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Message-ID: <2xxp3cytad6rou53mwjnv4xt5lkxqfl7g2s4ig2q5g2u3ptvko@xnsh5bbd4rbx>
Date: Mon, 27 Oct 2025 13:33:33 +0100
From: Michał Winiarski <michal.winiarski@...el.com>
To: Michal Wajdeczko <michal.wajdeczko@...el.com>
CC: Alex Williamson <alex.williamson@...hat.com>, Lucas De Marchi
<lucas.demarchi@...el.com>, Thomas Hellström
<thomas.hellstrom@...ux.intel.com>, Rodrigo Vivi <rodrigo.vivi@...el.com>,
Jason Gunthorpe <jgg@...pe.ca>, Yishai Hadas <yishaih@...dia.com>, Kevin Tian
<kevin.tian@...el.com>, <intel-xe@...ts.freedesktop.org>,
<linux-kernel@...r.kernel.org>, <kvm@...r.kernel.org>, Matthew Brost
<matthew.brost@...el.com>, <dri-devel@...ts.freedesktop.org>, Jani Nikula
<jani.nikula@...ux.intel.com>, Joonas Lahtinen
<joonas.lahtinen@...ux.intel.com>, Tvrtko Ursulin <tursulin@...ulin.net>,
David Airlie <airlied@...il.com>, Simona Vetter <simona@...ll.ch>, "Lukasz
Laguna" <lukasz.laguna@...el.com>
Subject: Re: [PATCH v2 04/26] drm/xe/pf: Add data structures and handlers for
migration rings
On Thu, Oct 23, 2025 at 12:06:05AM +0200, Michal Wajdeczko wrote:
>
>
> On 10/22/2025 12:41 AM, Michał Winiarski wrote:
> > Migration data is queued in a per-GT ptr_ring to decouple the worker
> > responsible for handling the data transfer from the .read() and .write()
> > syscalls.
> > Add the data structures and handlers that will be used in future
> > commits.
> >
> > Signed-off-by: Michał Winiarski <michal.winiarski@...el.com>
> > ---
> > drivers/gpu/drm/xe/xe_gt_sriov_pf_control.c | 259 +++++++++++++++++-
> > drivers/gpu/drm/xe/xe_gt_sriov_pf_control.h | 6 +-
> > .../gpu/drm/xe/xe_gt_sriov_pf_control_types.h | 12 +
> > drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.c | 183 +++++++++++++
> > drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.h | 14 +
> > .../drm/xe/xe_gt_sriov_pf_migration_types.h | 11 +
> > drivers/gpu/drm/xe/xe_gt_sriov_pf_types.h | 3 +
> > drivers/gpu/drm/xe/xe_sriov_pf_migration.c | 143 ++++++++++
> > drivers/gpu/drm/xe/xe_sriov_pf_migration.h | 7 +
> > .../gpu/drm/xe/xe_sriov_pf_migration_types.h | 58 ++++
> > drivers/gpu/drm/xe/xe_sriov_pf_types.h | 3 +
> > 11 files changed, 684 insertions(+), 15 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_pf_control.c b/drivers/gpu/drm/xe/xe_gt_sriov_pf_control.c
> > index b770916e88e53..cad73fdaee93c 100644
> > --- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_control.c
> > +++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_control.c
> > @@ -19,6 +19,7 @@
> > #include "xe_guc_ct.h"
> > #include "xe_sriov.h"
> > #include "xe_sriov_pf_control.h"
> > +#include "xe_sriov_pf_migration.h"
> > #include "xe_sriov_pf_service.h"
> > #include "xe_tile.h"
> >
> > @@ -185,9 +186,15 @@ static const char *control_bit_to_string(enum xe_gt_sriov_control_bits bit)
> > CASE2STR(PAUSE_FAILED);
> > CASE2STR(PAUSED);
> > CASE2STR(SAVE_WIP);
> > + CASE2STR(SAVE_PROCESS_DATA);
> > + CASE2STR(SAVE_WAIT_DATA);
> > + CASE2STR(SAVE_DATA_DONE);
> > CASE2STR(SAVE_FAILED);
> > CASE2STR(SAVED);
> > CASE2STR(RESTORE_WIP);
> > + CASE2STR(RESTORE_PROCESS_DATA);
> > + CASE2STR(RESTORE_WAIT_DATA);
> > + CASE2STR(RESTORE_DATA_DONE);
> > CASE2STR(RESTORE_FAILED);
> > CASE2STR(RESTORED);
> > CASE2STR(RESUME_WIP);
> > @@ -804,9 +811,50 @@ int xe_gt_sriov_pf_control_resume_vf(struct xe_gt *gt, unsigned int vfid)
> > return -ECANCELED;
> > }
> >
> > +/**
> > + * DOC: The VF SAVE state machine
> > + *
> > + * SAVE extends the PAUSED state.
> > + *
> > + * The VF SAVE state machine looks like::
> > + *
> > + * ....PAUSED....................................................
> > + * : :
> > + * : (O)<---------o :
> > + * : | \ :
> > + * : save (SAVED) (SAVE_FAILED) :
> > + * : | ^ ^ :
> > + * : | | | :
> > + * : ....V...............o...........o......SAVE_WIP......... :
> > + * : : | | | : :
> > + * : : | empty | : :
> > + * : : | | | : :
> > + * : : | | | : :
> > + * : : | DATA_DONE | : :
> > + * : : | ^ | : :
> > + * : : | | error : :
> > + * : : | no_data / : :
> > + * : : | / / : :
> > + * : : | / / : :
> > + * : : | / / : :
> > + * : : o---------->PROCESS_DATA<----consume : :
> > + * : : \ \ : :
> > + * : : \ \ : :
> > + * : : \ \ : :
> > + * : : ring_full----->WAIT_DATA : :
> > + * : : : :
> > + * : :......................................................: :
> > + * :............................................................:
>
> this will not render correctly (missing extra indent, RESTORE_WIP below is fine)
Ok.
