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* [PATCH] virtio_ring: check desc == NULL when packed and indirect
@ 2021-09-27  3:06 Xuan Zhuo
  2021-09-27  3:20 ` Jason Wang
  2021-09-27  9:36 ` Michael S. Tsirkin
  0 siblings, 2 replies; 5+ messages in thread
From: Xuan Zhuo @ 2021-09-27  3:06 UTC (permalink / raw)
  To: virtualization; +Cc: David S. Miller, Tiwei Bie, Michael S. Tsirkin

In the case of packed, use indirect desc, since desc is allocated by
kmalloc_array(), we should check whether its return value is NULL.

Fixes: 1ce9e6055fa ("virtio_ring: introduce packed ring support")
Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
---
 drivers/virtio/virtio_ring.c | 27 ++++++++++++++++-----------
 1 file changed, 16 insertions(+), 11 deletions(-)

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index dd95dfd85e98..7dd381eae725 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -1050,21 +1050,20 @@ static struct vring_packed_desc *alloc_indirect_packed(unsigned int total_sg,
 }
 
 static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq,
-				       struct scatterlist *sgs[],
-				       unsigned int total_sg,
-				       unsigned int out_sgs,
-				       unsigned int in_sgs,
-				       void *data,
-				       gfp_t gfp)
+					 struct scatterlist *sgs[],
+					 struct vring_packed_desc *desc,
+					 unsigned int total_sg,
+					 unsigned int out_sgs,
+					 unsigned int in_sgs,
+					 void *data,
+					 gfp_t gfp)
 {
-	struct vring_packed_desc *desc;
 	struct scatterlist *sg;
 	unsigned int i, n, err_idx;
 	u16 head, id;
 	dma_addr_t addr;
 
 	head = vq->packed.next_avail_idx;
-	desc = alloc_indirect_packed(total_sg, gfp);
 
 	if (unlikely(vq->vq.num_free < 1)) {
 		pr_debug("Can't add buf len 1 - avail = 0\n");
@@ -1191,9 +1190,15 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq,
 
 	BUG_ON(total_sg == 0);
 
-	if (virtqueue_use_indirect(_vq, total_sg))
-		return virtqueue_add_indirect_packed(vq, sgs, total_sg,
-				out_sgs, in_sgs, data, gfp);
+	if (virtqueue_use_indirect(_vq, total_sg)) {
+		desc = alloc_indirect_packed(total_sg, gfp);
+		if (desc) {
+			return virtqueue_add_indirect_packed(vq, sgs, desc,
+							     total_sg,
+							     out_sgs, in_sgs,
+							     data, gfp);
+		}
+	}
 
 	head = vq->packed.next_avail_idx;
 	avail_used_flags = vq->packed.avail_used_flags;
-- 
2.31.0

_______________________________________________
Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization

^ permalink raw reply related	[flat|nested] 5+ messages in thread

* Re: [PATCH] virtio_ring: check desc == NULL when packed and indirect
  2021-09-27  3:06 [PATCH] virtio_ring: check desc == NULL when packed and indirect Xuan Zhuo
@ 2021-09-27  3:20 ` Jason Wang
  2021-09-27  3:25   ` Xuan Zhuo
  2021-09-27  9:36 ` Michael S. Tsirkin
  1 sibling, 1 reply; 5+ messages in thread
From: Jason Wang @ 2021-09-27  3:20 UTC (permalink / raw)
  To: Xuan Zhuo; +Cc: Michael S. Tsirkin, David S. Miller, Tiwei Bie, virtualization

On Mon, Sep 27, 2021 at 11:06 AM Xuan Zhuo <xuanzhuo@linux.alibaba.com> wrote:
>
> In the case of packed, use indirect desc, since desc is allocated by
> kmalloc_array(), we should check whether its return value is NULL.
>
> Fixes: 1ce9e6055fa ("virtio_ring: introduce packed ring support")
> Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
> ---
>  drivers/virtio/virtio_ring.c | 27 ++++++++++++++++-----------
>  1 file changed, 16 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
> index dd95dfd85e98..7dd381eae725 100644
> --- a/drivers/virtio/virtio_ring.c
> +++ b/drivers/virtio/virtio_ring.c
> @@ -1050,21 +1050,20 @@ static struct vring_packed_desc *alloc_indirect_packed(unsigned int total_sg,
>  }
>
>  static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq,
> -                                      struct scatterlist *sgs[],
> -                                      unsigned int total_sg,
> -                                      unsigned int out_sgs,
> -                                      unsigned int in_sgs,
> -                                      void *data,
> -                                      gfp_t gfp)
> +                                        struct scatterlist *sgs[],
> +                                        struct vring_packed_desc *desc,
> +                                        unsigned int total_sg,
> +                                        unsigned int out_sgs,
> +                                        unsigned int in_sgs,
> +                                        void *data,
> +                                        gfp_t gfp)

It looks to me the style changes are mixed with bug fix here.

