[PATCH 2/3] drm/xe/pf: Make sure PF is ready to configure VFs
Cavitt, Jonathan
jonathan.cavitt at intel.com
Wed Jul 30 21:09:56 UTC 2025
-----Original Message-----
From: Intel-xe <intel-xe-bounces at lists.freedesktop.org> On Behalf Of Michal Wajdeczko
Sent: Wednesday, July 30, 2025 10:49 AM
To: intel-xe at lists.freedesktop.org
Cc: Wajdeczko, Michal <Michal.Wajdeczko at intel.com>
Subject: [PATCH 2/3] drm/xe/pf: Make sure PF is ready to configure VFs
>
> The PF driver might be resumed just to configure VFs, but since
> it is doing some asynchronous GuC reconfigurations after fresh
> reset, we should wait until all pending works are completed.
>
> This is especially important in case of LMEM provisioning, since
> we also need to update the LMTT and send invalidation requests
> to all GuCs, which are expected to be already in the VGT mode.
>
> Fixes: 68ae022278a1 ("drm/xe/pf: Force GuC virtualization mode")
> Signed-off-by: Michal Wajdeczko <michal.wajdeczko at intel.com>
> ---
> drivers/gpu/drm/xe/xe_gt_sriov_pf.c | 28 +++++++++++++++++++++
> drivers/gpu/drm/xe/xe_gt_sriov_pf.h | 1 +
> drivers/gpu/drm/xe/xe_gt_sriov_pf_debugfs.c | 4 ++-
> drivers/gpu/drm/xe/xe_pci_sriov.c | 7 +++++-
> drivers/gpu/drm/xe/xe_sriov_pf.c | 27 ++++++++++++++++++++
> drivers/gpu/drm/xe/xe_sriov_pf.h | 1 +
> 6 files changed, 66 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_pf.c b/drivers/gpu/drm/xe/xe_gt_sriov_pf.c
> index 2761319fdc26..8bc7d7f9f47a 100644
> --- a/drivers/gpu/drm/xe/xe_gt_sriov_pf.c
> +++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf.c
> @@ -16,6 +16,7 @@
> #include "xe_gt_sriov_pf_migration.h"
> #include "xe_gt_sriov_pf_service.h"
> #include "xe_gt_sriov_printk.h"
> +#include "xe_guc_submit.h"
> #include "xe_mmio.h"
> #include "xe_pm.h"
>
> @@ -258,3 +259,30 @@ void xe_gt_sriov_pf_restart(struct xe_gt *gt)
> {
> pf_queue_restart(gt);
> }
> +
> +static bool pf_flush_restart(struct xe_gt *gt)
> +{
> + xe_gt_assert(gt, IS_SRIOV_PF(gt_to_xe(gt)));
Asserting here seems unnecessary. If we're certain that the pf functions
will never be called in a non-pf context, then we probably don't need to
assert the system is in sriov-pf mode here. And if we aren't certain of this,
it probably makes more sense to put the assertion in
xe_gt_sriov_pf_wait_ready instead, or to have a separate return path instead
of breaking instantly.
Unless the system can exit sriov-pf mode in the middle of execution? I don't
think that's a possibility, though.
The assertion by itself isn't harmful if we're assuming the system would never
hit the assertion in a non-sriov-pf context, though, so I won't block on it's
removal. Though a justification would do well here, if only for my sake.
Everything else is
Reviewed-by: Jonathan Cavitt <jonathan.cavitt at intel.com>
-Jonathan Cavitt
> +
> + return flush_work(>->sriov.pf.workers.restart);
> +}
> +
> +/**
> + * xe_gt_sriov_pf_wait_ready() - Wait until per-GT PF SR-IOV support is ready.
> + * @gt: the &xe_gt
> + *
> + * This function can only be called on PF.
> + *
> + * Return: 0 on success or a negative error code on failure.
