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.
Signed-off-by: Alex Bennée <alex.bennee@xxxxxxxxxx>
Reviewed-by: Philippe Mathieu-Daudé <philmd@xxxxxxxxxx>
Message-Id: <20230519170454.2353945-5-alex.bennee@xxxxxxxxxx>
---
v2
- more kerneldoc annotations
---
include/sysemu/accel-ops.h | 18 ++++++++++++-
include/sysemu/cpu-timers.h | 27 ++++++++++++++++++-
softmmu/cpus.c | 11 ++++++++
...t-virtual-clock.c => cpus-virtual-clock.c} | 5 ++++
stubs/meson.build | 2 +-
5 files changed, 60 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 3c1fab4b1e..224e85a649 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;
@@ -43,7 +48,18 @@ 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 2e786fe7fb..31ab2bbd4e 100644
--- a/include/sysemu/cpu-timers.h
+++ b/include/sysemu/cpu-timers.h
@@ -84,8 +84,33 @@ 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 */
+/**
+ * cpus_get_virtual_clock() - return current virtual clock.
+ *
+ * This is a wrapper around accelerator specific get_virtual_clock()
+ *
+ * Returns: ns of virtual time
+ */
int64_t cpus_get_virtual_clock(void);
+
+/**
+ * cpus_set_virtual_clock() - set the virtual clock
+ * @new_time: new value in ns
+ *
+ * This is a wrapper around accelerator specific set_virtual_clock()
+ */
+void cpus_set_virtual_clock(int64_t new_time);
+
+/**
+ * cpus_get_elapsed_ticks() - get elapsed host time
+ *
+ * This is usually the current value of the host tick counter (i.e.
+ * not taking into account guest pauses). However some accelerators
+ * which want to keep elapsed time in sync with virtual time will
+ * return the virtual clock.
+ *
+ * Returns: ticks of elapsed host time (usually ns)
+ */
int64_t cpus_get_elapsed_ticks(void);
#endif /* SYSEMU_CPU_TIMERS_H */
diff --git a/softmmu/cpus.c b/softmmu/cpus.c
index 0848e0dbdb..b645c462e1 100644
--- a/softmmu/cpus.c
+++ b/softmmu/cpus.c
@@ -221,6 +221,17 @@ 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/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/stubs/meson.build b/stubs/meson.build
index ef6e39a64d..2ea43ee076 100644
--- a/stubs/meson.build
+++ b/stubs/meson.build
@@ -5,7 +5,7 @@ stub_ss.add(files('blockdev-close-all-bdrv-states.c'))
stub_ss.add(files('change-state-handler.c'))
stub_ss.add(files('cmos.c'))
stub_ss.add(files('cpu-get-clock.c'))
-stub_ss.add(files('cpus-get-virtual-clock.c'))
+stub_ss.add(files('cpus-virtual-clock.c'))
stub_ss.add(files('qemu-timer-notify-cb.c'))
stub_ss.add(files('icount.c'))
stub_ss.add(files('dump.c'))
--
2.39.2