>  {
> -       struct vring_packed_desc *desc;
>         struct scatterlist *sg;
>         unsigned int i, n, err_idx;
>         u16 head, id;
>         dma_addr_t addr;
>
>         head = vq->packed.next_avail_idx;
> -       desc = alloc_indirect_packed(total_sg, gfp);
>
>         if (unlikely(vq->vq.num_free < 1)) {
>                 pr_debug("Can't add buf len 1 - avail = 0\n");
> @@ -1191,9 +1190,15 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq,
>
>         BUG_ON(total_sg == 0);
>
> -       if (virtqueue_use_indirect(_vq, total_sg))
> -               return virtqueue_add_indirect_packed(vq, sgs, total_sg,
> -                               out_sgs, in_sgs, data, gfp);
> +       if (virtqueue_use_indirect(_vq, total_sg)) {
> +               desc = alloc_indirect_packed(total_sg, gfp);
> +               if (desc) {
> +                       return virtqueue_add_indirect_packed(vq, sgs, desc,
> +                                                            total_sg,
> +                                                            out_sgs, in_sgs,
> +                                                            data, gfp);
> +               }
> +       }

Any reason that we can't fix virtqueue_add_indirect_packed()? It can
help to reduce the changeset and ease the backport.

Thanks

>
>         head = vq->packed.next_avail_idx;
>         avail_used_flags = vq->packed.avail_used_flags;
> --
> 2.31.0
>

_______________________________________________
Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH] virtio_ring: check desc == NULL when packed and indirect
  2021-09-27  3:20 ` Jason Wang
@ 2021-09-27  3:25   ` Xuan Zhuo
  2021-09-27  3:43     ` Jason Wang
  0 siblings, 1 reply; 5+ messages in thread
From: Xuan Zhuo @ 2021-09-27  3:25 UTC (permalink / raw)
  To: Jason Wang; +Cc: Michael S. Tsirkin, David S. Miller, Tiwei Bie, virtualization

On Mon, 27 Sep 2021 11:20:16 +0800, Jason Wang <jasowang@redhat.com> wrote:
> On Mon, Sep 27, 2021 at 11:06 AM Xuan Zhuo <xuanzhuo@linux.alibaba.com> wrote:
> >
> > In the case of packed, use indirect desc, since desc is allocated by
> > kmalloc_array(), we should check whether its return value is NULL.
> >
> > Fixes: 1ce9e6055fa ("virtio_ring: introduce packed ring support")
> > Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
> > ---
> >  drivers/virtio/virtio_ring.c | 27 ++++++++++++++++-----------
> >  1 file changed, 16 insertions(+), 11 deletions(-)
> >
> > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
> > index dd95dfd85e98..7dd381eae725 100644
> > --- a/drivers/virtio/virtio_ring.c
> > +++ b/drivers/virtio/virtio_ring.c
> > @@ -1050,21 +1050,20 @@ static struct vring_packed_desc *alloc_indirect_packed(unsigned int total_sg,
> >  }
> >
> >  static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq,
> > -                                      struct scatterlist *sgs[],
> > -                                      unsigned int total_sg,
> > -                                      unsigned int out_sgs,
> > -                                      unsigned int in_sgs,
> > -                                      void *data,
> > -                                      gfp_t gfp)
> > +                                        struct scatterlist *sgs[],
> > +                                        struct vring_packed_desc *desc,
> > +                                        unsigned int total_sg,
> > +                                        unsigned int out_sgs,
> > +                                        unsigned int in_sgs,
> > +                                        void *data,
> > +                                        gfp_t gfp)
>
> It looks to me the style changes are mixed with bug fix here.


I will make a separate patch for the next version.

>
> >  {
> > -       struct vring_packed_desc *desc;
> >         struct scatterlist *sg;
> >         unsigned int i, n, err_idx;
> >         u16 head, id;
> >         dma_addr_t addr;
> >
> >         head = vq->packed.next_avail_idx;
> > -       desc = alloc_indirect_packed(total_sg, gfp);
> >
> >         if (unlikely(vq->vq.num_free < 1)) {
> >                 pr_debug("Can't add buf len 1 - avail = 0\n");
> > @@ -1191,9 +1190,15 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq,
> >
> >         BUG_ON(total_sg == 0);
> >
> > -       if (virtqueue_use_indirect(_vq, total_sg))
> > -               return virtqueue_add_indirect_packed(vq, sgs, total_sg,
> > -                               out_sgs, in_sgs, data, gfp);
> > +       if (virtqueue_use_indirect(_vq, total_sg)) {
> > +               desc = alloc_indirect_packed(total_sg, gfp);
> > +               if (desc) {
> > +                       return virtqueue_add_indirect_packed(vq, sgs, desc,
> > +                                                            total_sg,
> > +                                                            out_sgs, in_sgs,
> > +                                                            data, gfp);
> > +               }
> > +       }
>
> Any reason that we can't fix virtqueue_add_indirect_packed()? It can
> help to reduce the changeset and ease the backport.