>
> > + *
> > + * For the full state machine view, see `The VF state machine`_.
> > + */
> > static void pf_exit_vf_save_wip(struct xe_gt *gt, unsigned int vfid)
> > {
> > - pf_exit_vf_state(gt, vfid, XE_GT_SRIOV_STATE_SAVE_WIP);
> > + if (pf_exit_vf_state(gt, vfid, XE_GT_SRIOV_STATE_SAVE_WIP)) {
> > + pf_escape_vf_state(gt, vfid, XE_GT_SRIOV_STATE_SAVE_PROCESS_DATA);
> > + pf_escape_vf_state(gt, vfid, XE_GT_SRIOV_STATE_SAVE_WAIT_DATA);
> > + pf_escape_vf_state(gt, vfid, XE_GT_SRIOV_STATE_SAVE_DATA_DONE);
> > + }
> > }
> >
> > static void pf_enter_vf_saved(struct xe_gt *gt, unsigned int vfid)
> > @@ -821,12 +869,39 @@ static void pf_enter_vf_saved(struct xe_gt *gt, unsigned int vfid)
> > pf_expect_vf_state(gt, vfid, XE_GT_SRIOV_STATE_PAUSED);
> > }
> >
> > +static void pf_enter_vf_save_failed(struct xe_gt *gt, unsigned int vfid)
> > +{
> > + pf_enter_vf_state(gt, vfid, XE_GT_SRIOV_STATE_SAVE_FAILED);
> > + pf_exit_vf_wip(gt, vfid);
> > +}
> > +
> > +static int pf_handle_vf_save_data(struct xe_gt *gt, unsigned int vfid)
> > +{
> > + return 0;
> > +}
> > +
> > static bool pf_handle_vf_save(struct xe_gt *gt, unsigned int vfid)
> > {
> > - if (!pf_exit_vf_state(gt, vfid, XE_GT_SRIOV_STATE_SAVE_WIP))
> > + int ret;
> > +
> > + if (!pf_exit_vf_state(gt, vfid, XE_GT_SRIOV_STATE_SAVE_PROCESS_DATA))
> > return false;
> >
> > - pf_enter_vf_saved(gt, vfid);
> > + pf_enter_vf_state(gt, vfid, XE_GT_SRIOV_STATE_SAVE_WAIT_DATA);
>
> this seems to be done too early
Yeah - I'll change this (and other save/restore related placed) to the
suggested pattern.
>
> > + if (xe_gt_sriov_pf_migration_ring_full(gt, vfid)) {
>
> you should enter(WAIT_DATA) here
>
> > + pf_enter_vf_state(gt, vfid, XE_GT_SRIOV_STATE_SAVE_PROCESS_DATA);
>
> and don't re-enter(PROCESS_DATA) as we shouldn't be in both sub-states at the same time
>
> transition from WAIT to PROCESS shall be done in
>
> pf_exit_vf_wait(gt, vf)
> {
> if (exit(WAIT))
> enter(PROCESS_DATA)
> queue
> }
>
> called from xe_gt_sriov_pf_control_process_save_data()
>
> > +
> > + return true;
> > + }
> > + pf_exit_vf_state(gt, vfid, XE_GT_SRIOV_STATE_SAVE_WAIT_DATA);
> > +
> > + ret = pf_handle_vf_save_data(gt, vfid);
> > + if (ret == -EAGAIN)
> > + pf_enter_vf_state(gt, vfid, XE_GT_SRIOV_STATE_SAVE_PROCESS_DATA);
> > + else if (ret)
> > + pf_enter_vf_save_failed(gt, vfid);
> > + else
> > + pf_enter_vf_state(gt, vfid, XE_GT_SRIOV_STATE_SAVE_DATA_DONE);
> >
> > return true;
> > }
> > @@ -834,6 +909,7 @@ static bool pf_handle_vf_save(struct xe_gt *gt, unsigned int vfid)
> > static bool pf_enter_vf_save_wip(struct xe_gt *gt, unsigned int vfid)
> > {
> > if (pf_enter_vf_state(gt, vfid, XE_GT_SRIOV_STATE_SAVE_WIP)) {
> > + pf_enter_vf_state(gt, vfid, XE_GT_SRIOV_STATE_SAVE_PROCESS_DATA);
> > pf_enter_vf_wip(gt, vfid);
> > pf_queue_vf(gt, vfid);
> > return true;
> > @@ -842,6 +918,36 @@ static bool pf_enter_vf_save_wip(struct xe_gt *gt, unsigned int vfid)
> > return false;
> > }
> >
> > +/**
> > + * xe_gt_sriov_pf_control_check_save_data_done() - Check if all save migration data was produced.
> > + * @gt: the &xe_gt
> > + * @vfid: the VF identifier
> > + *
> > + * This function is for PF only.
> > + *
> > + * Return: 0 on success or a negative error code on failure.
> > + */
> > +bool xe_gt_sriov_pf_control_check_save_data_done(struct xe_gt *gt, unsigned int vfid)
> > +{
> > + return pf_check_vf_state(gt, vfid, XE_GT_SRIOV_STATE_SAVE_DATA_DONE);
> > +}
> > +
> > +/**
> > + * xe_gt_sriov_pf_control_process_save_data() - Queue VF save migration data processing.
> > + * @gt: the &xe_gt
> > + * @vfid: the VF identifier
> > + *
> > + * This function is for PF only.
> > + */
> > +void xe_gt_sriov_pf_control_process_save_data(struct xe_gt *gt, unsigned int vfid)
> > +{
> > + if (xe_gt_sriov_pf_control_check_save_data_done(gt, vfid))
> > + return;
> > +
> > + if (pf_exit_vf_state(gt, vfid, XE_GT_SRIOV_STATE_SAVE_WAIT_DATA))
> > + pf_queue_vf(gt, vfid);
>
> this should wrapped into:
>
> exit_vf_wait_data()
>
> where actual transition to PROCESS will happen
>
> > +}
> > +
> > /**
> > * xe_gt_sriov_pf_control_trigger_save_vf() - Start an SR-IOV VF migration data save sequence.
