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[PATCH v1 31/36] vfio/pci: drop nth_page() usage within SG entry

David Hildenbrand posted 36 patches 1 month ago
There is a newer version of this series
[PATCH v1 31/36] vfio/pci: drop nth_page() usage within SG entry
Posted by David Hildenbrand 1 month ago 
It's no longer required to use nth_page() when iterating pages within a
single SG entry, so let's drop the nth_page() usage.

Cc: Brett Creeley <brett.creeley@amd.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Yishai Hadas <yishaih@nvidia.com>
Cc: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Cc: Kevin Tian <kevin.tian@intel.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
 drivers/vfio/pci/pds/lm.c         | 3 +--
 drivers/vfio/pci/virtio/migrate.c | 3 +--
 2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/vfio/pci/pds/lm.c b/drivers/vfio/pci/pds/lm.c
index f2673d395236a..4d70c833fa32e 100644
--- a/drivers/vfio/pci/pds/lm.c
+++ b/drivers/vfio/pci/pds/lm.c
@@ -151,8 +151,7 @@ static struct page *pds_vfio_get_file_page(struct pds_vfio_lm_file *lm_file,
 			lm_file->last_offset_sg = sg;
 			lm_file->sg_last_entry += i;
 			lm_file->last_offset = cur_offset;
-			return nth_page(sg_page(sg),
-					(offset - cur_offset) / PAGE_SIZE);
+			return sg_page(sg) + (offset - cur_offset) / PAGE_SIZE;
 		}
 		cur_offset += sg->length;
 	}
diff --git a/drivers/vfio/pci/virtio/migrate.c b/drivers/vfio/pci/virtio/migrate.c
index ba92bb4e9af94..7dd0ac866461d 100644
--- a/drivers/vfio/pci/virtio/migrate.c
+++ b/drivers/vfio/pci/virtio/migrate.c
@@ -53,8 +53,7 @@ virtiovf_get_migration_page(struct virtiovf_data_buffer *buf,
 			buf->last_offset_sg = sg;
 			buf->sg_last_entry += i;
 			buf->last_offset = cur_offset;
-			return nth_page(sg_page(sg),
-					(offset - cur_offset) / PAGE_SIZE);
+			return sg_page(sg) + (offset - cur_offset) / PAGE_SIZE;
 		}
 		cur_offset += sg->length;
 	}
-- 
2.50.1
Re: [PATCH v1 31/36] vfio/pci: drop nth_page() usage within SG entry
Posted by Brett Creeley 1 month ago 

On 8/27/2025 3:01 PM, David Hildenbrand wrote:
> Caution: This message originated from an External Source. Use proper caution when opening attachments, clicking links, or responding.
> 
> 
> It's no longer required to use nth_page() when iterating pages within a
> single SG entry, so let's drop the nth_page() usage.
> 
> Cc: Brett Creeley <brett.creeley@amd.com>
> Cc: Jason Gunthorpe <jgg@ziepe.ca>
> Cc: Yishai Hadas <yishaih@nvidia.com>
> Cc: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
> Cc: Kevin Tian <kevin.tian@intel.com>
> Cc: Alex Williamson <alex.williamson@redhat.com>
> Signed-off-by: David Hildenbrand <david@redhat.com>
> ---
>   drivers/vfio/pci/pds/lm.c         | 3 +--
>   drivers/vfio/pci/virtio/migrate.c | 3 +--
>   2 files changed, 2 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/vfio/pci/pds/lm.c b/drivers/vfio/pci/pds/lm.c
> index f2673d395236a..4d70c833fa32e 100644
> --- a/drivers/vfio/pci/pds/lm.c
> +++ b/drivers/vfio/pci/pds/lm.c
> @@ -151,8 +151,7 @@ static struct page *pds_vfio_get_file_page(struct pds_vfio_lm_file *lm_file,
>                          lm_file->last_offset_sg = sg;
>                          lm_file->sg_last_entry += i;
>                          lm_file->last_offset = cur_offset;
> -                       return nth_page(sg_page(sg),
> -                                       (offset - cur_offset) / PAGE_SIZE);
> +                       return sg_page(sg) + (offset - cur_offset) / PAGE_SIZE;
>                  }
>                  cur_offset += sg->length;
>          }
> diff --git a/drivers/vfio/pci/virtio/migrate.c b/drivers/vfio/pci/virtio/migrate.c
> index ba92bb4e9af94..7dd0ac866461d 100644
> --- a/drivers/vfio/pci/virtio/migrate.c
> +++ b/drivers/vfio/pci/virtio/migrate.c
> @@ -53,8 +53,7 @@ virtiovf_get_migration_page(struct virtiovf_data_buffer *buf,
>                          buf->last_offset_sg = sg;
>                          buf->sg_last_entry += i;
>                          buf->last_offset = cur_offset;
> -                       return nth_page(sg_page(sg),
> -                                       (offset - cur_offset) / PAGE_SIZE);
> +                       return sg_page(sg) + (offset - cur_offset) / PAGE_SIZE;
>                  }
>                  cur_offset += sg->length;
>          }

LGTM. Thanks.

