dev_iommu_ops() is essentially only used in iommu subsystem, so move to a private header to avoid being abused by other drivers.

Suggested-by: Jason Gunthorpe jgg@nvidia.com Reviewed-by: Kevin Tian kevin.tian@intel.com Reviewed-by: Lu Baolu baolu.lu@linux.intel.com Reviewed-by: Jason Gunthorpe jgg@nvidia.com Signed-off-by: Yi Liu yi.l.liu@intel.com --- drivers/iommu/iommu-priv.h | 11 +++++++++++ include/linux/iommu.h | 11 ----------- 2 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/drivers/iommu/iommu-priv.h b/drivers/iommu/iommu-priv.h index 7c8011bfd153..a6e694f59f64 100644 --- a/drivers/iommu/iommu-priv.h +++ b/drivers/iommu/iommu-priv.h @@ -4,6 +4,17 @@

#include <linux/iommu.h>

+static inline const struct iommu_ops *dev_iommu_ops(struct device *dev) +{ + /* + * Assume that valid ops must be installed if iommu_probe_device() + * has succeeded. The device ops are essentially for internal use + * within the IOMMU subsystem itself, so we should be able to trust + * ourselves not to misuse the helper. + */ + return dev->iommu->iommu_dev->ops; +} + int iommu_group_replace_domain(struct iommu_group *group, struct iommu_domain *new_domain);

diff --git a/include/linux/iommu.h b/include/linux/iommu.h index d31642596675..e0245aa82b75 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -450,17 +450,6 @@ static inline void iommu_iotlb_gather_init(struct iommu_iotlb_gather *gather) }; }

-static inline const struct iommu_ops *dev_iommu_ops(struct device *dev) -{ - /* - * Assume that valid ops must be installed if iommu_probe_device() - * has succeeded. The device ops are essentially for internal use - * within the IOMMU subsystem itself, so we should be able to trust - * ourselves not to misuse the helper. - */ - return dev->iommu->iommu_dev->ops; -} - extern int bus_iommu_probe(const struct bus_type *bus); extern bool iommu_present(const struct bus_type *bus); extern bool device_iommu_capable(struct device *dev, enum iommu_cap cap);

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 need to be compatible 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_GET_HW_INFO ioctl to query the IOMMU hardware information (a.k.a capability) 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.

Reviewed-by: Lu Baolu baolu.lu@linux.intel.com 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/main.c | 97 ++++++++++++++++++++++++++++++++++++ include/uapi/linux/iommufd.h | 36 +++++++++++++ 2 files changed, 133 insertions(+)

diff --git a/drivers/iommu/iommufd/main.c b/drivers/iommu/iommufd/main.c index 94c498b8fdf6..54e61fbf56f8 100644 --- a/drivers/iommu/iommufd/main.c +++ b/drivers/iommu/iommufd/main.c @@ -17,6 +17,7 @@ #include <linux/bug.h> #include <uapi/linux/iommufd.h> #include <linux/iommufd.h> +#include "../iommu-priv.h"

#include "io_pagetable.h" #include "iommufd_private.h" @@ -177,6 +178,99 @@ static int iommufd_destroy(struct iommufd_ucmd *ucmd) return 0; }

+static int iommufd_zero_fill_user(void __user *ptr, size_t bytes) +{ + int index = 0; + + for (; index < bytes; index++) { + if (put_user(0, (uint8_t __user *)(ptr + index))) + return -EFAULT; + } + return 0; +} + +static int iommufd_fill_hw_info(struct device *dev, void __user *user_ptr, + unsigned int *length, u32 *type) +{ + const struct iommu_ops *ops; + unsigned int data_len; + void *data; + int rc = 0; + + ops = dev_iommu_ops(dev); + if (!ops->hw_info) { + *length = 0; + *type = IOMMU_HW_INFO_TYPE_NONE; + return 0; + } + + data = ops->hw_info(dev, &data_len, type); + if (IS_ERR(data)) + return PTR_ERR(data); + + /* + * drivers that have hw_info callback should have a unique + * iommu_hw_info_type. + */ + if (WARN_ON_ONCE(*type == IOMMU_HW_INFO_TYPE_NONE)) { + rc = -ENODEV; + goto err_free; + } + + *length = min(*length, data_len); + if (copy_to_user(user_ptr, data, *length)) { + rc = -EFAULT; + goto err_free; + } + +err_free: + kfree(data); + return rc; +} + +static int iommufd_get_hw_info(struct iommufd_ucmd *ucmd) +{ + struct iommu_hw_info *cmd = ucmd->cmd; + unsigned int length = cmd->data_len; + struct iommufd_device *idev; + void __user *user_ptr; + u32 hw_info_type; + int rc = 0; + + 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); + + user_ptr = u64_to_user_ptr(cmd->data_ptr); + + rc = iommufd_fill_hw_info(idev->dev, user_ptr, + &length, &hw_info_type); + if (rc) + goto err_put; + + /* + * 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(user_ptr + length, + cmd->data_len - length); + if (rc) + goto err_put; + } + + cmd->data_len = length; + cmd->out_data_type = hw_info_type; + rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd)); + +err_put: + iommufd_put_object(&idev->obj); + return rc; +} + static int iommufd_fops_open(struct inode *inode, struct file *filp) { struct iommufd_ctx *ictx; @@ -265,6 +359,7 @@ static int iommufd_option(struct iommufd_ucmd *ucmd)