> > * @gt: the &xe_gt
> > @@ -887,19 +993,62 @@ int xe_gt_sriov_pf_control_trigger_save_vf(struct xe_gt *gt, unsigned int vfid)
> > */
> > int xe_gt_sriov_pf_control_finish_save_vf(struct xe_gt *gt, unsigned int vfid)
> > {
> > - if (!pf_expect_vf_state(gt, vfid, XE_GT_SRIOV_STATE_SAVED)) {
> > - pf_enter_vf_mismatch(gt, vfid);
> > + if (!pf_check_vf_state(gt, vfid, XE_GT_SRIOV_STATE_SAVE_DATA_DONE)) {
> > + xe_gt_sriov_err(gt, "VF%u save is still in progress!\n", vfid);
> > return -EIO;
> > }
> >
> > pf_expect_vf_state(gt, vfid, XE_GT_SRIOV_STATE_PAUSED);
> > + pf_exit_vf_state(gt, vfid, XE_GT_SRIOV_STATE_SAVE_DATA_DONE);
> > + pf_enter_vf_saved(gt, vfid);
> >
> > return 0;
> > }
> >
> > +/**
> > + * DOC: The VF RESTORE state machine
> > + *
> > + * RESTORE extends the PAUSED state.
> > + *
> > + * The VF RESTORE state machine looks like::
> > + *
> > + * ....PAUSED....................................................
> > + * : :
> > + * : (O)<---------o :
> > + * : | \ :
> > + * : restore (RESTORED) (RESTORE_FAILED) :
> > + * : | ^ ^ :
> > + * : | | | :
> > + * : ....V...............o...........o......RESTORE_WIP...... :
> > + * : : | | | : :
> > + * : : | empty | : :
> > + * : : | | | : :
> > + * : : | | | : :
> > + * : : | DATA_DONE | : :
> > + * : : | ^ | : :
> > + * : : | | error : :
> > + * : : | trailer / : :
> > + * : : | / / : :
> > + * : : | / / : :
> > + * : : | / / : :
> > + * : : o---------->PROCESS_DATA<----produce : :
> > + * : : \ \ : :
> > + * : : \ \ : :
> > + * : : \ \ : :
> > + * : : ring_empty---->WAIT_DATA : :
> > + * : : : :
> > + * : :......................................................: :
> > + * :............................................................:
> > + *
> > + * For the full state machine view, see `The VF state machine`_.
> > + */
> > static void pf_exit_vf_restore_wip(struct xe_gt *gt, unsigned int vfid)
> > {
> > - pf_exit_vf_state(gt, vfid, XE_GT_SRIOV_STATE_RESTORE_WIP);
> > + if (pf_exit_vf_state(gt, vfid, XE_GT_SRIOV_STATE_RESTORE_WIP)) {
> > + pf_escape_vf_state(gt, vfid, XE_GT_SRIOV_STATE_RESTORE_PROCESS_DATA);
> > + pf_escape_vf_state(gt, vfid, XE_GT_SRIOV_STATE_RESTORE_WAIT_DATA);
> > + pf_escape_vf_state(gt, vfid, XE_GT_SRIOV_STATE_RESTORE_DATA_DONE);
> > + }
> > }
> >
> > static void pf_enter_vf_restored(struct xe_gt *gt, unsigned int vfid)
> > @@ -914,12 +1063,50 @@ static void pf_enter_vf_restored(struct xe_gt *gt, unsigned int vfid)
> > pf_expect_vf_state(gt, vfid, XE_GT_SRIOV_STATE_PAUSED);
> > }
> >
> > +static void pf_enter_vf_restore_failed(struct xe_gt *gt, unsigned int vfid)
> > +{
> > + pf_enter_vf_state(gt, vfid, XE_GT_SRIOV_STATE_RESTORE_FAILED);
> > + pf_exit_vf_wip(gt, vfid);
> > +}
> > +
> > +static int
>
> no need to split the line
Ok.
