[RFC PATCH 1/3] vfio: selftests: Add support of creating iommus from iommufd
COOLING10d
From: Samiullah Khawaja <hidden>
Date: 2026-09-25 01:13:27
Also in:
linux-iommu, lkml
Subsystem:
kernel selftest framework, the rest, vfio driver, vfio selftests · Maintainers:
Shuah Khan, Shuah Khan, Linus Torvalds, Alex Williamson, David Matlack
Add API to init a struct iommu using an already opened iommufd instance and attach devices to it. Signed-off-by: Samiullah Khawaja <redacted> --- .../vfio/lib/include/libvfio/iommu.h | 2 + .../lib/include/libvfio/vfio_pci_device.h | 2 + tools/testing/selftests/vfio/lib/iommu.c | 60 +++++++++++++++++-- .../selftests/vfio/lib/vfio_pci_device.c | 25 ++++++-- 4 files changed, 80 insertions(+), 9 deletions(-)
diff --git a/tools/testing/selftests/vfio/lib/include/libvfio/iommu.h b/tools/testing/selftests/vfio/lib/include/libvfio/iommu.h
index e9a3386a4719..62f1e8affd2b 100644
--- a/tools/testing/selftests/vfio/lib/include/libvfio/iommu.h
+++ b/tools/testing/selftests/vfio/lib/include/libvfio/iommu.h@@ -29,10 +29,12 @@ struct iommu { int container_fd; int iommufd; u32 ioas_id; + u32 hwpt_id; struct list_head dma_regions; }; struct iommu *iommu_init(const char *iommu_mode); +struct iommu *iommufd_iommu_init(int iommufd, u32 dev_id); void iommu_cleanup(struct iommu *iommu); int __iommu_map(struct iommu *iommu, struct dma_region *region);
diff --git a/tools/testing/selftests/vfio/lib/include/libvfio/vfio_pci_device.h b/tools/testing/selftests/vfio/lib/include/libvfio/vfio_pci_device.h
index e19bd94b8dd2..4dcc23bc9b78 100644
--- a/tools/testing/selftests/vfio/lib/include/libvfio/vfio_pci_device.h
+++ b/tools/testing/selftests/vfio/lib/include/libvfio/vfio_pci_device.h@@ -19,6 +19,7 @@ struct vfio_pci_device { const char *bdf; int fd; int group_fd; + u32 dev_id; struct iommu *iommu;
@@ -82,6 +83,7 @@ static inline void vfio_pci_cmd_clear(struct vfio_pci_device *device, u16 bits) vfio_pci_config_writew(device, PCI_COMMAND, cmd & ~bits); } +void vfio_pci_device_attach_iommu(struct vfio_pci_device *device, struct iommu *iommu); void vfio_pci_irq_enable(struct vfio_pci_device *device, u32 index, u32 vector, int count); void vfio_pci_irq_disable(struct vfio_pci_device *device, u32 index);
diff --git a/tools/testing/selftests/vfio/lib/iommu.c b/tools/testing/selftests/vfio/lib/iommu.c
index b6f3c5c84e01..6d2d5c82813c 100644
--- a/tools/testing/selftests/vfio/lib/iommu.c
+++ b/tools/testing/selftests/vfio/lib/iommu.c@@ -405,6 +405,18 @@ struct iommu_iova_range *iommu_iova_ranges(struct iommu *iommu, u32 *nranges) return ranges; } +static u32 iommufd_hwpt_alloc(struct iommu *iommu, u32 dev_id) +{ + struct iommu_hwpt_alloc args = { + .size = sizeof(args), + .pt_id = iommu->ioas_id, + .dev_id = dev_id, + }; + + ioctl_assert(iommu->iommufd, IOMMU_HWPT_ALLOC, &args); + return args.out_hwpt_id; +} + static u32 iommufd_ioas_alloc(int iommufd) { struct iommu_ioas_alloc args = {
