From patchwork Mon Feb 22 21:26:48 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marcelo Tosatti X-Patchwork-Id: 46019 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [199.232.76.165]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 63246B7CEA for ; Tue, 23 Feb 2010 08:48:09 +1100 (EST) Received: from localhost ([127.0.0.1]:60006 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Njfxe-0000jb-F8 for incoming@patchwork.ozlabs.org; Mon, 22 Feb 2010 16:37:02 -0500 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1Njfor-0006uv-BY for qemu-devel@nongnu.org; Mon, 22 Feb 2010 16:27:57 -0500 Received: from [199.232.76.173] (port=56405 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Njfor-0006un-02 for qemu-devel@nongnu.org; Mon, 22 Feb 2010 16:27:57 -0500 Received: from Debian-exim by monty-python.gnu.org with spam-scanned (Exim 4.60) (envelope-from ) id 1Njfom-00036g-11 for qemu-devel@nongnu.org; Mon, 22 Feb 2010 16:27:57 -0500 Received: from mx1.redhat.com ([209.132.183.28]:16632) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1Njfok-000365-Jk for qemu-devel@nongnu.org; Mon, 22 Feb 2010 16:27:51 -0500 Received: from int-mx03.intmail.prod.int.phx2.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.16]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id o1MLRlto021635 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Mon, 22 Feb 2010 16:27:47 -0500 Received: from ns3.rdu.redhat.com (ns3.rdu.redhat.com [10.11.255.199]) by int-mx03.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id o1MLRkKQ019193; Mon, 22 Feb 2010 16:27:47 -0500 Received: from amt.cnet (vpn-11-163.rdu.redhat.com [10.11.11.163]) by ns3.rdu.redhat.com (8.13.8/8.13.8) with ESMTP id o1MLRi6t016389; Mon, 22 Feb 2010 16:27:45 -0500 Received: from amt.cnet (amt.cnet [127.0.0.1]) by amt.cnet (Postfix) with ESMTP id B9DE266E11C; Mon, 22 Feb 2010 18:27:16 -0300 (BRT) Received: (from marcelo@localhost) by amt.cnet (8.14.3/8.14.3/Submit) id o1MLRDOn000790; Mon, 22 Feb 2010 18:27:13 -0300 From: Marcelo Tosatti To: Anthony Liguori Date: Mon, 22 Feb 2010 18:26:48 -0300 Message-Id: In-Reply-To: References: X-Scanned-By: MIMEDefang 2.67 on 10.5.11.16 X-detected-operating-system: by monty-python.gnu.org: Genre and OS details not recognized. Cc: Marcelo Tosatti , qemu-devel@nongnu.org, kvm@vger.kernel.org, Avi Kivity Subject: [Qemu-devel] [PATCH 6/8] kvm: consume internal signal with sigtimedwait X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Change the way the internal qemu signal, used for communication between iothread and vcpus, is handled. Block and consume it with sigtimedwait on the outer vcpu loop, which allows more precise timing control. Change from standard signal (SIGUSR1) to real-time one, so multiple signals are not collapsed. Set the signal number on KVM's in-kernel allowed sigmask. Signed-off-by: Marcelo Tosatti Signed-off-by: Avi Kivity --- kvm-all.c | 19 +++++++++++++ kvm.h | 1 + vl.c | 89 ++++++++++++++++++++++++++++++++++++++++++++++++++++-------- 3 files changed, 97 insertions(+), 12 deletions(-) diff --git