>
> > +pf_handle_vf_restore_data(struct xe_gt *gt, unsigned int vfid)
> > +{
> > + struct xe_sriov_migration_data *data = xe_gt_sriov_pf_migration_restore_consume(gt, vfid);
> > +
> > + xe_gt_assert(gt, data);
> > +
> > + xe_gt_sriov_notice(gt, "Skipping VF%u unknown data type: %d\n", vfid, data->type);
> > +
> > + return 0;
> > +}
> > +
> > static bool pf_handle_vf_restore(struct xe_gt *gt, unsigned int vfid)
> > {
> > - if (!pf_exit_vf_state(gt, vfid, XE_GT_SRIOV_STATE_RESTORE_WIP))
> > + int ret;
> > +
> > + if (!pf_exit_vf_state(gt, vfid, XE_GT_SRIOV_STATE_RESTORE_PROCESS_DATA))
> > return false;
> >
> > - pf_enter_vf_restored(gt, vfid);
> > + pf_enter_vf_state(gt, vfid, XE_GT_SRIOV_STATE_RESTORE_WAIT_DATA);
>
> maybe you shouldn't enter(WAIT_DATA) here
>
> > + if (xe_gt_sriov_pf_migration_ring_empty(gt, vfid)) {
>
> but here
>
> > + if (pf_exit_vf_state(gt, vfid, XE_GT_SRIOV_STATE_RESTORE_DATA_DONE)) {
>
> hmm, there should be no direct transition from WAIT_DATA to DONE
>
> > + pf_exit_vf_state(gt, vfid, XE_GT_SRIOV_STATE_RESTORE_WAIT_DATA);
> > + pf_enter_vf_restored(gt, vfid);
> > +
> > + return true;
> > + }
>
> or just here
>
> > +
> > + pf_enter_vf_state(gt, vfid, XE_GT_SRIOV_STATE_RESTORE_PROCESS_DATA);
>
> and transition back to PROCESS only on exit(WAIT) called below
>
> > + return true;
> > + }
> > + pf_exit_vf_state(gt, vfid, XE_GT_SRIOV_STATE_RESTORE_WAIT_DATA);
> > +
> > + ret = pf_handle_vf_restore_data(gt, vfid);
> > + if (ret)
> > + pf_enter_vf_restore_failed(gt, vfid);
> > + else
> > + pf_enter_vf_state(gt, vfid, XE_GT_SRIOV_STATE_RESTORE_PROCESS_DATA);
> >
> > return true;
> > }
> > @@ -927,6 +1114,7 @@ static bool pf_handle_vf_restore(struct xe_gt *gt, unsigned int vfid)
> > static bool pf_enter_vf_restore_wip(struct xe_gt *gt, unsigned int vfid)
> > {
> > if (pf_enter_vf_state(gt, vfid, XE_GT_SRIOV_STATE_RESTORE_WIP)) {
> > + pf_enter_vf_state(gt, vfid, XE_GT_SRIOV_STATE_RESTORE_PROCESS_DATA);
> > pf_enter_vf_wip(gt, vfid);
> > pf_queue_vf(gt, vfid);
> > return true;
> > @@ -935,6 +1123,41 @@ static bool pf_enter_vf_restore_wip(struct xe_gt *gt, unsigned int vfid)
> > return false;
> > }
> >
> > +/**
> > + * xe_gt_sriov_pf_control_restore_data_done() - Indicate the end of VF migration data stream.
> > + * @gt: the &xe_gt
> > + * @vfid: the VF identifier
> > + *
> > + * This function is for PF only.
> > + *
> > + * Return: 0 on success or a negative error code on failure.
> > + */
> > +int xe_gt_sriov_pf_control_restore_data_done(struct xe_gt *gt, unsigned int vfid)
> > +{
>
> shouldn't we have additional state checks here?
>
> expect(RESTORE_WIP)
> expect(RESTORE_PROCESS_DATA) ?
>
> this one below just looks for one-time entry, but can we really enter anytime ?
expect(RESTORE_WIP) makes sense - I'll add it.
>
> > + if (!pf_enter_vf_state(gt, vfid, XE_GT_SRIOV_STATE_RESTORE_DATA_DONE)) {
> > + pf_enter_vf_state_machine_bug(gt, vfid);
> > + return -EIO;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +/**
> > + * xe_gt_sriov_pf_control_process_restore_data() - Queue VF restore migration data processing.
> > + * @gt: the &xe_gt
> > + * @vfid: the VF identifier
> > + *
> > + * This function is for PF only.
> > + */
> > +void xe_gt_sriov_pf_control_process_restore_data(struct xe_gt *gt, unsigned int vfid)
> > +{
> > + if (!pf_expect_vf_state(gt, vfid, XE_GT_SRIOV_STATE_RESTORE_WIP))
> > + pf_enter_vf_state_machine_bug(gt, vfid);
> > +
> > + if (pf_exit_vf_state(gt, vfid, XE_GT_SRIOV_STATE_RESTORE_WAIT_DATA))
> > + pf_queue_vf(gt, vfid);
>
> IMO the transition to PROCESS shall be also done as part of exit(WAIT_DATA)
>
> > +}
> > +
> > /**
> > * xe_gt_sriov_pf_control_trigger restore_vf() - Start an SR-IOV VF migration data restore sequence.
> > * @gt: the &xe_gt
> > @@ -1000,11 +1223,9 @@ int xe_gt_sriov_pf_control_finish_restore_vf(struct xe_gt *gt, unsigned int vfid
> > {
> > int ret;
> >
> > - if (pf_check_vf_state(gt, vfid, XE_GT_SRIOV_STATE_RESTORE_WIP)) {
> > - ret = pf_wait_vf_restore_done(gt, vfid);
> > - if (ret)
> > - return ret;
> > - }
> > + ret = pf_wait_vf_restore_done(gt, vfid);
> > + if (ret)
> > + return ret;
> >
> > if (!pf_expect_vf_state(gt, vfid, XE_GT_SRIOV_STATE_RESTORED)) {
> > pf_enter_vf_mismatch(gt, vfid);
> > @@ -1703,9 +1924,21 @@ static bool pf_process_vf_state_machine(struct xe_gt *gt, unsigned int vfid)
> > if (pf_exit_vf_pause_save_guc(gt, vfid))
> > return true;
> >
> > + if (pf_check_vf_state(gt, vfid, XE_GT_SRIOV_STATE_SAVE_WAIT_DATA)) {
> > + xe_gt_sriov_dbg_verbose(gt, "VF%u in %s\n", vfid,
> > + control_bit_to_string(XE_GT_SRIOV_STATE_SAVE_WAIT_DATA));
> > + return false;
> > + }
> > +
> > if (pf_handle_vf_save(gt, vfid))
> > return true;
> >
> > + if (pf_check_vf_state(gt, vfid, XE_GT_SRIOV_STATE_RESTORE_WAIT_DATA)) {
> > + xe_gt_sriov_dbg_verbose(gt, "VF%u in %s\n", vfid,
> > + control_bit_to_string(XE_GT_SRIOV_STATE_RESTORE_WAIT_DATA));
> > + return false;
> > + }
> > +
> > if (pf_handle_vf_restore(gt, vfid))
> > return true;
> >
> > diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_pf_control.h b/drivers/gpu/drm/xe/xe_gt_sriov_pf_control.h
