int64_t new_time)
+{
+ if (cpus_accel && cpus_accel->set_virtual_clock) {
+ cpus_accel->set_virtual_clock(new_time);
+ }
+}
+
/*
* return the time elapsed in VM between vm_start and vm_stop. Unless
* icount is active, cpus_get_elapsed_ticks() uses units of the host CPU cycle
diff --git a/stubs/meson.build b/stubs/meson.build
index f15b48d01f..772a3e817d 100644
--- a/stubs/meson.build
+++ b/stubs/meson.build
@@ -29,7 +29,7 @@ endif
if have_block or have_ga
stub_ss.add(files('replay-tools.c'))
# stubs for hooks in util/main-loop.c, util/async.c etc.
- stub_ss.add(files('cpus-get-virtual-clock.c'))
+ stub_ss.add(files('cpus-virtual-clock.c'))
stub_ss.add(files('icount.c'))
stub_ss.add(files('graph-lock.c'))
if linux_io_uring.found()
--
2.39.2
