From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57151) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XwsTS-0000xO-IU for qemu-devel@nongnu.org; Fri, 05 Dec 2014 07:59:14 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XwsTL-0002Vt-1c for qemu-devel@nongnu.org; Fri, 05 Dec 2014 07:59:06 -0500 Received: from mail.ispras.ru ([83.149.199.45]:36022) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XwsTK-0002Vk-PW for qemu-devel@nongnu.org; Fri, 05 Dec 2014 07:58:58 -0500 From: "Pavel Dovgaluk" References: <20141126103841.7772.11864.stgit@PASHA-ISP> <20141126103925.7772.13043.stgit@PASHA-ISP> <547EE34D.4000500@redhat.com> <000c01d00fb1$c2010860$46031920$@Dovgaluk@ispras.ru> <548082E2.2060602@redhat.com> <000301d0104d$29dc3d10$7d94b730$@Dovgaluk@ispras.ru> <54818AC0.50400@redhat.com> <001301d0107a$0388b5d0$0a9a2170$@Dovgaluk@ispras.ru> <54819A74.9090607@redhat.com> In-Reply-To: <54819A74.9090607@redhat.com> Date: Fri, 5 Dec 2014 15:59:01 +0300 Message-ID: <001a01d0108b$3da5d0c0$b8f17240$@Dovgaluk@ispras.ru> MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Content-Language: ru Subject: Re: [Qemu-devel] [RFC PATCH v5 07/31] icount: implement icount requesting List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: 'Paolo Bonzini' , qemu-devel@nongnu.org Cc: peter.maydell@linaro.org, peter.crosthwaite@xilinx.com, mark.burton@greensocs.com, real@ispras.ru, batuzovk@ispras.ru, maria.klimushenkova@ispras.ru, alex.bennee@linaro.org, afaerber@suse.de, fred.konrad@greensocs.com > From: Paolo Bonzini [mailto:pbonzini@redhat.com] > On 05/12/2014 11:55, Pavel Dovgaluk wrote: > >> > > >> > And why is can_do_io zero? :) Is the fix to move the place where > >> > can_do_io becomes nonzero? > > can_do_io is set by gen_io_start function. > > As I understand, it is used to protect determinism in icount mode, > > because it allows non-deterministic (port io, raising interrupt) > > operations only at the end of the translation blocks. > > When someone tries to use MMIO in the middle of TB, that TB is > > recompiled to place this instruction at the end of the block. > > > > Do you mean that we can set can_do_io before execution of the block > > and reset it at the beginning of the execution? > > Yes, we could try setting it after execution of the block and clearing > it afterwards. Peter knows that part of icount better though (I know > mostly the timer/warping parts). Ok, how about these changes? diff --git a/cpu-exec.c b/cpu-exec.c index f52f292..88675ca 100644 --- a/cpu-exec.c +++ b/cpu-exec.c @@ -168,7 +168,9 @@ static inline tcg_target_ulong cpu_tb_exec(CPUState *cpu, uint8_t *tb_ptr) } #endif /* DEBUG_DISAS */ + cpu->can_do_io = 0; next_tb = tcg_qemu_tb_exec(env, tb_ptr); + cpu->can_do_io = 1; trace_exec_tb_exit((void *) (next_tb & ~TB_EXIT_MASK), next_tb & TB_EXIT_MASK); @@ -548,6 +550,7 @@ int cpu_exec(CPUArchState *env) cpu = current_cpu; env = cpu->env_ptr; cc = CPU_GET_CLASS(cpu); + cpu->can_do_io = 1; #ifdef TARGET_I386 x86_cpu = X86_CPU(cpu); #endif diff --git a/cpus.c b/cpus.c index 0c33458..7a45a51 100644 --- a/cpus.c +++ b/cpus.c @@ -934,6 +934,7 @@ static void *qemu_kvm_cpu_thread_fn(void *arg) qemu_mutex_lock(&qemu_global_mutex); qemu_thread_get_self(cpu->thread); cpu->thread_id = qemu_get_thread_id(); + cpu->can_do_io = 1; current_cpu = cpu; r = kvm_init_vcpu(cpu); @@ -974,6 +975,7 @@ static void *qemu_dummy_cpu_thread_fn(void *arg) qemu_mutex_lock_iothread(); qemu_thread_get_self(cpu->thread); cpu->thread_id = qemu_get_thread_id(); + cpu->can_do_io = 1; sigemptyset(&waitset); sigaddset(&waitset, SIG_IPI); @@ -1016,6 +1018,7 @@ static void *qemu_tcg_cpu_thread_fn(void *arg) CPU_FOREACH(cpu) { cpu->thread_id = qemu_get_thread_id(); cpu->created = true; + cpu->can_do_io = 1; } qemu_cond_signal(&qemu_cpu_cond);