From f794eec86c7cd9a340a66109e6f32f8659ff30fa Mon Sep 17 00:00:00 2001 From: Jason Gunthorpe Date: Thu, 8 Sep 2022 15:44:58 -0300 Subject: [PATCH 01/10] vfio: Simplify vfio_create_group() The vfio.group_lock is now only used to serialize vfio_group creation and destruction, we don't need a micro-optimization of searching, unlocking, then allocating and searching again. Just hold the lock the whole time. Grabbed from: https://lore.kernel.org/kvm/20220922152338.2a2238fe.alex.williamson@redhat.com/ Link: https://lore.kernel.org/r/20221201145535.589687-2-yi.l.liu@intel.com Reviewed-by: Kevin Tian Reviewed-by: Jason Gunthorpe Tested-by: Lixiao Yang Tested-by: Yu He Signed-off-by: Jason Gunthorpe Signed-off-by: Alex Williamson Signed-off-by: Yi Liu --- drivers/vfio/vfio_main.c | 33 ++++++++++----------------------- 1 file changed, 10 insertions(+), 23 deletions(-) diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c index 6d51b700764e..f913d862a386 100644 --- a/drivers/vfio/vfio_main.c +++ b/drivers/vfio/vfio_main.c @@ -143,10 +143,12 @@ EXPORT_SYMBOL_GPL(vfio_device_set_open_count); * Group objects - create, release, get, put, search */ static struct vfio_group * -__vfio_group_get_from_iommu(struct iommu_group *iommu_group) +vfio_group_get_from_iommu(struct iommu_group *iommu_group) { struct vfio_group *group; + lockdep_assert_held(&vfio.group_lock); + /* * group->iommu_group from the vfio.group_list cannot be NULL * under the vfio.group_lock. @@ -160,17 +162,6 @@ __vfio_group_get_from_iommu(struct iommu_group *iommu_group) return NULL; } -static struct vfio_group * -vfio_group_get_from_iommu(struct iommu_group *iommu_group) -{ - struct vfio_group *group; - - mutex_lock(&vfio.group_lock); - group = __vfio_group_get_from_iommu(iommu_group); - mutex_unlock(&vfio.group_lock); - return group; -} - static void vfio_group_release(struct device *dev) { struct vfio_group *group = container_of(dev, struct vfio_group, dev); @@ -225,6 +216,8 @@ static struct vfio_group *vfio_create_group(struct iommu_group *iommu_group, struct vfio_group *ret; int err; + lockdep_assert_held(&vfio.group_lock); + group = vfio_group_alloc(iommu_group, type); if (IS_ERR(group)) return group; @@ -237,26 +230,16 @@ static struct vfio_group *vfio_create_group(struct iommu_group *iommu_group, goto err_put; } - mutex_lock(&vfio.group_lock); - - /* Did we race creating this group? */ - ret = __vfio_group_get_from_iommu(iommu_group); - if (ret) - goto err_unlock; - err = cdev_device_add(&group->cdev, &group->dev); if (err) { ret = ERR_PTR(err); - goto err_unlock; + goto err_put; } list_add(&group->vfio_next, &vfio.group_list); - mutex_unlock(&vfio.group_lock); return group; -err_unlock: - mutex_unlock(&vfio.group_lock); err_put: put_device(&group->dev); return ret; @@ -467,7 +450,9 @@ static struct vfio_group *vfio_noiommu_group_alloc(struct device *dev, if (ret) goto out_put_group; + mutex_lock(&vfio.group_lock); group = vfio_create_group(iommu_group, type); + mutex_unlock(&vfio.group_lock); if (IS_ERR(group)) { ret = PTR_ERR(group); goto out_remove_device; @@ -516,9 +501,11 @@ static struct vfio_group *vfio_group_find_or_alloc(struct device *dev) return ERR_PTR(-EINVAL); } + mutex_lock(&vfio.group_lock); group = vfio_group_get_from_iommu(iommu_group); if (!group) group = vfio_create_group(iommu_group, VFIO_IOMMU); + mutex_unlock(&vfio.group_lock); /* The vfio_group holds a reference to the iommu_group */ iommu_group_put(iommu_group); From dcb93d0364a238315dd71f834b199d4b95ae09eb Mon Sep 17 00:00:00 2001 From: Jason Gunthorpe Date: Thu, 8 Sep 2022 15:44:59 -0300 Subject: [PATCH 02/10] vfio: Move the sanity check of the group to vfio_create_group() This avoids opening group specific code in __vfio_register_dev() for the sanity check if an (existing) group is not corrupted by having two copies of the same struct device in it. It also simplifies the error unwind for this sanity check since the failure can be detected in the group allocation. This also prepares for moving the group specific code into separate group.c. Grabbed from: https://lore.kernel.org/kvm/20220922152338.2a2238fe.alex.williamson@redhat.com/ Link: https://lore.kernel.org/r/20221201145535.589687-3-yi.l.liu@intel.com Reviewed-by: Kevin Tian Reviewed-by: Jason Gunthorpe Tested-by: Lixiao Yang Tested-by: Yu He Signed-off-by: Jason Gunthorpe Signed-off-by: Alex Williamson Signed-off-by: Yi Liu --- drivers/vfio/vfio_main.c | 62 ++++++++++++++++------------------------ 1 file changed, 25 insertions(+), 37 deletions(-) diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c index f913d862a386..87d9a1670a2f 100644 --- a/drivers/vfio/vfio_main.c +++ b/drivers/vfio/vfio_main.c @@ -143,7 +143,7 @@ EXPORT_SYMBOL_GPL(vfio_device_set_open_count); * Group objects - create, release, get, put, search */ static struct vfio_group * -vfio_group_get_from_iommu(struct iommu_group *iommu_group) +vfio_group_find_from_iommu(struct iommu_group *iommu_group) { struct vfio_group *group; @@ -154,10 +154,8 @@ vfio_group_get_from_iommu(struct iommu_group *iommu_group) * under the vfio.group_lock. */ list_for_each_entry(group, &vfio.group_list, vfio_next) { - if (group->iommu_group == iommu_group) { - refcount_inc(&group->drivers); + if (group->iommu_group == iommu_group) return group; - } } return NULL; } @@ -307,23 +305,6 @@ static bool vfio_device_try_get_registration(struct vfio_device *device) return refcount_inc_not_zero(&device->refcount); } -static struct vfio_device *vfio_group_get_device(struct vfio_group *group, - struct device *dev) -{ - struct vfio_device *device; - - mutex_lock(&group->device_lock); - list_for_each_entry(device, &group->device_list, group_next) { - if (device->dev == dev && - vfio_device_try_get_registration(device)) { - mutex_unlock(&group->device_lock); - return device; - } - } - mutex_unlock(&group->device_lock); - return NULL; -} - /* * VFIO driver API */ @@ -467,6 +448,21 @@ static struct vfio_group *vfio_noiommu_group_alloc(struct device *dev, return ERR_PTR(ret); } +static bool vfio_group_has_device(struct vfio_group *group, struct device *dev) +{ + struct vfio_device *device; + + mutex_lock(&group->device_lock); + list_for_each_entry(device, &group->device_list, group_next) { + if (device->dev == dev) { + mutex_unlock(&group->device_lock); + return true; + } + } + mutex_unlock(&group->device_lock); + return false; +} + static struct vfio_group *vfio_group_find_or_alloc(struct device *dev) { struct iommu_group *iommu_group; @@ -502,9 +498,15 @@ static struct vfio_group *vfio_group_find_or_alloc(struct device *dev) } mutex_lock(&vfio.group_lock); - group = vfio_group_get_from_iommu(iommu_group); - if (!group) + group = vfio_group_find_from_iommu(iommu_group); + if (group) { + if (WARN_ON(vfio_group_has_device(group, dev))) + group = ERR_PTR(-EINVAL); + else + refcount_inc(&group->drivers); + } else { group = vfio_create_group(iommu_group, VFIO_IOMMU); + } mutex_unlock(&vfio.group_lock); /* The vfio_group holds a reference to the iommu_group */ @@ -515,7 +517,6 @@ static struct vfio_group *vfio_group_find_or_alloc(struct device *dev) static int __vfio_register_dev(struct vfio_device *device, struct vfio_group *group) { - struct vfio_device *existing_device; int ret; /* @@ -537,19 +538,6 @@ static int __vfio_register_dev(struct vfio_device *device, if (!device->dev_set) vfio_assign_device_set(device, device); - existing_device = vfio_group_get_device(group, device->dev); - if (existing_device) { - /* - * group->iommu_group is non-NULL because we hold the drivers - * refcount. - */ - dev_WARN(device->dev, "Device already exists on group %d\n", - iommu_group_id(group->iommu_group)); - vfio_device_put_registration(existing_device); - ret = -EBUSY; - goto err_out; - } - /* Our reference on group is moved to the device */ device->group = group; From 32e0922821f2115eb8940b6a6b942ba61eff15c2 Mon Sep 17 00:00:00 2001 From: Yi Liu Date: Fri, 23 Sep 2022 02:19:34 -0700 Subject: [PATCH 03/10] vfio: Create wrappers for group register/unregister This avoids decoding group fields in the common functions used by vfio_device registration, and prepares for further moving the vfio group specific code into separate file. Link: https://lore.kernel.org/r/20221201145535.589687-4-yi.l.liu@intel.com Reviewed-by: Kevin Tian Reviewed-by: Jason Gunthorpe Reviewed-by: Alex Williamson Tested-by: Lixiao Yang Tested-by: Yu He Signed-off-by: Yi Liu Signed-off-by: Jason Gunthorpe --- drivers/vfio/vfio_main.c | 23 ++++++++++++++++------- 1 file changed, 16 insertions(+), 7 deletions(-) diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c index 87d9a1670a2f..a5122fa4bf4d 100644 --- a/drivers/vfio/vfio_main.c +++ b/drivers/vfio/vfio_main.c @@ -514,6 +514,20 @@ static struct vfio_group *vfio_group_find_or_alloc(struct device *dev) return group; } +static void vfio_device_group_register(struct vfio_device *device) +{ + mutex_lock(&device->group->device_lock); + list_add(&device->group_next, &device->group->device_list); + mutex_unlock(&device->group->device_lock); +} + +static void vfio_device_group_unregister(struct vfio_device *device) +{ + mutex_lock(&device->group->device_lock); + list_del(&device->group_next); + mutex_unlock(&device->group->device_lock); +} + static int __vfio_register_dev(struct vfio_device *device, struct vfio_group *group) { @@ -552,9 +566,7 @@ static int __vfio_register_dev(struct vfio_device *device, /* Refcounting can't start until the driver calls register */ refcount_set(&device->refcount, 1); - mutex_lock(&group->device_lock); - list_add(&device->group_next, &group->device_list); - mutex_unlock(&group->device_lock); + vfio_device_group_register(device); return 0; err_out: @@ -614,7 +626,6 @@ static struct vfio_device *vfio_device_get_from_name(struct vfio_group *group, * removed. Open file descriptors for the device... */ void vfio_unregister_group_dev(struct vfio_device *device) { - struct vfio_group *group = device->group; unsigned int i = 0; bool interrupted = false; long rc; @@ -642,9 +653,7 @@ void vfio_unregister_group_dev(struct vfio_device *device) } } - mutex_lock(&group->device_lock); - list_del(&device->group_next); - mutex_unlock(&group->device_lock); + vfio_device_group_unregister(device); /* Balances device_add in register path */ device_del(&device->device); From 49ea02d390a34a538a3f54b9ce5665e474690bc7 Mon Sep 17 00:00:00 2001 From: Yi Liu Date: Thu, 24 Nov 2022 21:22:27 -0800 Subject: [PATCH 04/10] vfio: Set device->group in helper function This avoids referencing device->group in __vfio_register_dev(). Link: https://lore.kernel.org/r/20221201145535.589687-5-yi.l.liu@intel.com Reviewed-by: Jason Gunthorpe Reviewed-by: Kevin Tian Reviewed-by: Alex Williamson Tested-by: Lixiao Yang Tested-by: Yu He Signed-off-by: Yi Liu Signed-off-by: Jason Gunthorpe --- drivers/vfio/vfio_main.c | 41 +++++++++++++++++++++++++--------------- 