From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:40836) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gk3my-0002rF-ES for qemu-devel@nongnu.org; Thu, 17 Jan 2019 04:16:42 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gk3mw-0002H1-QG for qemu-devel@nongnu.org; Thu, 17 Jan 2019 04:16:40 -0500 Received: from mx1.redhat.com ([209.132.183.28]:56910) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gk3mw-00022u-Gw for qemu-devel@nongnu.org; Thu, 17 Jan 2019 04:16:38 -0500 References: <20190111165801.15181-1-eric.auger@redhat.com> <20190111165801.15181-2-eric.auger@redhat.com> From: Auger Eric Message-ID: <739abfa7-5faa-0c0c-7e81-80136e702e08@redhat.com> Date: Thu, 17 Jan 2019 10:16:32 +0100 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 1/2] vfio-pci: Introduce vfio_register_event_notifier helper List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexey Kardashevskiy , eric.auger.pro@gmail.com, qemu-devel@nongnu.org, alex.williamson@redhat.com Hi Alexey, Cornelia, On 1/17/19 4:46 AM, Alexey Kardashevskiy wrote: > > > On 12/01/2019 03:58, Eric Auger wrote: >> The code used to attach the eventfd handler for the ERR and >> REQ irq indices can be factorized into a helper. In subsequent >> patches we will extend this helper to support other irq indices. >> >> We test the notification is allowed outside of the helper: >> respectively check vdev->pci_aer and VFIO_FEATURE_ENABLE_REQ. >> Depending on the returned value we set vdev->pci_aer and >> vdev->req_enabled. An error handle is introduced for future usage >> although not strictly useful here.> >> Signed-off-by: Eric Auger >> --- >> hw/vfio/pci.c | 291 ++++++++++++++++++++++---------------------------- >> 1 file changed, 127 insertions(+), 164 deletions(-) >> >> diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c >> index c0cb1ec289..c589a4e666 100644 >> --- a/hw/vfio/pci.c >> +++ b/hw/vfio/pci.c >> @@ -105,6 +105,95 @@ static void vfio_intx_eoi(VFIODevice *vbasedev) >> vfio_unmask_single_irqindex(vbasedev, VFIO_PCI_INTX_IRQ_INDEX); >> } >> >> +/* >> + * vfio_register_event_notifier - setup/tear down eventfd >> + * notification and handling for IRQ indices that span over >> + * a single IRQ >> + * >> + * @vdev: VFIO device handle >> + * @index: IRQ index the eventfd/handler is associated to >> + * @target_state: true means notifier needs to be set up >> + * @handler to attach if @target_state is true >> + * @errp error handle >> + */ >> +static int vfio_register_event_notifier(VFIOPCIDevice *vdev, >> + int index, >> + bool target_state, >> + void (*handler)(void *opaque), >> + Error **errp) >> +{ >> + struct vfio_irq_info irq_info = { .argsz = sizeof(irq_info), >> + .index = index }; >> + struct vfio_irq_set *irq_set; >> + EventNotifier *notifier; >> + int argsz, ret = 0; >> + int32_t *pfd, fd; >> + >> + switch (index) { > > I'd pass the notifier as a parameter as well so index/handler/notifier > would walk together. I tend to agree with Cornelia. moving the notifier out of this helper would remove some factorization and this way, the caller does not have to care about it. > > >> + case