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 e3e3b2015854..2024a2313348 100644 --- a/drivers/iommu/iommu-priv.h +++ b/drivers/iommu/iommu-priv.h @@ -6,6 +6,17 @@

#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 by the output @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/device.c | 73 +++++++++++++++++++++++++ drivers/iommu/iommufd/iommufd_private.h | 1 + drivers/iommu/iommufd/main.c | 3 + include/uapi/linux/iommufd.h | 42 ++++++++++++++ 4 files changed, 119 insertions(+)

diff --git a/drivers/iommu/iommufd/device.c b/drivers/iommu/iommufd/device.c index 90f88c295ce0..36dff7ca3ae4 100644 --- a/drivers/iommu/iommufd/device.c +++ b/drivers/iommu/iommufd/device.c @@ -4,6 +4,7 @@ #include <linux/iommufd.h> #include <linux/slab.h> #include <linux/iommu.h> +#include <uapi/linux/iommufd.h> #include "../iommu-priv.h"

#include "io_pagetable.h" @@ -1119,3 +1120,75 @@ int iommufd_access_rw(struct iommufd_access *access, unsigned long iova, return rc; } EXPORT_SYMBOL_NS_GPL(iommufd_access_rw, IOMMUFD); + +int iommufd_get_hw_info(struct iommufd_ucmd *ucmd) +{ + struct iommu_hw_info *cmd = ucmd->cmd; + void __user *user_ptr = u64_to_user_ptr(cmd->data_uptr); + const struct iommu_ops *ops; + struct iommufd_device *idev; + unsigned int data_len; + unsigned int copy_len; + void *data = NULL; + int rc; + + if (cmd->flags || cmd->__reserved) + 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->hw_info) { + data = ops->hw_info(idev->dev, &data_len, &cmd->out_data_type); + if (IS_ERR(data)) { + rc = PTR_ERR(data); + goto err_put; + } + + /* + * drivers that have hw_info callback should have a unique + * iommu_hw_info_type. + */ + if (WARN_ON_ONCE(cmd->out_data_type == + IOMMU_HW_INFO_TYPE_NONE)) { + rc = -ENODEV; + goto out; + } + } else { + cmd->out_data_type = IOMMU_HW_INFO_TYPE_NONE; + data_len = 0; + data = NULL; + } + + copy_len = min(cmd->data_len, data_len); + if (copy_to_user(user_ptr, data, copy_len)) { + rc = -EFAULT; + goto out; + } + + /* + * Zero the trailing bytes if the user buffer is bigger than the + * data size kernel actually has. + */ + if (copy_len < cmd->data_len) { + if (clear_user(user_ptr + copy_len, cmd->data_len - copy_len)) { + rc = -EFAULT; + goto out; + } + } + + /* + * We return the length the kernel supports so userspace may know what + * the kernel capability is. It could be larger than the input buffer. + */ + cmd->data_len = data_len; + + rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd)); +out: + kfree(data); +err_put: + iommufd_put_object(&idev->obj); + return rc; +} diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h index 5a45b8ba2e26..2c58670011fe 100644 --- a/drivers/iommu/iommufd/iommufd_private.h +++ b/drivers/iommu/iommufd/iommufd_private.h @@ -296,6 +296,7 @@ iommufd_get_device(struct iommufd_ucmd *ucmd, u32 id) }

void iommufd_device_destroy(struct iommufd_object *obj); +int iommufd_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 5f7e9fa45502..e71523cbd0de 100644 --- a/drivers/iommu/iommufd/main.c +++ b/drivers/iommu/iommufd/main.c @@ -305,6 +305,7 @@ 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; @@ -337,6 +338,8 @@ 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..09d5e9cff7b3 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 +380,45 @@ 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 a user buffer in bytes. Output the length of + * data that kernel supports + * @data_uptr: User pointer to a user-space buffer used by the kernel to fill + * the iommu type specific hardware information data + * @out_data_type: Output the iommu hardware info type as defined in the enum + * iommu_hw_info_type. + * @__reserved: Must be 0 + * + * Query an iommu type specific hardware information data from an iommu behind + * a given device that has been bound to iommufd. This hardware info data will + * be used to sync capabilities between the virtual iommu and the physical + * iommu, e.g. a nested translation setup needs to check the hardware info, so + * a guest stage-1 page table can be compatible with the physical iommu. + * + * To capture an iommu type specific hardware information data, @data_uptr and + * its length @data_len must be provided. Trailing bytes will be zeroed if the + * user buffer is larger than the data that kernel has. Otherwise, kernel only + * fills the buffer using the given length in @data_len. If the ioctl succeeds, + * @data_len will be updated to the length that kernel actually supports, + * @out_data_type will be filled to decode the data filled in the buffer + * pointed by @data_uptr. Input @data_len == zero is allowed, no information + * data will be filled to user, but user space could get the iommu_hw_info_type + * filled in @out_data_type and the iommu hardware information data length + * supported by kernel filled in @data_len. + */ +struct iommu_hw_info { + __u32 size; + __u32 flags; + __u32 dev_id; + __u32 data_len; + __aligned_u64 data_uptr; + __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 | 30 +++++++++- .../selftests/iommu/iommufd_fail_nth.c | 4 ++ tools/testing/selftests/iommu/iommufd_utils.h | 56 +++++++++++++++++++ 5 files changed, 114 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 9223ff3f23f9..90e7c5400282 100644 --- a/drivers/iommu/iommufd/selftest.c +++ b/drivers/iommu/iommufd/selftest.c @@ -131,6 +131,21 @@ 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; @@ -290,6 +305,7 @@ static struct iommu_device *mock_probe_device(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..a068bfbe9f83 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 +292,32 @@ TEST_F(iommufd_ioas, ioas_area_auto_destroy) } }

