From patchwork Thu Feb 4 15:27:55 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Michael S. Tsirkin" X-Patchwork-Id: 77035 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter.kernel.org (8.14.3/8.14.3) with ESMTP id o14FVAkn017015 for ; Thu, 4 Feb 2010 15:31:10 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932798Ab0BDPbH (ORCPT ); Thu, 4 Feb 2010 10:31:07 -0500 Received: from mx1.redhat.com ([209.132.183.28]:15175 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932221Ab0BDPbG (ORCPT ); Thu, 4 Feb 2010 10:31:06 -0500 Received: from int-mx05.intmail.prod.int.phx2.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.18]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id o14FV5ie005278 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Thu, 4 Feb 2010 10:31:05 -0500 Received: from redhat.com (vpn2-9-138.ams2.redhat.com [10.36.9.138]) by int-mx05.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with SMTP id o14FV4ca005127 for ; Thu, 4 Feb 2010 10:31:04 -0500 Date: Thu, 4 Feb 2010 17:27:55 +0200 From: "Michael S. Tsirkin" To: kvm@vger.kernel.org Subject: [PATCH 06/20] notifier: event notifier implementation Message-ID: <20100204152755.GG8461@redhat.com> References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.19 (2009-01-05) X-Scanned-By: MIMEDefang 2.67 on 10.5.11.18 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.3 (demeter.kernel.org [140.211.167.41]); Thu, 04 Feb 2010 15:31:10 +0000 (UTC) diff --git a/Makefile.target b/Makefile.target index 0ddd2a0..7df9535 100644 --- a/Makefile.target +++ b/Makefile.target @@ -183,6 +183,7 @@ obj-y = vl.o async.o monitor.o pci.o pci_host.o pcie_host.o machine.o gdbstub.o # virtio has to be here due to weird dependency between PCI and virtio-net. # need to fix this properly obj-y += virtio-blk.o virtio-balloon.o virtio-net.o virtio-pci.o virtio-serial-bus.o +obj-y += notifier.o obj-$(CONFIG_KVM) += kvm.o kvm-all.o # MSI-X depends on kvm for interrupt injection, # so moved it from Makefile.objs to Makefile.target for now diff --git a/hw/notifier.c b/hw/notifier.c new file mode 100644 index 0000000..dff38de --- /dev/null +++ b/hw/notifier.c @@ -0,0 +1,50 @@ +#include "hw.h" +#include "notifier.h" +#ifdef CONFIG_EVENTFD +#include +#endif + +int event_notifier_init(EventNotifier *e, int active) +{ +#ifdef CONFIG_EVENTFD + int fd = eventfd(!!active, EFD_NONBLOCK | EFD_CLOEXEC); + if (fd < 0) + return -errno; + e->fd = fd; + return 0; +#else + return -ENOSYS; +#endif +} + +void event_notifier_cleanup(EventNotifier *e) +{ + close(e->fd); +} + +int event_notifier_get_fd(EventNotifier *e) +{ + return e->fd; +} + +int event_notifier_test_and_clear(EventNotifier *e) +{ + uint64_t value; + int r = read(e->fd, &value, sizeof value); + return r == sizeof value; +} + +int event_notifier_test(EventNotifier *e) +{ + uint64_t value; + int r = read(e->fd, &value, sizeof value); + if (r == sizeof value) { + /* restore previous value. */ + int s = write(e->fd, &value, sizeof value); + /* never blocks because we use EFD_SEMAPHORE. + * If we didn't we'd get EAGAIN on overflow + * and we'd have to write code to ignore it. */ + assert(s == sizeof value); + } + return r == sizeof value; +} diff --git a/hw/notifier.h b/hw/notifier.h new file mode 100644 index 0000000..24117ea --- /dev/null +++ b/hw/notifier.h @@ -0,0 +1,16 @@ +#ifndef QEMU_EVENT_NOTIFIER_H +#define QEMU_EVENT_NOTIFIER_H + +#include "qemu-common.h" + +struct EventNotifier { + int fd; +}; + +int event_notifier_init(EventNotifier *, int active); +void event_notifier_cleanup(EventNotifier *); +int event_notifier_get_fd(EventNotifier *); +int event_notifier_test_and_clear(EventNotifier *); +int event_notifier_test(EventNotifier *); + +#endif diff --git a/qemu-common.h b/qemu-common.h index bf14a22..5e935d1 100644 --- a/qemu-common.h +++ b/qemu-common.h @@ -224,6 +224,7 @@ typedef struct uWireSlave uWireSlave; typedef struct I2SCodec I2SCodec; typedef struct DeviceState DeviceState; typedef struct SSIBus SSIBus; +typedef struct EventNotifier EventNotifier; /* CPU save/load. */ void cpu_save(QEMUFile *f, void *opaque);