1 file changed, 26 insertions(+), 15 deletions(-) diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c index a5122fa4bf4d..7e42ee0ee1bc 100644 --- a/drivers/vfio/vfio_main.c +++ b/drivers/vfio/vfio_main.c @@ -528,18 +528,29 @@ static void vfio_device_group_unregister(struct vfio_device *device) mutex_unlock(&device->group->device_lock); } -static int __vfio_register_dev(struct vfio_device *device, - struct vfio_group *group) +static int vfio_device_set_group(struct vfio_device *device, + enum vfio_group_type type) { - int ret; + struct vfio_group *group; + + if (type == VFIO_IOMMU) + group = vfio_group_find_or_alloc(device->dev); + else + group = vfio_noiommu_group_alloc(device->dev, type); - /* - * In all cases group is the output of one of the group allocation - * functions and we have group->drivers incremented for us. - */ if (IS_ERR(group)) return PTR_ERR(group); + /* Our reference on group is moved to the device */ + device->group = group; + return 0; +} + +static int __vfio_register_dev(struct vfio_device *device, + enum vfio_group_type type) +{ + int ret; + if (WARN_ON(device->ops->bind_iommufd && (!device->ops->unbind_iommufd || !device->ops->attach_ioas))) @@ -552,12 +563,13 @@ static int __vfio_register_dev(struct vfio_device *device, if (!device->dev_set) vfio_assign_device_set(device, device); - /* Our reference on group is moved to the device */ - device->group = group; - ret = dev_set_name(&device->device, "vfio%d", device->index); if (ret) - goto err_out; + return ret; + + ret = vfio_device_set_group(device, type); + if (ret) + return ret; ret = device_add(&device->device); if (ret) @@ -576,8 +588,7 @@ static int __vfio_register_dev(struct vfio_device *device, int vfio_register_group_dev(struct vfio_device *device) { - return __vfio_register_dev(device, - vfio_group_find_or_alloc(device->dev)); + return __vfio_register_dev(device, VFIO_IOMMU); } EXPORT_SYMBOL_GPL(vfio_register_group_dev); @@ -587,8 +598,7 @@ EXPORT_SYMBOL_GPL(vfio_register_group_dev); */ int vfio_register_emulated_iommu_dev(struct vfio_device *device) { - return __vfio_register_dev(device, - vfio_noiommu_group_alloc(device->dev, VFIO_EMULATED_IOMMU)); + return __vfio_register_dev(device, VFIO_EMULATED_IOMMU); } EXPORT_SYMBOL_GPL(vfio_register_emulated_iommu_dev); @@ -658,6 +668,7 @@ void vfio_unregister_group_dev(struct vfio_device *device) /* Balances device_add in register path */ device_del(&device->device); + /* Balances vfio_device_set_group in register path */ vfio_device_remove_group(device); } EXPORT_SYMBOL_GPL(vfio_unregister_group_dev); From 07b465863325faceb865871ff5f22c1ebba6df54 Mon Sep 17 00:00:00 2001 From: Yi Liu Date: Thu, 10 Nov 2022 07:26:09 -0800 Subject: [PATCH 05/10] vfio: Swap order of vfio_device_container_register() and open_device() This makes the DMA unmap callback registration to container be consistent across the vfio iommufd compat mode and the legacy container mode. In the vfio iommufd compat mode, this registration is done in the vfio_iommufd_bind() when creating access which has an unmap callback. This is prior to calling the open_device() op. The existing mdev drivers have been converted to be OK with this order. So it is ok to swap the order of vfio_device_container_register() and open_device() for legacy mode. This also prepares for further moving group specific code into separate source file. Link: https://lore.kernel.org/r/20221201145535.589687-6-yi.l.liu@intel.com Reviewed-by: Kevin Tian Reviewed-by: Jason Gunthorpe Reviewed-by: Alex Williamson Tested-by: Lixiao Yang Tested-by: Yu He Signed-off-by: Yi Liu Signed-off-by: Jason Gunthorpe --- drivers/vfio/vfio_main.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c index 7e42ee0ee1bc..5dddf962f650 100644 --- a/drivers/vfio/vfio_main.c +++ b/drivers/vfio/vfio_main.c @@ -807,6 +807,7 @@ static int vfio_device_first_open(struct vfio_device *device) ret = vfio_group_use_container(device->group); if (ret) goto err_module_put; + vfio_device_container_register(device); } else if (device->group->iommufd) { ret = vfio_iommufd_bind(device, device->group->iommufd); if (ret) @@ -819,17 +820,17 @@ static int vfio_device_first_open(struct vfio_device *device) if (ret) goto err_container; } - if (device->group->container) - vfio_device_container_register(device); mutex_unlock(&device->group->group_lock); return 0; err_container: device->kvm = NULL; - if (device->group->container) + if (device->group->container) { + vfio_device_container_unregister(device); vfio_group_unuse_container(device->group); - else if (device->group->iommufd) + } else if (device->group->iommufd) { vfio_iommufd_unbind(device); + } err_module_put: mutex_unlock(&device->group->group_lock); module_put(device->dev->driver->owner); @@ -841,15 +842,15 @@ static void vfio_device_last_close(struct vfio_device *device) lockdep_assert_held(&device->dev_set->lock); mutex_lock(&device->group->group_lock); - if (device->group->container) - vfio_device_container_unregister(device); if (device->ops->close_device) device->ops->close_device(device); device->kvm = NULL; - if (device->group->container) + if (device->group->container) { + vfio_device_container_unregister(device); vfio_group_unuse_container(device->group); - else if (device->group->iommufd) + } else if (device->group->iommufd) { vfio_iommufd_unbind(device); + } mutex_unlock(&device->group->group_lock); module_put(device->dev->driver->owner); } From 5cfff0774353ee35601e3d3fe2f0bd95c33aa5db Mon Sep 17 00:00:00 2001 From: Yi Liu Date: Fri, 30 Sep 2022 03:22:55 -0700 Subject: [PATCH 06/10] vfio: Make vfio_device_open() truly device specific Then move group related logic into vfio_device_open_file(). Accordingly introduce a vfio_device_close() to pair up. Link: https://lore.kernel.org/r/20221201145535.589687-7-yi.l.liu@intel.com Reviewed-by: Kevin Tian Reviewed-by: Jason Gunthorpe Reviewed-by: Alex Williamson Tested-by: Lixiao Yang Tested-by: Yu He Signed-off-by: Yi Liu Signed-off-by: Jason Gunthorpe --- drivers/vfio/vfio_main.c | 46 +++++++++++++++++++++++++--------------- 1 file changed, 29 insertions(+), 17 deletions(-) diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c index 5dddf962f650..37413ac254c0 100644 --- a/drivers/vfio/vfio_main.c +++ b/drivers/vfio/vfio_main.c @@ -855,20 +855,41 @@ static void vfio_device_last_close(struct vfio_device *device) module_put(device->dev->driver->owner); } -static struct file *vfio_device_open(struct vfio_device *device) +static int vfio_device_open(struct vfio_device *device) { - struct file *filep; - int ret; + int ret = 0; mutex_lock(&device->dev_set->lock); device->open_count++; if (device->open_count == 1) { ret = vfio_device_first_open(device); if (ret) - goto err_unlock; + device->open_count--; } mutex_unlock(&device->dev_set->lock); + return ret; +} + +static void vfio_device_close(struct vfio_device *device) +{ + mutex_lock(&device->dev_set->lock); + vfio_assert_device_open(device); + if (device->open_count == 1) + vfio_device_last_close(device); + device->open_count--; + mutex_unlock(&device->dev_set->lock); +} + +static struct file *vfio_device_open_file(struct vfio_device *device) +{ + struct file *filep; + int ret; + + ret = vfio_device_open(device); + if (ret) + goto err_out; + /* * We can't use anon_inode_getfd() because we need to modify * the f_mode flags directly to allow more than just ioctls @@ -897,12 +918,8 @@ static struct file *vfio_device_open(struct vfio_device *device) return filep; err_close_device: - mutex_lock(&device->dev_set->lock); - if (device->open_count == 1) - vfio_device_last_close(device); -err_unlock: - device->open_count--; - mutex_unlock(&device->dev_set->lock); + vfio_device_close(device); +err_out: return ERR_PTR(ret); } @@ -930,7 +947,7 @@ static int vfio_group_ioctl_get_device_fd(struct vfio_group *group, goto err_put_device; } - filep = vfio_device_open(device); + filep = vfio_device_open_file(device); if (IS_ERR(filep)) { ret = PTR_ERR(filep); goto err_put_fdno; @@ -1113,12 +1130,7 @@ static int vfio_device_fops_release(struct inode *inode, struct file *filep) { struct vfio_device *device = filep->private_data; - mutex_lock(&device->dev_set->lock); - vfio_assert_device_open(device); - if (device->open_count == 1) - vfio_device_last_close(device); - device->open_count--; - mutex_unlock(&device->dev_set->lock); + vfio_device_close(device); vfio_device_put_registration(device); From 5c8d3d93f6a7c9371212690b0195160e5f88bdff Mon Sep 17 00:00:00 2001 From: Yi Liu Date: Wed, 2 Nov 2022 04:42:25 -0700 Subject: [PATCH 07/10] vfio: Refactor vfio_device open and close This refactor makes the vfio_device_open() to accept device, iommufd_ctx pointer and kvm pointer. These parameters are generic items in today's group path and future device cdev path. Caller of vfio_device_open() should take care the necessary protections. e.g. the current group path need to hold the group_lock to ensure the iommufd_ctx and kvm pointer are valid. This refactor also wraps the group spefcific codes in the device open and close paths to be paired helpers like: - vfio_device_group_open/close(): call vfio_device_open/close() - vfio_device_group_use/unuse_iommu(): this pair is container specific. iommufd vs. container is selected in vfio_device_first_open(). Such helpers are supposed to be moved to group.c. While iommufd related codes will be kept in the generic helpers since future device cdev path also need to handle iommufd. Link: https://lore.kernel.org/r/20221201145535.589687-8-yi.l.liu@intel.com Reviewed-by: Kevin Tian Reviewed-by: Jason Gunthorpe Reviewed-by: Alex Williamson Tested-by: Lixiao Yang Tested-by: Yu He Signed-off-by: Yi Liu Signed-off-by: Jason Gunthorpe --- drivers/vfio/vfio_main.c | 133 +++++++++++++++++++++++++-------------- 1 file changed, 87 insertions(+), 46 deletions(-) diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c index 37413ac254c0..a4583f4827e5 100644 --- a/drivers/vfio/vfio_main.c +++ b/drivers/vfio/vfio_main.c @@ -783,7 +783,38 @@ static bool vfio_assert_device_open(struct vfio_device *device) return !WARN_ON_ONCE(!READ_ONCE(device->open_count)); } -static int vfio_device_first_open(struct vfio_device *device) +static int vfio_device_group_use_iommu(struct vfio_device *device) +{ + struct vfio_group *group = device->group; + int ret = 0; + + lockdep_assert_held(&group->group_lock); + + if (WARN_ON(!group->container)) + return -EINVAL; + + ret = vfio_group_use_container(group); + if (ret) + return ret; + vfio_device_container_register(device); + return 0; +} + +static void vfio_device_group_unuse_iommu(struct vfio_device *device) +{ + struct vfio_group *group = device->group; + + lockdep_assert_held(&group->group_lock); + + if (WARN_ON(!group->container)) + return; + + vfio_device_container_unregister(device); + vfio_group_unuse_container(group); +} + +static int