In addition to generic VFIO PCI functionality, the driver implements VFIO migration uAPI, allowing userspace to enable migration for Intel Graphics SR-IOV Virtual Functions. The driver binds to VF device and uses API exposed by Xe driver to transfer the VF migration data under the control of PF device.
Signed-off-by: Michał Winiarski <[email protected]> Acked-by: Rodrigo Vivi <[email protected]> --- MAINTAINERS | 7 + drivers/vfio/pci/Kconfig | 2 + drivers/vfio/pci/Makefile | 2 + drivers/vfio/pci/xe/Kconfig | 12 + drivers/vfio/pci/xe/Makefile | 3 + drivers/vfio/pci/xe/main.c | 568 +++++++++++++++++++++++++++++++++++ 6 files changed, 594 insertions(+) create mode 100644 drivers/vfio/pci/xe/Kconfig create mode 100644 drivers/vfio/pci/xe/Makefile create mode 100644 drivers/vfio/pci/xe/main.c diff --git a/MAINTAINERS b/MAINTAINERS index 3e3373fb59100..72486df08b9f7 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -27012,6 +27012,13 @@ L: [email protected] S: Maintained F: drivers/vfio/pci/virtio +VFIO XE PCI DRIVER +M: Michał Winiarski <[email protected]> +L: [email protected] +L: [email protected] +S: Supported +F: drivers/vfio/pci/xe + VGA_SWITCHEROO R: Lukas Wunner <[email protected]> S: Maintained diff --git a/drivers/vfio/pci/Kconfig b/drivers/vfio/pci/Kconfig index 2b0172f546652..c100f0ab87f2d 100644 --- a/drivers/vfio/pci/Kconfig +++ b/drivers/vfio/pci/Kconfig @@ -67,4 +67,6 @@ source "drivers/vfio/pci/nvgrace-gpu/Kconfig" source "drivers/vfio/pci/qat/Kconfig" +source "drivers/vfio/pci/xe/Kconfig" + endmenu diff --git a/drivers/vfio/pci/Makefile b/drivers/vfio/pci/Makefile index cf00c0a7e55c8..f5d46aa9347b9 100644 --- a/drivers/vfio/pci/Makefile +++ b/drivers/vfio/pci/Makefile @@ -19,3 +19,5 @@ obj-$(CONFIG_VIRTIO_VFIO_PCI) += virtio/ obj-$(CONFIG_NVGRACE_GPU_VFIO_PCI) += nvgrace-gpu/ obj-$(CONFIG_QAT_VFIO_PCI) += qat/ + +obj-$(CONFIG_XE_VFIO_PCI) += xe/ diff --git a/drivers/vfio/pci/xe/Kconfig b/drivers/vfio/pci/xe/Kconfig new file mode 100644 index 0000000000000..4253f2a86ca1f --- /dev/null +++ b/drivers/vfio/pci/xe/Kconfig @@ -0,0 +1,12 @@ +# SPDX-License-Identifier: GPL-2.0-only +config XE_VFIO_PCI + tristate "VFIO support for Intel Graphics" + depends on DRM_XE + select VFIO_PCI_CORE + help + This option enables device specific VFIO driver variant for Intel Graphics. + In addition to generic VFIO PCI functionality, it implements VFIO + migration uAPI allowing userspace to enable migration for + Intel Graphics SR-IOV Virtual Functions supported by the Xe driver. + + If you don't know what to do here, say N. diff --git a/drivers/vfio/pci/xe/Makefile b/drivers/vfio/pci/xe/Makefile new file mode 100644 index 0000000000000..13aa0fd192cd4 --- /dev/null +++ b/drivers/vfio/pci/xe/Makefile @@ -0,0 +1,3 @@ +# SPDX-License-Identifier: GPL-2.0-only +obj-$(CONFIG_XE_VFIO_PCI) += xe-vfio-pci.o +xe-vfio-pci-y := main.o diff --git a/drivers/vfio/pci/xe/main.c b/drivers/vfio/pci/xe/main.c new file mode 100644 index 0000000000000..ce0ed82ee4d31 --- /dev/null +++ b/drivers/vfio/pci/xe/main.c @@ -0,0 +1,568 