> > index abc233f6302ed..6b1ab339e3b73 100644
> > --- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_control.h
> > +++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_control.h
> > @@ -14,12 +14,14 @@ struct xe_gt;
> > int xe_gt_sriov_pf_control_init(struct xe_gt *gt);
> > void xe_gt_sriov_pf_control_restart(struct xe_gt *gt);
> >
> > -bool xe_gt_sriov_pf_control_check_vf_data_wip(struct xe_gt *gt, unsigned int vfid);
> > -
> > int xe_gt_sriov_pf_control_pause_vf(struct xe_gt *gt, unsigned int vfid);
> > int xe_gt_sriov_pf_control_resume_vf(struct xe_gt *gt, unsigned int vfid);
> > +bool xe_gt_sriov_pf_control_check_save_data_done(struct xe_gt *gt, unsigned int vfid);
> > +void xe_gt_sriov_pf_control_process_save_data(struct xe_gt *gt, unsigned int vfid);
> > int xe_gt_sriov_pf_control_trigger_save_vf(struct xe_gt *gt, unsigned int vfid);
> > int xe_gt_sriov_pf_control_finish_save_vf(struct xe_gt *gt, unsigned int vfid);
> > +int xe_gt_sriov_pf_control_restore_data_done(struct xe_gt *gt, unsigned int vfid);
> > +void xe_gt_sriov_pf_control_process_restore_data(struct xe_gt *gt, unsigned int vfid);
> > int xe_gt_sriov_pf_control_trigger_restore_vf(struct xe_gt *gt, unsigned int vfid);
> > int xe_gt_sriov_pf_control_finish_restore_vf(struct xe_gt *gt, unsigned int vfid);
> > int xe_gt_sriov_pf_control_stop_vf(struct xe_gt *gt, unsigned int vfid);
> > diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_pf_control_types.h b/drivers/gpu/drm/xe/xe_gt_sriov_pf_control_types.h
> > index e113dc98b33ce..6e19a8ea88f0b 100644
> > --- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_control_types.h
> > +++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_control_types.h
> > @@ -32,9 +32,15 @@
> > * @XE_GT_SRIOV_STATE_PAUSE_FAILED: indicates that a VF pause operation has failed.
> > * @XE_GT_SRIOV_STATE_PAUSED: indicates that the VF is paused.
> > * @XE_GT_SRIOV_STATE_SAVE_WIP: indicates that VF save operation is in progress.
> > + * @XE_GT_SRIOV_STATE_SAVE_PROCESS_DATA: indicates that VF migration data is being produced.
> > + * @XE_GT_SRIOV_STATE_SAVE_WAIT_DATA: indicates that PF awaits for space in migration data ring.
> > + * @XE_GT_SRIOV_STATE_SAVE_DATA_DONE: indicates that all migration data was produced by Xe.
> > * @XE_GT_SRIOV_STATE_SAVE_FAILED: indicates that VF save operation has failed.
> > * @XE_GT_SRIOV_STATE_SAVED: indicates that VF data is saved.
> > * @XE_GT_SRIOV_STATE_RESTORE_WIP: indicates that VF restore operation is in progress.
> > + * @XE_GT_SRIOV_STATE_RESTORE_PROCESS_DATA: indicates that VF migration data is being consumed.
> > + * @XE_GT_SRIOV_STATE_RESTORE_WAIT_DATA: indicates that PF awaits for data in migration data ring.
> > + * @XE_GT_SRIOV_STATE_RESTORE_DATA_DONE: indicates that all migration data was produced by the user.
> > * @XE_GT_SRIOV_STATE_RESTORE_FAILED: indicates that VF restore operation has failed.
> > * @XE_GT_SRIOV_STATE_RESTORED: indicates that VF data is restored.
> > * @XE_GT_SRIOV_STATE_RESUME_WIP: indicates the a VF resume operation is in progress.
> > @@ -70,10 +76,16 @@ enum xe_gt_sriov_control_bits {
> > XE_GT_SRIOV_STATE_PAUSED,
> >
> > XE_GT_SRIOV_STATE_SAVE_WIP,
> > + XE_GT_SRIOV_STATE_SAVE_PROCESS_DATA,
> > + XE_GT_SRIOV_STATE_SAVE_WAIT_DATA,
> > + XE_GT_SRIOV_STATE_SAVE_DATA_DONE,
> > XE_GT_SRIOV_STATE_SAVE_FAILED,
> > XE_GT_SRIOV_STATE_SAVED,
> >
> > XE_GT_SRIOV_STATE_RESTORE_WIP,
> > + XE_GT_SRIOV_STATE_RESTORE_PROCESS_DATA,
> > + XE_GT_SRIOV_STATE_RESTORE_WAIT_DATA,
> > + XE_GT_SRIOV_STATE_RESTORE_DATA_DONE,
> > XE_GT_SRIOV_STATE_RESTORE_FAILED,
> > XE_GT_SRIOV_STATE_RESTORED,
> >
> > diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.c b/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.c
> > index ca28f45aaf481..b6ffd982d6007 100644
> > --- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.c
> > +++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.c
> > @@ -7,6 +7,7 @@
> >
> > #include "abi/guc_actions_sriov_abi.h"
> > #include "xe_bo.h"
> > +#include "xe_gt_sriov_pf_control.h"
> > #include "xe_gt_sriov_pf_helpers.h"
> > #include "xe_gt_sriov_pf_migration.h"
> > #include "xe_gt_sriov_printk.h"
> > @@ -15,6 +16,17 @@
> > #include "xe_sriov.h"
> > #include "xe_sriov_pf_migration.h"
> >
> > +#define XE_GT_SRIOV_PF_MIGRATION_RING_SIZE 5
> > +
> > +static struct xe_gt_sriov_migration_data *pf_pick_gt_migration(struct xe_gt *gt, unsigned int vfid)
> > +{
> > + xe_gt_assert(gt, IS_SRIOV_PF(gt_to_xe(gt)));
> > + xe_gt_assert(gt, vfid != PFID);
> > + xe_gt_assert(gt, vfid <= xe_sriov_pf_get_totalvfs(gt_to_xe(gt)));
> > +
> > + return >->sriov.pf.vfs[vfid].migration;
> > +}
> > +
> > /* Return: number of dwords saved/restored/required or a negative error code on failure */
> > static int guc_action_vf_save_restore(struct xe_guc *guc, u32 vfid, u32 opcode,
> > u64 addr, u32 ndwords)
> > @@ -382,6 +394,162 @@ ssize_t xe_gt_sriov_pf_migration_write_guc_state(struct xe_gt *gt, unsigned int
> > }
> > #endif /* CONFIG_DEBUG_FS */
> >
> > +/**
> > + * xe_gt_sriov_pf_migration_ring_empty() - Check if a migration ring is empty.
