If intel_gvt_dma_map_guest_page failed, it will call ppgtt_invalidate_spt, which will finally free the spt. But the caller does not notice that, it will free spt again in error path.
Fix this by spliting invalidate and free in ppgtt_invalidate_spt. Only free spt when in good case. Reported-by: Zheng Wang <hackerzheng...@gmail.com> Signed-off-by: Zheng Wang <zyytlz...@163.com> --- v2: - split initial function into two api function suggested by Greg v1: https://lore.kernel.org/all/20220928033340.1063949-1-zyytlz...@163.com/ --- drivers/gpu/drm/i915/gvt/gtt.c | 31 +++++++++++++++++++++---------- 1 file changed, 21 insertions(+), 10 deletions(-) diff --git a/drivers/gpu/drm/i915/gvt/gtt.c b/drivers/gpu/drm/i915/gvt/gtt.c index ce0eb03709c3..55d8e1419302 100644 --- a/drivers/gpu/drm/i915/gvt/gtt.c +++ b/drivers/gpu/drm/i915/gvt/gtt.c @@ -959,6 +959,7 @@ static inline int ppgtt_put_spt(struct intel_vgpu_ppgtt_spt *spt) return atomic_dec_return(&spt->refcount); } +static int ppgtt_invalidate_and_free_spt(struct intel_vgpu_ppgtt_spt *spt); static int ppgtt_invalidate_spt(struct intel_vgpu_ppgtt_spt *spt); static int ppgtt_invalidate_spt_by_shadow_entry(struct intel_vgpu *vgpu, @@ -995,7 +996,7 @@ static int ppgtt_invalidate_spt_by_shadow_entry(struct intel_vgpu *vgpu, ops->get_pfn(e)); return -ENXIO; } - return ppgtt_invalidate_spt(s); + return ppgtt_invalidate_and_free_spt(s); } static inline void ppgtt_invalidate_pte(struct intel_vgpu_ppgtt_spt *spt, @@ -1016,18 +1017,31 @@ static inline void ppgtt_invalidate_pte(struct intel_vgpu_ppgtt_spt *spt, intel_gvt_dma_unmap_guest_page(vgpu, pfn << PAGE_SHIFT); } -static int ppgtt_invalidate_spt(struct intel_vgpu_ppgtt_spt *spt) +static int ppgtt_invalidate_and_free_spt(struct intel_vgpu_ppgtt_spt *spt) { struct intel_vgpu *vgpu = spt->vgpu; - struct intel_gvt_gtt_entry e; - unsigned long index; int ret; trace_spt_change(spt->vgpu->id, "die", spt, - spt->guest_page.gfn, spt->shadow_page.type); - + spt->guest_page.gfn, spt->shadow_page.type); if (ppgtt_put_spt(spt) > 0) return 0; + ret = ppgtt_invalidate_spt(spt); + if (!ret) { + trace_spt_change(spt->vgpu->id, "release", spt, + spt->guest_page.gfn, spt->shadow_page.type); + ppgtt_free_spt(spt); + } + + return ret; +} + +static int ppgtt_invalidate_spt(struct intel_vgpu_ppgtt_spt *spt) +{ + struct intel_vgpu *vgpu = spt->vgpu; + struct intel_gvt_gtt_entry e; + unsigned long index; + int ret; for_each_present_shadow_entry(spt, &e, index) { switch (e.type) { @@ -1059,9 +1073,6 @@ static int ppgtt_invalidate_spt(struct intel_vgpu_ppgtt_spt *spt) } } - trace_spt_change(spt->vgpu->id, "release", spt, - spt->guest_page.gfn, spt->shadow_page.type); - ppgtt_free_spt(spt); return 0; fail: gvt_vgpu_err("fail: shadow page %p shadow entry 0x%llx type %d\n", @@ -1393,7 +1404,7 @@ static int ppgtt_handle_guest_entry_removal(struct intel_vgpu_ppgtt_spt *spt, ret = -ENXIO; goto fail; } - ret = ppgtt_invalidate_spt(s); + ret = ppgtt_invalidate_and_free_spt(s); if (ret) goto fail; } else { -- 2.25.1
