From b79c52aef3cdee903017c1e9834b53996d70010e Mon Sep 17 00:00:00 2001 From: Zhi Wang Date: Thu, 30 Mar 2017 01:48:39 +0800 Subject: [PATCH] drm/i915/gvt: Activate/de-activate vGPU in mdev ops. This patch introduces two functions for activating/de-activating vGPU in mdev ops. A racing condition was found between virtual vblank emulation and KVGMT mdev release path. V-blank emulation will emulate and inject V-blank interrupt for every active vGPU with holding gvt->lock, while in mdev release path, it will directly release hypervisor handle without changing vGPU status or taking gvt->lock, so a kernel oops is encountered when vblank emulation is injecting a interrupt with a invalid hypervisor handle. (Reported by Terrence) To solve this problem, we factor out vGPU activation/de-activation from vGPU creation/destruction path and let KVMGT mdev release ops de-activate the vGPU before release hypervisor handle. Once a vGPU is de-activated, GVT-g will not emulate v-blank for it or touch the hypervisor handle. Fixes: 659643f ("drm/i915/gvt/kvmgt: add vfio/mdev support to KVMGT") Signed-off-by: Zhi Wang Signed-off-by: Zhenyu Wang --- drivers/gpu/drm/i915/gvt/gvt.c | 2 ++ drivers/gpu/drm/i915/gvt/gvt.h | 5 ++- drivers/gpu/drm/i915/gvt/kvmgt.c | 4 +++ drivers/gpu/drm/i915/gvt/vgpu.c | 53 ++++++++++++++++++++++++++------ 4 files changed, 53 insertions(+), 11 deletions(-) diff --git a/drivers/gpu/drm/i915/gvt/gvt.c b/drivers/gpu/drm/i915/gvt/gvt.c index 3b9d59e457ba..ef3baa0c4754 100644 --- a/drivers/gpu/drm/i915/gvt/gvt.c +++ b/drivers/gpu/drm/i915/gvt/gvt.c @@ -52,6 +52,8 @@ static const struct intel_gvt_ops intel_gvt_ops = { .vgpu_create = intel_gvt_create_vgpu, .vgpu_destroy = intel_gvt_destroy_vgpu, .vgpu_reset = intel_gvt_reset_vgpu, + .vgpu_activate = intel_gvt_activate_vgpu, + .vgpu_deactivate = intel_gvt_deactivate_vgpu, }; /** diff --git a/drivers/gpu/drm/i915/gvt/gvt.h b/drivers/gpu/drm/i915/gvt/gvt.h index 23791920ced1..2387eacf74bb 100644 --- a/drivers/gpu/drm/i915/gvt/gvt.h +++ b/drivers/gpu/drm/i915/gvt/gvt.h @@ -382,7 +382,8 @@ void intel_gvt_destroy_vgpu(struct intel_vgpu *vgpu); void intel_gvt_reset_vgpu_locked(struct intel_vgpu *vgpu, bool dmlr, unsigned int engine_mask); void intel_gvt_reset_vgpu(struct intel_vgpu *vgpu); - +void intel_gvt_activate_vgpu(struct intel_vgpu *vgpu); +void intel_gvt_deactivate_vgpu(struct intel_vgpu *vgpu); /* validating GM functions */ #define vgpu_gmadr_is_aperture(vgpu, gmadr) \ @@ -449,6 +450,8 @@ struct intel_gvt_ops { struct intel_vgpu_type *); void (*vgpu_destroy)(struct intel_vgpu *); void (*vgpu_reset)(struct intel_vgpu *); + void (*vgpu_activate)(struct intel_vgpu *); + void (*vgpu_deactivate)(struct intel_vgpu *); }; diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c index d641214578a7..9843d74056a8 100644 --- a/drivers/gpu/drm/i915/gvt/kvmgt.c +++ b/drivers/gpu/drm/i915/gvt/kvmgt.c @@ -544,6 +544,8 @@ static int intel_vgpu_open(struct mdev_device *mdev) if (ret) goto undo_group; + intel_gvt_ops->vgpu_activate(vgpu); + atomic_set(&vgpu->vdev.released, 0); return ret; @@ -569,6 +571,8 @@ static void __intel_vgpu_release(struct intel_vgpu *vgpu) if (atomic_cmpxchg(&vgpu->vdev.released, 0, 1)) return; + intel_gvt_ops->vgpu_deactivate(vgpu); + ret = vfio_unregister_notifier(mdev_dev(vgpu->vdev.mdev), VFIO_IOMMU_NOTIFY, &vgpu->vdev.iommu_notifier); WARN(ret, "vfio_unregister_notifier for iommu failed: %d\n", ret); diff --git a/drivers/gpu/drm/i915/gvt/vgpu.c b/drivers/gpu/drm/i915/gvt/vgpu.c index 41cfa5ccae84..2f5792a1ce38 100644 --- a/drivers/gpu/drm/i915/gvt/vgpu.c +++ b/drivers/gpu/drm/i915/gvt/vgpu.c @@ -178,6 +178,47 @@ static void intel_gvt_update_vgpu_types(struct intel_gvt *gvt) } } +/** + * intel_gvt_active_vgpu - activate a virtual GPU + * @vgpu: virtual GPU + * + * This function is called when user wants to activate a virtual GPU. + * + */ +void intel_gvt_activate_vgpu(struct intel_vgpu *vgpu) +{ + mutex_lock(&vgpu->gvt->lock); + vgpu->active = true; + mutex_unlock(&vgpu->gvt->lock); +} + +/** + * intel_gvt_deactive_vgpu - deactivate a virtual GPU + * @vgpu: virtual GPU + * + * This function is called when user wants to deactivate a virtual GPU. + * All virtual GPU runtime information will be destroyed. + * + */ +void intel_gvt_deactivate_vgpu(struct intel_vgpu *vgpu) +{ + struct intel_gvt *gvt = vgpu->gvt; + + mutex_lock(&gvt->lock); + + vgpu->active = false; + + if (atomic_read(&vgpu->running_workload_num)) { + mutex_unlock(&gvt->lock); + intel_gvt_wait_vgpu_idle(vgpu); + mutex_lock(&gvt->lock); + } + + intel_vgpu_stop_schedule(vgpu); + + mutex_unlock(&gvt->lock); +} + /** * intel_gvt_destroy_vgpu - destroy a virtual GPU * @vgpu: virtual GPU @@ -191,16 +232,9 @@ void intel_gvt_destroy_vgpu(struct intel_vgpu *vgpu) mutex_lock(&gvt->lock); - vgpu->active = false; + WARN(vgpu->active, "vGPU is still active!\n"); + idr_remove(&gvt->vgpu_idr, vgpu->id); - - if (atomic_read(&vgpu->running_workload_num)) { - mutex_unlock(&gvt->lock); - intel_gvt_wait_vgpu_idle(vgpu); - mutex_lock(&gvt->lock); - } - - intel_vgpu_stop_schedule(vgpu); intel_vgpu_clean_sched_policy(vgpu); intel_vgpu_clean_gvt_context(vgpu); intel_vgpu_clean_execlist(vgpu); @@ -277,7 +311,6 @@ static struct intel_vgpu *__intel_gvt_create_vgpu(struct intel_gvt *gvt, if (ret) goto out_clean_shadow_ctx; - vgpu->active = true; mutex_unlock(&gvt->lock); return vgpu;