From 1d05906b95e7f2a35be2392506f9af8f89ff39a5 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Alex=20Benn=C3=A9e?= Date: Wed, 5 Apr 2017 10:53:47 +0100 Subject: cpus: call cpu_update_icount on read MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This ensures each time the vCPU thread reads the icount we update the master timer_state.qemu_icount field. This way as long as updates are in BQL protected sections (which they should be) the main-loop can never come to update the log and find time has gone backwards. Signed-off-by: Alex Bennée --- cpus.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) (limited to 'cpus.c') diff --git a/cpus.c b/cpus.c index 9c8bd2c991..740b8dc3f8 100644 --- a/cpus.c +++ b/cpus.c @@ -253,19 +253,21 @@ void cpu_update_icount(CPUState *cpu) int64_t cpu_get_icount_raw(void) { - int64_t icount; CPUState *cpu = current_cpu; - icount = atomic_read(&timers_state.qemu_icount); if (cpu && cpu->running) { if (!cpu->can_do_io) { fprintf(stderr, "Bad icount read\n"); exit(1); } /* Take into account what has run */ - icount += cpu_get_icount_executed(cpu); + cpu_update_icount(cpu); } - return icount; +#ifdef CONFIG_ATOMIC64 + return atomic_read__nocheck(&timers_state.qemu_icount); +#else /* FIXME: we need 64bit atomics to do this safely */ + return timers_state.qemu_icount; +#endif } /* Return the virtual CPU time, based on the instruction counter. */ -- cgit v1.2.1