> > + * @gt: the &xe_gt
> > + * @vfid: the VF identifier
> > + *
> > + * Return: true if the ring is empty, otherwise false.
> > + */
> > +bool xe_gt_sriov_pf_migration_ring_empty(struct xe_gt *gt, unsigned int vfid)
> > +{
> > + return ptr_ring_empty(&pf_pick_gt_migration(gt, vfid)->ring);
> > +}
> > +
> > +/**
> > + * xe_gt_sriov_pf_migration_ring_full() - Check if a migration ring is full.
> > + * @gt: the &xe_gt
> > + * @vfid: the VF identifier
> > + *
> > + * Return: true if the ring is full, otherwise false.
> > + */
> > +bool xe_gt_sriov_pf_migration_ring_full(struct xe_gt *gt, unsigned int vfid)
> > +{
> > + return ptr_ring_full(&pf_pick_gt_migration(gt, vfid)->ring);
> > +}
> > +
> > +/**
> > + * xe_gt_sriov_pf_migration_save_produce() - Add VF save data packet to migration ring.
> > + * @gt: the &xe_gt
> > + * @vfid: the VF identifier
> > + * @data: &xe_sriov_migration_data packet
> > + *
> > + * Called by the save migration data producer (PF SR-IOV Control worker) when
> > + * processing migration data.
> > + * Wakes up the save migration data consumer (userspace), that is potentially
> > + * waiting for data when the ring is empty.
> > + *
> > + * Return: 0 on success or a negative error code on failure.
> > + */
> > +int xe_gt_sriov_pf_migration_save_produce(struct xe_gt *gt, unsigned int vfid,
> > + struct xe_sriov_migration_data *data)
> > +{
> > + int ret;
> > +
> > + ret = ptr_ring_produce(&pf_pick_gt_migration(gt, vfid)->ring, data);
> > + if (ret)
> > + return ret;
> > +
> > + wake_up_all(xe_sriov_pf_migration_waitqueue(gt_to_xe(gt), vfid));
> > +
> > + return 0;
> > +}
> > +
> > +/**
> > + * xe_gt_sriov_pf_migration_restore_consume() - Get VF restore data packet from migration ring.
> > + * @gt: the &xe_gt
> > + * @vfid: the VF identifier
> > + *
> > + * Called by the restore migration data consumer (PF SR-IOV Control worker) when
> > + * processing migration data.
> > + * Wakes up the restore migration data producer (userspace), that is
> > + * potentially waiting to add more data when the ring is full.
> > + *
> > + * Return: Pointer to &struct xe_sriov_migration_data on success,
> > + * NULL if ring is empty.
> > + */
> > +struct xe_sriov_migration_data *
> > +xe_gt_sriov_pf_migration_restore_consume(struct xe_gt *gt, unsigned int vfid)
> > +{
> > + struct xe_gt_sriov_migration_data *migration = pf_pick_gt_migration(gt, vfid);
> > + struct wait_queue_head *wq = xe_sriov_pf_migration_waitqueue(gt_to_xe(gt), vfid);
> > + struct xe_sriov_migration_data *data;
> > +
> > + data = ptr_ring_consume(&migration->ring);
> > + if (data)
> > + wake_up_all(wq);
> > +
> > + return data;
> > +}
> > +
> > +/**
> > + * xe_gt_sriov_pf_migration_restore_produce() - Add VF restore data packet to migration ring.
> > + * @gt: the &xe_gt
> > + * @vfid: the VF identifier
> > + * @data: &xe_sriov_migration_data packet
> > + *
> > + * Called by the restore migration data producer (userspace) when processing
> > + * migration data.
> > + * If the ring is full, waits until there is space.
> > + * Queues the restore migration data consumer (PF SR-IOV Control worker), that
> > + * is potentially waiting for data when the ring is empty.
> > + *
> > + * Return: 0 on success or a negative error code on failure.
> > + */
> > +int xe_gt_sriov_pf_migration_restore_produce(struct xe_gt *gt, unsigned int vfid,
> > + struct xe_sriov_migration_data *data)
> > +{
> > + struct wait_queue_head *wq = xe_sriov_pf_migration_waitqueue(gt_to_xe(gt), vfid);
> > + struct xe_gt_sriov_migration_data *migration = pf_pick_gt_migration(gt, vfid);
> > + int ret;
> > +
> > + xe_gt_assert(gt, data->tile == gt->tile->id);
> > + xe_gt_assert(gt, data->gt == gt->info.id);
> > +
> > + while (1) {
>
> or for (;;)
Ok.
>
> > + ret = ptr_ring_produce(&migration->ring, data);
> > + if (!ret)
> > + break;
> > +
> > + ret = wait_event_interruptible(*wq, !ptr_ring_full(&migration->ring));
> > + if (ret)
> > + return ret;
> > + }
> > +
> > + xe_gt_sriov_pf_control_process_restore_data(gt, vfid);
> > +
> > + return 0;
> > +}
> > +
> > +/**
> > + * xe_gt_sriov_pf_migration_save_consume() - Get VF save data packet from migration ring.
> > + * @gt: the &xe_gt
> > + * @vfid: the VF identifier
> > + *
> > + * Called by the save migration data consumer (userspace) when
> > + * processing migration data.
