Re: [PATCH 6/9] drm/xe/sriov: Move VF bootstrap and query_config to vf_guc_init

[Rodrigo Vivi <rodrigo.vivi@intel.com>]

On Fri, Nov 15, 2024 at 08:50:01PM +0100, Maarten Lankhorst wrote:
> Hey,
> 
> Den 2024-11-15 kl. 20:06, skrev Rodrigo Vivi:
> > On Fri, Nov 15, 2024 at 03:21:43PM +0100, Maarten Lankhorst wrote:
> > > Hey,
> > > 
> > > Den 2024-11-14 kl. 17:09, skrev Rodrigo Vivi:
> > > > On Thu, Nov 07, 2024 at 11:01:37AM +0100, Maarten Lankhorst wrote:
> > > > > We want to split up GUC init to an alloc and noalloc part to keep the
> > > > > init path the same for VF and !VF as much as possible.
> > > > > 
> > > > > Everything in vf_guc_init should be done as early as possible, otherwise
> > > > > VRAM probing becomes impossible.
> > > > > 
> > > > > Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
> > > > > Link: https://patchwork.freedesktop.org/patch/msgid/20241105121857.17389-6-maarten.lankhorst@linux.intel.com
> > > > > Signed-off-by: Maarten Lankhorst,,, <dev@lankhorst.se>
> > > > > ---
> > > > >   drivers/gpu/drm/xe/xe_gt_sriov_vf.c |  1 -
> > > > >   drivers/gpu/drm/xe/xe_guc.c         | 17 +++++++++--------
> > > > >   2 files changed, 9 insertions(+), 9 deletions(-)
> > > > > 
> > > > > diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_vf.c b/drivers/gpu/drm/xe/xe_gt_sriov_vf.c
> > > > > index cca5d57328021..997438047a037 100644
> > > > > --- a/drivers/gpu/drm/xe/xe_gt_sriov_vf.c
> > > > > +++ b/drivers/gpu/drm/xe/xe_gt_sriov_vf.c
> > > > > @@ -948,7 +948,6 @@ u32 xe_gt_sriov_vf_read32(struct xe_gt *gt, struct xe_reg reg)
> > > > >   	struct vf_runtime_reg *rr;
> > > > >   	xe_gt_assert(gt, IS_SRIOV_VF(gt_to_xe(gt)));
> > > > > -	xe_gt_assert(gt, gt->sriov.vf.pf_version.major);
> > > > >   	xe_gt_assert(gt, !reg.vf);
> > > > >   	if (reg.addr == GMD_ID.addr) {
> > > > > diff --git a/drivers/gpu/drm/xe/xe_guc.c b/drivers/gpu/drm/xe/xe_guc.c
> > > > > index 7224593c9ce9b..5a050a5379911 100644
> > > > > --- a/drivers/gpu/drm/xe/xe_guc.c
> > > > > +++ b/drivers/gpu/drm/xe/xe_guc.c
> > > > > @@ -301,6 +301,7 @@ static int xe_guc_realloc_post_hwconfig(struct xe_guc *guc)
> > > > >   static int vf_guc_init(struct xe_guc *guc)
> > > > >   {
> > > > > +	struct xe_gt *gt = guc_to_gt(guc);
> > > > >   	int err;
> > > > >   	xe_guc_comm_init_early(guc);
> > > > > @@ -313,6 +314,14 @@ static int vf_guc_init(struct xe_guc *guc)
> > > > >   	if (err)
> > > > >   		return err;
> > > > > +	err = xe_gt_sriov_vf_bootstrap(gt);
> > > > > +	if (err)
> > > > > +		return err;
> > > > > +
> > > > > +	err = xe_gt_sriov_vf_query_config(gt);
> > > > > +	if (err)
> > > > > +		return err;
> > > > > +
> > > > >   	return 0;
> > > > >   }
> > > > > @@ -753,14 +762,6 @@ static int vf_guc_min_load_for_hwconfig(struct xe_guc *guc)
> > > > Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
> > > > 
> > > > as I believe there was a good reason for these functions to be called this early.
> > > 
> > > This is in fact called slightly earlier than before. It's now called in xe_uc_init instead of xe_uc_init_hwconfig. :-)
> > 
> > Oh! Indeed! one step earlier actually... that name min_for_hwconfig got me confused, I'm sorry.
> > 
> > The only difference that I see now is that this functions are not avoided anymore if xe.force_execlist=1...
> > 
> > We should probably add some skips inside the function? I know I know we likely have many other bugs
> > if using force_execlists, but let's at least try to avoid introducing more cases...
> 
> I don't think it's even possible to use execists in VF mode. :-)

yeap, it is not... this is why we should ensure these functions are not called, liked
they were not called before this patch...

> 
> Cheers,
> ~Maarten