From 52988009843160c5b366b4082ed6df48041c655c Mon Sep 17 00:00:00 2001 From: Xiaolin Zhang Date: Fri, 23 Aug 2019 14:57:31 +0800 Subject: [PATCH] drm/i915: to make vgpu ppgtt notificaiton as atomic operation vgpu ppgtt notification was split into 2 steps, the first step is to update PVINFO's pdp register and then write PVINFO's g2v_notify register with action code to tirgger ppgtt notification to GVT side. currently these steps were not atomic operations due to no any protection, so it is easy to enter race condition state during the MTBF, stress and IGT test to cause GPU hang. the solution is to add a lock to make vgpu ppgtt notication as atomic operation. Cc: stable@vger.kernel.org Signed-off-by: Xiaolin Zhang Acked-by: Chris Wilson Signed-off-by: Chris Wilson Link: https://patchwork.freedesktop.org/patch/msgid/1566543451-13955-1-git-send-email-xiaolin.zhang@intel.com --- drivers/gpu/drm/i915/i915_drv.h | 1 + drivers/gpu/drm/i915/i915_gem_gtt.c | 12 +++++++----- drivers/gpu/drm/i915/i915_vgpu.c | 1 + 3 files changed, 9 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index f5e39a3bfff6..b42651a387d9 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -966,6 +966,7 @@ struct i915_frontbuffer_tracking { }; struct i915_virtual_gpu { + struct mutex lock; /* serialises sending of g2v_notify command pkts */ bool active; u32 caps; }; diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c index e0e9b9b52544..0db82921fb38 100644 --- a/drivers/gpu/drm/i915/i915_gem_gtt.c +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c @@ -834,10 +834,9 @@ static void mark_tlbs_dirty(struct i915_ppgtt *ppgtt) ppgtt->pd_dirty_engines = ALL_ENGINES; } -static int gen8_ppgtt_notify_vgt(struct i915_ppgtt *ppgtt, bool create) +static void gen8_ppgtt_notify_vgt(struct i915_ppgtt *ppgtt, bool create) { - struct i915_address_space *vm = &ppgtt->vm; - struct drm_i915_private *dev_priv = vm->i915; + struct drm_i915_private *dev_priv = ppgtt->vm.i915; enum vgt_g2v_type msg; int i; @@ -846,7 +845,9 @@ static int gen8_ppgtt_notify_vgt(struct i915_ppgtt *ppgtt, bool create) else atomic_dec(px_used(ppgtt->pd)); - if (i915_vm_is_4lvl(vm)) { + mutex_lock(&dev_priv->vgpu.lock); + + if (i915_vm_is_4lvl(&ppgtt->vm)) { const u64 daddr = px_dma(ppgtt->pd); I915_WRITE(vgtif_reg(pdp[0].lo), lower_32_bits(daddr)); @@ -866,9 +867,10 @@ static int gen8_ppgtt_notify_vgt(struct i915_ppgtt *ppgtt, bool create) VGT_G2V_PPGTT_L3_PAGE_TABLE_DESTROY); } + /* g2v_notify atomically (via hv trap) consumes the message packet. */ I915_WRITE(vgtif_reg(g2v_notify), msg); - return 0; + mutex_unlock(&dev_priv->vgpu.lock); } /* Index shifts into the pagetable are offset by GEN8_PTE_SHIFT [12] */ diff --git a/drivers/gpu/drm/i915/i915_vgpu.c b/drivers/gpu/drm/i915/i915_vgpu.c index 39bebf16edbe..968be26735c5 100644 --- a/drivers/gpu/drm/i915/i915_vgpu.c +++ b/drivers/gpu/drm/i915/i915_vgpu.c @@ -94,6 +94,7 @@ void i915_detect_vgpu(struct drm_i915_private *dev_priv) dev_priv->vgpu.caps = readl(shared_area + vgtif_offset(vgt_caps)); dev_priv->vgpu.active = true; + mutex_init(&dev_priv->vgpu.lock); DRM_INFO("Virtual GPU for Intel GVT-g detected.\n"); out: -- 2.30.2