[Intel-gfx] [PATCH v6 13/14] drm/i915/gvt: Fix error handling in ppgtt_populate_spt_by_guest_entry

[changbin . du]

From: Changbin Du <changbin...@intel.com>

Don't forget to free allocated spt if shadowing failed.

Signed-off-by: Changbin Du <changbin...@intel.com>
---
 drivers/gpu/drm/i915/gvt/gtt.c | 33 +++++++++++++++++++++------------
 1 file changed, 21 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/i915/gvt/gtt.c b/drivers/gpu/drm/i915/gvt/gtt.c
index 2bf85be..f83ac08 100644
--- a/drivers/gpu/drm/i915/gvt/gtt.c
+++ b/drivers/gpu/drm/i915/gvt/gtt.c
@@ -907,15 +907,22 @@ static struct intel_vgpu_ppgtt_spt *ppgtt_alloc_spt_gfn(
             i += (spt->shadow_page.pde_ips ? GTT_64K_PTE_STRIDE : 1)) \
                if (!ppgtt_get_shadow_entry(spt, e, i))
 
-static void ppgtt_get_spt(struct intel_vgpu_ppgtt_spt *spt)
+static inline void ppgtt_get_spt(struct intel_vgpu_ppgtt_spt *spt)
 {
        int v = atomic_read(&spt->refcount);
 
        trace_spt_refcount(spt->vgpu->id, "inc", spt, v, (v + 1));
-
        atomic_inc(&spt->refcount);
 }
 
+static inline int ppgtt_put_spt(struct intel_vgpu_ppgtt_spt *spt)
+{
+       int v = atomic_read(&spt->refcount);
+
+       trace_spt_refcount(spt->vgpu->id, "dec", spt, v, (v - 1));
+       return atomic_dec_return(&spt->refcount);
+}
+
 static int ppgtt_invalidate_spt(struct intel_vgpu_ppgtt_spt *spt);
 
 static int ppgtt_invalidate_spt_by_shadow_entry(struct intel_vgpu *vgpu,
@@ -967,14 +974,11 @@ static int ppgtt_invalidate_spt(struct 
intel_vgpu_ppgtt_spt *spt)
        struct intel_gvt_gtt_entry e;
        unsigned long index;
        int ret;
-       int v = atomic_read(&spt->refcount);
 
        trace_spt_change(spt->vgpu->id, "die", spt,
                        spt->guest_page.gfn, spt->shadow_page.type);
 
-       trace_spt_refcount(spt->vgpu->id, "dec", spt, v, (v - 1));
-
-       if (atomic_dec_return(&spt->refcount) > 0)
+       if (ppgtt_put_spt(spt) > 0)
                return 0;
 
        for_each_present_shadow_entry(spt, &e, index) {
@@ -1056,8 +1060,10 @@ static struct intel_vgpu_ppgtt_spt 
*ppgtt_populate_spt_by_guest_entry(
                        gvt_dbg_mm("reshadow PDE since ips changed\n");
                        clear_page(spt->shadow_page.vaddr);
                        ret = ppgtt_populate_spt(spt);
-                       if (ret)
-                               goto fail;
+                       if (ret) {
+                               ppgtt_put_spt(spt);
+                               goto err;
+                       }
                }
        } else {
                int type = get_next_pt_type(we->type);
@@ -1065,22 +1071,25 @@ static struct intel_vgpu_ppgtt_spt 
*ppgtt_populate_spt_by_guest_entry(
                spt = ppgtt_alloc_spt_gfn(vgpu, type, ops->get_pfn(we), ips);
                if (IS_ERR(spt)) {
                        ret = PTR_ERR(spt);
-                       goto fail;
+                       goto err;
                }
 
                ret = intel_vgpu_enable_page_track(vgpu, spt->guest_page.gfn);
                if (ret)
-                       goto fail;
+                       goto err_free_spt;
 
                ret = ppgtt_populate_spt(spt);
                if (ret)
-                       goto fail;
+                       goto err_free_spt;
 
                trace_spt_change(vgpu->id, "new", spt, spt->guest_page.gfn,
                                 spt->shadow_page.type);
        }
        return spt;
-fail:
+
+err_free_spt:
+       ppgtt_free_spt(spt);
+err:
        gvt_vgpu_err("fail: shadow page %p guest entry 0x%llx type %d\n",
                     spt, we->val64, we->type);
        return ERR_PTR(ret);
-- 
2.7.4

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