[PATCH v4 13/14] drm/i915/gvt: Fix error handling in ppgtt_populate_spt_by_guest_entry
Zhenyu Wang
zhenyuw at linux.intel.com
Mon May 7 03:17:31 UTC 2018
On 2018.05.04 17:50:39 +0800, changbin.du at intel.com wrote:
> From: Changbin Du <changbin.du at intel.com>
>
> Don't forget to free allocated spt if shadowing failed.
>
> Signed-off-by: Changbin Du <changbin.du at intel.com>
> ---
> drivers/gpu/drm/i915/gvt/gtt.c | 31 ++++++++++++++++++++-----------
> 1 file changed, 20 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gvt/gtt.c b/drivers/gpu/drm/i915/gvt/gtt.c
> index 2bf85be..4af6fee3 100644
> --- a/drivers/gpu/drm/i915/gvt/gtt.c
> +++ b/drivers/gpu/drm/i915/gvt/gtt.c
> @@ -912,10 +912,17 @@ static 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 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);
> +}
Use atomic_fetch_dec()
> +
> 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
>
> _______________________________________________
> intel-gvt-dev mailing list
> intel-gvt-dev at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/intel-gvt-dev
--
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