| Message ID | 20230309075358.571567-4-yi.l.liu@intel.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | iommufd: Add iommu hardware info reporting | expand |
On 2023/3/9 15:53, Yi Liu wrote: > Under nested IOMMU translation, userspace owns the stage-1 translation > table (e.g. the stage-1 page table of Intel VT-d or the context table > of ARM SMMUv3, and etc.). Stage-1 translation tables are vendor specific, > and needs to be compatiable with the underlying IOMMU hardware. Hence, > userspace should know the IOMMU hardware capability before creating and > configuring the stage-1 translation table to kernel. > > This adds IOMMU_DEVICE_GET_HW_INFO to query the IOMMU hardware information > for a given device. The returned data is vendor specific, userspace needs > to decode it with the structure mapped by the @out_data_type field. > > As only physical devices have IOMMU hardware, so this will return error > if the given device is not a physical device. > > Co-developed-by: Nicolin Chen <nicolinc@nvidia.com> > Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> > Signed-off-by: Yi Liu <yi.l.liu@intel.com> > --- > drivers/iommu/iommufd/device.c | 74 +++++++++++++++++++++++++ > drivers/iommu/iommufd/iommufd_private.h | 1 + > drivers/iommu/iommufd/main.c | 3 + > include/uapi/linux/iommufd.h | 40 +++++++++++++ > 4 files changed, 118 insertions(+) > > diff --git a/drivers/iommu/iommufd/device.c b/drivers/iommu/iommufd/device.c > index c10e02f6a0be..6948539488a5 100644 > --- a/drivers/iommu/iommufd/device.c > +++ b/drivers/iommu/iommufd/device.c > @@ -257,6 +257,80 @@ struct iommufd_ctx *iommufd_device_to_ictx(struct iommufd_device *idev) > } > EXPORT_SYMBOL_NS_GPL(iommufd_device_to_ictx, IOMMUFD); > > +static int iommufd_zero_fill_user(u64 ptr, int bytes) > +{ > + int index = 0; > + > + for (; index < bytes; index++) { > + if (put_user(0, (uint8_t __user *)(ptr + index))) > + return -EFAULT; > + } > + return 0; > +} > + > +int iommufd_device_get_hw_info(struct iommufd_ucmd *ucmd) > +{ > + struct iommu_hw_info *cmd = ucmd->cmd; > + struct iommufd_device *idev; > + const struct iommu_ops *ops; > + void *data; > + unsigned int length, data_len; > + int rc; Reverse christmas tree order for declarations. > + > + if (cmd->flags || cmd->__reserved || !cmd->data_len) > + return -EOPNOTSUPP; > + > + idev = iommufd_get_device(ucmd, cmd->dev_id); > + if (IS_ERR(idev)) > + return PTR_ERR(idev); > + > + ops = dev_iommu_ops(idev->dev); > + if (!ops || !ops->hw_info) { dev_iommu_ops() will never return a NULL. Need below check dev->iommu && dev->iommu->iommu_dev before dev_iommu_ops(). Perhaps something like below? if (!dev->iommu || !dev->iommu->iommu_dev) return -EINVAL; ops = dev_iommu_ops(idev->dev); if (!ops->hw_info) return -ENODEV; > + rc = -EOPNOTSUPP; > + goto out_put; > + } > + > + /* driver has hw_info callback should have a unique driver_type */ > + if (WARN_ON(ops->driver_type == IOMMU_HW_INFO_TYPE_DEFAULT)) { If so, perhaps IOMMU_HW_INFO_TYPE_INVALID is more readable? I'm not sure if a calltrace is really necessary here. If not, perhaps, if (ops->driver_type == IOMMU_HW_INFO_TYPE_DEFAULT) { pr_warn_ratelimited("iommu driver set an invalid type\n"); rc = -ENODEV; goto out_put; } > + rc = -EOPNOTSUPP; > + goto out_put; > + } > + > + data = ops->hw_info(idev->dev, &data_len); > + if (IS_ERR(data)) { > + rc = PTR_ERR(data); > + goto out_put; > + } > + > + length = min(cmd->data_len, data_len); > + if (copy_to_user(u64_to_user_ptr(cmd->data_ptr), data, length)) { > + rc = -EFAULT; > + goto out_free_data; > + } > + > + /* > + * Zero the trailing bytes if the user buffer is bigger than the > + * data size kernel actually has. > + */ > + if (length < cmd->data_len) { > + rc = iommufd_zero_fill_user(cmd->data_ptr + length, > + cmd->data_len - length); > + if (rc) > + goto out_free_data; > + } > + > + cmd->out_data_type = ops->driver_type; > + cmd->data_len = length; > + > + rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd)); > + > +out_free_data: > + kfree(data); > +out_put: > + iommufd_put_object(&idev->obj); > + return rc; > +} > + > static int iommufd_group_setup_msi(struct iommufd_group *igroup, > struct iommufd_hw_pagetable *hwpt) > { > diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h > index b18f843ad6a4..05b5ad66f716 100644 > --- a/drivers/iommu/iommufd/iommufd_private.h > +++ b/drivers/iommu/iommufd/iommufd_private.h > @@ -307,6 +307,7 @@ iommufd_get_device(struct iommufd_ucmd *ucmd, u32 id) > } > > void iommufd_device_destroy(struct iommufd_object *obj); > +int iommufd_device_get_hw_info(struct iommufd_ucmd *ucmd); > > struct iommufd_access { > struct iommufd_object obj; > diff --git a/drivers/iommu/iommufd/main.c b/drivers/iommu/iommufd/main.c > index 694da191e4b1..f079c0bda46b 100644 > --- a/drivers/iommu/iommufd/main.c > +++ b/drivers/iommu/iommufd/main.c > @@ -262,6 +262,7 @@ static int iommufd_option(struct iommufd_ucmd *ucmd) > union ucmd_buffer { > struct iommu_destroy destroy; > struct iommu_hwpt_alloc hwpt; > + struct iommu_hw_info info; > struct iommu_ioas_alloc alloc; > struct iommu_ioas_allow_iovas allow_iovas; > struct iommu_ioas_copy ioas_copy; > @@ -295,6 +296,8 @@ static const struct iommufd_ioctl_op iommufd_ioctl_ops[] = { > IOCTL_OP(IOMMU_DESTROY, iommufd_destroy, struct iommu_destroy, id), > IOCTL_OP(IOMMU_HWPT_ALLOC, iommufd_hwpt_alloc, struct iommu_hwpt_alloc, > __reserved), > + IOCTL_OP(IOMMU_DEVICE_GET_HW_INFO, iommufd_device_get_hw_info, > + struct iommu_hw_info, __reserved), > IOCTL_OP(IOMMU_IOAS_ALLOC, iommufd_ioas_alloc_ioctl, > struct iommu_ioas_alloc, out_ioas_id), > IOCTL_OP(IOMMU_IOAS_ALLOW_IOVAS, iommufd_ioas_allow_iovas, > diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h > index 955cbef640da..4ac525897b82 100644 > --- a/include/uapi/linux/iommufd.h > +++ b/include/uapi/linux/iommufd.h > @@ -46,6 +46,7 @@ enum { > IOMMUFD_CMD_OPTION, > IOMMUFD_CMD_VFIO_IOAS, > IOMMUFD_CMD_HWPT_ALLOC, > + IOMMUFD_CMD_DEVICE_GET_HW_INFO, > }; > > /** > @@ -377,4 +378,43 @@ struct iommu_hwpt_alloc { > enum iommu_hw_info_type { > IOMMU_HW_INFO_TYPE_DEFAULT, > }; > + > +/** > + * struct iommu_hw_info - ioctl(IOMMU_DEVICE_GET_HW_INFO) > + * @size: sizeof(struct iommu_hw_info) > + * @flags: Must be 0 > + * @dev_id: The device being attached to the iommufd > + * @data_len: Input the length of the user buffer in bytes. Output the > + * length of data filled to the user buffer. > + * @data_ptr: Pointer to the type specific structure > + * @out_data_type: Output the iommu hardware info type, it is one of > + * enum iommu_hw_info_type. > + * @__reserved: Must be 0 > + * > + * Query the hardware iommu information for given device which has been > + * bound to iommufd. @data_len is the size of the buffer which captures > + * iommu type specific data and the data will be filled. Trailing bytes > + * are zeroed if the user buffer is larger than the data kernel has. > + * > + * The type specific data would be used to sync capability between the > + * vIOMMU and the