On Mon, Apr 10, 2017 at 02:40:24AM +0000, Dong, Chuanxiao wrote: > > -----Original Message----- > > From: intel-gvt-dev [mailto:intel-gvt-dev-bounces@xxxxxxxxxxxxxxxxxxxxx] On > > Behalf Of Dong, Chuanxiao > > Sent: Thursday, April 6, 2017 11:19 PM > > To: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > > Cc: Tian, Kevin <kevin.tian@xxxxxxxxx>; intel-gvt-dev@xxxxxxxxxxxxxxxxxxxxx; > > intel-gfx@xxxxxxxxxxxxxxxxxxxxx; joonas.lahtinen@xxxxxxxxxxxxxxx; Zheng, > > Xiao <xiao.zheng@xxxxxxxxx>; Wang, Zhi A <zhi.a.wang@xxxxxxxxx> > > Subject: RE: [PATCH v2 2/2] drm/i915/scheduler: add gvt notification for guc > > > > > > > > > -----Original Message----- > > > From: Chris Wilson [mailto:chris@xxxxxxxxxxxxxxxxxx] > > > Sent: Thursday, April 6, 2017 11:07 PM > > > To: Dong, Chuanxiao > > > Cc: intel-gfx@xxxxxxxxxxxxxxxxxxxxx; > > > intel-gvt-dev@xxxxxxxxxxxxxxxxxxxxx; > > > Zheng, Xiao; Tian, Kevin; joonas.lahtinen@xxxxxxxxxxxxxxx; Wang, Zhi A > > > Subject: Re: [PATCH v2 2/2] drm/i915/scheduler: add gvt notification > > > for guc > > > > > > On Thu, Apr 06, 2017 at 02:49:54PM +0000, Dong, Chuanxiao wrote: > > > > > > > > > > > > > -----Original Message----- > > > > > From: Chris Wilson [mailto:chris@xxxxxxxxxxxxxxxxxx] > > > > > Sent: Thursday, April 6, 2017 10:19 PM > > > > > To: Dong, Chuanxiao > > > > > Cc: intel-gfx@xxxxxxxxxxxxxxxxxxxxx; > > > > > intel-gvt-dev@xxxxxxxxxxxxxxxxxxxxx; > > > > > Zheng, Xiao; Tian, Kevin; joonas.lahtinen@xxxxxxxxxxxxxxx > > > > > Subject: Re: [PATCH v2 2/2] drm/i915/scheduler: add gvt > > > > > notification for guc > > > > > > > > > > On Thu, Apr 06, 2017 at 02:05:15PM +0000, Dong, Chuanxiao wrote: > > > > > > > > > > > > > > > > > > > -----Original Message----- > > > > > > > From: Chris Wilson [mailto:chris@xxxxxxxxxxxxxxxxxx] > > > > > > > Sent: Thursday, April 6, 2017 9:32 PM > > > > > > > To: Dong, Chuanxiao > > > > > > > Cc: intel-gfx@xxxxxxxxxxxxxxxxxxxxx; > > > > > > > intel-gvt-dev@xxxxxxxxxxxxxxxxxxxxx; > > > > > > > Zheng, Xiao; Tian, Kevin; joonas.lahtinen@xxxxxxxxxxxxxxx > > > > > > > Subject: Re: [PATCH v2 2/2] drm/i915/scheduler: add gvt > > > > > > > notification for guc > > > > > > > > > > > > > > On Tue, Mar 28, 2017 at 05:38:41PM +0800, Chuanxiao Dong wrote: > > > > > > > > GVT request needs a manual mmio load/restore. Before GuC > > > > > > > > submit a request, send notification to gvt for mmio loading. > > > > > > > > And after the GuC finished this GVT request, notify gvt > > > > > > > > again for > > > mmio restore. > > > > > > > > This follows the usage when using execlists submission. > > > > > > > > > > > > > > > > Cc: xiao.zheng@xxxxxxxxx > > > > > > > > Cc: kevin.tian@xxxxxxxxx > > > > > > > > Cc: joonas.lahtinen@xxxxxxxxxxxxxxx > > > > > > > > Cc: chris@xxxxxxxxxxxxxxxxxx > > > > > > > > Signed-off-by: Chuanxiao Dong <chuanxiao.dong@xxxxxxxxx> > > > > > > > > --- > > > > > > > > drivers/gpu/drm/i915/i915_guc_submission.c | 4 ++++ > > > > > > > > drivers/gpu/drm/i915/intel_gvt.h | 12 ++++++++++++ > > > > > > > > drivers/gpu/drm/i915/intel_lrc.c | 21 +++------------------ > > > > > > > > 3 files changed, 19 insertions(+), 18 deletions(-) > > > > > > > > > > > > > > > > diff --git a/drivers/gpu/drm/i915/i915_guc_submission.c > > > > > > > > b/drivers/gpu/drm/i915/i915_guc_submission.c > > > > > > > > index 58087630..d8a5942 100644 > > > > > > > > --- a/drivers/gpu/drm/i915/i915_guc_submission.c > > > > > > > > +++ b/drivers/gpu/drm/i915/i915_guc_submission.c > > > > > > > > @@ -606,6 +606,8 @@ static void __i915_guc_submit(struct > > > > > > > drm_i915_gem_request *rq) > > > > > > > > unsigned long