union ucmd_buffer { struct iommu_destroy destroy; + struct iommu_hw_info info; struct iommu_hwpt_alloc hwpt; struct iommu_ioas_alloc alloc; struct iommu_ioas_allow_iovas allow_iovas; @@ -297,6 +392,8 @@ struct iommufd_ioctl_op { } static const struct iommufd_ioctl_op iommufd_ioctl_ops[] = { IOCTL_OP(IOMMU_DESTROY, iommufd_destroy, struct iommu_destroy, id), + IOCTL_OP(IOMMU_GET_HW_INFO, iommufd_get_hw_info, struct iommu_hw_info, + __reserved), IOCTL_OP(IOMMU_HWPT_ALLOC, iommufd_hwpt_alloc, struct iommu_hwpt_alloc, __reserved), IOCTL_OP(IOMMU_IOAS_ALLOC, iommufd_ioas_alloc_ioctl, diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h index ac11ace21edb..4a00f8fb2d54 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_GET_HW_INFO, };

/** @@ -379,4 +380,39 @@ struct iommu_hwpt_alloc { enum iommu_hw_info_type { IOMMU_HW_INFO_TYPE_NONE, }; + +/** + * struct iommu_hw_info - ioctl(IOMMU_GET_HW_INFO) + * @size: sizeof(struct iommu_hw_info) + * @flags: Must be 0 + * @dev_id: The device bound to the iommufd + * @data_len: Input the length of the user buffer in bytes. Output the length + * of data filled in the user buffer. + * @data_ptr: Pointer to the user buffer + * @out_data_type: Output the iommu hardware info type as defined in the enum + * iommu_hw_info_type. + * @__reserved: Must be 0 + * + * Query the hardware information from an iommu behind a given device that has + * been bound to iommufd. @data_len is the size of the buffer, which captures an + * iommu type specific input data and a filled output data. Trailing bytes will + * be zeroed if the user buffer is larger than the data kernel has. + * + * The type specific data would be used to sync capabilities between the virtual + * IOMMU and the hardware IOMMU, e.g. a nested translation setup needs to check + * the hardware information, so the guest stage-1 page table will be compatible. + * + * 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. + */ +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_GET_HW_INFO _IO(IOMMUFD_TYPE, IOMMUFD_CMD_GET_HW_INFO) #endif

From: Nicolin Chen nicolinc@nvidia.com

Add a mock_domain_hw_info function and an iommu_test_hw_info data structure. This allows to test the IOMMU_GET_HW_INFO ioctl passing the test_reg value for the mock_dev.

Signed-off-by: Nicolin Chen nicolinc@nvidia.com Signed-off-by: Yi Liu yi.l.liu@intel.com --- drivers/iommu/iommufd/iommufd_test.h | 9 +++++++ drivers/iommu/iommufd/selftest.c | 16 ++++++++++++ tools/testing/selftests/iommu/iommufd.c | 17 +++++++++++- tools/testing/selftests/iommu/iommufd_utils.h | 26 +++++++++++++++++++ 4 files changed, 67 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/iommufd/iommufd_test.h b/drivers/iommu/iommufd/iommufd_test.h index 258de2253b61..3f3644375bf1 100644 --- a/drivers/iommu/iommufd/iommufd_test.h +++ b/drivers/iommu/iommufd/iommufd_test.h @@ -100,4 +100,13 @@ struct iommu_test_cmd { }; #define IOMMU_TEST_CMD _IO(IOMMUFD_TYPE, IOMMUFD_CMD_BASE + 32)

+/* Mock structs for IOMMU_DEVICE_GET_HW_INFO ioctl */ +#define IOMMU_HW_INFO_TYPE_SELFTEST 0xfeedbeef +#define IOMMU_HW_INFO_SELFTEST_REGVAL 0xdeadbeef + +struct iommu_test_hw_info { + __u32 flags; + __u32 test_reg; +}; + #endif diff --git a/drivers/iommu/iommufd/selftest.c b/drivers/iommu/iommufd/selftest.c index bb2cd54ca7b6..ab4011e3a7c6 100644 --- a/drivers/iommu/iommufd/selftest.c +++ b/drivers/iommu/iommufd/selftest.c @@ -128,6 +128,21 @@ static struct iommu_domain mock_blocking_domain = { .ops = &mock_blocking_ops, };