a/kvm-all.c b/kvm-all.c index 79345b2..38c372f 100644 --- a/kvm-all.c +++ b/kvm-all.c @@ -771,6 +771,7 @@ int kvm_cpu_exec(CPUState *env) kvm_arch_post_run(env, run); if (ret == -EINTR || ret == -EAGAIN) { + cpu_exit(env); dprintf("io window exit\n"); ret = 0; break; @@ -1116,3 +1117,21 @@ void kvm_remove_all_breakpoints(CPUState *current_env) { } #endif /* !KVM_CAP_SET_GUEST_DEBUG */ + +int kvm_set_signal_mask(CPUState *env, const sigset_t *sigset) +{ + struct kvm_signal_mask *sigmask; + int r; + + if (!sigset) + return kvm_vcpu_ioctl(env, KVM_SET_SIGNAL_MASK, NULL); + + sigmask = qemu_malloc(sizeof(*sigmask) + sizeof(*sigset)); + + sigmask->len = 8; + memcpy(sigmask->sigset, sigset, sizeof(*sigset)); + r = kvm_vcpu_ioctl(env, KVM_SET_SIGNAL_MASK, sigmask); + free(sigmask); + + return r; +} diff --git a/kvm.h b/kvm.h index e24bbde..9a9cdd5 100644 --- a/kvm.h +++ b/kvm.h @@ -53,6 +53,7 @@ int kvm_remove_breakpoint(CPUState *current_env, target_ulong addr, target_ulong len, int type); void kvm_remove_all_breakpoints(CPUState *current_env); int kvm_update_guest_debug(CPUState *env, unsigned long reinject_trap); +int kvm_set_signal_mask(CPUState *env, const sigset_t *sigset); int kvm_pit_in_kernel(void); int kvm_irqchip_in_kernel(void); diff --git a/vl.c b/vl.c index af198c1..dc05da3 100644 --- a/vl.c +++ b/vl.c @@ -271,6 +271,12 @@ uint8_t qemu_uuid[16]; static QEMUBootSetHandler *boot_set_handler; static void *boot_set_opaque; +#ifdef SIGRTMIN +#define SIG_IPI (SIGRTMIN+4) +#else +#define SIG_IPI SIGUSR1 +#endif + static int default_serial = 1; static int default_parallel = 1; static int default_virtcon = 1; @@ -3380,7 +3386,8 @@ static QemuCond qemu_cpu_cond; static QemuCond qemu_system_cond; static QemuCond qemu_pause_cond; -static void block_io_signals(void); +static void tcg_block_io_signals(void); +static void kvm_block_io_signals(CPUState *env); static void unblock_io_signals(void); static int tcg_has_work(void); static int cpu_has_work(CPUState *env); @@ -3432,11 +3439,36 @@ static void qemu_wait_io_event(CPUState *env) qemu_wait_io_event_common(env); } +static void qemu_kvm_eat_signal(CPUState *env, int timeout) +{ + struct timespec ts; + int r, e; + siginfo_t siginfo; + sigset_t waitset; + + ts.tv_sec = timeout / 1000; + ts.tv_nsec = (timeout % 1000) * 1000000; + + sigemptyset(&waitset); + sigaddset(&waitset, SIG_IPI); + + qemu_mutex_unlock(&qemu_global_mutex); + r = sigtimedwait(&waitset, &siginfo, &ts); + e = errno; + qemu_mutex_lock(&qemu_global_mutex); + + if (r == -1 && !(e == EAGAIN || e == EINTR)) { + fprintf(stderr, "sigtimedwait: %s\n", strerror(e)); + exit(1); + } +} + static void qemu_kvm_wait_io_event(CPUState *env) { while (!cpu_has_work(env)) qemu_cond_timedwait(env->halt_cond, &qemu_global_mutex, 1000); + qemu_kvm_eat_signal(env, 0); qemu_wait_io_event_common(env); } @@ -3446,11 +3478,12 @@ static void *kvm_cpu_thread_fn(void *arg) { CPUState *env = arg; - block_io_signals(); qemu_thread_self(env->thread); if (kvm_enabled()) kvm_init_vcpu(env); + kvm_block_io_signals(env); + /* signal CPU