> + */
> +int xe_gt_sriov_pf_wait_ready(struct xe_gt *gt)
> +{
> + /* don't wait if there is another ongoing reset */
> + if (xe_guc_read_stopped(>->uc.guc))
> + return -EBUSY;
> +
> + if (pf_flush_restart(gt))
> + xe_gt_sriov_dbg_verbose(gt, "ready after restart\n");
> +
> + return 0;
> +}
> diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_pf.h b/drivers/gpu/drm/xe/xe_gt_sriov_pf.h
> index e2b2ff8132dc..e7fde3f9937a 100644
> --- a/drivers/gpu/drm/xe/xe_gt_sriov_pf.h
> +++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf.h
> @@ -11,6 +11,7 @@ struct xe_gt;
> #ifdef CONFIG_PCI_IOV
> int xe_gt_sriov_pf_init_early(struct xe_gt *gt);
> int xe_gt_sriov_pf_init(struct xe_gt *gt);
> +int xe_gt_sriov_pf_wait_ready(struct xe_gt *gt);
> void xe_gt_sriov_pf_init_hw(struct xe_gt *gt);
> void xe_gt_sriov_pf_sanitize_hw(struct xe_gt *gt, unsigned int vfid);
> void xe_gt_sriov_pf_stop_prepare(struct xe_gt *gt);
> diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_pf_debugfs.c b/drivers/gpu/drm/xe/xe_gt_sriov_pf_debugfs.c
> index bf679b21f485..3ed245e04d0c 100644
> --- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_debugfs.c
> +++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_debugfs.c
> @@ -22,6 +22,7 @@
> #include "xe_gt_sriov_pf_policy.h"
> #include "xe_gt_sriov_pf_service.h"
> #include "xe_pm.h"
> +#include "xe_sriov_pf.h"
>
> /*
> * /sys/kernel/debug/dri/0/
> @@ -205,7 +206,8 @@ static int CONFIG##_set(void *data, u64 val) \
> return -EOVERFLOW; \
> \
> xe_pm_runtime_get(xe); \
> - err = xe_gt_sriov_pf_config_set_##CONFIG(gt, vfid, val); \
> + err = xe_sriov_pf_wait_ready(xe) ?: \
> + xe_gt_sriov_pf_config_set_##CONFIG(gt, vfid, val); \
> xe_pm_runtime_put(xe); \
> \
> return err; \
> diff --git a/drivers/gpu/drm/xe/xe_pci_sriov.c b/drivers/gpu/drm/xe/xe_pci_sriov.c
> index 27b148eab49c..af05db07162e 100644
> --- a/drivers/gpu/drm/xe/xe_pci_sriov.c
> +++ b/drivers/gpu/drm/xe/xe_pci_sriov.c
> @@ -16,6 +16,7 @@
> #include "xe_pci_sriov.h"
> #include "xe_pm.h"
> #include "xe_sriov.h"
> +#include "xe_sriov_pf.h"
> #include "xe_sriov_pf_helpers.h"
> #include "xe_sriov_printk.h"
>
> @@ -154,6 +155,10 @@ static int pf_enable_vfs(struct xe_device *xe, int num_vfs)
> xe_assert(xe, num_vfs <= total_vfs);
> xe_sriov_dbg(xe, "enabling %u VF%s\n", num_vfs, str_plural(num_vfs));
>
> + err = xe_sriov_pf_wait_ready(xe);
> + if (err)
> + goto out;
> +
> /*
> * We must hold additional reference to the runtime PM to keep PF in D0
> * during VFs lifetime, as our VFs do not implement the PM capability.
> @@ -191,7 +196,7 @@ static int pf_enable_vfs(struct xe_device *xe, int num_vfs)
> failed:
> pf_unprovision_vfs(xe, num_vfs);
> xe_pm_runtime_put(xe);
> -
> +out:
> xe_sriov_notice(xe, "Failed to enable %u VF%s (%pe)\n",
> num_vfs, str_plural(num_vfs), ERR_PTR(err));
> return err;
> diff --git a/drivers/gpu/drm/xe/xe_sriov_pf.c b/drivers/gpu/drm/xe/xe_sriov_pf.c
> index afbdd894bd6e..7e8f3d3ac656 100644
> --- a/drivers/gpu/drm/xe/xe_sriov_pf.c
> +++ b/drivers/gpu/drm/xe/xe_sriov_pf.c
> @@ -9,6 +9,7 @@
>
> #include "xe_assert.h"
> #include "xe_device.h"
> +#include "xe_gt_sriov_pf.h"
> #include "xe_module.h"
> #include "xe_sriov.h"
> #include "xe_sriov_pf.h"
> @@ -102,6 +103,32 @@ int xe_sriov_pf_init_early(struct xe_device *xe)
> return 0;
> }
>
> +/**
> + * xe_sriov_pf_wait_ready() - Wait until PF is ready to operate.
> + * @xe: the &xe_device to test
> + *
> + * This function can only be called on PF.
> + *
> + * Return: 0 on success or a negative error code on failure.
> + */
> +int xe_sriov_pf_wait_ready(struct xe_device *xe)
> +{
> + struct xe_gt *gt;
> + unsigned int id;
> + int err = 0;
> +
> + if (xe_device_wedged(xe))
> + return -ECANCELED;
> +
> + for_each_gt(gt, xe, id) {
> + err = xe_gt_sriov_pf_wait_ready(gt);
> + if (err)
> + break;
> + }
> +
> + return err;
> +}
> +
> /**
> * xe_sriov_pf_print_vfs_summary - Print SR-IOV PF information.
> * @xe: the &xe_device to print info from
> diff --git a/drivers/gpu/drm/xe/xe_sriov_pf.h b/drivers/gpu/drm/xe/xe_sriov_pf.h
> index c392c3fcf085..e3b34f8f5e04 100644
> --- a/drivers/gpu/drm/xe/xe_sriov_pf.h
> +++ b/drivers/gpu/drm/xe/xe_sriov_pf.h
> @@ -15,6 +15,7 @@ struct xe_device;
> #ifdef CONFIG_PCI_IOV
> bool xe_sriov_pf_readiness(struct xe_device *xe);
> int xe_sriov_pf_init_early(struct xe_device *xe);
> +int xe_sriov_pf_wait_ready(struct xe_device *xe);
> void xe_sriov_pf_debugfs_register(struct xe_device *xe, struct dentry *root);
> void xe_sriov_pf_print_vfs_summary(struct xe_device *xe, struct drm_printer *p);
> #else
> --
> 2.47.1
>
>
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