From 42ac9bd18d4fc28c36c7927847f0f6e90ecd7710 Mon Sep 17 00:00:00 2001 From: Antonios Motakis Date: Mon, 16 Mar 2015 14:08:54 -0600 Subject: vfio: initialize the virqfd workqueue in VFIO generic code Now we have finally completely decoupled virqfd from VFIO_PCI. We can initialize it from the VFIO generic code, in order to safely use it from multiple independent VFIO bus drivers. Signed-off-by: Antonios Motakis Signed-off-by: Baptiste Reynal Reviewed-by: Eric Auger Tested-by: Eric Auger Signed-off-by: Alex Williamson --- drivers/vfio/vfio.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'drivers/vfio/vfio.c') diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c index 4cde85501444..23ba12afe01f 100644 --- a/drivers/vfio/vfio.c +++ b/drivers/vfio/vfio.c @@ -1553,6 +1553,11 @@ static int __init vfio_init(void) if (ret) goto err_cdev_add; + /* Start the virqfd cleanup handler used by some VFIO bus drivers */ + ret = vfio_virqfd_init(); + if (ret) + goto err_virqfd; + pr_info(DRIVER_DESC " version: " DRIVER_VERSION "\n"); /* @@ -1565,6 +1570,8 @@ static int __init vfio_init(void) return 0; +err_virqfd: + cdev_del(&vfio.group_cdev); err_cdev_add: unregister_chrdev_region(vfio.group_devt, MINORMASK); err_alloc_chrdev: @@ -1579,6 +1586,7 @@ static void __exit vfio_cleanup(void) { WARN_ON(!list_empty(&vfio.group_list)); + vfio_virqfd_exit(); idr_destroy(&vfio.group_idr); cdev_del(&vfio.group_cdev); unregister_chrdev_region(vfio.group_devt, MINORMASK); -- cgit v1.2.3 From 2f51bf4be99386f49841b6365a85a5cabc148565 Mon Sep 17 00:00:00 2001 From: Zhen Lei Date: Mon, 16 Mar 2015 14:08:56 -0600 Subject: vfio: put off the allocation of "minor" in vfio_create_group The next code fragment "list_for_each_entry" is not depend on "minor". With this patch, the free of "minor" in "list_for_each_entry" can be reduced, and there is no functional change. Signed-off-by: Zhen Lei Signed-off-by: Alex Williamson --- drivers/vfio/vfio.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) (limited to 'drivers/vfio/vfio.c') diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c index 23ba12afe01f..86aac7e4a050 100644 --- a/drivers/vfio/vfio.c +++ b/drivers/vfio/vfio.c @@ -234,22 +234,21 @@ static struct vfio_group *vfio_create_group(struct iommu_group *iommu_group) mutex_lock(&vfio.group_lock); - minor = vfio_alloc_group_minor(group); - if (minor < 0) { - vfio_group_unlock_and_free(group); - return ERR_PTR(minor); - } - /* Did we race creating this group? */ list_for_each_entry(tmp, &vfio.group_list, vfio_next) { if (tmp->iommu_group == iommu_group) { vfio_group_get(tmp); - vfio_free_group_minor(minor); vfio_group_unlock_and_free(group); return tmp; } } + minor = vfio_alloc_group_minor(group); + if (minor < 0) { + vfio_group_unlock_and_free(group); + return ERR_PTR(minor); + } + dev = device_create(vfio.class, NULL, MKDEV(MAJOR(vfio.group_devt), minor), group, "%d", iommu_group_id(iommu_group)); -- cgit v1.2.3 From 71be3423a62be548c56bab5b818e1a1383e659d2 Mon Sep 17 00:00:00 2001 From: Alex Williamson Date: Tue, 17 Mar 2015 08:33:38 -0600 Subject: vfio: Split virqfd into a separate module for vfio bus drivers An unintended consequence of commit 42ac9bd18d4f ("vfio: initialize the virqfd workqueue in VFIO generic code") is that the vfio module is renamed to vfio_core so that it can include both vfio and virqfd. That's a user visible change that may break module loading scritps and it imposes eventfd