creation */ qemu_mutex_lock(&qemu_global_mutex); env->created = 1; @@ -3475,7 +3508,7 @@ static void *tcg_cpu_thread_fn(void *arg) { CPUState *env = arg; - block_io_signals(); + tcg_block_io_signals(); qemu_thread_self(env->thread); /* signal CPU creation */ @@ -3501,7 +3534,7 @@ void qemu_cpu_kick(void *_env) CPUState *env = _env; qemu_cond_broadcast(env->halt_cond); if (kvm_enabled()) - qemu_thread_signal(env->thread, SIGUSR1); + qemu_thread_signal(env->thread, SIG_IPI); } int qemu_cpu_self(void *_env) @@ -3520,7 +3553,7 @@ static void cpu_signal(int sig) cpu_exit(cpu_single_env); } -static void block_io_signals(void) +static void tcg_block_io_signals(void) { sigset_t set; struct sigaction sigact; @@ -3533,12 +3566,44 @@ static void block_io_signals(void) pthread_sigmask(SIG_BLOCK, &set, NULL); sigemptyset(&set); - sigaddset(&set, SIGUSR1); + sigaddset(&set, SIG_IPI); pthread_sigmask(SIG_UNBLOCK, &set, NULL); memset(&sigact, 0, sizeof(sigact)); sigact.sa_handler = cpu_signal; - sigaction(SIGUSR1, &sigact, NULL); + sigaction(SIG_IPI, &sigact, NULL); +} + +static void dummy_signal(int sig) +{ +} + +static void kvm_block_io_signals(CPUState *env) +{ + int r; + sigset_t set; + struct sigaction sigact; + + sigemptyset(&set); + sigaddset(&set, SIGUSR2); + sigaddset(&set, SIGIO); + sigaddset(&set, SIGALRM); + sigaddset(&set, SIGCHLD); + sigaddset(&set, SIG_IPI); + pthread_sigmask(SIG_BLOCK, &set, NULL); + + pthread_sigmask(SIG_BLOCK, NULL, &set); + sigdelset(&set, SIG_IPI); + + memset(&sigact, 0, sizeof(sigact)); + sigact.sa_handler = dummy_signal; + sigaction(SIG_IPI, &sigact, NULL); + + r = kvm_set_signal_mask(env, &set); + if (r) { + fprintf(stderr, "kvm_set_signal_mask: %s\n", strerror(r)); + exit(1); + } } static void unblock_io_signals(void) @@ -3552,7 +3617,7 @@ static void unblock_io_signals(void) pthread_sigmask(SIG_UNBLOCK, &set, NULL); sigemptyset(&set); - sigaddset(&set, SIGUSR1); + sigaddset(&set, SIG_IPI); pthread_sigmask(SIG_BLOCK, &set, NULL); } @@ -3561,7 +3626,7 @@ static void qemu_signal_lock(unsigned int msecs) qemu_mutex_lock(&qemu_fair_mutex); while (qemu_mutex_trylock(&qemu_global_mutex)) { - qemu_thread_signal(tcg_cpu_thread, SIGUSR1); + qemu_thread_signal(tcg_cpu_thread, SIG_IPI); if (!qemu_mutex_timedlock(&qemu_global_mutex, msecs)) break; } @@ -3602,7 +3667,7 @@ static void pause_all_vcpus(void) while (penv) { penv->stop = 1; - qemu_thread_signal(penv->thread, SIGUSR1); + qemu_thread_signal(penv->thread, SIG_IPI); qemu_cpu_kick(penv); penv = (CPUState *)penv->next_cpu; } @@ -3611,7 +3676,7 @@ static void pause_all_vcpus(void) qemu_cond_timedwait(&qemu_pause_cond, &qemu_global_mutex, 100); penv = first_cpu; while (penv) { - qemu_thread_signal(penv->thread, SIGUSR1); + qemu_thread_signal(penv->thread, SIG_IPI); penv = (CPUState *)penv->next_cpu; } } @@ -3624,7 +3689,7 @@ static void resume_all_vcpus(void) while (penv) { penv->stop = 0; penv->stopped = 0; - qemu_thread_signal(penv->thread, SIGUSR1); + qemu_thread_signal(penv->thread, SIG_IPI); qemu_cpu_kick(penv); penv = (CPUState *)penv->next_cpu; }