@@ -415,17 +427,25 @@ static u32 iommufd_ioas_alloc(int iommufd) return args.out_ioas_id; } -struct iommu *iommu_init(const char *iommu_mode) +static struct iommu *iommu_alloc(const char *iommu_mode) { - const char *container_path; struct iommu *iommu; - int version; iommu = calloc_assert(1, sizeof(*iommu)); INIT_LIST_HEAD(&iommu->dma_regions); iommu->mode = lookup_iommu_mode(iommu_mode); + return iommu; +} + +struct iommu *iommu_init(const char *iommu_mode) +{ + const char *container_path; + struct iommu *iommu; + int version; + + iommu = iommu_alloc(iommu_mode); container_path = iommu->mode->container_path; if (container_path) {
@@ -449,10 +469,42 @@ struct iommu *iommu_init(const char *iommu_mode) return iommu; } +struct iommu *iommufd_iommu_init(int iommufd, u32 dev_id) +{ + struct iommu *iommu; + + iommu = iommu_alloc("iommufd"); + + iommu->iommufd = dup(iommufd); + VFIO_ASSERT_GT(iommu->iommufd, 0); + + iommu->ioas_id = iommufd_ioas_alloc(iommu->iommufd); + iommu->hwpt_id = iommufd_hwpt_alloc(iommu, dev_id); + + return iommu; +} + +static void iommufd_cleanup(struct iommu *iommu) +{ + struct iommu_destroy args = { + .size = sizeof(args), + }; + + if (iommu->hwpt_id) { + args.id = iommu->hwpt_id; + ioctl_assert(iommu->iommufd, IOMMU_DESTROY, &args); + } + + args.id = iommu->ioas_id; + ioctl_assert(iommu->iommufd, IOMMU_DESTROY, &args); + + VFIO_ASSERT_EQ(close(iommu->iommufd), 0); +} + void iommu_cleanup(struct iommu *iommu) { if (iommu->iommufd) - VFIO_ASSERT_EQ(close(iommu->iommufd), 0); + iommufd_cleanup(iommu); else VFIO_ASSERT_EQ(close(iommu->container_fd), 0);
diff --git a/tools/testing/selftests/vfio/lib/vfio_pci_device.c b/tools/testing/selftests/vfio/lib/vfio_pci_device.c
index 774d1e90ec0e..81d3879d064f 100644
--- a/tools/testing/selftests/vfio/lib/vfio_pci_device.c
+++ b/tools/testing/selftests/vfio/lib/vfio_pci_device.c@@ -469,15 +469,15 @@ int __vfio_device_bind_iommufd(int device_fd, int iommufd, const char *vf_token) if (ioctl(device_fd, VFIO_DEVICE_BIND_IOMMUFD, &args)) return -errno; - return 0; + return args.out_devid; } -static void vfio_device_bind_iommufd(int device_fd, int iommufd, - const char *vf_token) +int vfio_device_bind_iommufd(int device_fd, int iommufd, const char *vf_token) { int ret = __vfio_device_bind_iommufd(device_fd, iommufd, vf_token); - VFIO_ASSERT_EQ(ret, 0, "Failed VFIO_DEVICE_BIND_IOMMUFD ioctl\n"); + VFIO_ASSERT_GE(ret, 0, "Failed VFIO_DEVICE_BIND_IOMMUFD ioctl\n"); + return ret; } static void vfio_device_attach_iommufd_pt(int device_fd, u32 pt_id)
@@ -503,10 +503,25 @@ static void vfio_pci_iommufd_setup(struct vfio_pci_device *device, const char *bdf, const char *vf_token) { vfio_pci_cdev_open(device, bdf); - vfio_device_bind_iommufd(device->fd, device->iommu->iommufd, vf_token); + device->dev_id = vfio_device_bind_iommufd(device->fd, device->iommu->iommufd, vf_token); vfio_device_attach_iommufd_pt(device->fd, device->iommu->ioas_id); } +void vfio_pci_device_attach_iommu(struct vfio_pci_device *device, struct iommu *iommu) +{ + u32 pt_id = iommu->ioas_id; + + /* Only iommufd supports changing struct iommu attachments */ + VFIO_ASSERT_TRUE(iommu->iommufd); + + if (iommu->hwpt_id) + pt_id = iommu->hwpt_id; + + VFIO_ASSERT_NE(pt_id, 0); + vfio_device_attach_iommufd_pt(device->fd, pt_id); + device->iommu = iommu; +} + struct vfio_pci_device *vfio_pci_device_alloc(const char *bdf, struct iommu *iommu) { struct vfio_pci_device *device;
--
2.56.0.rc1.315.gc6ed9934b7-goog