support as a dependency on the core vfio code, which it's really not. virqfd is intended to be provided as a service to vfio bus drivers, so instead of wrapping it into vfio.ko, we can make it a stand-alone module toggled by vfio bus drivers. This has the additional benefit of removing initialization and exit from the core vfio code. Signed-off-by: Alex Williamson --- drivers/vfio/Kconfig | 5 +++++ drivers/vfio/Makefile | 5 +++-- drivers/vfio/pci/Kconfig | 1 + drivers/vfio/platform/Kconfig | 1 + drivers/vfio/vfio.c | 8 -------- drivers/vfio/virqfd.c | 17 +++++++++++++++-- include/linux/vfio.h | 2 -- 7 files changed, 25 insertions(+), 14 deletions(-) (limited to 'drivers/vfio/vfio.c') diff --git a/drivers/vfio/Kconfig b/drivers/vfio/Kconfig index d5322a434a7a..7d092ddc8119 100644 --- a/drivers/vfio/Kconfig +++ b/drivers/vfio/Kconfig @@ -13,6 +13,11 @@ config VFIO_SPAPR_EEH depends on EEH && VFIO_IOMMU_SPAPR_TCE default n +config VFIO_VIRQFD + tristate + depends on VFIO && EVENTFD + default n + menuconfig VFIO tristate "VFIO Non-Privileged userspace driver framework" depends on IOMMU_API diff --git a/drivers/vfio/Makefile b/drivers/vfio/Makefile index d798b0959603..7b8a31f63fea 100644 --- a/drivers/vfio/Makefile +++ b/drivers/vfio/Makefile @@ -1,6 +1,7 @@ -vfio_core-y := vfio.o virqfd.o +vfio_virqfd-y := virqfd.o -obj-$(CONFIG_VFIO) += vfio_core.o +obj-$(CONFIG_VFIO) += vfio.o +obj-$(CONFIG_VFIO_VIRQFD) += vfio_virqfd.o obj-$(CONFIG_VFIO_IOMMU_TYPE1) += vfio_iommu_type1.o obj-$(CONFIG_VFIO_IOMMU_SPAPR_TCE) += vfio_iommu_spapr_tce.o obj-$(CONFIG_VFIO_SPAPR_EEH) += vfio_spapr_eeh.o diff --git a/drivers/vfio/pci/Kconfig b/drivers/vfio/pci/Kconfig index c6bb5da2d2a7..579d83bf5358 100644 --- a/drivers/vfio/pci/Kconfig +++ b/drivers/vfio/pci/Kconfig @@ -1,6 +1,7 @@ config VFIO_PCI tristate "VFIO support for PCI devices" depends on VFIO && PCI && EVENTFD + select VFIO_VIRQFD help Support for the PCI VFIO bus driver. This is required to make use of PCI drivers using the VFIO framework. diff --git a/drivers/vfio/platform/Kconfig b/drivers/vfio/platform/Kconfig index c0a3bff8baee..9a4403e2a36c 100644 --- a/drivers/vfio/platform/Kconfig +++ b/drivers/vfio/platform/Kconfig @@ -1,6 +1,7 @@ config VFIO_PLATFORM tristate "VFIO support for platform devices" depends on VFIO && EVENTFD && ARM + select VFIO_VIRQFD help Support for platform devices with VFIO. This is required to make use of platform devices present on the system using the VFIO diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c index 86aac7e4a050..0d336625ac71 100644 --- a/drivers/vfio/vfio.c +++ b/drivers/vfio/vfio.c @@ -1552,11 +1552,6 @@ static int __init vfio_init(void) if (ret) goto err_cdev_add; - /* Start the virqfd cleanup handler used by some VFIO bus drivers */ - ret = vfio_virqfd_init(); - if (ret) - goto err_virqfd; - pr_info(DRIVER_DESC " version: " DRIVER_VERSION "\n"); /* @@ -1569,8 +1564,6 @@ static int __init vfio_init(void) return 0; -err_virqfd: - cdev_del(&vfio.group_cdev); err_cdev_add: unregister_chrdev_region(vfio.group_devt, MINORMASK); err_alloc_chrdev: @@ -1585,7 +1578,6 @@ static void __exit vfio_cleanup(void) { WARN_ON(!list_empty(&vfio.group_list)); - vfio_virqfd_exit(); idr_destroy(&vfio.group_idr); cdev_del(&vfio.group_cdev); unregister_chrdev_region(vfio.group_devt, MINORMASK); diff --git a/drivers/vfio/virqfd.c b/drivers/vfio/virqfd.c index 3d19aaf0e6c9..27c89cd5d70b 100644 --- a/drivers/vfio/virqfd.c +++ b/drivers/vfio/virqfd.c @@ -13,12 +13,17 @@ #include #include #include +#include #include +#define DRIVER_VERSION "0.1" +#define DRIVER_AUTHOR "Alex Williamson " +#define DRIVER_DESC "IRQFD support for VFIO bus drivers" + static struct workqueue_struct *vfio_irqfd_cleanup_wq; static DEFINE_SPINLOCK(virqfd_lock); -int __init vfio_virqfd_init(void) +static int __init vfio_virqfd_init(void) { vfio_irqfd_cleanup_wq = create_singlethread_workqueue("vfio-irqfd-cleanup"); @@ -28,7 +33,7 @@ int __init vfio_virqfd_init(void) return 0; } -void vfio_virqfd_exit(void) +static void __exit vfio_virqfd_exit(void) { destroy_workqueue(vfio_irqfd_cleanup_wq); } @@ -211,3 +216,11 @@ void vfio_virqfd_disable(struct virqfd **pvirqfd) flush_workqueue(vfio_irqfd_cleanup_wq); } EXPORT_SYMBOL_GPL(vfio_virqfd_disable); + +module_init(vfio_virqfd_init); +module_exit(vfio_virqfd_exit); + +MODULE_VERSION(DRIVER_VERSION); +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR(DRIVER_AUTHOR); +MODULE_DESCRIPTION(DRIVER_DESC); diff --git a/include/linux/vfio.h b/include/linux/vfio.h index 683b5146022e..cbed15f194e0 100644 --- a/include/linux/vfio.h +++ b/include/linux/vfio.h @@ -142,8 +142,6 @@ struct virqfd { struct virqfd **pvirqfd; }; -extern int vfio_virqfd_init(void); -extern void vfio_virqfd_exit(void); extern int vfio_virqfd_enable(void *opaque, int (*handler)(void *, void *), void (*thread)(void *, void *), -- cgit v1.2.3 From db7d4d7f40215843000cb9d441c9149fd42ea36b Mon Sep 17 00:00:00 2001 From: Alex Williamson Date: Fri, 1 May 2015 16:31:41 -0600 Subject: vfio: Fix runaway interruptible timeout Commit 13060b64b819 ("vfio: Add and use device request op for vfio bus drivers") incorrectly makes use of an interruptible timeout. When interrupted, the signal remains pending resulting in subsequent timeouts occurring instantly. This makes the loop spin at a much higher rate than intended. Instead of making this completely non-interruptible, we can change this into a sort of interruptible-once behavior and use the "once" to log debug information. The driver API doesn't allow us to abort and return an error code. Signed-off-by: Alex Williamson Fixes: 13060b64b819 Cc: stable@vger.kernel.org # v4.0 --- drivers/vfio/vfio.c | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-) (limited to 'drivers/vfio/vfio.c') diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c index 0d336625ac71..e1278fe04b1e 100644 --- a/drivers/vfio/vfio.c +++ b/drivers/vfio/vfio.c @@ -710,6 +710,8 @@ void *vfio_del_group_dev(struct device *dev) void *device_data = device->device_data; struct vfio_unbound_dev *unbound; unsigned int i = 0; + long ret; + bool interrupted = false; /* * The group exists so long as we have a device reference. Get @@ -755,9 +757,22 @@ void *vfio_del_group_dev(struct device *dev) vfio_device_put(device); - } while (wait_event_interruptible_timeout(vfio.release_q, - !vfio_dev_present(group, dev), - HZ * 10) <= 0); + if (interrupted) { + ret = wait_event_timeout(vfio.release_q, + !vfio_dev_present(group, dev), HZ * 10); + } else { + ret = wait_event_interruptible_timeout(vfio.release_q, + !vfio_dev_present(group, dev), HZ * 10); + if (ret == -ERESTARTSYS) { + interrupted = true; + dev_warn(dev, + "Device is currently in use, task" + " \"%s\" (%d) " + "blocked until device is released", + current->comm, task_pid_nr(current)); + } + } + } while (ret <= 0); vfio_group_put(group); -- cgit v1.2.3