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright © 2025 Intel Corporation + */ + +#include <linux/anon_inodes.h> +#include <linux/delay.h> +#include <linux/file.h> +#include <linux/module.h> +#include <linux/pci.h> +#include <linux/sizes.h> +#include <linux/types.h> +#include <linux/vfio.h> +#include <linux/vfio_pci_core.h> + +#include <drm/intel/xe_sriov_vfio.h> +#include <drm/intel/pciids.h> + +struct xe_vfio_pci_migration_file { + struct file *filp; + /* serializes accesses to migration data */ + struct mutex lock; + bool disabled; + struct xe_vfio_pci_core_device *xe_vdev; +}; + +struct xe_vfio_pci_core_device { + struct vfio_pci_core_device core_device; + struct xe_device *xe; + /* PF internal control uses vfid index starting from 1 */ + unsigned int vfid; + u8 migrate_cap:1; + u8 deferred_reset:1; + /* protects migration state */ + struct mutex state_mutex; + enum vfio_device_mig_state mig_state; + /* protects the reset_done flow */ + spinlock_t reset_lock; + struct xe_vfio_pci_migration_file *migf; +}; + +#define xe_vdev_to_dev(xe_vdev) (&(xe_vdev)->core_device.pdev->dev) + +static void xe_vfio_pci_disable_file(struct xe_vfio_pci_migration_file *migf) +{ + mutex_lock(&migf->lock); + migf->disabled = true; + mutex_unlock(&migf->lock); +} + +static void xe_vfio_pci_put_file(struct xe_vfio_pci_core_device *xe_vdev) +{ + xe_vfio_pci_disable_file(xe_vdev->migf); + fput(xe_vdev->migf->filp); + xe_vdev->migf = NULL; +} + +static void xe_vfio_pci_reset(struct xe_vfio_pci_core_device *xe_vdev) +{ + if (xe_vdev->migf) + xe_vfio_pci_put_file(xe_vdev); + + xe_vdev->mig_state = VFIO_DEVICE_STATE_RUNNING; +} + +static void xe_vfio_pci_state_mutex_lock(struct xe_vfio_pci_core_device *xe_vdev) +{ + mutex_lock(&xe_vdev->state_mutex); +} + +/* + * This function is called in all state_mutex unlock cases to + * handle a 'deferred_reset' if exists. + */ +static void xe_vfio_pci_state_mutex_unlock(struct xe_vfio_pci_core_device *xe_vdev) +{ +again: + spin_lock(&xe_vdev->reset_lock); + if (xe_vdev->deferred_reset) { + xe_vdev->deferred_reset = false; + spin_unlock(&xe_vdev->reset_lock); + xe_vfio_pci_reset(xe_vdev); + goto again; + } + mutex_unlock(&xe_vdev->state_mutex); + spin_unlock(&xe_vdev->reset_lock); +} + +static void xe_vfio_pci_reset_done(struct pci_dev *pdev) +{ + struct xe_vfio_pci_core_device *xe_vdev = pci_get_drvdata(pdev); + int ret; + + if (!xe_vdev->vfid) + return; + + /* + * VF FLR requires additional processing done by PF driver. + * The processing is done after FLR is already finished from PCIe + * perspective. + * In order to avoid a scenario where VF is used while PF processing + * is still in progress, additional synchronization point is needed. + */ + ret = xe_sriov_vfio_wait_flr_done(xe_vdev->xe, xe_vdev->vfid); + if (ret) + dev_err(&pdev->dev, "Failed to wait for FLR: %d\n", ret); + + if (!xe_vdev->migrate_cap) + return; + + /* + * As the higher VFIO layers are holding locks across reset and using + * those same locks with the mm_lock we need to prevent ABBA deadlock + * with the state_mutex and mm_lock. + * In case the state_mutex