hardware IOMMU. e.g. nested translation requires to > + * check the hardware IOMMU capability, since a stage-1 translation table > + * is owned by user but used by hardware IOMMU. > + * > + * The @out_data_type will be filled if the ioctl succeeds. It would > + * be used to decode the data filled in the buffer pointed by @data_ptr. > + * > + * This is only available for the physical devices bound to iommufd as > + * only physical devices can have hardware IOMMU. > + */ > +struct iommu_hw_info { > + __u32 size; > + __u32 flags; > + __u32 dev_id; > + __u32 data_len; > + __aligned_u64 data_ptr; > + __u32 out_data_type; > + __u32 __reserved; > +}; > +#define IOMMU_DEVICE_GET_HW_INFO _IO(IOMMUFD_TYPE, IOMMUFD_CMD_DEVICE_GET_HW_INFO) > #endif Other look good to me. Best regards, baolu
On Thu, Mar 09, 2023 at 09:50:18PM +0800, Baolu Lu wrote: > > + if (cmd->flags || cmd->__reserved || !cmd->data_len) > > + return -EOPNOTSUPP; > > + > > + idev = iommufd_get_device(ucmd, cmd->dev_id); > > + if (IS_ERR(idev)) > > + return PTR_ERR(idev); > > + > > + ops = dev_iommu_ops(idev->dev); > > + if (!ops || !ops->hw_info) { > > dev_iommu_ops() will never return a NULL. > > Need below check > > dev->iommu && dev->iommu->iommu_dev > > before dev_iommu_ops(). Perhaps something like below? > > if (!dev->iommu || !dev->iommu->iommu_dev) > return -EINVAL; At this point the device has become owned through the ownership API, it absolutely has to have an iommu and an ops. No need to check anything. Jason
> From: Jason Gunthorpe <jgg@nvidia.com> > Sent: Friday, March 10, 2023 1:21 AM > > On Thu, Mar 09, 2023 at 09:50:18PM +0800, Baolu Lu wrote: > > > > + if (cmd->flags || cmd->__reserved || !cmd->data_len) > > > + return -EOPNOTSUPP; > > > + > > > + idev = iommufd_get_device(ucmd, cmd->dev_id); > > > + if (IS_ERR(idev)) > > > + return PTR_ERR(idev); > > > + > > > + ops = dev_iommu_ops(idev->dev); > > > + if (!ops || !ops->hw_info) { > > > > dev_iommu_ops() will never return a NULL. > > > > Need below check > > > > dev->iommu && dev->iommu->iommu_dev > > > > before dev_iommu_ops(). Perhaps something like below? > > > > if (!dev->iommu || !dev->iommu->iommu_dev) > > return -EINVAL; > > At this point the device has become owned through the ownership API, > it absolutely has to have an iommu and an ops. No need to check > anything. ok. so just needs to check hw_info callback.
> From: Liu, Yi L <yi.l.liu@intel.com> > Sent: Thursday, March 9, 2023 3:54 PM > + > +int iommufd_device_get_hw_info(struct iommufd_ucmd *ucmd) > +{ > + struct iommu_hw_info *cmd = ucmd->cmd; > + struct iommufd_device *idev; > + const struct iommu_ops *ops; > + void *data; > + unsigned int length, data_len; > + int rc; > + > + if (cmd->flags || cmd->__reserved || !cmd->data_len) > + return -EOPNOTSUPP; > + > + idev = iommufd_get_device(ucmd, cmd->dev_id); > + if (IS_ERR(idev)) > + return PTR_ERR(idev); > + > + ops = dev_iommu_ops(idev->dev); > + if (!ops || !ops->hw_info) { > + rc = -EOPNOTSUPP; > + goto out_put; > + } > + > + /* driver has hw_info callback should have a unique driver_type */ > + if (WARN_ON(ops->driver_type == > IOMMU_HW_INFO_TYPE_DEFAULT)) { > + rc = -EOPNOTSUPP; > + goto out_put; > + } ok, here is where the check is done. > + > + data = ops->hw_info(idev->dev, &data_len); if we directly return type in @hw_info, this becomes: data = ops->hw_info(idev->dev, &data_len, &driver_type); > +/** > + * struct iommu_hw_info - ioctl(IOMMU_DEVICE_GET_HW_INFO) > + * @size: sizeof(struct