From: Yishai Hadas yishaih@nvidia.com
PCI wants to have the usual open/close_device() logic with the slight twist that the open/close_device() must be done under a singelton lock shared by all of the vfio_devices that are in the PCI "reset group".
The reset group, and thus the device set, is determined by what devices pci_reset_bus() touches, which is either the entire bus or only the slot.
Rely on the core code to do everything reflck was doing and delete reflck entirely.
Signed-off-by: Yishai Hadas yishaih@nvidia.com Reviewed-by: Christoph Hellwig hch@lst.de Signed-off-by: Jason Gunthorpe jgg@nvidia.com --- drivers/vfio/pci/vfio_pci.c | 162 +++++++--------------------- drivers/vfio/pci/vfio_pci_private.h | 7 -- 2 files changed, 37 insertions(+), 132 deletions(-)
diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c index fab3715d60d4ba..5d6db93d6c680f 100644 --- a/drivers/vfio/pci/vfio_pci.c +++ b/drivers/vfio/pci/vfio_pci.c @@ -530,53 +530,40 @@ static void vfio_pci_vf_token_user_add(struct vfio_pci_device *vdev, int val) vfio_device_put(&pf_vdev->vdev); }
-static void vfio_pci_release(struct vfio_device *core_vdev) +static void vfio_pci_close_device(struct vfio_device *core_vdev) { struct vfio_pci_device *vdev = container_of(core_vdev, struct vfio_pci_device, vdev);
- mutex_lock(&vdev->reflck->lock); - - if (!(--vdev->refcnt)) { - vfio_pci_vf_token_user_add(vdev, -1); - vfio_spapr_pci_eeh_release(vdev->pdev); - vfio_pci_disable(vdev); + vfio_pci_vf_token_user_add(vdev, -1); + vfio_spapr_pci_eeh_release(vdev->pdev); + vfio_pci_disable(vdev);
- mutex_lock(&vdev->igate); - if (vdev->err_trigger) { - eventfd_ctx_put(vdev->err_trigger); - vdev->err_trigger = NULL; - } - if (vdev->req_trigger) { - eventfd_ctx_put(vdev->req_trigger); - vdev->req_trigger = NULL; - } - mutex_unlock(&vdev->igate); + mutex_lock(&vdev->igate); + if (vdev->err_trigger) { + eventfd_ctx_put(vdev->err_trigger); + vdev->err_trigger = NULL; } - - mutex_unlock(&vdev->reflck->lock); + if (vdev->req_trigger) { + eventfd_ctx_put(vdev->req_trigger); + vdev->req_trigger = NULL; + } + mutex_unlock(&vdev->igate); }
-static int vfio_pci_open(struct vfio_device *core_vdev) +static int vfio_pci_open_device(struct vfio_device *core_vdev) { struct vfio_pci_device *vdev = container_of(core_vdev, struct vfio_pci_device, vdev); int ret = 0;
- mutex_lock(&vdev->reflck->lock); - - if (!vdev->refcnt) { - ret = vfio_pci_enable(vdev); - if (ret) - goto error; + ret = vfio_pci_enable(vdev); + if (ret) + return ret;
- vfio_spapr_pci_eeh_open(vdev->pdev); - vfio_pci_vf_token_user_add(vdev, 1); - } - vdev->refcnt++; -error: - mutex_unlock(&vdev->reflck->lock); - return ret; + vfio_spapr_pci_eeh_open(vdev->pdev); + vfio_pci_vf_token_user_add(vdev, 1); + return 0; }
static int vfio_pci_get_irq_count(struct vfio_pci_device *vdev, int irq_type) @@ -1870,8 +1857,8 @@ static int vfio_pci_match(struct vfio_device *core_vdev, char *buf)
static const struct vfio_device_ops vfio_pci_ops = { .name = "vfio-pci", - .open = vfio_pci_open, - .release = vfio_pci_release, + .open_device = vfio_pci_open_device, + .close_device = vfio_pci_close_device, .ioctl = vfio_pci_ioctl, .read = vfio_pci_read, .write = vfio_pci_write, @@ -1880,9 +1867,6 @@ static const struct vfio_device_ops vfio_pci_ops = { .match = vfio_pci_match, };
-static int vfio_pci_reflck_attach(struct vfio_pci_device *vdev); -static void vfio_pci_reflck_put(struct vfio_pci_reflck *reflck); - static int vfio_pci_bus_notifier(struct notifier_block *nb, unsigned long action, void *data) { @@ -2020,12 +2004,23 @@ static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) INIT_LIST_HEAD(&vdev->vma_list); init_rwsem(&vdev->memory_lock);