flags; > > > > > > > > int b_ret; > > > > > > > > > > > > > > > > + intel_gvt_notify_context_status(rq, > > > > > > > > +INTEL_CONTEXT_SCHEDULE_IN); > > > > > > > > + > > > > > > > > /* WA to flush out the pending GMADR writes to ring buffer. > > > */ > > > > > > > > if (i915_vma_is_map_and_fenceable(rq->ring->vma)) > > > > > > > > POSTING_READ_FW(GUC_STATUS); @@ -725,6 > > > +727,8 @@ static > > > > > > > > void i915_guc_irq_handler(unsigned long > > > > > data) > > > > > > > > rq = port[0].request; > > > > > > > > while (rq && i915_gem_request_completed(rq)) { > > > > > > > > trace_i915_gem_request_out(rq); > > > > > > > > + intel_gvt_notify_context_status(rq, > > > > > > > > + > > > INTEL_CONTEXT_SCHEDULE_OUT); > > > > > > > > > > > > > > This is incorrect though. This is no better than just waiting > > > > > > > for the request, which is not enough since the idea is that > > > > > > > you need to wait for the context image to be completely > > > > > > > written to memory before > > > > > you read it. > > > > > > > -Chris > > > > > > > > > > > > The wait for the context image to be completely written will be > > > > > > done in the > > > > > notification from the GVT, by checking the CSB. If put the wait > > > > > here will made each i915 request to wait, which seems not necessary. > > > > > > > > > > Urm, no. I hope you mean the wait will be on some other thread > > > > > than inside this interrupt handler. > > > > > > > > The SCHEDULE_OUT means to stop GuC to submit another request > > before > > > the current one is completed by GVT so GVT can manually restore the > > MMIO. > > > So this irq handler should wait until SCHEDULE_OUT is completed. How > > > it possible to make this irq handler to wait for another thread? From > > > the current software architecture there is no other thread.... > > > > > > No. It is not acceptable to have any blocking here. Rather you > > > delegate the polling of CSB to a thread/worker that you kick off from this > > notify. > > > -Chris > > > > The major issue is that we should wait for the context image to be > > completely written to memory before GVT read it. I will double check if we > > are really reading from context image in this SCHEDULE_OUT event and > > return back later. > > Hi Chris, > > Had a discussion with Zhi, actually the context image is accessed from the workload_thread to update the guest context but not directly from the SCHEDULE_OUT event. So my previous comment is wrong and the CSB waiting should be in workload_thread instead of this IRQ handler. That's better, still a little worried about having to remember to review these hooks later. The other concern I express at the start of this was: diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c index 9e327049b735..5a86abd715df 100644 --- a/drivers/gpu/drm/i915/intel_lrc.c +++ b/drivers/gpu/drm/i915/intel_lrc.c @@ -430,16 +430,6 @@ static void execlists_dequeue(struct intel_engine_cs *engine) if (port != engine->execlist_port) break; - /* If GVT overrides us we only ever submit port[0], - * leaving port[1] empty. Note that we also have - * to be careful that we don't queue the same - * context (even though a different request) to - * the second port. - */ - if (ctx_single_port_submission(last->ctx) || - ctx_single_port_submission(cursor->ctx)) - break; - Afaict that requirement is completely bogus (since your workloads do only active on gvt requests and there will only ever be one scheduled-in at any time) and burdensome on non-gvt. -Chris -- Chris Wilson, Intel Open Source Technology Centre _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