+static void *mock_domain_hw_info(struct device *dev, u32 *length, u32 *type) +{ + struct iommu_test_hw_info *info; + + info = kzalloc(sizeof(*info), GFP_KERNEL); + if (!info) + return ERR_PTR(-ENOMEM); + + info->test_reg = IOMMU_HW_INFO_SELFTEST_REGVAL; + *length = sizeof(*info); + *type = IOMMU_HW_INFO_TYPE_SELFTEST; + + return info; +} + static struct iommu_domain *mock_domain_alloc(unsigned int iommu_domain_type) { struct mock_iommu_domain *mock; @@ -279,6 +294,7 @@ static void mock_domain_set_plaform_dma_ops(struct device *dev) static const struct iommu_ops mock_ops = { .owner = THIS_MODULE, .pgsize_bitmap = MOCK_IO_PAGE_SIZE, + .hw_info = mock_domain_hw_info, .domain_alloc = mock_domain_alloc, .capable = mock_domain_capable, .set_platform_dma_ops = mock_domain_set_plaform_dma_ops, diff --git a/tools/testing/selftests/iommu/iommufd.c b/tools/testing/selftests/iommu/iommufd.c index 8acd0af37aa5..6b075a68b928 100644 --- a/tools/testing/selftests/iommu/iommufd.c +++ b/tools/testing/selftests/iommu/iommufd.c @@ -113,6 +113,7 @@ TEST_F(iommufd, cmd_length) }

TEST_LENGTH(iommu_destroy, IOMMU_DESTROY); + TEST_LENGTH(iommu_hw_info, IOMMU_GET_HW_INFO); TEST_LENGTH(iommu_ioas_alloc, IOMMU_IOAS_ALLOC); TEST_LENGTH(iommu_ioas_iova_ranges, IOMMU_IOAS_IOVA_RANGES); TEST_LENGTH(iommu_ioas_allow_iovas, IOMMU_IOAS_ALLOW_IOVAS); @@ -185,6 +186,7 @@ FIXTURE(iommufd_ioas) uint32_t ioas_id; uint32_t stdev_id; uint32_t hwpt_id; + uint32_t device_id; uint64_t base_iova; };

@@ -211,7 +213,7 @@ FIXTURE_SETUP(iommufd_ioas)

for (i = 0; i != variant->mock_domains; i++) { test_cmd_mock_domain(self->ioas_id, &self->stdev_id, - &self->hwpt_id, NULL); + &self->hwpt_id, &self->device_id); self->base_iova = MOCK_APERTURE_START; } } @@ -290,6 +292,19 @@ TEST_F(iommufd_ioas, ioas_area_auto_destroy) } }

+TEST_F(iommufd_ioas, get_hw_info) +{ + struct iommu_test_hw_info info; + + if (self->device_id) { + test_cmd_get_hw_info(self->device_id, sizeof(info), &info); + assert(info.test_reg == IOMMU_HW_INFO_SELFTEST_REGVAL); + } else { + test_err_get_hw_info(ENOENT, self->device_id, + sizeof(info), &info); + } +} + TEST_F(iommufd_ioas, area) { int i; diff --git a/tools/testing/selftests/iommu/iommufd_utils.h b/tools/testing/selftests/iommu/iommufd_utils.h index 70353e68e599..d6d223435881 100644 --- a/tools/testing/selftests/iommu/iommufd_utils.h +++ b/tools/testing/selftests/iommu/iommufd_utils.h @@ -348,3 +348,29 @@ static void teardown_iommufd(int fd, struct __test_metadata *_metadata) })

#endif + +static int _test_cmd_get_hw_info(int fd, __u32 device_id, + void *data, size_t data_len) +{ + struct iommu_hw_info cmd = { + .size = sizeof(cmd), + .dev_id = device_id, + .data_len = data_len, + .data_ptr = (uint64_t)data, + }; + int ret; + + ret = ioctl(fd, IOMMU_GET_HW_INFO, &cmd); + if (ret) + return ret; + return 0; +} + +#define test_cmd_get_hw_info(device_id, data_len, data) \ + ASSERT_EQ(0, _test_cmd_get_hw_info(self->fd, device_id, \ + data, data_len)) + +#define test_err_get_hw_info(_errno, device_id, data_len, data) \ + EXPECT_ERRNO(_errno, \ + _test_cmd_get_hw_info(self->fd, device_id, \ + data, data_len))