+TEST_F(iommufd_ioas, get_hw_info) +{ + struct iommu_test_hw_info buffer_exact; + struct iommu_test_hw_info_buffer { + struct iommu_test_hw_info info; + uint64_t trailing_bytes; + } buffer_larger; + + if (self->device_id) { + /* Provide a zero-size user_buffer */ + test_cmd_get_hw_info(self->device_id, NULL, 0); + /* Provide a user_buffer with exact size */ + test_cmd_get_hw_info(self->device_id, &buffer_exact, sizeof(buffer_exact)); + /* + * Provide a user_buffer with size larger than the exact size to check if + * kernel zero the trailing bytes. + */ + test_cmd_get_hw_info(self->device_id, &buffer_larger, sizeof(buffer_larger)); + } else { + test_err_get_hw_info(ENOENT, self->device_id, + &buffer_exact, sizeof(buffer_exact)); + test_err_get_hw_info(ENOENT, self->device_id, + &buffer_larger, sizeof(buffer_larger)); + } +} + TEST_F(iommufd_ioas, area) { int i; diff --git a/tools/testing/selftests/iommu/iommufd_fail_nth.c b/tools/testing/selftests/iommu/iommufd_fail_nth.c index d4c552e56948..a220ca2a689d 100644 --- a/tools/testing/selftests/iommu/iommufd_fail_nth.c +++ b/tools/testing/selftests/iommu/iommufd_fail_nth.c @@ -576,6 +576,7 @@ TEST_FAIL_NTH(basic_fail_nth, access_pin_domain) /* device.c */ TEST_FAIL_NTH(basic_fail_nth, device) { + struct iommu_test_hw_info info; uint32_t ioas_id; uint32_t ioas_id2; uint32_t stdev_id; @@ -611,6 +612,9 @@ TEST_FAIL_NTH(basic_fail_nth, device) &idev_id)) return -1;

+ if (_test_cmd_get_hw_info(self->fd, idev_id, &info, sizeof(info))) + return -1; + if (_test_cmd_hwpt_alloc(self->fd, idev_id, ioas_id, &hwpt_id)) return -1;

diff --git a/tools/testing/selftests/iommu/iommufd_utils.h b/tools/testing/selftests/iommu/iommufd_utils.h index 70353e68e599..097418f2fdb3 100644 --- a/tools/testing/selftests/iommu/iommufd_utils.h +++ b/tools/testing/selftests/iommu/iommufd_utils.h @@ -348,3 +348,59 @@ static void teardown_iommufd(int fd, struct __test_metadata *_metadata) })

#endif + +/* @data can be NULL */ +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_uptr = (uint64_t)data, + }; + struct iommu_test_hw_info *info = (struct iommu_test_hw_info *)data; + int ret; + + ret = ioctl(fd, IOMMU_GET_HW_INFO, &cmd); + if (ret) + return ret; + + assert(cmd.out_data_type == IOMMU_HW_INFO_TYPE_SELFTEST); + + /* + * The struct iommu_test_hw_info should be the one defined + * by the current kernel. + */ + assert(cmd.data_len == sizeof(struct iommu_test_hw_info)); + + /* + * Trailing bytes should be 0 if user buffer is larger than + * the data that kernel reports. + */ + if (data_len > cmd.data_len) { + char *ptr = (char *)(data + cmd.data_len); + int idx = 0; + + while (idx < data_len - cmd.data_len) { + assert(!*(ptr + idx)); + idx++; + } + } + + if (info) { + assert(info->test_reg == IOMMU_HW_INFO_SELFTEST_REGVAL); + assert(!info->flags); + } + + return 0; +} + +#define test_cmd_get_hw_info(device_id, data, data_len) \ + 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, data_len) \ + EXPECT_ERRNO(_errno, \ + _test_cmd_get_hw_info(self->fd, device_id, \ + data, data_len))