diff options
Diffstat (limited to 'drivers/vfio/vfio_main.c')
| -rw-r--r-- | drivers/vfio/vfio_main.c | 77 |
1 files changed, 66 insertions, 11 deletions
diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c index 5177bb061b17..43bd6b76e2b6 100644 --- a/drivers/vfio/vfio_main.c +++ b/drivers/vfio/vfio_main.c @@ -16,6 +16,9 @@ #include <linux/fs.h> #include <linux/idr.h> #include <linux/iommu.h> +#ifdef CONFIG_HAVE_KVM +#include <linux/kvm_host.h> +#endif #include <linux/list.h> #include <linux/miscdevice.h> #include <linux/module.h> @@ -45,6 +48,13 @@ static struct vfio { struct ida device_ida; } vfio; +#ifdef CONFIG_VFIO_NOIOMMU +bool vfio_noiommu __read_mostly; +module_param_named(enable_unsafe_noiommu_mode, + vfio_noiommu, bool, S_IRUGO | S_IWUSR); +MODULE_PARM_DESC(enable_unsafe_noiommu_mode, "Enable UNSAFE, no-IOMMU mode. This mode provides no device isolation, no DMA translation, no host kernel protection, cannot be used for device assignment to virtual machines, requires RAWIO permissions, and will taint the kernel. If you do not know what this is for, step away. (default: false)"); +#endif + static DEFINE_XARRAY(vfio_device_set_xa); int vfio_assign_device_set(struct vfio_device *device, void *set_id) @@ -338,6 +348,55 @@ void vfio_unregister_group_dev(struct vfio_device *device) } EXPORT_SYMBOL_GPL(vfio_unregister_group_dev); +#ifdef CONFIG_HAVE_KVM +void _vfio_device_get_kvm_safe(struct vfio_device *device, struct kvm *kvm) +{ + void (*pfn)(struct kvm *kvm); + bool (*fn)(struct kvm *kvm); + bool ret; + + lockdep_assert_held(&device->dev_set->lock); + + pfn = symbol_get(kvm_put_kvm); + if (WARN_ON(!pfn)) + return; + + fn = symbol_get(kvm_get_kvm_safe); + if (WARN_ON(!fn)) { + symbol_put(kvm_put_kvm); + return; + } + + ret = fn(kvm); + symbol_put(kvm_get_kvm_safe); + if (!ret) { + symbol_put(kvm_put_kvm); + return; + } + + device->put_kvm = pfn; + device->kvm = kvm; +} + +void vfio_device_put_kvm(struct vfio_device *device) +{ + lockdep_assert_held(&device->dev_set->lock); + + if (!device->kvm) + return; + + if (WARN_ON(!device->put_kvm)) + goto clear; + + device->put_kvm(device->kvm); + device->put_kvm = NULL; + symbol_put(kvm_put_kvm); + +clear: + device->kvm = NULL; +} +#endif + /* true if the vfio_device has open_device() called but not close_device() */ static bool vfio_assert_device_open(struct vfio_device *device) { @@ -345,7 +404,7 @@ static bool vfio_assert_device_open(struct vfio_device *device) } static int vfio_device_first_open(struct vfio_device *device, - struct iommufd_ctx *iommufd, struct kvm *kvm) + struct iommufd_ctx *iommufd) { int ret; @@ -361,7 +420,6 @@ static int vfio_device_first_open(struct vfio_device *device, if (ret) goto err_module_put; - device->kvm = kvm; if (device->ops->open_device) { ret = device->ops->open_device(device); if (ret) @@ -370,7 +428,6 @@ static int vfio_device_first_open(struct vfio_device *device, return 0; err_unuse_iommu: - device->kvm = NULL; if (iommufd) vfio_iommufd_unbind(device); else @@ -387,7 +444,6 @@ static void vfio_device_last_close(struct vfio_device *device, if (device->ops->close_device) device->ops->close_device(device); - device->kvm = NULL; if (iommufd) vfio_iommufd_unbind(device); else @@ -395,19 +451,18 @@ static void vfio_device_last_close(struct vfio_device *device, module_put(device->dev->driver->owner); } -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) { int ret = 0; - mutex_lock(&device->dev_set->lock); + lockdep_assert_held(&device->dev_set->lock); + device->open_count++; if (device->open_count == 1) { - ret = vfio_device_first_open(device, iommufd, kvm); + ret = vfio_device_first_open(device, iommufd); if (ret) device->open_count--; } - mutex_unlock(&device->dev_set->lock); return ret; } @@ -415,12 +470,12 @@ int vfio_device_open(struct vfio_device *device, void vfio_device_close(struct vfio_device *device, struct iommufd_ctx *iommufd) { - mutex_lock(&device->dev_set->lock); + lockdep_assert_held(&device->dev_set->lock); + vfio_assert_device_open(device); if (device->open_count == 1) vfio_device_last_close(device, iommufd); device->open_count--; - mutex_unlock(&device->dev_set->lock); } /* |