diff options
| -rw-r--r-- | drivers/vfio/vfio.c | 30 | ||||
| -rw-r--r-- | include/linux/vfio.h | 3 | ||||
| -rw-r--r-- | virt/kvm/vfio.c | 16 |
3 files changed, 36 insertions, 13 deletions
diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c index 4805e18f2272..c2a360437e6c 100644 --- a/drivers/vfio/vfio.c +++ b/drivers/vfio/vfio.c @@ -1701,11 +1701,35 @@ struct iommu_group *vfio_file_iommu_group(struct file *file) } EXPORT_SYMBOL_GPL(vfio_file_iommu_group); -long vfio_external_check_extension(struct vfio_group *group, unsigned long arg) +/** + * 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) { - return vfio_ioctl_check_extension(group->container, arg); + struct vfio_group *group = file->private_data; + bool ret; + + if (file->f_op != &vfio_group_fops) + return true; + + /* + * Since the coherency state is determined only once a container is + * attached the user must do so before they can prove they have + * permission. + */ + if (vfio_group_add_container_user(group)) + return true; + ret = vfio_ioctl_check_extension(group->container, VFIO_DMA_CC_IOMMU); + vfio_group_try_dissolve_container(group); + return ret; } -EXPORT_SYMBOL_GPL(vfio_external_check_extension); +EXPORT_SYMBOL_GPL(vfio_file_enforced_coherent); /* * Sub-module support diff --git a/include/linux/vfio.h b/include/linux/vfio.h index df0adecdf1ea..7cc374da4839 100644 --- a/include/linux/vfio.h +++ b/include/linux/vfio.h @@ -139,8 +139,7 @@ int vfio_mig_get_next_state(struct vfio_device *device, extern struct vfio_group *vfio_group_get_external_user(struct file *filep); extern void vfio_group_put_external_user(struct vfio_group *group); extern struct iommu_group *vfio_file_iommu_group(struct file *file); -extern long vfio_external_check_extension(struct vfio_group *group, - unsigned long arg); +extern bool vfio_file_enforced_coherent(struct file *file); #define VFIO_PIN_PAGES_MAX_ENTRIES (PAGE_SIZE/sizeof(unsigned long)) diff --git a/virt/kvm/vfio.c b/virt/kvm/vfio.c index 0b84916c3f71..d44cb3efb0b9 100644 --- a/virt/kvm/vfio.c +++ b/virt/kvm/vfio.c @@ -75,20 +75,20 @@ static void kvm_vfio_group_set_kvm(struct vfio_group *group, struct kvm *kvm) symbol_put(vfio_group_set_kvm); } -static bool kvm_vfio_group_is_coherent(struct vfio_group *vfio_group) +static bool kvm_vfio_file_enforced_coherent(struct file *file) { - long (*fn)(struct vfio_group *, unsigned long); - long ret; + bool (*fn)(struct file *file); + bool ret; - fn = symbol_get(vfio_external_check_extension); + fn = symbol_get(vfio_file_enforced_coherent); if (!fn) return false; - ret = fn(vfio_group, VFIO_DMA_CC_IOMMU); + ret = fn(file); - symbol_put(vfio_external_check_extension); + symbol_put(vfio_file_enforced_coherent); - return ret > 0; + return ret; } #ifdef CONFIG_SPAPR_TCE_IOMMU @@ -136,7 +136,7 @@ static void kvm_vfio_update_coherency(struct kvm_device *dev) mutex_lock(&kv->lock); list_for_each_entry(kvg, &kv->group_list, node) { - if (!kvm_vfio_group_is_coherent(kvg->vfio_group)) { + if (!kvm_vfio_file_enforced_coherent(kvg->file)) { noncoherent = true; break; } |