vfio_device_first_open(struct vfio_device *device, + struct iommufd_ctx *iommufd, struct kvm *kvm) { int ret; @@ -792,77 +823,56 @@ static int vfio_device_first_open(struct vfio_device *device) if (!try_module_get(device->dev->driver->owner)) return -ENODEV; - /* - * Here we pass the KVM pointer with the group under the lock. If the - * device driver will use it, it must obtain a reference and release it - * during close_device. - */ - mutex_lock(&device->group->group_lock); - if (!vfio_group_has_iommu(device->group)) { - ret = -EINVAL; + if (iommufd) + ret = vfio_iommufd_bind(device, iommufd); + else + ret = vfio_device_group_use_iommu(device); + if (ret) goto err_module_put; - } - if (device->group->container) { - ret = vfio_group_use_container(device->group); - if (ret) - goto err_module_put; - vfio_device_container_register(device); - } else if (device->group->iommufd) { - ret = vfio_iommufd_bind(device, device->group->iommufd); - if (ret) - goto err_module_put; - } - - device->kvm = device->group->kvm; + device->kvm = kvm; if (device->ops->open_device) { ret = device->ops->open_device(device); if (ret) - goto err_container; + goto err_unuse_iommu; } - mutex_unlock(&device->group->group_lock); return 0; -err_container: +err_unuse_iommu: device->kvm = NULL; - if (device->group->container) { - vfio_device_container_unregister(device); - vfio_group_unuse_container(device->group); - } else if (device->group->iommufd) { + if (iommufd) vfio_iommufd_unbind(device); - } + else + vfio_device_group_unuse_iommu(device); err_module_put: - mutex_unlock(&device->group->group_lock); module_put(device->dev->driver->owner); return ret; } -static void vfio_device_last_close(struct vfio_device *device) +static void vfio_device_last_close(struct vfio_device *device, + struct iommufd_ctx *iommufd) { lockdep_assert_held(&device->dev_set->lock); - mutex_lock(&device->group->group_lock); if (device->ops->close_device) device->ops->close_device(device); device->kvm = NULL; - if (device->group->container) { - vfio_device_container_unregister(device); - vfio_group_unuse_container(device->group); - } else if (device->group->iommufd) { + if (iommufd) vfio_iommufd_unbind(device); - } - mutex_unlock(&device->group->group_lock); + else + vfio_device_group_unuse_iommu(device); module_put(device->dev->driver->owner); } -static int vfio_device_open(struct vfio_device *device) +static int vfio_device_open(struct vfio_device *device, + struct iommufd_ctx *iommufd, struct kvm *kvm) { int ret = 0; mutex_lock(&device->dev_set->lock); device->open_count++; if (device->open_count == 1) { - ret = vfio_device_first_open(device); + ret = vfio_device_first_open(device, iommufd, kvm); if (ret) device->open_count--; } @@ -871,22 +881,53 @@ static int vfio_device_open(struct vfio_device *device) return ret; } -static void vfio_device_close(struct vfio_device *device) +static void vfio_device_close(struct vfio_device *device, + struct iommufd_ctx *iommufd) { mutex_lock(&device->dev_set->lock); vfio_assert_device_open(device); if (device->open_count == 1) - vfio_device_last_close(device); + vfio_device_last_close(device, iommufd); device->open_count--; mutex_unlock(&device->dev_set->lock); } +static int vfio_device_group_open(struct vfio_device *device) +{ + int ret; + + mutex_lock(&device->group->group_lock); + if (!vfio_group_has_iommu(device->group)) { + ret = -EINVAL; + goto out_unlock; + } + + /* + * Here we pass the KVM pointer with the group under the lock. If the + * device driver will use it, it must obtain a reference and release it + * during close_device. + */ + ret = vfio_device_open(device, device->group->iommufd, + device->group->kvm); + +out_unlock: + mutex_unlock(&device->group->group_lock); + return ret; +} + +static void vfio_device_group_close(struct vfio_device *device) +{ + mutex_lock(&device->group->group_lock); + vfio_device_close(device, device->group->iommufd); + mutex_unlock(&device->group->group_lock); +} + static struct file *vfio_device_open_file(struct vfio_device *device) { struct file *filep; int ret; - ret = vfio_device_open(device); + ret = vfio_device_group_open(device); if (ret) goto err_out; @@ -918,7 +959,7 @@ static struct file *vfio_device_open_file(struct vfio_device *device) return filep; err_close_device: - vfio_device_close(device); + vfio_device_group_close(device); err_out: return ERR_PTR(ret); } @@ -1130,7 +1171,7 @@ static int vfio_device_fops_release(struct inode *inode, struct file *filep) { struct vfio_device *device = filep->private_data; - vfio_device_close(device); + vfio_device_group_close(device); vfio_device_put_registration(device); From 1334e47ee798ac4715330a6ade0afc929cd54aff Mon Sep 17 00:00:00 2001 From: Yi Liu Date: Fri, 23 Sep 2022 07:08:36 -0700 Subject: [PATCH 08/10] vfio: Wrap vfio group module init/clean code into helpers This wraps the init/clean code of vfio group global variable to be helpers, and prepares for further moving vfio group specific code into separate file. As container is used by group, so vfio_container_init/cleanup() is moved into vfio_group_init/cleanup(). Link: https://lore.kernel.org/r/20221201145535.589687-9-yi.l.liu@intel.com Reviewed-by: Kevin Tian Reviewed-by: Jason Gunthorpe Reviewed-by: Alex Williamson Tested-by: Lixiao Yang Tested-by: Yu He Signed-off-by: Yi Liu Signed-off-by: Jason Gunthorpe --- drivers/vfio/vfio_main.c | 56 ++++++++++++++++++++++++++-------------- 1 file changed, 36 insertions(+), 20 deletions(-) diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c index a4583f4827e5..e053998baffd 100644 --- a/drivers/vfio/vfio_main.c +++ b/drivers/vfio/vfio_main.c @@ -2066,12 +2066,11 @@ static char *vfio_devnode(struct device *dev, umode_t *mode) return kasprintf(GFP_KERNEL, "vfio/%s", dev_name(dev)); } -static int __init vfio_init(void) +static int __init vfio_group_init(void) { int ret; ida_init(&vfio.group_ida); - ida_init(&vfio.device_ida); mutex_init(&vfio.group_lock); INIT_LIST_HEAD(&vfio.group_list); @@ -2088,24 +2087,12 @@ static int __init vfio_init(void) vfio.class->devnode = vfio_devnode; - /* /sys/class/vfio-dev/vfioX */ - vfio.device_class = class_create(THIS_MODULE, "vfio-dev"); - if (IS_ERR(vfio.device_class)) { - ret = PTR_ERR(vfio.device_class); - goto err_dev_class; - } - ret = alloc_chrdev_region(&vfio.group_devt, 0, MINORMASK + 1, "vfio"); if (ret) goto err_alloc_chrdev; - - pr_info(DRIVER_DESC " version: " DRIVER_VERSION "\n"); return 0; err_alloc_chrdev: - class_destroy(vfio.device_class); - vfio.device_class = NULL; -err_dev_class: class_destroy(vfio.class); vfio.class = NULL; err_group_class: @@ -2113,18 +2100,47 @@ static int __init vfio_init(void) return ret; } -static void __exit vfio_cleanup(void) +static void vfio_group_cleanup(void) { WARN_ON(!list_empty(&vfio.group_list)); - - ida_destroy(&vfio.device_ida); ida_destroy(&vfio.group_ida); unregister_chrdev_region(vfio.group_devt, MINORMASK + 1); + class_destroy(vfio.class); + vfio.class = NULL; + vfio_container_cleanup(); +} + +static int __init vfio_init(void) +{ + int ret; + + ida_init(&vfio.device_ida); + + ret = vfio_group_init(); + if (ret) + return ret; + + /* /sys/class/vfio-dev/vfioX */ + vfio.device_class = class_create(THIS_MODULE, "vfio-dev"); + if (IS_ERR(vfio.device_class)) { + ret = PTR_ERR(vfio.device_class); + goto err_dev_class; + } + + pr_info(DRIVER_DESC " version: " DRIVER_VERSION "\n"); + return 0; + +err_dev_class: + vfio_group_cleanup(); + return ret; +} + +static void __exit vfio_cleanup(void) +{ + ida_destroy(&vfio.device_ida); class_destroy(vfio.device_class); vfio.device_class = NULL; - class_destroy(vfio.class); - vfio_container_cleanup(); - vfio.class = NULL; + vfio_group_cleanup(); xa_destroy(&vfio_device_set_xa); } From 8da7a0e79f9b15330ae68d8532425399f4c27045 Mon Sep 17 00:00:00 2001 From: Yi Liu Date: Thu, 10 Nov 2022 18:57:01 -0800 Subject: [PATCH 09/10] vfio: Refactor dma APIs for emulated devices To use group helpers instead of opening group related code in the API. This prepares moving group specific code out of vfio_main.c. Link: https://lore.kernel.org/r/20221201145535.589687-10-yi.l.liu@intel.com Reviewed-by: Kevin Tian Reviewed-by: Jason Gunthorpe Reviewed-by: Alex Williamson Tested-by: Lixiao Yang Tested-by: Yu He Signed-off-by: Yi Liu Signed-off-by: Nicolin Chen Signed-off-by: Jason Gunthorpe --- drivers/vfio/container.c | 20 +++++++++++++------- drivers/vfio/vfio.h | 32 ++++++++++++++++---------------- drivers/vfio/vfio_main.c | 25 ++++++++++++++----------- 3 files changed, 43 insertions(+), 34 deletions(-) diff --git a/drivers/vfio/container.c b/drivers/vfio/container.c index 6b362d97d682..b7a9560ab25e 100644 --- a/drivers/vfio/container.c +++ b/drivers/vfio/container.c @@ -540,10 +540,12 @@ void vfio_group_unuse_container(struct vfio_group *group) fput(group->opened_file); } -int vfio_container_pin_pages(struct vfio_container *container, - struct iommu_group *iommu_group, dma_addr_t iova, - int npage, int prot, struct page **pages) +int vfio_device_container_pin_pages(struct vfio_device *device, + dma_addr_t iova, int npage, + int prot, struct page **pages) { + struct vfio_container *container = device->group->container; + struct iommu_group *iommu_group = device->group->iommu_group; struct vfio_iommu_driver *driver = container->iommu_driver; if (npage > VFIO_PIN_PAGES_MAX_ENTRIES) @@ -555,9 +557,11 @@ int vfio_container_pin_pages(struct vfio_container *container, npage, prot, pages); } -void vfio_container_unpin_pages(struct vfio_container *container, - dma_addr_t iova, int npage) +void vfio_device_container_unpin_pages(struct vfio_device *device, + dma_addr_t iova, int npage) { + struct vfio_container *container = device->group->container; + if (WARN_ON(npage <= 0 || npage > VFIO_PIN_PAGES_MAX_ENTRIES)) return; @@ -565,9 +569,11 @@ void vfio_container_unpin_pages(struct vfio_container *container, npage); } -int vfio_container_dma_rw(struct vfio_container *container, dma_addr_t iova, - void *data, size_t len, bool write) +int vfio_device_container_dma_rw(struct vfio_device *device, + dma_addr_t iova, void *data, + size_t len, bool write) { + struct vfio_container *container = device->group->container; struct vfio_iommu_driver *driver = container->iommu_driver; if (unlikely(!driver || !driver->ops->dma_rw)) diff --git a/drivers/vfio/vfio.h b/drivers/vfio/vfio.h index ce5fe3fc493b..a112e8f2b291 100644 --- a/drivers/vfio/vfio.h +++ b/drivers/vfio/vfio.h @@ -122,13 +122,14 @@ int vfio_container_attach_group(struct vfio_container *container, void vfio_group_detach_container(struct vfio_group *group); void vfio_device_container_register(struct vfio_device *device); void vfio_device_container_unregister(struct vfio_device *device); -int vfio_container_pin_pages(struct vfio_container *container, - struct iommu_group *iommu_group, dma_addr_t iova, - int npage, int prot, struct page **pages); -void vfio_container_unpin_pages(struct vfio_container *container, - dma_addr_t iova, int npage); -int vfio_container_dma_rw(struct vfio_container *container, dma_addr_t iova, - void *data, size_t len, bool write); +int vfio_device_container_pin_pages(struct vfio_device *device, + dma_addr_t iova, int npage, + int prot, struct page **pages); +void vfio_device_container_unpin_pages(struct vfio_device *device, + dma_addr_t iova, int npage); +int vfio_device_container_dma_rw(struct vfio_device *device, + dma_addr_t iova, void *data, + size_t len, bool write); int __init vfio_container_init(void); void vfio_container_cleanup(void); @@ -166,22 +167,21 @@ static inline void vfio_device_container_unregister(struct vfio_device *device) { } -static inline int vfio_container_pin_pages(struct vfio_container *container, - struct iommu_group *iommu_group, - dma_addr_t iova, int npage, int prot, - struct page **pages) +static inline int vfio_device_container_pin_pages(struct vfio_device *device, + dma_addr_t iova, int npage, + int prot, struct page **pages) { return -EOPNOTSUPP; } -static inline void vfio_container_unpin_pages(struct vfio_container *container, - dma_addr_t iova, int npage) +static inline void vfio_device_container_unpin_pages(struct vfio_device *device, + dma_addr_t iova, int npage) { } -static inline int vfio_container_dma_rw(struct vfio_container *container, - dma_addr_t iova, void *data, size_t len, - bool write) +static inline int vfio_device_container_dma_rw(struct vfio_device *device, + dma_addr_t iova, void *data, + size_t len, bool write) { return -EOPNOTSUPP; } diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c index e053998baffd..b7f94ace7b10 100644 --- a/drivers/vfio/vfio_main.c +++ b/drivers/vfio/vfio_main.c @@ -1938,6 +1938,11 @@ int vfio_set_irqs_validate_and_prepare(struct vfio_irq_set *hdr, int num_irqs, } EXPORT_SYMBOL(vfio_set_irqs_validate_and_prepare); +static bool vfio_device_has_container(struct vfio_device *device) +{ + return device->group->container; +} + /* * Pin contiguous user pages and return their associated host pages for local * domain only. @@ -1950,7 +1955,7 @@ EXPORT_SYMBOL(vfio_set_irqs_validate_and_prepare); * Return error or number of pages pinned. * * A driver may only call this function if the vfio_device was created - * by vfio_register_emulated_iommu_dev() due to vfio_container_pin_pages(). + * by vfio_register_emulated_iommu_dev() due to vfio_device_container_pin_pages(). */ int vfio_pin_pages(struct vfio_device *device, dma_addr_t iova, int npage, int prot, struct page **pages) @@ -1958,10 +1963,9 @@ int vfio_pin_pages(struct vfio_device *device, dma_addr_t iova, /* group->container cannot change while a vfio device is open */ if (!pages || !npage || WARN_ON(!vfio_assert_device_open(device))) return -EINVAL; - if (device->group->container) - return vfio_container_pin_pages(device->group->container, - device->group->iommu_group, - iova, npage, prot, pages); + if (vfio_device_has_container(device)) + return vfio_device_container_pin_pages(device, iova, + npage, prot, pages); if (device->iommufd_access) { int ret; @@ -1997,9 +2001,8 @@ void vfio_unpin_pages(struct vfio_device *device, dma_addr_t iova, int npage) if (WARN_ON(!vfio_assert_device_open(device))) return; - if (device->group->container) { - vfio_container_unpin_pages(device->group->container, iova, - npage); + if (vfio_device_has_container(device)) { + vfio_device_container_unpin_pages(device, iova, npage); return; } if (device->iommufd_access) { @@ -2036,9 +2039,9 @@ int vfio_dma_rw(struct vfio_device *device, dma_addr_t iova, void *data, if (!data || len <= 0 || !vfio_assert_device_open(device)) return -EINVAL; - if (device->group->container) - return vfio_container_dma_rw(device->group->container, iova, - data, len, write); + if (vfio_device_has_container(device)) + return vfio_device_container_dma_rw(device, iova, + data, len, write); if (device->iommufd_access) { unsigned int flags = 0; From 9eefba8002c27d65ab52a533fd0611b099b73591 Mon Sep 17 00:00:00 2001 From: Yi Liu Date: Fri, 25 Nov 2022 03:26:42 -0800 Subject: [PATCH 10/10] vfio: Move vfio group specific code into group.c This prepares for compiling out vfio group after vfio device cdev is added. No vfio_group decode code should be in vfio_main.c, and neither device->group reference should be in vfio_main.c. No functional change is intended. Link: https://lore.kernel.org/r/20221201145535.589687-11-yi.l.liu@intel.com Reviewed-by: Kevin Tian Reviewed-by: Jason Gunthorpe Reviewed-by: Alex Williamson Tested-by: Yu He Tested-by: Lixiao Yang Signed-off-by: Yi Liu Signed-off-by: Jason Gunthorpe --- drivers/vfio/Makefile | 1 + drivers/vfio/group.c | 877 +++++++++++++++++++++++++++++++++++++++ drivers/vfio/vfio.h | 22 + drivers/vfio/vfio_main.c | 877 +-------------------------------------- 4 files changed, 907 insertions(+), 870 deletions(-) create mode 100644 drivers/vfio/group.c diff --git a/drivers/vfio/Makefile b/drivers/vfio/Makefile index b953517dc70f..3783db7e8082 100644 --- a/drivers/vfio/Makefile +++ b/drivers/vfio/Makefile @@ -4,6 +4,7 @@ vfio_virqfd-y := virqfd.o obj-$(CONFIG_VFIO) += vfio.o vfio-y += vfio_main.o \ + group.o \ iova_bitmap.o vfio-$(CONFIG_IOMMUFD) += iommufd.o vfio-$(CONFIG_VFIO_CONTAINER) += container.o diff --git a/drivers/vfio/group.c b/drivers/vfio/group.c new file mode 100644 index 000000000000..c5d8bf10495e --- /dev/null +++ b/drivers/vfio/group.c @@ -0,0 +1,877 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * VFIO core + * + * Copyright (C) 2012 Red Hat, Inc. All rights reserved. + * Author: Alex Williamson + * + * Derived from original vfio: + * Copyright 2010 Cisco Systems, Inc. All rights reserved. + * Author: Tom Lyon, pugs@cisco.com + */ + +#include +#include +#include +#include "vfio.h" + +static struct vfio { + struct class *class; + struct list_head group_list; + struct mutex group_lock; /* locks group_list */ + struct ida group_ida; + dev_t group_devt; +} vfio; + +static struct vfio_device *vfio_device_get_from_name(struct vfio_group *group, + char *buf) +{ + struct vfio_device *it, *device = ERR_PTR(-ENODEV); + + mutex_lock(&group->device_lock); + list_for_each_entry(it, &group->device_list, group_next) { + int ret; + + if (it->ops->match) { + ret = it->ops->match(it, buf); + if (ret < 0) { + device = ERR_PTR(ret); + break; + } + } else { + ret = !strcmp(dev_name(it->dev), buf); + } + + if (ret && vfio_device_try_get_registration(it)) { + device = it; + break; + } + } + mutex_unlock(&group->device_lock); + + return device; +} + +/* + * VFIO Group fd, /dev/vfio/$GROUP + */ +static bool vfio_group_has_iommu(struct vfio_group *group) +{ + lockdep_assert_held(&group->group_lock); + /* + * There can only be users if there is a container, and if there is a + * container there must be users. + */ + WARN_ON(!group->container != !group->container_users); + + return group->container || group->iommufd; +} + +/* + * VFIO_GROUP_UNSET_CONTAINER should fail if there are other users or + * if there was no container to unset. Since the ioctl is called on + * the group, we know that still exists, therefore the only valid + * transition here is 1->0. + */ +static int vfio_group_ioctl_unset_container(struct vfio_group *group) +{ + int ret = 0; + + mutex_lock(&group->group_lock); + if (!vfio_group_has_iommu(group)) { + ret = -EINVAL; + goto out_unlock; + } + if (group->container) { + if (group->container_users != 1) { + ret = -EBUSY; + goto out_unlock; + } + vfio_group_detach_container(group); + } + if (group->iommufd) { + iommufd_ctx_put(group->iommufd); + group->iommufd = NULL; + } + +out_unlock: + mutex_unlock(&group->group_lock); + return ret; +} + +static int vfio_group_ioctl_set_container(struct vfio_group *group, + int __user *arg) +{ + struct vfio_container *container; + struct iommufd_ctx *iommufd; + struct fd f; + int ret; + int fd; + + if (get_user(fd, arg)) + return -EFAULT; + + f = fdget(fd); + if (!f.file) + return -EBADF; + + mutex_lock(&group->group_lock); + if (vfio_group_has_iommu(group)) { + ret = -EINVAL; + goto out_unlock; + } + if (!group->iommu_group) { + ret = -ENODEV; + goto out_unlock; + } + + container = vfio_container_from_file(f.file); + if (container) { + ret = vfio_container_attach_group(container, group); + goto out_unlock; + } + + iommufd = iommufd_ctx_from_file(f.file); + if (!IS_ERR(iommufd)) { + u32 ioas_id; + + ret = iommufd_vfio_compat_ioas_id(iommufd, &ioas_id); + if (ret) { + iommufd_ctx_put(group->iommufd); + goto out_unlock; + } + + group->iommufd = iommufd; + goto out_unlock; + } + + /* The FD passed is not recognized. */ + ret = -EBADFD; + +out_unlock: + mutex_unlock(&group->group_lock); + fdput(f); + return ret; +} + +static int vfio_device_group_open(struct vfio_device *device) +{ + int ret; + + mutex_lock(&device->group->group_lock); + if (!vfio_group_has_iommu(device->group)) { + ret = -EINVAL; + goto out_unlock; + } + + /* + * Here we pass the KVM pointer with the group under the lock. If the + * device driver will use it, it must obtain a reference and release it + * during close_device. + */ + ret = vfio_device_open(device, device->group->iommufd, + device->group->kvm); + +out_unlock: + mutex_unlock(&device->group->group_lock); + return ret; +} + +void vfio_device_group_close(struct vfio_device *device) +{ + mutex_lock(&device->group->group_lock); + vfio_device_close(device, device->group->iommufd); + mutex_unlock(&device->group->group_lock); +} + +static struct file *vfio_device_open_file(struct vfio_device *device) +{ + struct file *filep; + int ret; + + ret = vfio_device_group_open(device); + if (ret) + goto err_out; + + /* + * We can't use anon_inode_getfd() because we need to modify + * the f_mode flags directly to allow more than just ioctls + */ + filep = anon_inode_getfile("[vfio-device]", &vfio_device_fops, + device, O_RDWR); + if (IS_ERR(filep)) { + ret = PTR_ERR(filep); + goto err_close_device; + } + + /* + * TODO: add an anon_inode interface to do this. + * Appears to be missing by lack of need rather than + * explicitly prevented. Now there's need. + */ + filep->f_mode |= (FMODE_PREAD | FMODE_PWRITE); + + if (device->group->type == VFIO_NO_IOMMU) + dev_warn(device->dev, "vfio-noiommu device opened by user " + "(%s:%d)\n", current->comm, task_pid_nr(current)); + /* + * On success the ref of device is moved to the file and + * put in vfio_device_fops_release() + */ + return filep; + +err_close_device: + vfio_device_group_close(device); +err_out: + return ERR_PTR(ret); +} + +static int vfio_group_ioctl_get_device_fd(struct vfio_group *group, + char __user *arg) +{ + struct vfio_device *device; + struct file *filep; + char *buf; + int fdno; + int ret; + + buf = strndup_user(arg, PAGE_SIZE); + if (IS_ERR(buf)) + return PTR_ERR(buf); + + device = vfio_device_get_from_name(group, buf); + kfree(buf); + if (IS_ERR(device)) + return PTR_ERR(device); + + fdno = get_unused_fd_flags(O_CLOEXEC); + if (fdno < 0) { + ret = fdno; + goto err_put_device; + } + + filep = vfio_device_open_file(device); + if (IS_ERR(filep)) { + ret = PTR_ERR(filep); + goto err_put_fdno; + } + + fd_install(fdno, filep); + return fdno; + +err_put_fdno: + put_unused_fd(fdno); +err_put_device: + vfio_device_put_registration(device); + return ret; +} + +static int vfio_group_ioctl_get_status(struct vfio_group *group, + struct vfio_group_status __user *arg) +{ + unsigned long minsz = offsetofend(struct vfio_group_status, flags); + struct vfio_group_status status; + + if (copy_from_user(&status, arg, minsz)) + return -EFAULT; + + if (status.argsz < minsz) + return -EINVAL; + + status.flags = 0; + + mutex_lock(&group->group_lock); + if (!group->iommu_group) { + mutex_unlock(&group->group_lock); + return -ENODEV; + } + + /* + * With the container FD the iommu_group_claim_dma_owner() is done + * during SET_CONTAINER but for IOMMFD this is done during + * VFIO_GROUP_GET_DEVICE_FD. Meaning that with iommufd + * VFIO_GROUP_FLAGS_VIABLE could be set but GET_DEVICE_FD will fail due + * to viability. + */ + if (vfio_group_has_iommu(group)) + status.flags |= VFIO_GROUP_FLAGS_CONTAINER_SET | + VFIO_GROUP_FLAGS_VIABLE; + else if (!iommu_group_dma_owner_claimed(group->iommu_group)) + status.flags |= VFIO_GROUP_FLAGS_VIABLE; + mutex_unlock(&group->group_lock); + + if (copy_to_user(arg, &status, minsz)) + return -EFAULT; + return 0; +} + +static long vfio_group_fops_unl_ioctl(struct file *filep, + unsigned int cmd, unsigned long arg) +{ + struct vfio_group *group = filep->private_data; + void __user *uarg = (void __user *)arg; + + switch (cmd) { + case VFIO_GROUP_GET_DEVICE_FD: + return vfio_group_ioctl_get_device_fd(group, uarg); + case VFIO_GROUP_GET_STATUS: + return vfio_group_ioctl_get_status(group, uarg); + case VFIO_GROUP_SET_CONTAINER: + return vfio_group_ioctl_set_container(group, uarg); + case VFIO_GROUP_UNSET_CONTAINER: + return vfio_group_ioctl_unset_container(group); + default: + return -ENOTTY; + } +} + +static int vfio_group_fops_open(struct inode *inode, struct file *filep) +{ + struct vfio_group *group = + container_of(inode->i_cdev, struct vfio_group, cdev); + int ret; + + mutex_lock(&group->group_lock); + + /* + * drivers can be zero if this races with vfio_device_remove_group(), it + * will be stable at 0 under the group rwsem + */ + if (refcount_read(&group->drivers) == 0) { + ret = -ENODEV; + goto out_unlock; + } + + if (group->type == VFIO_NO_IOMMU && !capable(CAP_SYS_RAWIO)) { + ret = -EPERM; + goto out_unlock; + } + + /* + * Do we need multiple instances of the group open? Seems not. + */ + if (group->opened_file) { + ret = -EBUSY; + goto out_unlock; + } + group->opened_file = filep; + filep->private_data = group; + ret = 0; +out_unlock: + mutex_unlock(&group->group_lock); + return ret; +} + +static int vfio_group_fops_release(struct inode *inode, struct file *filep) +{ + struct vfio_group *group = filep->private_data; + + filep->private_data = NULL; + + mutex_lock(&group->group_lock); + /* + * Device FDs hold a group file reference, therefore the group release + * is only called when there are no open devices. + */ + WARN_ON(group->notifier.head); + if (group->container) + vfio_group_detach_container(group); + if (group->iommufd) { + iommufd_ctx_put(group->iommufd); + group->iommufd = NULL; + } + group->opened_file = NULL; + mutex_unlock(&group->group_lock); + return 0; +} + +static const struct file_operations vfio_group_fops = { + .owner = THIS_MODULE, + .unlocked_ioctl = vfio_group_fops_unl_ioctl, + .compat_ioctl = compat_ptr_ioctl, + .open = vfio_group_fops_open, + .release = vfio_group_fops_release, +}; + +/* + * Group objects - create, release, get, put, search + */ +static struct vfio_group * +vfio_group_find_from_iommu(struct iommu_group *iommu_group) +{ + struct vfio_group *group; + + lockdep_assert_held(&vfio.group_lock); + + /* + * group->iommu_group from the vfio.group_list cannot be NULL + * under the vfio.group_lock. + */ + list_for_each_entry(group, &vfio.group_list, vfio_next) { + if (group->iommu_group == iommu_group) + return group; + } + return NULL; +} + +static void vfio_group_release(struct device *dev) +{ + struct vfio_group *group = container_of(dev, struct vfio_group, dev); + + mutex_destroy(&group->device_lock); + mutex_destroy(&group->group_lock); + WARN_ON(group->iommu_group); + ida_free(&vfio.group_ida, MINOR(group->dev.devt)); + kfree(group); +} + +static struct vfio_group *vfio_group_alloc(struct iommu_group *iommu_group, + enum vfio_group_type type) +{ + struct vfio_group *group; + int minor; + + group = kzalloc(sizeof(*group), GFP_KERNEL); + if (!group) + return ERR_PTR(-ENOMEM); + + minor = ida_alloc_max(&vfio.group_ida, MINORMASK, GFP_KERNEL); + if (minor < 0) { + kfree(group); + return ERR_PTR(minor); + } + + device_initialize(&group->dev); + group->dev.devt = MKDEV(MAJOR(vfio.group_devt), minor); + group->dev.class = vfio.class; + group->dev.release = vfio_group_release; + cdev_init(&group->cdev, &vfio_group_fops); + group->cdev.owner = THIS_MODULE; + + refcount_set(&group->drivers, 1); + mutex_init(&group->group_lock); + INIT_LIST_HEAD(&group->device_list); + mutex_init(&group->device_lock); + group->iommu_group = iommu_group; + /* put in vfio_group_release() */ + iommu_group_ref_get(iommu_group); + group->type = type; + BLOCKING_INIT_NOTIFIER_HEAD(&group->notifier); + + return group; +} + +static struct vfio_group *vfio_create_group(struct iommu_group *iommu_group, + enum vfio_group_type type) +{ + struct vfio_group *group; + struct vfio_group *ret; + int err; + + lockdep_assert_held(&vfio.group_lock); + + group = vfio_group_alloc(iommu_group, type); + if (IS_ERR(group)) + return group; + + err = dev_set_name(&group->dev, "%s%d", + group->type == VFIO_NO_IOMMU ? "noiommu-" : "", + iommu_group_id(iommu_group)); + if (err) { + ret = ERR_PTR(err); + goto err_put; + } + + err = cdev_device_add(&group->cdev, &group->dev); + if (err) { + ret = ERR_PTR(err); + goto err_put; + } + + list_add(&group->vfio_next, &vfio.group_list); + + return group; + +err_put: + put_device(&group->dev); + return ret; +} + +static struct vfio_group *vfio_noiommu_group_alloc(struct device *dev, + enum vfio_group_type type) +{ + struct iommu_group *iommu_group; + struct vfio_group *group; + int ret; + + iommu_group = iommu_group_alloc(); + if (IS_ERR(iommu_group)) + return ERR_CAST(iommu_group); + + ret = iommu_group_set_name(iommu_group, "vfio-noiommu"); + if (ret) + goto out_put_group; + ret = iommu_group_add_device(iommu_group, dev); + if (ret) + goto out_put_group; + + mutex_lock(&vfio.group_lock); + group = vfio_create_group(iommu_group, type); + mutex_unlock(&vfio.group_lock); + if (IS_ERR(group)) { + ret = PTR_ERR(group); + goto out_remove_device; + } + iommu_group_put(iommu_group); + return group; + +out_remove_device: + iommu_group_remove_device(dev); +out_put_group: + iommu_group_put(iommu_group); + return ERR_PTR(ret); +} + +static bool vfio_group_has_device(struct vfio_group *group, struct device *dev) +{ + struct vfio_device *device; + + mutex_lock(&group->device_lock); + list_for_each_entry(device, &group->device_list, group_next) { + if (device->dev == dev) { + mutex_unlock(&group->device_lock); + return true; + } + } + mutex_unlock(&group->device_lock); + return false; +} + +static struct vfio_group *vfio_group_find_or_alloc(struct device *dev) +{ + struct iommu_group *iommu_group; + struct vfio_group *group; + + iommu_group = iommu_group_get(dev); + if (!iommu_group && vfio_noiommu) { + /* + * With noiommu enabled, create an IOMMU group for devices that + * don't already have one, implying no IOMMU hardware/driver + * exists. Taint the kernel because we're about to give a DMA + * capable device to a user without IOMMU protection. + */ + group = vfio_noiommu_group_alloc(dev, VFIO_NO_IOMMU); + if (!IS_ERR(group)) { + add_taint(TAINT_USER, LOCKDEP_STILL_OK); + dev_warn(dev, "Adding kernel taint for vfio-noiommu group on device\n"); + } + return group; + } + + if (!iommu_group) + return ERR_PTR(-EINVAL); + + /* + * VFIO always sets IOMMU_CACHE because we offer no way for userspace to + * restore cache coherency. It has to be checked here because it is only + * valid for cases where we are using iommu groups. + */ + if (!device_iommu_capable(dev, IOMMU_CAP_CACHE_COHERENCY)) { + iommu_group_put(iommu_group); + return ERR_PTR(-EINVAL); + } + + mutex_lock(&vfio.group_lock); + group = vfio_group_find_from_iommu(iommu_group); + if (group) { + if (WARN_ON(vfio_group_has_device(group, dev))) + group = ERR_PTR(-EINVAL); + else + refcount_inc(&group->drivers); + } else { + group = vfio_create_group(iommu_group, VFIO_IOMMU); + } + mutex_unlock(&vfio.group_lock); + + /* The vfio_group holds a reference to the iommu_group */ + iommu_group_put(iommu_group); + return group; +} + +int vfio_device_set_group(struct vfio_device *device, + enum vfio_group_type type) +{ + struct vfio_group *group; + + if (type == VFIO_IOMMU) + group = vfio_group_find_or_alloc(device->dev); + else + group = vfio_noiommu_group_alloc(device->dev, type); + + if (IS_ERR(group)) + return PTR_ERR(group); + + /* Our reference on group is moved to the device */ + device->group = group; + return 0; +} + +void vfio_device_remove_group(struct vfio_device *device) +{ + struct vfio_group *group = device->group; + struct iommu_group *iommu_group; + + if (group->type == VFIO_NO_IOMMU || group->type == VFIO_EMULATED_IOMMU) + iommu_group_remove_device(device->dev); + + /* Pairs with vfio_create_group() / vfio_group_get_from_iommu() */ + if (!refcount_dec_and_mutex_lock(&group->drivers, &vfio.group_lock)) + return; + list_del(&group->vfio_next); + + /* + * We could concurrently probe another driver in the group that might + * race vfio_device_remove_group() with vfio_get_group(), so we have to + * ensure that the sysfs is all cleaned up under lock otherwise the + * cdev_device_add() will fail due to the name aready existing. + */ + cdev_device_del(&group->cdev, &group->dev); + + mutex_lock(&group->group_lock); + /* + * These data structures all have paired operations that can only be + * undone when the caller holds a live reference on the device. Since + * all pairs must be undone these WARN_ON's indicate some caller did not + * properly hold the group reference. + */ + WARN_ON(!list_empty(&group->device_list)); + WARN_ON(group->notifier.head); + + /* + * Revoke all users of group->iommu_group. At this point we know there + * are no devices active because we are unplugging the last one. Setting + * iommu_group to NULL blocks all new users. + */ + if (group->container) + vfio_group_detach_container(group); + iommu_group = group->iommu_group; + group->iommu_group = NULL; + mutex_unlock(&group->group_lock); + mutex_unlock(&vfio.group_lock); + + iommu_group_put(iommu_group); + put_device(&group->dev); +} + +void vfio_device_group_register(struct vfio_device *device) +{ + mutex_lock(&device->group->device_lock); + list_add(&device->group_next, &device->group->device_list); + mutex_unlock(&device->group->device_lock); +} + +void vfio_device_group_unregister(struct vfio_device *device) +{ + mutex_lock(&device->group->device_lock); + list_del(&device->group_next); + mutex_unlock(&device->group->device_lock); +} + +int vfio_device_group_use_iommu(struct vfio_device *device) +{ + struct vfio_group *group = device->group; + int ret = 0; + + lockdep_assert_held(&group->group_lock); + + if (WARN_ON(!group->container)) + return -EINVAL; + + ret = vfio_group_use_container(group); + if (ret) + return ret; + vfio_device_container_register(device); + return 0; +} + +void vfio_device_group_unuse_iommu(struct vfio_device *device) +{ + struct vfio_group *group = device->group; + + lockdep_assert_held(&group->group_lock); + + if (WARN_ON(!group->container)) + return; + + vfio_device_container_unregister(device); + vfio_group_unuse_container(group); +} + +bool vfio_device_has_container(struct vfio_device *device) +{ + return device->group->container; +} + +/** + * vfio_file_iommu_group - Return the struct iommu_group for the vfio group file + * @file: VFIO group file + * + * The returned iommu_group is valid as long as a ref is held on the file. This + * returns a reference on the group. This function is deprecated, only the SPAPR + * path in kvm should call it. + */ +struct iommu_group *vfio_file_iommu_group(struct file *file) +{ + struct vfio_group *group = file->private_data; + struct iommu_group *iommu_group = NULL; + + if (!IS_ENABLED(CONFIG_SPAPR_TCE_IOMMU)) + return NULL; + + if (!vfio_file_is_group(file)) + return NULL; + + mutex_lock(&group->group_lock); + if (group->iommu_group) { + iommu_group = group->iommu_group; + iommu_group_ref_get(iommu_group); + } + mutex_unlock(&group->group_lock); + return iommu_group; +} +EXPORT_SYMBOL_GPL(vfio_file_iommu_group); + +/** + * vfio_file_is_group - True if the file is usable with VFIO aPIS + * @file: VFIO group file + */ +bool vfio_file_is_group(struct file *file) +{ + return file->f_op == &vfio_group_fops; +} +EXPORT_SYMBOL_GPL(vfio_file_is_group); + +/** + * vfio_file_enforced_coherent - True if the DMA associated with the VFIO file + * is always CPU cache coherent + * @file: VFIO group file + * + * Enforced coherency means that the IOMMU ignores things like the PCIe no-snoop + * bit in DMA transactions. A return of false indicates that the user has + * rights to access additional instructions such as wbinvd on x86. + */ +bool vfio_file_enforced_coherent(struct file *file) +{ + struct vfio_group *group = file->private_data; + struct vfio_device *device; + bool ret = true; + + if (!vfio_file_is_group(file)) + return true; + + /* + * If the device does not have IOMMU_CAP_ENFORCE_CACHE_COHERENCY then + * any domain later attached to it will also not support it. If the cap + * is set then the iommu_domain eventually attached to the device/group + * must use a domain with enforce_cache_coherency(). + */ + mutex_lock(&group->device_lock); + list_for_each_entry(device, &group->device_list, group_next) { + if (!device_iommu_capable(device->dev, + IOMMU_CAP_ENFORCE_CACHE_COHERENCY)) { + ret = false; + break; + } + } + mutex_unlock(&group->device_lock); + return ret; +} +EXPORT_SYMBOL_GPL(vfio_file_enforced_coherent); + +/** + * vfio_file_set_kvm - Link a kvm with VFIO drivers + * @file: VFIO group file + * @kvm: KVM to link + * + * When a VFIO device is first opened the KVM will be available in + * device->kvm if one was associated with the group. + */ +void vfio_file_set_kvm(struct file *file, struct kvm *kvm) +{ + struct vfio_group *group = file->private_data; + + if (!vfio_file_is_group(file)) + return; + + mutex_lock(&group->group_lock); + group->kvm = kvm; + mutex_unlock(&group->group_lock); +} +EXPORT_SYMBOL_GPL(vfio_file_set_kvm); + +/** + * vfio_file_has_dev - True if the VFIO file is a handle for device + * @file: VFIO file to check + * @device: Device that must be part of the file + * + * Returns true if given file has permission to manipulate the given device. + */ +bool vfio_file_has_dev(struct file *file, struct vfio_device *device) +{ + struct vfio_group *group = file->private_data; + + if (!vfio_file_is_group(file)) + return false; + + return group == device->group; +} +EXPORT_SYMBOL_GPL(vfio_file_has_dev); + +static char *vfio_devnode(struct device *dev, umode_t *mode) +{ + return kasprintf(GFP_KERNEL, "vfio/%s", dev_name(dev)); +} + +int __init vfio_group_init(void) +{ + int ret; + + ida_init(&vfio.group_ida); + mutex_init(&vfio.group_lock); + INIT_LIST_HEAD(&vfio.group_list); + + ret = vfio_container_init(); + if (ret) + return ret; + + /* /dev/vfio/$GROUP */ + vfio.class = class_create(THIS_MODULE, "vfio"); + if (IS_ERR(vfio.class)) { + ret = PTR_ERR(vfio.class); + goto err_group_class; + } + + vfio.class->devnode = vfio_devnode; + + ret = alloc_chrdev_region(&vfio.group_devt, 0, MINORMASK + 1, "vfio"); + if (ret) + goto err_alloc_chrdev; + return 0; + +err_alloc_chrdev: + class_destroy(vfio.class); + vfio.class = NULL; +err_group_class: + vfio_container_cleanup(); + return ret; +} + +void vfio_group_cleanup(void) +{ + WARN_ON(!list_empty(&vfio.group_list)); + ida_destroy(&vfio.group_ida); + unregister_chrdev_region(vfio.group_devt, MINORMASK + 1); + class_destroy(vfio.class); + vfio.class = NULL; + vfio_container_cleanup(); +} diff --git a/drivers/vfio/vfio.h b/drivers/vfio/vfio.h index a112e8f2b291..2e05418fd18d 100644 --- a/drivers/vfio/vfio.h +++ b/drivers/vfio/vfio.h @@ -6,6 +6,7 @@ #ifndef __VFIO_VFIO_H__ #define __VFIO_VFIO_H__ +#include #include #include #include @@ -15,6 +16,15 @@ struct iommu_group; struct vfio_device; struct vfio_container; +void vfio_device_put_registration(struct vfio_device *device); +bool vfio_device_try_get_registration(struct vfio_device *device); +int vfio_device_open(struct vfio_device *device, + struct iommufd_ctx *iommufd, struct kvm *kvm); +void vfio_device_close(struct vfio_device *device, + struct iommufd_ctx *iommufd); + +extern const struct file_operations vfio_device_fops; + enum vfio_group_type { /* * Physical device with IOMMU backing. @@ -66,6 +76,18 @@ struct vfio_group { struct iommufd_ctx *iommufd; }; +int vfio_device_set_group(struct vfio_device *device, + enum vfio_group_type type); +void vfio_device_remove_group(struct vfio_device *device); +void vfio_device_group_register(struct vfio_device *device); +void vfio_device_group_unregister(struct vfio_device *device); +int vfio_device_group_use_iommu(struct vfio_device *device); +void vfio_device_group_unuse_iommu(struct vfio_device *device); +void vfio_device_group_close(struct vfio_device *device); +bool vfio_device_has_container(struct vfio_device *device); +int __init vfio_group_init(void); +void vfio_group_cleanup(void); + #if IS_ENABLED(CONFIG_VFIO_CONTAINER) /* events for the backend driver notify callback */ enum vfio_iommu_notify_type { diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c index b7f94ace7b10..e21ff965141e 100644 --- a/drivers/vfio/vfio_main.c +++ b/drivers/vfio/vfio_main.c @@ -13,8 +13,6 @@ #include #include #include -#include -#include #include #include #include @@ -43,17 +41,11 @@ #define DRIVER_DESC "VFIO - User Level meta-driver" static struct vfio { - struct class *class; - struct list_head group_list; - struct mutex group_lock; /* locks group_list */ - struct ida group_ida; - dev_t group_devt; struct class *device_class; struct ida device_ida; } vfio; static DEFINE_XARRAY(vfio_device_set_xa); -static const struct file_operations vfio_group_fops; int vfio_assign_device_set(struct vfio_device *device, void *set_id) { @@ -139,168 +131,17 @@ unsigned int vfio_device_set_open_count(struct vfio_device_set *dev_set) } EXPORT_SYMBOL_GPL(vfio_device_set_open_count); -/* - * Group objects - create, release, get, put, search - */ -static struct vfio_group * -vfio_group_find_from_iommu(struct iommu_group *iommu_group) -{ - struct vfio_group *group; - - lockdep_assert_held(&vfio.group_lock); - - /* - * group->iommu_group from the vfio.group_list cannot be NULL - * under the vfio.group_lock. - */ - list_for_each_entry(group, &vfio.group_list, vfio_next) { - if (group->iommu_group == iommu_group) - return group; - } - return NULL; -} - -static void vfio_group_release(struct device *dev) -{ - struct vfio_group *group = container_of(dev, struct vfio_group, dev); - - mutex_destroy(&group->device_lock); - mutex_destroy(&group->group_lock); - WARN_ON(group->iommu_group); - ida_free(&vfio.group_ida, MINOR(group->dev.devt)); - kfree(group); -} - -static struct vfio_group *vfio_group_alloc(struct iommu_group *iommu_group, - enum vfio_group_type type) -{ - struct vfio_group *group; - int minor; - - group = kzalloc(sizeof(*group), GFP_KERNEL); - if (!group) - return ERR_PTR(-ENOMEM); - - minor = ida_alloc_max(&vfio.group_ida, MINORMASK, GFP_KERNEL); - if (minor < 0) { - kfree(group); - return ERR_PTR(minor); - } - - device_initialize(&group->dev); - group->dev.devt = MKDEV(MAJOR(vfio.group_devt), minor); - group->dev.class = vfio.class; - group->dev.release = vfio_group_release; - cdev_init(&group->cdev, &vfio_group_fops); - group->cdev.owner = THIS_MODULE; - - refcount_set(&group->drivers, 1); - mutex_init(&group->group_lock); - INIT_LIST_HEAD(&group->device_list); - mutex_init(&group->device_lock); - group->iommu_group = iommu_group; - /* put in vfio_group_release() */ - iommu_group_ref_get(iommu_group); - group->type = type; - BLOCKING_INIT_NOTIFIER_HEAD(&group->notifier); - - return group; -} - -static struct vfio_group *vfio_create_group(struct iommu_group *iommu_group, - enum vfio_group_type type) -{ - struct vfio_group *group; - struct vfio_group *ret; - int err; - - lockdep_assert_held(&vfio.group_lock); - - group = vfio_group_alloc(iommu_group, type); - if (IS_ERR(group)) - return group; - - err = dev_set_name(&group->dev, "%s%d", - group->type == VFIO_NO_IOMMU ? "noiommu-" : "", - iommu_group_id(iommu_group)); - if (err) { - ret = ERR_PTR(err); - goto err_put; - } - - err = cdev_device_add(&group->cdev, &group->dev); - if (err) { - ret = ERR_PTR(err); - goto err_put; - } - - list_add(&group->vfio_next, &vfio.group_list); - - return group; - -err_put: - put_device(&group->dev); - return ret; -} - -static void vfio_device_remove_group(struct vfio_device *device) -{ - struct vfio_group *group = device->group; - struct iommu_group *iommu_group; - - if (group->type == VFIO_NO_IOMMU || group->type == VFIO_EMULATED_IOMMU) - iommu_group_remove_device(device->dev); - - /* Pairs with vfio_create_group() / vfio_group_get_from_iommu() */ - if (!refcount_dec_and_mutex_lock(&group->drivers, &vfio.group_lock)) - return; - list_del(&group->vfio_next); - - /* - * We