The purpose of this is to fall back to not using indirect when
alloc_indirect_packed returns NULL.

If we check the return value of alloc_indirect_packed() in
virtqueue_add_indirect_packed(), then MUST check the error returned by
virtqueue_add_indirect_packed() to determine whether to fall back to the mode
that does not use indirect.

Thanks.

>
> Thanks
>
> >
> >         head = vq->packed.next_avail_idx;
> >         avail_used_flags = vq->packed.avail_used_flags;
> > --
> > 2.31.0
> >
>
_______________________________________________
Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH] virtio_ring: check desc == NULL when packed and indirect
  2021-09-27  3:25   ` Xuan Zhuo
@ 2021-09-27  3:43     ` Jason Wang
  0 siblings, 0 replies; 5+ messages in thread
From: Jason Wang @ 2021-09-27  3:43 UTC (permalink / raw)
  To: Xuan Zhuo; +Cc: Michael S. Tsirkin, David S. Miller, Tiwei Bie, virtualization

On Mon, Sep 27, 2021 at 11:29 AM Xuan Zhuo <xuanzhuo@linux.alibaba.com> wrote:
>
> On Mon, 27 Sep 2021 11:20:16 +0800, Jason Wang <jasowang@redhat.com> wrote:
> > On Mon, Sep 27, 2021 at 11:06 AM Xuan Zhuo <xuanzhuo@linux.alibaba.com> wrote:
> > >
> > > In the case of packed, use indirect desc, since desc is allocated by
> > > kmalloc_array(), we should check whether its return value is NULL.
> > >
> > > Fixes: 1ce9e6055fa ("virtio_ring: introduce packed ring support")
> > > Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
> > > ---
> > >  drivers/virtio/virtio_ring.c | 27 ++++++++++++++++-----------
> > >  1 file changed, 16 insertions(+), 11 deletions(-)
> > >
> > > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
> > > index dd95dfd85e98..7dd381eae725 100644
> > > --- a/drivers/virtio/virtio_ring.c
> > > +++ b/drivers/virtio/virtio_ring.c
> > > @@ -1050,21 +1050,20 @@ static struct vring_packed_desc *alloc_indirect_packed(unsigned int total_sg,
> > >  }
> > >
> > >  static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq,
> > > -                                      struct scatterlist *sgs[],
> > > -                                      unsigned int total_sg,
> > > -                                      unsigned int out_sgs,
> > > -                                      unsigned int in_sgs,
> > > -                                      void *data,
> > > -                                      gfp_t gfp)
> > > +                                        struct scatterlist *sgs[],
> > > +                                        struct vring_packed_desc *desc,
> > > +                                        unsigned int total_sg,
> > > +                                        unsigned int out_sgs,
> > > +                                        unsigned int in_sgs,
> > > +                                        void *data,
> > > +                                        gfp_t gfp)
> >
> > It looks to me the style changes are mixed with bug fix here.
>
>
> I will make a separate patch for the next version.

Please make it a patch on top of the fix to ease the backport.

>
> >
> > >  {
> > > -       struct vring_packed_desc *desc;
> > >         struct scatterlist *sg;
> > >         unsigned int i, n, err_idx;
> > >         u16 head, id;
> > >         dma_addr_t addr;
> > >
> > >         head = vq->packed.next_avail_idx;
> > > -       desc = alloc_indirect_packed(total_sg, gfp);
> > >
> > >         if (unlikely(vq->vq.num_free < 1)) {
> > >                 pr_debug("Can't add buf len 1 - avail = 0\n");
> > > @@ -1191,9 +1190,15 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq,
> > >
> > >         BUG_ON(total_sg == 0);
> > >
> > > -       if (virtqueue_use_indirect(_vq, total_sg))
> > > -               return virtqueue_add_indirect_packed(vq, sgs, total_sg,
> > > -                               out_sgs, in_sgs, data, gfp);
> > > +       if (virtqueue_use_indirect(_vq, total_sg)) {
> > > +               desc = alloc_indirect_packed(total_sg, gfp);
> > > +               if (desc) {
> > > +                       return virtqueue_add_indirect_packed(vq, sgs, desc,
> > > +                                                            total_sg,
> > > +                                                            out_sgs, in_sgs,
> > > +                                                            data, gfp);
> > > +               }
> > > +       }
> >
> > Any reason that we can't fix virtqueue_add_indirect_packed()? It can
> > help to reduce the changeset and ease the backport.
>
> The purpose of this is to fall back to not using indirect when
> alloc_indirect_packed returns NULL.
>
> If we check the return value of alloc_indirect_packed() in
> virtqueue_add_indirect_packed(), then MUST check the error returned by
> virtqueue_add_indirect_packed() to determine whether to fall back to the mode
> that does not use indirect.

