On Tue, Nov 25, 2025 at 01:08:14PM -0700, Alex Williamson wrote:
> On Tue, 25 Nov 2025 00:08:41 +0100
> Michał Winiarski <[email protected]> wrote:
>
> > 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]>
> > Reviewed-by: Kevin Tian <[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 acc951f122eaf..adb5aa9cd29e9 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -27025,6 +27025,13 @@ 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;
>
> Move to the end to avoid a hole? Unless you know mutex leaves a gap.
> Maybe also use a bitfield u8 for consistency to flags in below struct.
I'll move it and switch to bitfield u8.
>
> > + 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;
>
> It seems like the above is intended to cause a stall for all VFs,
> regardless of migration support, but vfid and xe are only set for VFs
> supporting migration. Maybe that much needs to be pulled out of
> migration_init into init_dev, which then gives the migrate_cap flag
> purpose where it otherwise seems redundant to testing xe or vfid.
Yeah - I'll remove migrate_cap and test for vfid instead.
The test for xe_vdev->vfid at the top of the function will be replaced
with check for pdev->is_virtfn, as we do want to exit early in case
xe-vfio-pci was bound to native PCI device (not VF).
>
> > +
> > + /*
> > + * 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;
> > +}
>
> Typically migration drivers are setting the initial RUNNING mig_state
> in their open_device function, are we implicitly relying on the
> reset_done callback for this instead?
We are relying on reset_done, and know that we want to make it explicit.
I'll add proper handling here and in close path.
>
> > +
> > +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);
>
> What does calling the above accomplish? If something is racing access,
> setting disabled immediately before we destroy the lock and free the
> object isn't going to solve anything.
I think we can savely remove it - IIUC, the upper layers are taking care
of the race by taking a ref as part of read/write.
I'll do that.
>
> > + 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);
>
> GFP_KERNEL_ACCOUNT
Ok.
>
> > + 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;
>
> As above, ordering here seems wrong if FLR is expecting vfid and xe set
> independent of support migration.
>
> > +
> > + ret = pci_iov_vf_id(pdev);
> > + if (ret < 0)
> > + return;
>
> Maybe this is just defensive, but @xe being non-NULL verifies @pdev is
> a VF bound to &xe_pci_driver, so we could pretty safely just use
> 'pci_iov_vf_id(pdev) + 1' below. Thanks,
It's a result of a review feedback from previous revision, but in that
revision xe_sriov_vfio_get_pf() helper didn't exist. I'll use it
directly below.
Thanks,
-Michał
>
> Alex
>
> > +
> > + 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");
>