was taken already we defer the cleanup work + * to the unlock flow of the other running context. + */ + spin_lock(&xe_vdev->reset_lock); + xe_vdev->deferred_reset = true; + if (!mutex_trylock(&xe_vdev->state_mutex)) { + spin_unlock(&xe_vdev->reset_lock); + return; + } + spin_unlock(&xe_vdev->reset_lock); + xe_vfio_pci_state_mutex_unlock(xe_vdev); + + xe_vfio_pci_reset(xe_vdev); +} + +static const struct pci_error_handlers xe_vfio_pci_err_handlers = { + .reset_done = xe_vfio_pci_reset_done, + .error_detected = vfio_pci_core_aer_err_detected, +}; + +static int xe_vfio_pci_open_device(struct vfio_device *core_vdev) +{ + struct xe_vfio_pci_core_device *xe_vdev = + container_of(core_vdev, struct xe_vfio_pci_core_device, core_device.vdev); + struct vfio_pci_core_device *vdev = &xe_vdev->core_device; + int ret; + + ret = vfio_pci_core_enable(vdev); + if (ret) + return ret; + + vfio_pci_core_finish_enable(vdev); + + return 0; +} + +static int xe_vfio_pci_release_file(struct inode *inode, struct file *filp) +{ + struct xe_vfio_pci_migration_file *migf = filp->private_data; + + xe_vfio_pci_disable_file(migf); + mutex_destroy(&migf->lock); + kfree(migf); + + return 0; +} + +static ssize_t xe_vfio_pci_save_read(struct file *filp, char __user *buf, size_t len, loff_t *pos) +{ + struct xe_vfio_pci_migration_file *migf = filp->private_data; + ssize_t ret; + + if (pos) + return -ESPIPE; + + mutex_lock(&migf->lock); + if (migf->disabled) { + mutex_unlock(&migf->lock); + return -ENODEV; + } + + ret = xe_sriov_vfio_data_read(migf->xe_vdev->xe, migf->xe_vdev->vfid, buf, len); + mutex_unlock(&migf->lock); + + return ret; +} + +static const struct file_operations xe_vfio_pci_save_fops = { + .owner = THIS_MODULE, + .read = xe_vfio_pci_save_read, + .release = xe_vfio_pci_release_file, + .llseek = noop_llseek, +}; + +static ssize_t xe_vfio_pci_resume_write(struct file *filp, const char __user *buf, + size_t len, loff_t *pos) +{ + struct xe_vfio_pci_migration_file *migf = filp->private_data; + ssize_t ret; + + if (pos) + return -ESPIPE; + + mutex_lock(&migf->lock); + if (migf->disabled) { + mutex_unlock(&migf->lock); + return -ENODEV; + } + + ret = xe_sriov_vfio_data_write(migf->xe_vdev->xe, migf->xe_vdev->vfid, buf, len); + mutex_unlock(&migf->lock); + + return ret; +} + +static const struct file_operations xe_vfio_pci_resume_fops = { + .owner = THIS_MODULE, + .write = xe_vfio_pci_resume_write, + .release = xe_vfio_pci_release_file, + .llseek = noop_llseek, +}; + +static const char *vfio_dev_state_str(u32 state) +{ + switch (state) { + case VFIO_DEVICE_STATE_RUNNING: return "running"; + case VFIO_DEVICE_STATE_RUNNING_P2P: return "running_p2p"; + case VFIO_DEVICE_STATE_STOP_COPY: return "stopcopy"; + case VFIO_DEVICE_STATE_STOP: return "stop"; + case VFIO_DEVICE_STATE_RESUMING: return "resuming"; + case VFIO_DEVICE_STATE_ERROR: return "error"; + default: return ""; + } +} + +enum xe_vfio_pci_file_type { + XE_VFIO_FILE_SAVE = 0, + XE_VFIO_FILE_RESUME, +}; + +static struct xe_vfio_pci_migration_file * +xe_vfio_pci_alloc_file(struct xe_vfio_pci_core_device *xe_vdev, + enum xe_vfio_pci_file_type type) +{ + struct xe_vfio_pci_migration_file *migf; + const struct file_operations *fops; + int flags; + + migf = kzalloc(sizeof(*migf), GFP_KERNEL); + if (!migf) + return ERR_PTR(-ENOMEM); + + fops = type == XE_VFIO_FILE_SAVE ? &xe_vfio_pci_save_fops : &xe_vfio_pci_resume_fops; + flags = type == XE_VFIO_FILE_SAVE ? O_RDONLY : O_WRONLY; + migf->filp = anon_inode_getfile("xe_vfio_mig", fops, migf, flags); + if (IS_ERR(migf->filp)) { + kfree(migf); + return ERR_CAST(migf->filp); + } + + mutex_init(&migf->lock); + migf->xe_vdev = xe_vdev; + xe_vdev->migf = migf; + + stream_open(migf->filp->f_inode, migf->filp); + + return migf; +} + +static struct file * +xe_vfio_set_state(struct xe_vfio_pci_core_device *xe_vdev, u32 new) +{ + u32 cur = xe_vdev->mig_state; + int ret; + + dev_dbg(xe_vdev_to_dev(xe_vdev), + "state: %s->%s\n", vfio_dev_state_str(cur), vfio_dev_state_str(new)); + + /* + * "STOP" handling is reused for "RUNNING_P2P", as the device doesn't + * have the capability to selectively block outgoing p2p DMA transfers. + * While the device is allowing BAR accesses when the VF is stopped, it + * is not processing any new workload requests, effectively stopping + * any outgoing DMA transfers (not just p2p). + * Any VRAM / MMIO accesses occurring during "RUNNING_P2P" are kept and + * will be migrated to target VF during stop-copy. + */ + if (cur == VFIO_DEVICE_STATE_RUNNING && new == VFIO_DEVICE_STATE_RUNNING_P2P) { + ret = xe_sriov_vfio_suspend_device(xe_vdev->xe, xe_vdev->vfid); + if (ret) + goto err; + + return NULL; + } + + if ((cur == VFIO_DEVICE_STATE_RUNNING_P2P && new == VFIO_DEVICE_STATE_STOP) || + (cur == VFIO_DEVICE_STATE_STOP && new == VFIO_DEVICE_STATE_RUNNING_P2P)) + return NULL; + + if (cur == VFIO_DEVICE_STATE_RUNNING_P2P && new == VFIO_DEVICE_STATE_RUNNING) { + ret = xe_sriov_vfio_resume_device(xe_vdev->xe, xe_vdev->vfid); + if (ret) + goto err; + + return NULL; + } + + if (cur == VFIO_DEVICE_STATE_STOP && new == VFIO_DEVICE_STATE_STOP_COPY) { + struct xe_vfio_pci_migration_file *migf; + + migf = xe_vfio_pci_alloc_file(xe_vdev, XE_VFIO_FILE_SAVE); + if (IS_ERR(migf)) { + ret = PTR_ERR(migf); + goto err; + } + get_file(migf->filp); + + ret = xe_sriov_vfio_stop_copy_enter(xe_vdev->xe, xe_vdev->vfid); + if (ret) { + fput(migf->filp); + goto err; + } + + return migf->filp; + } + + if (cur == VFIO_DEVICE_STATE_STOP_COPY && new == VFIO_DEVICE_STATE_STOP) { + if (xe_vdev->migf) + xe_vfio_pci_put_file(xe_vdev); + + ret = xe_sriov_vfio_stop_copy_exit(xe_vdev->xe, xe_vdev->vfid); + if (ret) + goto err; + + return NULL; + } + + if (cur == VFIO_DEVICE_STATE_STOP && new == VFIO_DEVICE_STATE_RESUMING) { + struct xe_vfio_pci_migration_file *migf; + + migf = xe_vfio_pci_alloc_file(xe_vdev, XE_VFIO_FILE_RESUME); + if (IS_ERR(migf)) { + ret = PTR_ERR(migf); + goto err; + } + get_file(migf->filp); + + ret = xe_sriov_vfio_resume_data_enter(xe_vdev->xe, xe_vdev->vfid); + if (ret) { + fput(migf->filp); + goto err; + } + + return migf->filp; + } + + if (cur == VFIO_DEVICE_STATE_RESUMING && new == VFIO_DEVICE_STATE_STOP) { + if (xe_vdev->migf) + xe_vfio_pci_put_file(xe_vdev); + + ret = xe_sriov_vfio_resume_data_exit(xe_vdev->xe, xe_vdev->vfid); + if (ret) + goto err; + + return NULL; + } + + WARN(true, "Unknown state transition %d->%d", cur, new); + return ERR_PTR(-EINVAL); + +err: + dev_dbg(xe_vdev_to_dev(xe_vdev), + "Failed to transition state: %s->%s err=%d\n", + vfio_dev_state_str(cur), vfio_dev_state_str(new), ret); + return ERR_PTR(ret); +} + +static struct file * +xe_vfio_pci_set_device_state(struct vfio_device *core_vdev, + enum vfio_device_mig_state new_state) +{ + struct xe_vfio_pci_core_device *xe_vdev = + container_of(core_vdev, struct xe_vfio_pci_core_device, core_device.vdev); + enum vfio_device_mig_state next_state; + struct file *f = NULL; + int ret; + + xe_vfio_pci_state_mutex_lock(xe_vdev); + while (new_state != xe_vdev->mig_state) { + ret = vfio_mig_get_next_state(core_vdev, xe_vdev->mig_state, + new_state, &next_state); + if (ret) { + xe_sriov_vfio_error(xe_vdev->xe, xe_vdev->vfid); + f = ERR_PTR(ret); + break; + } + f = xe_vfio_set_state(xe_vdev, next_state); + if (IS_ERR(f)) + break; + + xe_vdev->mig_state = next_state; + + /* Multiple state transitions with non-NULL file in the middle */ + if (f && new_state != xe_vdev->mig_state) { + fput(f); + f = ERR_PTR(-EINVAL); + break; + } + } + xe_vfio_pci_state_mutex_unlock(xe_vdev); + + return f; +} + +static int xe_vfio_pci_get_device_state(struct vfio_device *core_vdev, + enum vfio_device_mig_state *curr_state) +{ + struct xe_vfio_pci_core_device *xe_vdev = + container_of(core_vdev, struct xe_vfio_pci_core_device, core_device.vdev); + + xe_vfio_pci_state_mutex_lock(xe_vdev); + *curr_state = xe_vdev->mig_state; + xe_vfio_pci_state_mutex_unlock(xe_vdev); + + return 0; +} + +static int xe_vfio_pci_get_data_size(struct vfio_device *vdev, + unsigned long *stop_copy_length) +{ + struct xe_vfio_pci_core_device *xe_vdev = + container_of(vdev, struct xe_vfio_pci_core_device, core_device.vdev); + + xe_vfio_pci_state_mutex_lock(xe_vdev); + *stop_copy_length = xe_sriov_vfio_stop_copy_size(xe_vdev->xe, xe_vdev->vfid); + xe_vfio_pci_state_mutex_unlock(xe_vdev); + + return 0; +} + +static const struct vfio_migration_ops xe_vfio_pci_migration_ops = { + .migration_set_state = xe_vfio_pci_set_device_state, + .migration_get_state = xe_vfio_pci_get_device_state, + .migration_get_data_size = xe_vfio_pci_get_data_size, +}; + +static void xe_vfio_pci_migration_init(struct xe_vfio_pci_core_device *xe_vdev) +{ + struct vfio_device *core_vdev = &xe_vdev->core_device.vdev; + struct pci_dev *pdev = to_pci_dev(core_vdev->dev); + struct xe_device *xe = xe_sriov_vfio_get_pf(pdev); + int ret; + + if (!xe) + return; + if (!xe_sriov_vfio_migration_supported(xe)) + return; + + ret = pci_iov_vf_id(pdev); + if (ret < 0) + return; + + mutex_init(&xe_vdev->state_mutex); + spin_lock_init(&xe_vdev->reset_lock); + + /* PF internal control uses vfid index starting from 1 */ + xe_vdev->vfid = ret + 1; + xe_vdev->xe = xe; + xe_vdev->migrate_cap = true; + + core_vdev->migration_flags = VFIO_MIGRATION_STOP_COPY | VFIO_MIGRATION_P2P; + core_vdev->mig_ops = &xe_vfio_pci_migration_ops; +} + +static void xe_vfio_pci_migration_fini(struct xe_vfio_pci_core_device *xe_vdev) +{ + if (!xe_vdev->migrate_cap) + return; + + mutex_destroy(&xe_vdev->state_mutex); +} + +static int xe_vfio_pci_init_dev(struct vfio_device *core_vdev) +{ + struct xe_vfio_pci_core_device *xe_vdev = + container_of(core_vdev, struct xe_vfio_pci_core_device, core_device.vdev); + + xe_vfio_pci_migration_init(xe_vdev); + + return vfio_pci_core_init_dev(core_vdev); +} + +static void xe_vfio_pci_release_dev(struct vfio_device *core_vdev) +{ + struct xe_vfio_pci_core_device *xe_vdev = + container_of(core_vdev, struct xe_vfio_pci_core_device, core_device.vdev); + + xe_vfio_pci_migration_fini(xe_vdev); +} + +static const struct vfio_device_ops xe_vfio_pci_ops = { + .name = "xe-vfio-pci", + .init = xe_vfio_pci_init_dev, + .release = xe_vfio_pci_release_dev, + .open_device = xe_vfio_pci_open_device, + .close_device = vfio_pci_core_close_device, + .ioctl = vfio_pci_core_ioctl, + .device_feature = vfio_pci_core_ioctl_feature, + .read = vfio_pci_core_read, + .write = vfio_pci_core_write, + .mmap = vfio_pci_core_mmap, + .request = vfio_pci_core_request, + .match = vfio_pci_core_match, + .match_token_uuid = vfio_pci_core_match_token_uuid, + .bind_iommufd = vfio_iommufd_physical_bind, + .unbind_iommufd = vfio_iommufd_physical_unbind, + .attach_ioas = vfio_iommufd_physical_attach_ioas, + .detach_ioas = vfio_iommufd_physical_detach_ioas, +}; + +static int xe_vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) +{ + struct xe_vfio_pci_core_device *xe_vdev; + int ret; + + xe_vdev = vfio_alloc_device(xe_vfio_pci_core_device, core_device.vdev, &pdev->dev, + &xe_vfio_pci_ops); + if (IS_ERR(xe_vdev)) + return PTR_ERR(xe_vdev); + + dev_set_drvdata(&pdev->dev, &xe_vdev->core_device); + + ret = vfio_pci_core_register_device(&xe_vdev->core_device); + if (ret) { + vfio_put_device(&xe_vdev->core_device.vdev); + return ret; + } + + return 0; +} + +static void xe_vfio_pci_remove(struct pci_dev *pdev) +{ + struct xe_vfio_pci_core_device *xe_vdev = pci_get_drvdata(pdev); + + vfio_pci_core_unregister_device(&xe_vdev->core_device); + vfio_put_device(&xe_vdev->core_device.vdev); +} + +#define INTEL_PCI_VFIO_DEVICE(_id) { \ + PCI_DRIVER_OVERRIDE_DEVICE_VFIO(PCI_VENDOR_ID_INTEL, (_id)) \ +} + +static const struct pci_device_id xe_vfio_pci_table[] = { + INTEL_PTL_IDS(INTEL_PCI_VFIO_DEVICE), + INTEL_WCL_IDS(INTEL_PCI_VFIO_DEVICE), + INTEL_BMG_IDS(INTEL_PCI_VFIO_DEVICE), + {} +}; +MODULE_DEVICE_TABLE(pci, xe_vfio_pci_table); + +static struct pci_driver xe_vfio_pci_driver = { + .name = "xe-vfio-pci", + .id_table = xe_vfio_pci_table, + .probe = xe_vfio_pci_probe, + .remove = xe_vfio_pci_remove, + .err_handler = &xe_vfio_pci_err_handlers, + .driver_managed_dma = true, +}; +module_pci_driver(xe_vfio_pci_driver); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Michał Winiarski <[email protected]>"); +MODULE_DESCRIPTION("VFIO PCI driver with migration support for Intel Graphics"); -- 2.51.2