iommu_hw_info) > + * @flags: Must be 0 > + * @dev_id: The device being attached to the iommufd "The device bound to the iommufd" > + * @data_len: Input the length of the user buffer in bytes. Output the > + * length of data filled to the user buffer. s/to/in/ > + * @data_ptr: Pointer to the type specific structure "Pointer to the user buffer" > + * @out_data_type: Output the iommu hardware info type, it is one of > + * enum iommu_hw_info_type. s/it is one of/as defined by/ > + * @__reserved: Must be 0 > + * > + * Query the hardware iommu information for given device which has been > + * bound to iommufd. @data_len is the size of the buffer which captures > + * iommu type specific data and the data will be filled. Trailing bytes > + * are zeroed if the user buffer is larger than the data kernel has. > + * > + * The type specific data would be used to sync capability between the > + * vIOMMU and the hardware IOMMU. e.g. nested translation requires to s/vIOMMU/virtual IOMMU/ > + * check the hardware IOMMU capability, since a stage-1 translation table > + * is owned by user but used by hardware IOMMU. "check ... capability so guest stage-1 page table uses a format compatible to the hardware IOMMU" > + * > + * The @out_data_type will be filled if the ioctl succeeds. It would > + * be used to decode the data filled in the buffer pointed by @data_ptr. > + * > + * This is only available for the physical devices bound to iommufd as > + * only physical devices can have hardware IOMMU. not required. User doesn't know whether it's physical or emulated device.
diff --git a/drivers/iommu/iommufd/device.c b/drivers/iommu/iommufd/device.c index c10e02f6a0be..6948539488a5 100644 --- a/drivers/iommu/iommufd/device.c +++ b/drivers/iommu/iommufd/device.c @@ -257,6 +257,80 @@ struct iommufd_ctx *iommufd_device_to_ictx(struct iommufd_device *idev) } EXPORT_SYMBOL_NS_GPL(iommufd_device_to_ictx, IOMMUFD); +static int iommufd_zero_fill_user(u64 ptr, int bytes) +{ + int index = 0; + + for (; index < bytes; index++) { + if (put_user(0, (uint8_t __user *)(ptr + index))) + return -EFAULT; + } + return 0; +} + +int iommufd_device_get_hw_info(struct iommufd_ucmd *ucmd) +{ + struct iommu_hw_info *cmd = ucmd->cmd; + struct iommufd_device *idev; + const struct iommu_ops *ops; + void *data; + unsigned int length, data_len; + int rc; + + if (cmd->flags || cmd->__reserved || !cmd->data_len) + return -EOPNOTSUPP; + + idev = iommufd_get_device(ucmd, cmd->dev_id); + if (IS_ERR(idev)) + return PTR_ERR(idev); + + ops = dev_iommu_ops(idev->dev); + if (!ops || !ops->hw_info) { + rc = -EOPNOTSUPP; + goto out_put; + } + + /* driver has hw_info callback should have a unique driver_type */ + if (WARN_ON(ops->driver_type == IOMMU_HW_INFO_TYPE_DEFAULT)) { + rc = -EOPNOTSUPP; + goto out_put; + } + + data = ops->hw_info(idev->dev, &data_len); + if (IS_ERR(data)) { + rc = PTR_ERR(data); + goto out_put; + } + + length = min(cmd->data_len, data_len); + if (copy_to_user(u64_to_user_ptr(cmd->data_ptr), data, length)) { + rc = -EFAULT; + goto out_free_data; + } + + /* + * Zero the trailing bytes if the user buffer is bigger than the + * data size kernel actually has. + */ + if (length < cmd->data_len) { + rc = iommufd_zero_fill_user(cmd->data_ptr + length, + cmd->data_len - length); + if (rc) + goto out_free_data; + } + + cmd->out_data_type = ops->driver_type; + cmd->data_len = length; + + rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd)); + +out_free_data: + kfree(data); +out_put: + iommufd_put_object(&idev->obj); + return rc; +} + static int iommufd_group_setup_msi(struct iommufd_group *igroup, struct iommufd_hw_pagetable *hwpt) { diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h index b18f843ad6a4..05b5ad66f716 100644 --- a/drivers/iommu/iommufd/iommufd_private.h +++ b/drivers/iommu/iommufd/iommufd_private.h @@ -307,6 +307,7 @@ iommufd_get_device(struct iommufd_ucmd *ucmd, u32 id) } void iommufd_device_destroy(struct iommufd_object *obj); +int iommufd_device_get_hw_info(struct iommufd_ucmd *ucmd); struct iommufd_access { struct iommufd_object obj; diff --git a/drivers/iommu/iommufd/main.c b/drivers/iommu/iommufd/main.c index 694da191e4b1..f079c0bda46b 100644 --- a/drivers/iommu/iommufd/main.c +++ b/drivers/iommu/iommufd/main.c @@ -262,6 +262,7 @@ static int iommufd_option(struct iommufd_ucmd *ucmd) union ucmd_buffer { struct iommu_destroy destroy; struct iommu_hwpt_alloc hwpt; + struct iommu_hw_info info; struct iommu_ioas_alloc alloc; struct iommu_ioas_allow_iovas allow_iovas; struct iommu_ioas_copy ioas_copy; @@ -295,6 +296,8 @@ static const struct iommufd_ioctl_op iommufd_ioctl_ops[] = { IOCTL_OP(IOMMU_DESTROY, iommufd_destroy, struct iommu_destroy, id), IOCTL_OP(IOMMU_HWPT_ALLOC, iommufd_hwpt_alloc, struct iommu_hwpt_alloc, __reserved), + IOCTL_OP(IOMMU_DEVICE_GET_HW_INFO, iommufd_device_get_hw_info, + struct iommu_hw_info, __reserved), IOCTL_OP(IOMMU_IOAS_ALLOC, iommufd_ioas_alloc_ioctl, struct iommu_ioas_alloc, out_ioas_id), IOCTL_OP(IOMMU_IOAS_ALLOW_IOVAS, iommufd_ioas_allow_iovas, diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h index 955cbef640da..4ac525897b82 100644 --- a/include/uapi/linux/iommufd.h +++ b/include/uapi/linux/iommufd.h @@ -46,6 +46,7 @@ enum { IOMMUFD_CMD_OPTION, IOMMUFD_CMD_VFIO_IOAS, IOMMUFD_CMD_HWPT_ALLOC, + IOMMUFD_CMD_DEVICE_GET_HW_INFO, }; /** @@ -377,4 +378,43 @@ struct iommu_hwpt_alloc { enum iommu_hw_info_type { IOMMU_HW_INFO_TYPE_DEFAULT, }; + +/** + * struct iommu_hw_info - ioctl(IOMMU_DEVICE_GET_HW_INFO) + * @size: sizeof(struct iommu_hw_info) + * @flags: Must be 0 + * @dev_id: The device being attached to the iommufd + * @data_len: Input the length of the user buffer in bytes. Output the + * length of data filled to the user buffer. + * @data_ptr: Pointer to the type specific structure + * @out_data_type: Output the iommu hardware info type, it is one of + * enum iommu_hw_info_type. + * @__reserved: Must be 0 + * + * Query the hardware iommu information for given device which has been + * bound to iommufd. @data_len is the size of the buffer which captures + * iommu type specific data and the data will be filled. Trailing bytes + * are zeroed if the user buffer is larger than the data kernel has. + * + * The type specific data would be used to sync capability between the + * vIOMMU and the hardware IOMMU. e.g. nested translation requires to + * check the hardware IOMMU capability, since a stage-1 translation table + * is owned by user but used by hardware IOMMU. + * + * The @out_data_type will be filled if the ioctl succeeds. It would + * be used to decode the data filled in the buffer pointed by @data_ptr. + * + * This is only available for the physical devices bound to iommufd as + * only physical devices can have hardware IOMMU. + */ +struct iommu_hw_info { + __u32 size; + __u32 flags; + __u32 dev_id; + __u32 data_len; + __aligned_u64 data_ptr; + __u32 out_data_type; + __u32 __reserved; +}; +#define IOMMU_DEVICE_GET_HW_INFO _IO(IOMMUFD_TYPE, IOMMUFD_CMD_DEVICE_GET_HW_INFO) #endif