VFIO_PCI_REQ_IRQ_INDEX: >> + notifier = &vdev->req_notifier; >> + break; >> + case VFIO_PCI_ERR_IRQ_INDEX: >> + notifier = &vdev->err_notifier; >> + break; >> + default: >> + return -EINVAL; >> + } >> + >> + if (ioctl(vdev->vbasedev.fd, >> + VFIO_DEVICE_GET_IRQ_INFO, &irq_info) < 0 || irq_info.count < 1) { >> + error_setg_errno(errp, errno, >> + "no irq index %d available", index); >> + return -EINVAL; >> + } >> + >> + if (target_state) { >> + ret = event_notifier_init(notifier, 0); >> + if (ret) { >> + error_setg_errno(errp, -ret, >> + "Unable to init event notifier for irq index %d", >> + index); >> + return ret; >> + } >> + } >> + >> + argsz = sizeof(*irq_set) + sizeof(*pfd); >> + >> + irq_set = g_malloc0(argsz); >> + irq_set->argsz = argsz; >> + irq_set->flags = VFIO_IRQ_SET_DATA_EVENTFD | >> + VFIO_IRQ_SET_ACTION_TRIGGER; >> + irq_set->index = index; >> + irq_set->start = 0; >> + irq_set->count = 1; >> + pfd = (int32_t *)&irq_set->data; >> + >> + if (!notifier) { >> + return -EINVAL; >> + } >> + >> + fd = event_notifier_get_fd(notifier); >> + >> + if (target_state) { >> + qemu_set_fd_handler(fd, handler, NULL, vdev); >> + *pfd = fd; >> + } else { >> + qemu_set_fd_handler(fd, NULL, NULL, vdev); >> + event_notifier_cleanup(notifier); >> + *pfd = -1; >> + } >> + >> + ret = ioctl(vdev->vbasedev.fd, VFIO_DEVICE_SET_IRQS, irq_set); >> + g_free(irq_set); >> + >> + if (ret) { >> + error_setg_errno(errp, -ret, >> + "vfio: Failed to %s eventfd signalling for index %d", >> + *pfd < 0 ? "set up" : "tear down", index); >> + } >> + return ret; >> +} >> + >> static void vfio_intx_enable_kvm(VFIOPCIDevice *vdev, Error **errp) >> { >> #ifdef CONFIG_KVM >> @@ -2621,86 +2710,6 @@ static void vfio_err_notifier_handler(void *opaque) >> vm_stop(RUN_STATE_INTERNAL_ERROR); >> } >> >> -/* >> - * Registers error notifier for devices supporting error recovery. >> - * If we encounter a failure in this function, we report an error >> - * and continue after disabling error recovery support for the >> - * device. >> - */ >> -static void vfio_register_err_notifier(VFIOPCIDevice *vdev) >> -{ >> - int ret; >> - int argsz; >> - struct vfio_irq_set *irq_set; >> - int32_t *pfd; >> - >> - if (!vdev->pci_aer) { >> - return; >> - } >> - >> - if (event_notifier_init(&vdev->err_notifier, 0)) { >> - error_report("vfio: Unable to init event notifier for error detection"); >> - vdev->pci_aer = false; >> - return; >> - } >> - >> - argsz = sizeof(*irq_set) + sizeof(*pfd); >> - >> - irq_set = g_malloc0(argsz); >> - irq_set->argsz = argsz; >> - irq_set->flags = VFIO_IRQ_SET_DATA_EVENTFD | >> - VFIO_IRQ_SET_ACTION_TRIGGER; >> - irq_set->index = VFIO_PCI_ERR_IRQ_INDEX; >> - irq_set->start = 0; >> - irq_set->count = 1; >> - pfd = (int32_t *)&irq_set->data; >> - >> - *pfd = event_notifier_get_fd(&vdev->err_notifier); >> - qemu_set_fd_handler(*pfd, vfio_err_notifier_handler, NULL, vdev); >> - >> - ret = ioctl(vdev->vbasedev.fd, VFIO_DEVICE_SET_IRQS, irq_set); >> - if (ret) { >> - error_report("vfio: Failed to set up error notification"); >> - qemu_set_fd_handler(*pfd, NULL, NULL, vdev); >> - event_notifier_cleanup(&vdev->err_notifier); > > > qemu_set_fd_handler() and