cpu-timers, icount: new modules

refactoring of cpus.c continues with cpu timer state extraction.

cpu-timers: responsible for the softmmu cpu timers state,
            including cpu clocks and ticks.

icount: counts the TCG instructions executed. As such it is specific to
the TCG accelerator. Therefore, it is built only under CONFIG_TCG.

One complication is due to qtest, which uses an icount field to warp time
as part of qtest (qtest_clock_warp).

In order to solve this problem, provide a separate counter for qtest.

This requires fixing assumptions scattered in the code that
qtest_enabled() implies icount_enabled(), checking each specific case.

Signed-off-by: Claudio Fontana <cfontana@suse.de>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
[remove redundant initialization with qemu_spice_init]
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
[fix lingering calls to icount_get]
Signed-off-by: Claudio Fontana <cfontana@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 87 insertions, 0 deletions

diff --git a/include/sysemu/cpu-timers.h b/include/sysemu/cpu-timers.h
new file mode 100644
index 0000000000..4b621fea51
--- /dev/null
+++ b/include/sysemu/cpu-timers.h
@@ -0,0 +1,87 @@
+/*
+ * CPU timers state API
+ *
+ * Copyright 2020 SUSE LLC
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+#ifndef SYSEMU_CPU_TIMERS_H
+#define SYSEMU_CPU_TIMERS_H
+
+#include "qemu/timer.h"
+
+/* init the whole cpu timers API, including icount, ticks, and cpu_throttle */
+void cpu_timers_init(void);
+
+/* icount - Instruction Counter API */
+
+/*
+ * icount enablement state:
+ *
+ * 0 = Disabled - Do not count executed instructions.
+ * 1 = Enabled - Fixed conversion of insn to ns via "shift" option
+ * 2 = Enabled - Runtime adaptive algorithm to compute shift
+ */
+#ifdef CONFIG_TCG
+extern int use_icount;
+#define icount_enabled() (use_icount)
+#else
+#define icount_enabled() 0
+#endif
+
+/*
+ * Update the icount with the executed instructions. Called by
+ * cpus-tcg vCPU thread so the main-loop can see time has moved forward.
+ */
+void cpu_update_icount(CPUState *cpu);
+
+/* get raw icount value */
+int64_t cpu_get_icount_raw(void);
+
+/* return the virtual CPU time in ns, based on the instruction counter. */
+int64_t cpu_get_icount(void);
+/*
+ * convert an instruction counter value to ns, based on the icount shift.
+ * This shift is set as a fixed value with the icount "shift" option
+ * (precise mode), or it is constantly approximated and corrected at
+ * runtime in adaptive mode.
+ */
+int64_t cpu_icount_to_ns(int64_t icount);
+
+/* configure the icount options, including "shift" */
+void configure_icount(QemuOpts *opts, Error **errp);
+
+/* used by tcg vcpu thread to calc icount budget */
+int64_t qemu_icount_round(int64_t count);
+
+/* if the CPUs are idle, start accounting real time to virtual clock. */
+void qemu_start_warp_timer(void);
+void qemu_account_warp_timer(void);
+
+/*
+ * CPU Ticks and Clock
+ */
+
+/* Caller must hold BQL */
+void cpu_enable_ticks(void);
+/* Caller must hold BQL */
+void cpu_disable_ticks(void);
+
+/*
+ * return the time elapsed in VM between vm_start and vm_stop.  Unless
+ * icount is active, cpu_get_ticks() uses units of the host CPU cycle
+ * counter.
+ */
+int64_t cpu_get_ticks(void);
+
+/*
+ * Returns the monotonic time elapsed in VM, i.e.,
+ * the time between vm_start and vm_stop
+ */
+int64_t cpu_get_clock(void);
+
+void qemu_timer_notify_cb(void *opaque, QEMUClockType type);
+
+#endif /* SYSEMU_CPU_TIMERS_H */