On 2019.08.27 16:39:23 +0800, Xiaolin Zhang wrote:
> when creating a vGPU workload, the guest context head pointer should
> be updated correctly by comparing with the exsiting workload in the
> guest worklod queue including the current running context.
>
> in some situation, there is a running context A and then received 2 new
> vGPU workload context B and A. in the new workload context A, it's head
> pointer should be updated with the running context A's tail.
>
> Fixes: 09975b861aa0 ("drm/i915/execlists: Disable preemption under GVT")
> Fixes: 22b7a426bbe1 ("drm/i915/execlists: Preempt-to-busy")
>
> v2: walk through guest workload list in backward way.
>
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Xiaolin Zhang <xiaolin.zhang@xxxxxxxxx>
> ---
Reviewed-by: Zhenyu Wang <zhenyuw@xxxxxxxxxxxxxxx>
Thanks for the fix!
> drivers/gpu/drm/i915/gvt/scheduler.c | 28 +++++++++++++++-------------
> 1 file changed, 15 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gvt/scheduler.c b/drivers/gpu/drm/i915/gvt/scheduler.c
> index 8940fa8..166b998 100644
> --- a/drivers/gpu/drm/i915/gvt/scheduler.c
> +++ b/drivers/gpu/drm/i915/gvt/scheduler.c
> @@ -1438,9 +1438,6 @@ static int prepare_mm(struct intel_vgpu_workload *workload)
> #define same_context(a, b) (((a)->context_id == (b)->context_id) && \
> ((a)->lrca == (b)->lrca))
>
> -#define get_last_workload(q) \
> - (list_empty(q) ? NULL : container_of(q->prev, \
> - struct intel_vgpu_workload, list))
> /**
> * intel_vgpu_create_workload - create a vGPU workload
> * @vgpu: a vGPU
> @@ -1460,7 +1457,7 @@ intel_vgpu_create_workload(struct intel_vgpu *vgpu, int ring_id,
> {
> struct intel_vgpu_submission *s = &vgpu->submission;
> struct list_head *q = workload_q_head(vgpu, ring_id);
> - struct intel_vgpu_workload *last_workload = get_last_workload(q);
> + struct intel_vgpu_workload *last_workload = NULL;
> struct intel_vgpu_workload *workload = NULL;
> struct drm_i915_private *dev_priv = vgpu->gvt->dev_priv;
> u64 ring_context_gpa;
> @@ -1486,15 +1483,20 @@ intel_vgpu_create_workload(struct intel_vgpu *vgpu, int ring_id,
> head &= RB_HEAD_OFF_MASK;
> tail &= RB_TAIL_OFF_MASK;
>
> - if (last_workload && same_context(&last_workload->ctx_desc, desc)) {
> - gvt_dbg_el("ring id %d cur workload == last\n", ring_id);
> - gvt_dbg_el("ctx head %x real head %lx\n", head,
> - last_workload->rb_tail);
> - /*
> - * cannot use guest context head pointer here,
> - * as it might not be updated at this time
> - */
> - head = last_workload->rb_tail;
> + list_for_each_entry_reverse(last_workload, q, list) {
> +
> + if (same_context(&last_workload->ctx_desc, desc)) {
> + gvt_dbg_el("ring id %d cur workload == last\n",
> + ring_id);
> + gvt_dbg_el("ctx head %x real head %lx\n", head,
> + last_workload->rb_tail);
> + /*
> + * cannot use guest context head pointer here,
> + * as it might not be updated at this time
> + */
> + head = last_workload->rb_tail;
> + break;
> + }
> }
>
> gvt_dbg_el("ring id %d begin a new workload\n", ring_id);
> --
> 2.7.4
>
> _______________________________________________
> intel-gvt-dev mailing list
> intel-gvt-dev@xxxxxxxxxxxxxxxxxxxxx
> https://lists.freedesktop.org/mailman/listinfo/intel-gvt-dev
--
Open Source Technology Center, Intel ltd.
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