> > + * Queues the save migration data producer (PF SR-IOV Control worker), that is
> > + * potentially waiting to add more data when the ring is full.
> > + *
> > + * Return: Pointer to &struct xe_sriov_migration_data on success,
> > + * NULL if ring is empty and there's no more data available,
> > + * ERR_PTR(-EAGAIN) if the ring is empty, but data is still produced.
> > + */
> > +struct xe_sriov_migration_data *
> > +xe_gt_sriov_pf_migration_save_consume(struct xe_gt *gt, unsigned int vfid)
> > +{
> > + struct xe_gt_sriov_migration_data *migration = pf_pick_gt_migration(gt, vfid);
> > + struct xe_sriov_migration_data *data;
> > +
> > + data = ptr_ring_consume(&migration->ring);
> > + if (data) {
> > + xe_gt_sriov_pf_control_process_save_data(gt, vfid);
> > + return data;
> > + }
> > +
> > + if (xe_gt_sriov_pf_control_check_save_data_done(gt, vfid))
> > + return NULL;
> > +
> > + return ERR_PTR(-EAGAIN);
> > +}
> > +
> > +static void action_ring_cleanup(struct drm_device *dev, void *arg)
> > +{
> > + struct ptr_ring *r = arg;
> > +
> > + ptr_ring_cleanup(r, NULL);
> > +}
> > +
> > /**
> > * xe_gt_sriov_pf_migration_init() - Initialize support for VF migration.
> > * @gt: the &xe_gt
> > @@ -393,6 +561,7 @@ ssize_t xe_gt_sriov_pf_migration_write_guc_state(struct xe_gt *gt, unsigned int
> > int xe_gt_sriov_pf_migration_init(struct xe_gt *gt)
> > {
> > struct xe_device *xe = gt_to_xe(gt);
> > + unsigned int n, totalvfs;
> > int err;
> >
> > xe_gt_assert(gt, IS_SRIOV_PF(xe));
> > @@ -404,5 +573,19 @@ int xe_gt_sriov_pf_migration_init(struct xe_gt *gt)
> > if (err)
> > return err;
> >
> > + totalvfs = xe_sriov_pf_get_totalvfs(xe);
> > + for (n = 1; n <= totalvfs; n++) {
> > + struct xe_gt_sriov_migration_data *migration = pf_pick_gt_migration(gt, n);
> > +
> > + err = ptr_ring_init(&migration->ring,
> > + XE_GT_SRIOV_PF_MIGRATION_RING_SIZE, GFP_KERNEL);
> > + if (err)
> > + return err;
> > +
> > + err = drmm_add_action_or_reset(&xe->drm, action_ring_cleanup, &migration->ring);
>
> should we wait until drmm cleanup or devm cleanup ?
Worker is drmm, so I did follow that, but yeah, I guess it should match
pdev lifetime rather than DRM dev lifetime.
>
>
> > + if (err)
> > + return err;
> > + }
> > +
> > return 0;
> > }
> > diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.h b/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.h
> > index 09faeae00ddbb..9e67f18ded205 100644
> > --- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.h
> > +++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.h
> > @@ -9,11 +9,25 @@
> > #include <linux/types.h>
> >
> > struct xe_gt;
> > +struct xe_sriov_migration_data;
> >
> > int xe_gt_sriov_pf_migration_init(struct xe_gt *gt);
> > int xe_gt_sriov_pf_migration_save_guc_state(struct xe_gt *gt, unsigned int vfid);
> > int xe_gt_sriov_pf_migration_restore_guc_state(struct xe_gt *gt, unsigned int vfid);
> >
> > +bool xe_gt_sriov_pf_migration_ring_empty(struct xe_gt *gt, unsigned int vfid);
> > +bool xe_gt_sriov_pf_migration_ring_full(struct xe_gt *gt, unsigned int vfid);
> > +
> > +int xe_gt_sriov_pf_migration_save_produce(struct xe_gt *gt, unsigned int vfid,
> > + struct xe_sriov_migration_data *data);
> > +struct xe_sriov_migration_data *
> > +xe_gt_sriov_pf_migration_restore_consume(struct xe_gt *gt, unsigned int vfid);
> > +
> > +int xe_gt_sriov_pf_migration_restore_produce(struct xe_gt *gt, unsigned int vfid,
> > + struct xe_sriov_migration_data *data);
> > +struct xe_sriov_migration_data *
> > +xe_gt_sriov_pf_migration_save_consume(struct xe_gt *gt, unsigned int vfid);
> > +
> > #ifdef CONFIG_DEBUG_FS
> > ssize_t xe_gt_sriov_pf_migration_read_guc_state(struct xe_gt *gt, unsigned int vfid,
> > char __user *buf, size_t count, loff_t *pos);
> > diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration_types.h b/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration_types.h
> > index 9d672feac5f04..84be6fac16c8b 100644
> > --- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration_types.h
> > +++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration_types.h
> > @@ -7,6 +7,7 @@
> > #define _XE_GT_SRIOV_PF_MIGRATION_TYPES_H_
> >
> > #include <linux/mutex.h>
> > +#include <linux/ptr_ring.h>
> > #include <linux/types.h>
> >
> > /**
> > @@ -24,6 +25,16 @@ struct xe_gt_sriov_state_snapshot {
> > } guc;
> > };
> >
> > +/**
> > + * struct xe_gt_sriov_migration_data - GT-level per-VF migration data.
> > + *
> > + * Used by the PF driver to maintain per-VF migration data.
> > + */
> > +struct xe_gt_sriov_migration_data {
> > + /** @ring: queue containing VF save / restore migration data */
> > + struct ptr_ring ring;
> > +};
> > +
> > /**
> > * struct xe_gt_sriov_pf_migration - GT-level data.