Right, this aligns the behaviour of the split path. But please
describe this in the commit log.

Thanks

>
> Thanks.
>
> >
> > Thanks
> >
> > >
> > >         head = vq->packed.next_avail_idx;
> > >         avail_used_flags = vq->packed.avail_used_flags;
> > > --
> > > 2.31.0
> > >
> >
>

_______________________________________________
Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH] virtio_ring: check desc == NULL when packed and indirect
  2021-09-27  3:06 [PATCH] virtio_ring: check desc == NULL when packed and indirect Xuan Zhuo
  2021-09-27  3:20 ` Jason Wang
@ 2021-09-27  9:36 ` Michael S. Tsirkin
  1 sibling, 0 replies; 5+ messages in thread
From: Michael S. Tsirkin @ 2021-09-27  9:36 UTC (permalink / raw)
  To: Xuan Zhuo; +Cc: David S. Miller, Tiwei Bie, virtualization

On Mon, Sep 27, 2021 at 11:06:18AM +0800, Xuan Zhuo wrote:
> In the case of packed, use indirect desc, since desc is allocated by
> kmalloc_array(), we should check whether its return value is NULL.
> 
> Fixes: 1ce9e6055fa ("virtio_ring: introduce packed ring support")
> Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
> ---
>  drivers/virtio/virtio_ring.c | 27 ++++++++++++++++-----------
>  1 file changed, 16 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
> index dd95dfd85e98..7dd381eae725 100644
> --- a/drivers/virtio/virtio_ring.c
> +++ b/drivers/virtio/virtio_ring.c
> @@ -1050,21 +1050,20 @@ static struct vring_packed_desc *alloc_indirect_packed(unsigned int total_sg,
>  }
>  
>  static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq,
> -				       struct scatterlist *sgs[],
> -				       unsigned int total_sg,
> -				       unsigned int out_sgs,
> -				       unsigned int in_sgs,
> -				       void *data,
> -				       gfp_t gfp)
> +					 struct scatterlist *sgs[],
> +					 struct vring_packed_desc *desc,
> +					 unsigned int total_sg,
> +					 unsigned int out_sgs,
> +					 unsigned int in_sgs,
> +					 void *data,
> +					 gfp_t gfp)
>  {
> -	struct vring_packed_desc *desc;
>  	struct scatterlist *sg;
>  	unsigned int i, n, err_idx;
>  	u16 head, id;
>  	dma_addr_t addr;
>  
>  	head = vq->packed.next_avail_idx;
> -	desc = alloc_indirect_packed(total_sg, gfp);
>  
>  	if (unlikely(vq->vq.num_free < 1)) {
>  		pr_debug("Can't add buf len 1 - avail = 0\n");
> @@ -1191,9 +1190,15 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq,
>  
>  	BUG_ON(total_sg == 0);
>  
> -	if (virtqueue_use_indirect(_vq, total_sg))
> -		return virtqueue_add_indirect_packed(vq, sgs, total_sg,
> -				out_sgs, in_sgs, data, gfp);
> +	if (virtqueue_use_indirect(_vq, total_sg)) {
> +		desc = alloc_indirect_packed(total_sg, gfp);
> +		if (desc) {
> +			return virtqueue_add_indirect_packed(vq, sgs, desc,
> +							     total_sg,
> +							     out_sgs, in_sgs,
> +							     data, gfp);
> +		}

Eschew {} for a single statement if conditions pls.


> +	}
>  
>  	head = vq->packed.next_avail_idx;
>  	avail_used_flags = vq->packed.avail_used_flags;
> -- 
> 2.31.0

_______________________________________________
Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization

^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2021-09-27  9:36 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-09-27  3:06 [PATCH] virtio_ring: check desc == NULL when packed and indirect Xuan Zhuo
2021-09-27  3:20 ` Jason Wang
2021-09-27  3:25   ` Xuan Zhuo
2021-09-27  3:43     ` Jason Wang
2021-09-27  9:36 ` Michael S. Tsirkin

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