From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59753) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Xmha2-0007CS-B7 for qemu-devel@nongnu.org; Fri, 07 Nov 2014 06:19:55 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XmhZw-0000ZD-L7 for qemu-devel@nongnu.org; Fri, 07 Nov 2014 06:19:50 -0500 Received: from mx1.redhat.com ([209.132.183.28]:36048) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XmhZw-0000Z7-C5 for qemu-devel@nongnu.org; Fri, 07 Nov 2014 06:19:44 -0500 Message-ID: <545CAAC0.7060904@redhat.com> Date: Fri, 07 Nov 2014 12:19:28 +0100 From: Paolo Bonzini MIME-Version: 1.0 References: <20141107103123.6136.18545.stgit@PASHA-ISP> <20141107103207.6136.22294.stgit@PASHA-ISP> In-Reply-To: <20141107103207.6136.22294.stgit@PASHA-ISP> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [RFC PATCH v4 07/25] icount: implement icount requesting List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Pavel Dovgalyuk , qemu-devel@nongnu.org Cc: peter.maydell@linaro.org, peter.crosthwaite@xilinx.com, alex.bennee@linaro.org, mark.burton@greensocs.com, real@ispras.ru, batuzovk@ispras.ru, maria.klimushenkova@ispras.ru, afaerber@suse.de, fred.konrad@greensocs.com On 07/11/2014 11:32, Pavel Dovgalyuk wrote: > Replay uses number of executed instructions to determine corrent events > injection moments. This patch introduces new function for querying the > instructions counter. > > Signed-off-by: Pavel Dovgalyuk > --- > cpus.c | 26 +++++++++++++++++++++++--- > include/qemu/timer.h | 1 + > 2 files changed, 24 insertions(+), 3 deletions(-) > > diff --git a/cpus.c b/cpus.c > index 7e8c507..2ec6d75 100644 > --- a/cpus.c > +++ b/cpus.c > @@ -136,8 +136,7 @@ typedef struct TimersState { > > static TimersState timers_state; > > -/* Return the virtual CPU time, based on the instruction counter. */ > -static int64_t cpu_get_icount_locked(void) > +static int64_t cpu_get_instructions_counter_locked(void) > { > int64_t icount; > CPUState *cpu = current_cpu; > @@ -145,10 +144,31 @@ static int64_t cpu_get_icount_locked(void) > icount = timers_state.qemu_icount; > if (cpu) { > if (!cpu_can_do_io(cpu)) { > - fprintf(stderr, "Bad clock read\n"); > + fprintf(stderr, "Bad icount read\n"); > + exit(1); > } > icount -= (cpu->icount_decr.u16.low + cpu->icount_extra); > } > + return icount; > +} > + > +int64_t cpu_get_instructions_counter(void) > +{ > + /* This function calls are synchnonized to timer changes, > + calling cpu_get_instructions_counter_locked without lock is safe */ > + int64_t icount = timers_state.qemu_icount; > + CPUState *cpu = current_cpu; > + > + if (cpu) { > + icount -= (cpu->icount_decr.u16.low + cpu->icount_extra); > + } > + return icount; > +} This is the same as Frederic's QEMU_CLOCK_ICOUNT clock, right? Any reason why one is better than the other? Paolo > +/* Return the virtual CPU time, based on the instruction counter. */ > +static int64_t cpu_get_icount_locked(void) > +{ > + int64_t icount = cpu_get_instructions_counter_locked(); > return timers_state.qemu_icount_bias + cpu_icount_to_ns(icount); > } > > diff --git a/include/qemu/timer.h b/include/qemu/timer.h > index 5f5210d..38a02c5 100644 > --- a/include/qemu/timer.h > +++ b/include/qemu/timer.h > @@ -743,6 +743,7 @@ static inline int64_t get_clock(void) > #endif > > /* icount */ > +int64_t cpu_get_instructions_counter(void); > int64_t cpu_get_icount(void); > int64_t cpu_get_clock(void); > int64_t cpu_get_clock_offset(void); >