> > *
> > diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_pf_types.h b/drivers/gpu/drm/xe/xe_gt_sriov_pf_types.h
> > index a64a6835ad656..812e74d3f8f80 100644
> > --- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_types.h
> > +++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_types.h
> > @@ -33,6 +33,9 @@ struct xe_gt_sriov_metadata {
> >
> > /** @snapshot: snapshot of the VF state data */
> > struct xe_gt_sriov_state_snapshot snapshot;
> > +
> > + /** @migration: per-VF migration data. */
> > + struct xe_gt_sriov_migration_data migration;
> > };
> >
> > /**
> > diff --git a/drivers/gpu/drm/xe/xe_sriov_pf_migration.c b/drivers/gpu/drm/xe/xe_sriov_pf_migration.c
> > index 8c523c392f98b..eaf581317bdef 100644
> > --- a/drivers/gpu/drm/xe/xe_sriov_pf_migration.c
> > +++ b/drivers/gpu/drm/xe/xe_sriov_pf_migration.c
> > @@ -3,8 +3,36 @@
> > * Copyright © 2025 Intel Corporation
> > */
> >
> > +#include <drm/drm_managed.h>
> > +
> > +#include "xe_device.h"
> > +#include "xe_gt_sriov_pf_control.h"
> > +#include "xe_gt_sriov_pf_migration.h"
> > +#include "xe_pm.h"
> > #include "xe_sriov.h"
> > +#include "xe_sriov_pf_helpers.h"
> > #include "xe_sriov_pf_migration.h"
> > +#include "xe_sriov_printk.h"
> > +
> > +static struct xe_sriov_pf_migration *pf_pick_migration(struct xe_device *xe, unsigned int vfid)
> > +{
> > + xe_assert(xe, IS_SRIOV_PF(xe));
> > + xe_assert(xe, vfid <= xe_sriov_pf_get_totalvfs(xe));
> > +
> > + return &xe->sriov.pf.vfs[vfid].migration;
> > +}
> > +
> > +/**
> > + * xe_sriov_pf_migration_waitqueue - Get waitqueue for migration.
> > + * @xe: the &xe_device
> > + * @vfid: the VF identifier
> > + *
> > + * Return: pointer to the migration waitqueue.
> > + */
> > +wait_queue_head_t *xe_sriov_pf_migration_waitqueue(struct xe_device *xe, unsigned int vfid)
> > +{
> > + return &pf_pick_migration(xe, vfid)->wq;
> > +}
> >
> > /**
> > * xe_sriov_pf_migration_supported() - Check if SR-IOV VF migration is supported by the device
> > @@ -33,9 +61,124 @@ static bool pf_check_migration_support(struct xe_device *xe)
> > */
> > int xe_sriov_pf_migration_init(struct xe_device *xe)
> > {
> > + unsigned int n, totalvfs;
> > +
> > xe_assert(xe, IS_SRIOV_PF(xe));
> >
> > xe->sriov.pf.migration.supported = pf_check_migration_support(xe);
> > + if (!xe_sriov_pf_migration_supported(xe))
> > + return 0;
> > +
> > + totalvfs = xe_sriov_pf_get_totalvfs(xe);
> > + for (n = 1; n <= totalvfs; n++) {
> > + struct xe_sriov_pf_migration *migration = pf_pick_migration(xe, n);
> > +
> > + init_waitqueue_head(&migration->wq);
> > + }
> >
> > return 0;
> > }
> > +
> > +static bool pf_migration_data_ready(struct xe_device *xe, unsigned int vfid)
> > +{
> > + struct xe_gt *gt;
> > + u8 gt_id;
> > +
> > + for_each_gt(gt, xe, gt_id) {
> > + if (!xe_gt_sriov_pf_migration_ring_empty(gt, vfid) ||
> > + xe_gt_sriov_pf_control_check_save_data_done(gt, vfid))
> > + return true;
> > + }
> > +
> > + return false;
> > +}
> > +
> > +static struct xe_sriov_migration_data *
> > +pf_migration_consume(struct xe_device *xe, unsigned int vfid)
> > +{
> > + struct xe_sriov_migration_data *data;
> > + struct xe_gt *gt;
> > + u8 gt_id;
> > + bool more_data = false;
> > +
> > + for_each_gt(gt, xe, gt_id) {
> > + data = xe_gt_sriov_pf_migration_save_consume(gt, vfid);
> > + if (data && PTR_ERR(data) != EAGAIN)
> > + return data;
> > + if (PTR_ERR(data) == -EAGAIN)
> > + more_data = true;
> > + }
> > +
> > + if (!more_data)
> > + return NULL;
> > +
> > + return ERR_PTR(-EAGAIN);
> > +}
> > +
> > +/**
> > + * xe_sriov_pf_migration_save_consume() - Consume a VF migration data packet from the device.
> > + * @xe: the &xe_device
> > + * @vfid: the VF identifier
> > + *
> > + * Called by the save migration data consumer (userspace) when
> > + * processing migration data.
> > + * If there is no migration data to process, wait until more data is available.
> > + *
> > + * Return: Pointer to &xe_sriov_migration_data on success,
> > + * NULL if ring is empty and no more migration data is expected,
> > + * ERR_PTR value in case of error.
> > + *
> > + * Return: 0 on success or a negative error code on failure.
> > + */
> > +struct xe_sriov_migration_data *
> > +xe_sriov_pf_migration_save_consume(struct xe_device *xe, unsigned int vfid)
> > +{
> > + struct xe_sriov_pf_migration *migration = pf_pick_migration(xe, vfid);
> > + struct xe_sriov_migration_data *data;
> > + int ret;
> > +
> > + xe_assert(xe, IS_SRIOV_PF(xe));
> > +
> > + while (1) {
> > + data = pf_migration_consume(xe, vfid);
> > + if (PTR_ERR(data) != -EAGAIN)
> > + goto out;
>
> just
> break; ?
Ok.
Thanks,
-Michał
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