could concurrently probe another driver in the group that might - * race vfio_device_remove_group() with vfio_get_group(), so we have to - * ensure that the sysfs is all cleaned up under lock otherwise the - * cdev_device_add() will fail due to the name aready existing. - */ - cdev_device_del(&group->cdev, &group->dev); - - mutex_lock(&group->group_lock); - /* - * These data structures all have paired operations that can only be - * undone when the caller holds a live reference on the device. Since - * all pairs must be undone these WARN_ON's indicate some caller did not - * properly hold the group reference. - */ - WARN_ON(!list_empty(&group->device_list)); - WARN_ON(group->notifier.head); - - /* - * Revoke all users of group->iommu_group. At this point we know there - * are no devices active because we are unplugging the last one. Setting - * iommu_group to NULL blocks all new users. - */ - if (group->container) - vfio_group_detach_container(group); - iommu_group = group->iommu_group; - group->iommu_group = NULL; - mutex_unlock(&group->group_lock); - mutex_unlock(&vfio.group_lock); - - iommu_group_put(iommu_group); - put_device(&group->dev); -} - /* * Device objects - create, release, get, put, search */ /* Device reference always implies a group reference */ -static void vfio_device_put_registration(struct vfio_device *device) +void vfio_device_put_registration(struct vfio_device *device) { if (refcount_dec_and_test(&device->refcount)) complete(&device->comp); } -static bool vfio_device_try_get_registration(struct vfio_device *device) +bool vfio_device_try_get_registration(struct vfio_device *device) { return refcount_inc_not_zero(&device->refcount); } @@ -413,139 +254,6 @@ void vfio_free_device(struct vfio_device *device) } EXPORT_SYMBOL_GPL(vfio_free_device); -static struct vfio_group *vfio_noiommu_group_alloc(struct device *dev, - enum vfio_group_type type) -{ - struct iommu_group *iommu_group; - struct vfio_group *group; - int ret; - - iommu_group = iommu_group_alloc(); - if (IS_ERR(iommu_group)) - return ERR_CAST(iommu_group); - - ret = iommu_group_set_name(iommu_group, "vfio-noiommu"); - if (ret) - goto out_put_group; - ret = iommu_group_add_device(iommu_group, dev); - if (ret) - goto out_put_group; - - mutex_lock(&vfio.group_lock); - group = vfio_create_group(iommu_group, type); - mutex_unlock(&vfio.group_lock); - if (IS_ERR(group)) { - ret = PTR_ERR(group); - goto out_remove_device; - } - iommu_group_put(iommu_group); - return group; - -out_remove_device: - iommu_group_remove_device(dev); -out_put_group: - iommu_group_put(iommu_group); - return ERR_PTR(ret); -} - -static bool vfio_group_has_device(struct vfio_group *group, struct device *dev) -{ - struct vfio_device *device; - - mutex_lock(&group->device_lock); - list_for_each_entry(device, &group->device_list, group_next) { - if (device->dev == dev) { - mutex_unlock(&group->device_lock); - return true; - } - } - mutex_unlock(&group->device_lock); - return false; -} - -static struct vfio_group *vfio_group_find_or_alloc(struct device *dev) -{ - struct iommu_group *iommu_group; - struct vfio_group *group; - - iommu_group = iommu_group_get(dev); - if (!iommu_group && vfio_noiommu) { - /* - * With noiommu enabled, create an IOMMU group for devices that - * don't already have one, implying no IOMMU hardware/driver - * exists. Taint the kernel because we're about to give a DMA - * capable device to a user without IOMMU protection. - */ - group = vfio_noiommu_group_alloc(dev, VFIO_NO_IOMMU); - if (!IS_ERR(group)) { - add_taint(TAINT_USER, LOCKDEP_STILL_OK); - dev_warn(dev, "Adding kernel taint for vfio-noiommu group on device\n"); - } - return group; - } - - if (!iommu_group) - return ERR_PTR(-EINVAL); - - /* - * VFIO always sets IOMMU_CACHE because we offer no way for userspace to - * restore cache coherency. It has to be checked here because it is only - * valid for cases where we are using iommu groups. - */ - if (!device_iommu_capable(dev, IOMMU_CAP_CACHE_COHERENCY)) { - iommu_group_put(iommu_group); - return ERR_PTR(-EINVAL); - } - - mutex_lock(&vfio.group_lock); - group = vfio_group_find_from_iommu(iommu_group); - if (group) { - if (WARN_ON(vfio_group_has_device(group, dev))) - group = ERR_PTR(-EINVAL); - else - refcount_inc(&group->drivers); - } else { - group = vfio_create_group(iommu_group, VFIO_IOMMU); - } - mutex_unlock(&vfio.group_lock); - - /* The vfio_group holds a reference to the iommu_group */ - iommu_group_put(iommu_group); - return group; -} - -static void vfio_device_group_register(struct vfio_device *device) -{ - mutex_lock(&device->group->device_lock); - list_add(&device->group_next, &device->group->device_list); - mutex_unlock(&device->group->device_lock); -} - -static void vfio_device_group_unregister(struct vfio_device *device) -{ - mutex_lock(&device->group->device_lock); - list_del(&device->group_next); - mutex_unlock(&device->group->device_lock); -} - -static int vfio_device_set_group(struct vfio_device *device, - enum vfio_group_type type) -{ - struct vfio_group *group; - - if (type == VFIO_IOMMU) - group = vfio_group_find_or_alloc(device->dev); - else - group = vfio_noiommu_group_alloc(device->dev, type); - - if (IS_ERR(group)) - return PTR_ERR(group); - - /* Our reference on group is moved to the device */ - device->group = group; - return 0; -} - static int __vfio_register_dev(struct vfio_device *device, enum vfio_group_type type) { @@ -602,35 +310,6 @@ int vfio_register_emulated_iommu_dev(struct vfio_device *device) } EXPORT_SYMBOL_GPL(vfio_register_emulated_iommu_dev); -static struct vfio_device *vfio_device_get_from_name(struct vfio_group *group, - char *buf) -{ - struct vfio_device *it, *device = ERR_PTR(-ENODEV); - - mutex_lock(&group->device_lock); - list_for_each_entry(it, &group->device_list, group_next) { - int ret; - - if (it->ops->match) { - ret = it->ops->match(it, buf); - if (ret < 0) { - device = ERR_PTR(ret); - break; - } - } else { - ret = !strcmp(dev_name(it->dev), buf); - } - - if (ret && vfio_device_try_get_registration(it)) { - device = it; - break; - } - } - mutex_unlock(&group->device_lock); - - return device; -} - /* * Decrement the device reference count and wait for the device to be * removed. Open file descriptors for the device... */ @@ -673,146 +352,12 @@ void vfio_unregister_group_dev(struct vfio_device *device) } EXPORT_SYMBOL_GPL(vfio_unregister_group_dev); -/* - * VFIO Group fd, /dev/vfio/$GROUP - */ -static bool vfio_group_has_iommu(struct vfio_group *group) -{ - lockdep_assert_held(&group->group_lock); - /* - * There can only be users if there is a container, and if there is a - * container there must be users. - */ - WARN_ON(!group->container != !group->container_users); - - return group->container || group->iommufd; -} - -/* - * VFIO_GROUP_UNSET_CONTAINER should fail if there are other users or - * if there was no container to unset. Since the ioctl is called on - * the group, we know that still exists, therefore the only valid - * transition here is 1->0. - */ -static int vfio_group_ioctl_unset_container(struct vfio_group *group) -{ - int ret = 0; - - mutex_lock(&group->group_lock); - if (!vfio_group_has_iommu(group)) { - ret = -EINVAL; - goto out_unlock; - } - if (group->container) { - if (group->container_users != 1) { - ret = -EBUSY; - goto out_unlock; - } - vfio_group_detach_container(group); - } - if (group->iommufd) { - iommufd_ctx_put(group->iommufd); - group->iommufd = NULL; - } - -out_unlock: - mutex_unlock(&group->group_lock); - return ret; -} - -static int vfio_group_ioctl_set_container(struct vfio_group *group, - int __user *arg) -{ - struct vfio_container *container; - struct iommufd_ctx *iommufd; - struct fd f; - int ret; - int fd; - - if (get_user(fd, arg)) - return -EFAULT; - - f = fdget(fd); - if (!f.file) - return -EBADF; - - mutex_lock(&group->group_lock); - if (vfio_group_has_iommu(group)) { - ret = -EINVAL; - goto out_unlock; - } - if (!group->iommu_group) { - ret = -ENODEV; - goto out_unlock; - } - - container = vfio_container_from_file(f.file); - if (container) { - ret = vfio_container_attach_group(container, group); - goto out_unlock; - } - - iommufd = iommufd_ctx_from_file(f.file); - if (!IS_ERR(iommufd)) { - u32 ioas_id; - - ret = iommufd_vfio_compat_ioas_id(iommufd, &ioas_id); - if (ret) { - iommufd_ctx_put(group->iommufd); - goto out_unlock; - } - - group->iommufd = iommufd; - goto out_unlock; - } - - /* The FD passed is not recognized. */ - ret = -EBADFD; - -out_unlock: - mutex_unlock(&group->group_lock); - fdput(f); - return ret; -} - -static const struct file_operations vfio_device_fops; - /* true if the vfio_device has open_device() called but not close_device() */ static bool vfio_assert_device_open(struct vfio_device *device) { return !WARN_ON_ONCE(!READ_ONCE(device->open_count)); } -static int vfio_device_group_use_iommu(struct vfio_device *device) -{ - struct vfio_group *group = device->group; - int ret = 0; - - lockdep_assert_held(&group->group_lock); - - if (WARN_ON(!group->container)) - return -EINVAL; - - ret = vfio_group_use_container(group); - if (ret) - return ret; - vfio_device_container_register(device); - return 0; -} - -static void vfio_device_group_unuse_iommu(struct vfio_device *device) -{ - struct vfio_group *group = device->group; - - lockdep_assert_held(&group->group_lock); - - if (WARN_ON(!group->container)) - return; - - vfio_device_container_unregister(device); - vfio_group_unuse_container(group); -} - static int vfio_device_first_open(struct vfio_device *device, struct iommufd_ctx *iommufd, struct kvm *kvm) { @@ -864,8 +409,8 @@ static void vfio_device_last_close(struct vfio_device *device, module_put(device->dev->driver->owner); } -static int vfio_device_open(struct vfio_device *device, - struct iommufd_ctx *iommufd, struct kvm *kvm) +int vfio_device_open(struct vfio_device *device, + struct iommufd_ctx *iommufd, struct kvm *kvm) { int ret = 0; @@ -881,8 +426,8 @@ static int vfio_device_open(struct vfio_device *device, return ret; } -static void vfio_device_close(struct vfio_device *device, - struct iommufd_ctx *iommufd) +void vfio_device_close(struct vfio_device *device, + struct iommufd_ctx *iommufd) { mutex_lock(&device->dev_set->lock); vfio_assert_device_open(device); @@ -892,245 +437,6 @@ static void vfio_device_close(struct vfio_device *device, mutex_unlock(&device->dev_set->lock); } -static int vfio_device_group_open(struct vfio_device *device) -{ - int ret; - - mutex_lock(&device->group->group_lock); - if (!vfio_group_has_iommu(device->group)) { - ret = -EINVAL; - goto out_unlock; - } - - /* - * Here we pass the KVM pointer with the group under the lock. If the - * device driver will use it, it must obtain a reference and release it - * during close_device. - */ - ret = vfio_device_open(device, device->group->iommufd, - device->group->kvm); - -out_unlock: - mutex_unlock(&device->group->group_lock); - return ret; -} - -static void vfio_device_group_close(struct vfio_device *device) -{ - mutex_lock(&device->group->group_lock); - vfio_device_close(device, device->group->iommufd); - mutex_unlock(&device->group->group_lock); -} - -static struct file *vfio_device_open_file(struct vfio_device *device) -{ - struct file *filep; - int ret; - - ret = vfio_device_group_open(device); - if (ret) - goto err_out; - - /* - * We can't use anon_inode_getfd() because we need to modify - * the f_mode flags directly to allow more than just ioctls - */ - filep = anon_inode_getfile("[vfio-device]", &vfio_device_fops, - device, O_RDWR); - if (IS_ERR(filep)) { - ret = PTR_ERR(filep); - goto err_close_device; - } - - /* - * TODO: add an anon_inode interface to do this. - * Appears to be missing by lack of need rather than - * explicitly prevented. Now there's need. - */ - filep->f_mode |= (FMODE_PREAD | FMODE_PWRITE); - - if (device->group->type == VFIO_NO_IOMMU) - dev_warn(device->dev, "vfio-noiommu device opened by user " - "(%s:%d)\n", current->comm, task_pid_nr(current)); - /* - * On success the ref of device is moved to the file and - * put in vfio_device_fops_release() - */ - return filep; - -err_close_device: - vfio_device_group_close(device); -err_out: - return ERR_PTR(ret); -} - -static int vfio_group_ioctl_get_device_fd(struct vfio_group *group, - char __user *arg) -{ - struct vfio_device *device; - struct file *filep; - char *buf; - int fdno; - int ret; - - buf = strndup_user(arg, PAGE_SIZE); - if (IS_ERR(buf)) - return PTR_ERR(buf); - - device = vfio_device_get_from_name(group, buf); - kfree(buf); - if (IS_ERR(device)) - return PTR_ERR(device); - - fdno = get_unused_fd_flags(O_CLOEXEC); - if (fdno < 0) { - ret = fdno; - goto err_put_device; - } - - filep = vfio_device_open_file(device); - if (IS_ERR(filep)) { - ret = PTR_ERR(filep); - goto err_put_fdno; - } - - fd_install(fdno, filep); - return fdno; - -err_put_fdno: - put_unused_fd(fdno); -err_put_device: - vfio_device_put_registration(device); - return ret; -} - -static int vfio_group_ioctl_get_status(struct vfio_group *group, - struct vfio_group_status __user *arg) -{ - unsigned long minsz = offsetofend(struct vfio_group_status, flags); - struct vfio_group_status status; - - if (copy_from_user(&status, arg, minsz)) - return -EFAULT; - - if (status.argsz < minsz) - return -EINVAL; - - status.flags = 0; - - mutex_lock(&group->group_lock); - if (!group->iommu_group) { - mutex_unlock(&group->group_lock); - return -ENODEV; - } - - /* - * With the container FD the iommu_group_claim_dma_owner() is done - * during SET_CONTAINER but for IOMMFD this is done during - * VFIO_GROUP_GET_DEVICE_FD. Meaning that with iommufd - * VFIO_GROUP_FLAGS_VIABLE could be set but GET_DEVICE_FD will fail due - * to viability. - */ - if (vfio_group_has_iommu(group)) - status.flags |= VFIO_GROUP_FLAGS_CONTAINER_SET | - VFIO_GROUP_FLAGS_VIABLE; - else if (!iommu_group_dma_owner_claimed(group->iommu_group)) - status.flags |= VFIO_GROUP_FLAGS_VIABLE; - mutex_unlock(&group->group_lock); - - if (copy_to_user(arg, &status, minsz)) - return -EFAULT; - return 0; -} - -static long vfio_group_fops_unl_ioctl(struct file *filep, - unsigned int cmd, unsigned long arg) -{ - struct vfio_group *group = filep->private_data; - void __user *uarg = (void __user *)arg; - - switch (cmd) { - case VFIO_GROUP_GET_DEVICE_FD: - return vfio_group_ioctl_get_device_fd(group, uarg); - case VFIO_GROUP_GET_STATUS: - return vfio_group_ioctl_get_status(group, uarg); - case VFIO_GROUP_SET_CONTAINER: - return vfio_group_ioctl_set_container(group, uarg); - case VFIO_GROUP_UNSET_CONTAINER: - return vfio_group_ioctl_unset_container(group); - default: - return -ENOTTY; - } -} - -static int vfio_group_fops_open(struct inode *inode, struct file *filep) -{ - struct vfio_group *group = - container_of(inode->i_cdev, struct vfio_group, cdev); - int ret; - - mutex_lock(&group->group_lock); - - /* - * drivers can be zero if this races with vfio_device_remove_group(), it - * will be stable at 0 under the group rwsem - */ - if (refcount_read(&group->drivers) == 0) { - ret = -ENODEV; - goto out_unlock; - } - - if (group->type == VFIO_NO_IOMMU && !capable(CAP_SYS_RAWIO)) { - ret = -EPERM; - goto out_unlock; - } - - /* - * Do we need multiple instances of the group open? Seems not. - */ - if (group->opened_file) { - ret = -EBUSY; - goto out_unlock; - } - group->opened_file = filep; - filep->private_data = group; - ret = 0; -out_unlock: - mutex_unlock(&group->group_lock); - return ret; -} - -static int vfio_group_fops_release(struct inode *inode, struct file *filep) -{ - struct vfio_group *group = filep->private_data; - - filep->private_data = NULL; - - mutex_lock(&group->group_lock); - /* - * Device FDs hold a group file reference, therefore the group release - * is only called when there are no open devices. - */ - WARN_ON(group->notifier.head); - if (group->container) - vfio_group_detach_container(group); - if (group->iommufd) { - iommufd_ctx_put(group->iommufd); - group->iommufd = NULL; - } - group->opened_file = NULL; - mutex_unlock(&group->group_lock); - return 0; -} - -static const struct file_operations vfio_group_fops = { - .owner = THIS_MODULE, - .unlocked_ioctl = vfio_group_fops_unl_ioctl, - .compat_ioctl = compat_ptr_ioctl, - .open = vfio_group_fops_open, - .release = vfio_group_fops_release, -}; - /* * Wrapper around pm_runtime_resume_and_get(). * Return error code on failure or 0 on success. @@ -1694,7 +1000,7 @@ static int vfio_device_fops_mmap(struct file *filep, struct vm_area_struct *vma) return device->ops->mmap(device, vma); } -static const struct file_operations vfio_device_fops = { +const struct file_operations vfio_device_fops = { .owner = THIS_MODULE, .release = vfio_device_fops_release, .read = vfio_device_fops_read, @@ -1704,121 +1010,6 @@ static const struct file_operations vfio_device_fops = { .mmap = vfio_device_fops_mmap, }; -/** - * vfio_file_iommu_group - Return the struct iommu_group for the vfio group file - * @file: VFIO group file - * - * The returned iommu_group is valid as long as a ref is held on the file. This - * returns a reference on the group. This function is deprecated, only the SPAPR - * path in kvm should call it. - */ -struct iommu_group *vfio_file_iommu_group(struct file *file) -{ - struct vfio_group *group = file->private_data; - struct iommu_group *iommu_group = NULL; - - if (!IS_ENABLED(CONFIG_SPAPR_TCE_IOMMU)) - return NULL; - - if (!vfio_file_is_group(file)) - return NULL; - - mutex_lock(&group->group_lock); - if (group->iommu_group) { - iommu_group = group->iommu_group; - iommu_group_ref_get(iommu_group); - } - mutex_unlock(&group->group_lock); - return iommu_group; -} -EXPORT_SYMBOL_GPL(vfio_file_iommu_group); - -/** - * vfio_file_is_group - True if the file is usable with VFIO aPIS - * @file: VFIO group file - */ -bool vfio_file_is_group(struct file *file) -{ - return file->f_op == &vfio_group_fops; -} -EXPORT_SYMBOL_GPL(vfio_file_is_group); - -/** - * vfio_file_enforced_coherent - True if the DMA associated with the VFIO file - * is always CPU cache coherent - * @file: VFIO group file - * - * Enforced coherency means that the IOMMU ignores things like the PCIe no-snoop - * bit in DMA transactions. A return of false indicates that the user has - * rights to access additional instructions such as wbinvd on x86. - */ -bool vfio_file_enforced_coherent(struct file *file) -{ - struct vfio_group *group = file->private_data; - struct vfio_device *device; - bool ret = true; - - if (!vfio_file_is_group(file)) - return true; - - /* - * If the device does not have IOMMU_CAP_ENFORCE_CACHE_COHERENCY then - * any domain later attached to it will also not support it. If the cap - * is set then the iommu_domain eventually attached to the device/group - * must use a domain with enforce_cache_coherency(). - */ - mutex_lock(&group->device_lock); - list_for_each_entry(device, &group->device_list, group_next) { - if (!device_iommu_capable(device->dev, - IOMMU_CAP_ENFORCE_CACHE_COHERENCY)) { - ret = false; - break; - } - } - mutex_unlock(&group->device_lock); - return ret; -} -EXPORT_SYMBOL_GPL(vfio_file_enforced_coherent); - -/** - * vfio_file_set_kvm - Link a kvm with VFIO drivers - * @file: VFIO group file - * @kvm: KVM to link - * - * When a VFIO device is first opened the KVM will be available in - * device->kvm if one was associated with the group. - */ -void vfio_file_set_kvm(struct file *file, struct kvm *kvm) -{ - struct vfio_group *group = file->private_data; - - if (!vfio_file_is_group(file)) - return; - - mutex_lock(&group->group_lock); - group->kvm = kvm; - mutex_unlock(&group->group_lock); -} -EXPORT_SYMBOL_GPL(vfio_file_set_kvm); - -/** - * vfio_file_has_dev - True if the VFIO file is a handle for device - * @file: VFIO file to check - * @device: Device that must be part of the file - * - * Returns true if given file has permission to manipulate the given device. - */ -bool vfio_file_has_dev(struct file *file, struct vfio_device *device) -{ - struct vfio_group *group = file->private_data; - - if (!vfio_file_is_group(file)) - return false; - - return group == device->group; -} -EXPORT_SYMBOL_GPL(vfio_file_has_dev); - /* * Sub-module support */ @@ -1938,11 +1129,6 @@ int vfio_set_irqs_validate_and_prepare(struct vfio_irq_set *hdr, int num_irqs, } EXPORT_SYMBOL(vfio_set_irqs_validate_and_prepare); -static bool vfio_device_has_container(struct vfio_device *device) -{ - return device->group->container; -} - /* * Pin contiguous user pages and return their associated host pages for local * domain only. @@ -2064,55 +1250,6 @@ EXPORT_SYMBOL(vfio_dma_rw); /* * Module/class support */ -static char *vfio_devnode(struct device *dev, umode_t *mode) -{ - return kasprintf(GFP_KERNEL, "vfio/%s", dev_name(dev)); -} - -static int __init vfio_group_init(void) -{ - int ret; - - ida_init(&vfio.group_ida); - mutex_init(&vfio.group_lock); - INIT_LIST_HEAD(&vfio.group_list); - - ret = vfio_container_init(); - if (ret) - return ret; - - /* /dev/vfio/$GROUP */ - vfio.class = class_create(THIS_MODULE, "vfio"); - if (IS_ERR(vfio.class)) { - ret = PTR_ERR(vfio.class); - goto err_group_class; - } - - vfio.class->devnode = vfio_devnode; - - ret = alloc_chrdev_region(&vfio.group_devt, 0, MINORMASK + 1, "vfio"); - if (ret) - goto err_alloc_chrdev; - return 0; - -err_alloc_chrdev: - class_destroy(vfio.class); - vfio.class = NULL; -err_group_class: - vfio_container_cleanup(); - return ret; -} - -static void vfio_group_cleanup(void) -{ - WARN_ON(!list_empty(&vfio.group_list)); - ida_destroy(&vfio.group_ida); - unregister_chrdev_region(vfio.group_devt, MINORMASK + 1); - class_destroy(vfio.class); - vfio.class = NULL; - vfio_container_cleanup(); -} - static int __init vfio_init(void) { int ret;