- ret = vfio_pci_reflck_attach(vdev); + if (pci_is_root_bus(pdev->bus)) { + ret = vfio_assign_device_set(&vdev->vdev, vdev); + } else if (!pci_probe_reset_slot(pdev->slot)) { + ret = vfio_assign_device_set(&vdev->vdev, pdev->slot); + } else { + /* + * If there is no slot reset support for this device, the whole + * bus needs to be grouped together to support bus-wide resets. + */ + ret = vfio_assign_device_set(&vdev->vdev, pdev->bus); + } + if (ret) goto out_uninit; ret = vfio_pci_vf_init(vdev); if (ret) - goto out_reflck; + goto out_uninit; ret = vfio_pci_vga_init(vdev); if (ret) goto out_vf; @@ -2057,8 +2052,6 @@ static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) vfio_pci_set_power_state(vdev, PCI_D0); out_vf: vfio_pci_vf_uninit(vdev); -out_reflck: - vfio_pci_reflck_put(vdev->reflck); out_uninit: vfio_uninit_group_dev(&vdev->vdev); kfree(vdev->pm_save); @@ -2077,7 +2070,6 @@ static void vfio_pci_remove(struct pci_dev *pdev) vfio_unregister_group_dev(&vdev->vdev);
vfio_pci_vf_uninit(vdev); - vfio_pci_reflck_put(vdev->reflck); vfio_uninit_group_dev(&vdev->vdev); vfio_pci_vga_uninit(vdev);
@@ -2153,86 +2145,6 @@ static struct pci_driver vfio_pci_driver = { .err_handler = &vfio_err_handlers, };
-static DEFINE_MUTEX(reflck_lock); - -static struct vfio_pci_reflck *vfio_pci_reflck_alloc(void) -{ - struct vfio_pci_reflck *reflck; - - reflck = kzalloc(sizeof(*reflck), GFP_KERNEL); - if (!reflck) - return ERR_PTR(-ENOMEM); - - kref_init(&reflck->kref); - mutex_init(&reflck->lock); - - return reflck; -} - -static void vfio_pci_reflck_get(struct vfio_pci_reflck *reflck) -{ - kref_get(&reflck->kref); -} - -static int vfio_pci_reflck_find(struct pci_dev *pdev, void *data) -{ - struct vfio_pci_reflck **preflck = data; - struct vfio_device *device; - struct vfio_pci_device *vdev; - - device = vfio_device_get_from_dev(&pdev->dev); - if (!device) - return 0; - - if (pci_dev_driver(pdev) != &vfio_pci_driver) { - vfio_device_put(device); - return 0; - } - - vdev = container_of(device, struct vfio_pci_device, vdev); - - if (vdev->reflck) { - vfio_pci_reflck_get(vdev->reflck); - *preflck = vdev->reflck; - vfio_device_put(device); - return 1; - } - - vfio_device_put(device); - return 0; -} - -static int vfio_pci_reflck_attach(struct vfio_pci_device *vdev) -{ - bool slot = !pci_probe_reset_slot(vdev->pdev->slot); - - mutex_lock(&reflck_lock); - - if (pci_is_root_bus(vdev->pdev->bus) || - vfio_pci_for_each_slot_or_bus(vdev->pdev, vfio_pci_reflck_find, - &vdev->reflck, slot) <= 0) - vdev->reflck = vfio_pci_reflck_alloc(); - - mutex_unlock(&reflck_lock); - - return PTR_ERR_OR_ZERO(vdev->reflck); -} - -static void vfio_pci_reflck_release(struct kref *kref) -{ - struct vfio_pci_reflck *reflck = container_of(kref, - struct vfio_pci_reflck, - kref); - - kfree(reflck); - mutex_unlock(&reflck_lock); -} - -static void vfio_pci_reflck_put(struct vfio_pci_reflck *reflck) -{ - kref_put_mutex(&reflck->kref, vfio_pci_reflck_release, &reflck_lock); -} - static int vfio_pci_get_unused_devs(struct pci_dev *pdev, void *data) { struct vfio_devices *devs = data; @@ -2254,7 +2166,7 @@ static int vfio_pci_get_unused_devs(struct pci_dev *pdev, void *data) vdev = container_of(device, struct vfio_pci_device, vdev);
/* Fault if the device is not unused */ - if (vdev->refcnt) { + if (device->open_count) { vfio_device_put(device); return -EBUSY; } @@ -2303,7 +2215,7 @@ static int vfio_pci_try_zap_and_vma_lock_cb(struct pci_dev *pdev, void *data) * - At least one of the affected devices is marked dirty via * needs_reset (such as by lack of FLR support) * Then attempt to perform that bus or slot reset. Callers are required - * to hold vdev->reflck->lock, protecting the bus/slot reset group from + * to hold vdev->dev_set->lock, protecting the bus/slot reset group from * concurrent opens. A vfio_device reference is acquired for each device * to prevent unbinds during the reset operation. * diff --git a/drivers/vfio/pci/vfio_pci_private.h b/drivers/vfio/pci/vfio_pci_private.h index bbc56c857ef081..70414b6c904d89 100644 --- a/drivers/vfio/pci/vfio_pci_private.h +++ b/drivers/vfio/pci/vfio_pci_private.h @@ -83,11 +83,6 @@ struct vfio_pci_dummy_resource { struct list_head res_next; };
-struct vfio_pci_reflck { - struct kref kref; - struct mutex lock; -}; - struct vfio_pci_vf_token { struct mutex lock; uuid_t uuid; @@ -130,8 +125,6 @@ struct vfio_pci_device { bool needs_pm_restore; struct pci_saved_state *pci_saved_state; struct pci_saved_state *pm_save; - struct vfio_pci_reflck *reflck; - int refcnt; int ioeventfds_nr; struct eventfd_ctx *err_trigger; struct eventfd_ctx *req_trigger;