event_notifier_cleanup() have not made it to > the new vfio_register_event_notifier() for the case when > ioctl(VFIO_DEVICE_SET_IRQS) failed. definitively missing. Thanks! > > >> - vdev->pci_aer = false; >> - } >> - g_free(irq_set); >> -} >> - >> -static void vfio_unregister_err_notifier(VFIOPCIDevice *vdev) >> -{ >> - int argsz; >> - struct vfio_irq_set *irq_set; >> - int32_t *pfd; >> - int ret; >> - >> - if (!vdev->pci_aer) { >> - return; >> - } >> - >> - argsz = sizeof(*irq_set) + sizeof(*pfd); >> - >> - irq_set = g_malloc0(argsz); >> - irq_set->argsz = argsz; >> - irq_set->flags = VFIO_IRQ_SET_DATA_EVENTFD | >> - VFIO_IRQ_SET_ACTION_TRIGGER; >> - irq_set->index = VFIO_PCI_ERR_IRQ_INDEX; >> - irq_set->start = 0; >> - irq_set->count = 1; >> - pfd = (int32_t *)&irq_set->data; >> - *pfd = -1; >> - >> - ret = ioctl(vdev->vbasedev.fd, VFIO_DEVICE_SET_IRQS, irq_set); >> - if (ret) { >> - error_report("vfio: Failed to de-assign error fd: %m"); >> - } >> - g_free(irq_set); >> - qemu_set_fd_handler(event_notifier_get_fd(&vdev->err_notifier), >> - NULL, NULL, vdev); >> - event_notifier_cleanup(&vdev->err_notifier); >> -} >> - >> static void vfio_req_notifier_handler(void *opaque) >> { >> VFIOPCIDevice *vdev = opaque; >> @@ -2716,86 +2725,6 @@ static void vfio_req_notifier_handler(void *opaque) >> } >> } >> >> -static void vfio_register_req_notifier(VFIOPCIDevice *vdev) >> -{ >> - struct vfio_irq_info irq_info = { .argsz = sizeof(irq_info), >> - .index = VFIO_PCI_REQ_IRQ_INDEX }; >> - int argsz; >> - struct vfio_irq_set *irq_set; >> - int32_t *pfd; >> - >> - if (!(vdev->features & VFIO_FEATURE_ENABLE_REQ)) { >> - return; >> - } >> - >> - if (ioctl(vdev->vbasedev.fd, >> - VFIO_DEVICE_GET_IRQ_INFO, &irq_info) < 0 || irq_info.count < 1) { >> - return; >> - } >> - >> - if (event_notifier_init(&vdev->req_notifier, 0)) { >> - error_report("vfio: Unable to init event notifier for device request"); >> - return; >> - } >> - >> - argsz = sizeof(*irq_set) + sizeof(*pfd); >> - >> - irq_set = g_malloc0(argsz); >> - irq_set->argsz = argsz; >> - irq_set->flags = VFIO_IRQ_SET_DATA_EVENTFD | >> - VFIO_IRQ_SET_ACTION_TRIGGER; >> - irq_set->index = VFIO_PCI_REQ_IRQ_INDEX; >> - irq_set->start = 0; >> - irq_set->count = 1; >> - pfd = (int32_t *)&irq_set->data; >> - >> - *pfd = event_notifier_get_fd(&vdev->req_notifier); >> - qemu_set_fd_handler(*pfd, vfio_req_notifier_handler, NULL, vdev); >> - >> - if (ioctl(vdev->vbasedev.fd, VFIO_DEVICE_SET_IRQS, irq_set)) { >> - error_report("vfio: Failed to set up device request notification"); >> - qemu_set_fd_handler(*pfd, NULL, NULL, vdev); > > Same here. > > >> - event_notifier_cleanup(&vdev->req_notifier); >> - } else { >> - vdev->req_enabled = true; >> - } >> - >> - g_free(irq_set); >> -} >> - >> -static void vfio_unregister_req_notifier(VFIOPCIDevice *vdev) >> -{ >> - int argsz; >> - struct vfio_irq_set *irq_set; >> - int32_t *pfd; >> - >> - if (!vdev->req_enabled) { >> - return; >> - } >> - >> - argsz = sizeof(*irq_set) + sizeof(*pfd); >> - >> - irq_set = g_malloc0(argsz); >> - irq_set->argsz = argsz; >> - irq_set->flags = VFIO_IRQ_SET_DATA_EVENTFD | >> - VFIO_IRQ_SET_ACTION_TRIGGER; >> - irq_set->index = VFIO_PCI_REQ_IRQ_INDEX; >> - irq_set->start = 0; >> - irq_set->count = 1; >> - pfd = (int32_t *)&irq_set->data; >> - *pfd = -1; >> - >> - if (ioctl(vdev->vbasedev.fd, VFIO_DEVICE_SET_IRQS, irq_set)) { >> - error_report("vfio: Failed to de-assign device request fd: %m"); >> - } >> - g_free(irq_set); >> - qemu_set_fd_handler(event_notifier_get_fd(&vdev->req_notifier), >> - NULL, NULL, vdev); >> - event_notifier_cleanup(&vdev->req_notifier); >> - >> - vdev->req_enabled = false; >> -} >> - >> static void vfio_realize(PCIDevice *pdev, Error **errp) >> { >> VFIOPCIDevice *vdev = PCI_VFIO(pdev); >> @@ -3069,8 +2998,29 @@ static void vfio_realize(PCIDevice *pdev, Error **errp) >> goto out_teardown; >> } >> >> - vfio_register_err_notifier(vdev); >> - vfio_register_req_notifier(vdev); >> + if (vdev->pci_aer) { >> + /* >> + * Registers error notifier for devices supporting error recovery. >> + * If we encounter a failure in this function, we report an error >> + * and continue after disabling error recovery support for the >> + * device. >> + */ >> + vdev->pci_aer = >> + !vfio_register_event_notifier(vdev, VFIO_PCI_ERR_IRQ_INDEX, true, >> + vfio_err_notifier_handler, &err); >> + if (err) { >> + warn_reportf_err(err, VFIO_MSG_PREFIX, vdev->vbasedev.name); >> + } > > > As the commit log said, these returned @err are not particularly useful > as they are handled exactly the same way and they are not forwarded further. Yes that's awkward but the issue is vfio_intx_enable() propagates the error. > > Also, the new helper returns int which is not tested anywhere and it can > also return with an error and err==NULL so these errors will be silently > skipped. Some consistency here would not hurt :) Yes I think I will make it a void function and the caller will only test err. Thank you for the review! Eric > > >> + } >> + >> + if (vdev->features & VFIO_FEATURE_ENABLE_REQ) { >> + vdev->req_enabled = >> + !vfio_register_event_notifier(vdev, VFIO_PCI_REQ_IRQ_INDEX, true, >> + vfio_req_notifier_handler, &err); >> + if (err) { >> + warn_reportf_err(err, VFIO_MSG_PREFIX, vdev->vbasedev.name); >> + } >> + } >> vfio_setup_resetfn_quirk(vdev); >> >> return; >> @@ -3106,9 +3056,22 @@ static void vfio_instance_finalize(Object *obj) >> static void vfio_exitfn(PCIDevice *pdev) >> { >> VFIOPCIDevice *vdev = PCI_VFIO(pdev); >> + Error *err = NULL; >> >> - vfio_unregister_req_notifier(vdev); >> - vfio_unregister_err_notifier(vdev); >> + if (vdev->req_enabled) { >> + vfio_register_event_notifier(vdev, VFIO_PCI_REQ_IRQ_INDEX, >> + false, NULL, &err); >> + if (err) { >> + warn_reportf_err(err, VFIO_MSG_PREFIX, vdev->vbasedev.name); >> + } >> + } >> + if (vdev->pci_aer) { >> + vfio_register_event_notifier(vdev, VFIO_PCI_ERR_IRQ_INDEX, >> + false, NULL, &err); >> + if (err) { >> + warn_reportf_err(err, VFIO_MSG_PREFIX, vdev->vbasedev.name); >> + } >> + } >> pci_device_set_intx_routing_notifier(&vdev->pdev, NULL); >> vfio_disable_interrupts(vdev); >> if (vdev->intx.mmap_timer) { >> >