Reviewed-by: Brett Creeley <brett.creeley@amd.com>

> --
> 2.50.1
>
Re: [PATCH v1 31/36] vfio/pci: drop nth_page() usage within SG entry
Posted by Alex Williamson 1 month ago 
On Thu, 28 Aug 2025 00:01:35 +0200
David Hildenbrand <david@redhat.com> wrote:

> It's no longer required to use nth_page() when iterating pages within a
> single SG entry, so let's drop the nth_page() usage.
> 
> Cc: Brett Creeley <brett.creeley@amd.com>
> Cc: Jason Gunthorpe <jgg@ziepe.ca>
> Cc: Yishai Hadas <yishaih@nvidia.com>
> Cc: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
> Cc: Kevin Tian <kevin.tian@intel.com>
> Cc: Alex Williamson <alex.williamson@redhat.com>
> Signed-off-by: David Hildenbrand <david@redhat.com>
> ---
>  drivers/vfio/pci/pds/lm.c         | 3 +--
>  drivers/vfio/pci/virtio/migrate.c | 3 +--
>  2 files changed, 2 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/vfio/pci/pds/lm.c b/drivers/vfio/pci/pds/lm.c
> index f2673d395236a..4d70c833fa32e 100644
> --- a/drivers/vfio/pci/pds/lm.c
> +++ b/drivers/vfio/pci/pds/lm.c
> @@ -151,8 +151,7 @@ static struct page *pds_vfio_get_file_page(struct pds_vfio_lm_file *lm_file,
>  			lm_file->last_offset_sg = sg;
>  			lm_file->sg_last_entry += i;
>  			lm_file->last_offset = cur_offset;
> -			return nth_page(sg_page(sg),
> -					(offset - cur_offset) / PAGE_SIZE);
> +			return sg_page(sg) + (offset - cur_offset) / PAGE_SIZE;
>  		}
>  		cur_offset += sg->length;
>  	}
> diff --git a/drivers/vfio/pci/virtio/migrate.c b/drivers/vfio/pci/virtio/migrate.c
> index ba92bb4e9af94..7dd0ac866461d 100644
> --- a/drivers/vfio/pci/virtio/migrate.c
> +++ b/drivers/vfio/pci/virtio/migrate.c
> @@ -53,8 +53,7 @@ virtiovf_get_migration_page(struct virtiovf_data_buffer *buf,
>  			buf->last_offset_sg = sg;
>  			buf->sg_last_entry += i;
>  			buf->last_offset = cur_offset;
> -			return nth_page(sg_page(sg),
> -					(offset - cur_offset) / PAGE_SIZE);
> +			return sg_page(sg) + (offset - cur_offset) / PAGE_SIZE;
>  		}
>  		cur_offset += sg->length;
>  	}

Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Re: [PATCH v1 31/36] vfio/pci: drop nth_page() usage within SG entry
Posted by Lorenzo Stoakes 1 month ago 
On Thu, Aug 28, 2025 at 12:01:35AM +0200, David Hildenbrand wrote:
> It's no longer required to use nth_page() when iterating pages within a
> single SG entry, so let's drop the nth_page() usage.
>
> Cc: Brett Creeley <brett.creeley@amd.com>
> Cc: Jason Gunthorpe <jgg@ziepe.ca>
> Cc: Yishai Hadas <yishaih@nvidia.com>
> Cc: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
> Cc: Kevin Tian <kevin.tian@intel.com>
> Cc: Alex Williamson <alex.williamson@redhat.com>
> Signed-off-by: David Hildenbrand <david@redhat.com>

LGTM, so:

Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>

> ---
>  drivers/vfio/pci/pds/lm.c         | 3 +--
>  drivers/vfio/pci/virtio/migrate.c | 3 +--
>  2 files changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/vfio/pci/pds/lm.c b/drivers/vfio/pci/pds/lm.c
> index f2673d395236a..4d70c833fa32e 100644
> --- a/drivers/vfio/pci/pds/lm.c
> +++ b/drivers/vfio/pci/pds/lm.c
> @@ -151,8 +151,7 @@ static struct page *pds_vfio_get_file_page(struct pds_vfio_lm_file *lm_file,
>  			lm_file->last_offset_sg = sg;
>  			lm_file->sg_last_entry += i;
>  			lm_file->last_offset = cur_offset;
> -			return nth_page(sg_page(sg),
> -					(offset - cur_offset) / PAGE_SIZE);
> +			return sg_page(sg) + (offset - cur_offset) / PAGE_SIZE;
>  		}
>  		cur_offset += sg->length;
>  	}
> diff --git a/drivers/vfio/pci/virtio/migrate.c b/drivers/vfio/pci/virtio/migrate.c
> index ba92bb4e9af94..7dd0ac866461d 100644
> --- a/drivers/vfio/pci/virtio/migrate.c
> +++ b/drivers/vfio/pci/virtio/migrate.c
> @@ -53,8 +53,7 @@ virtiovf_get_migration_page(struct virtiovf_data_buffer *buf,
>  			buf->last_offset_sg = sg;
>  			buf->sg_last_entry += i;
>  			buf->last_offset = cur_offset;
> -			return nth_page(sg_page(sg),
> -					(offset - cur_offset) / PAGE_SIZE);
> +			return sg_page(sg) + (offset - cur_offset) / PAGE_SIZE;
>  		}
>  		cur_offset += sg->length;
>  	}
> --
> 2.50.1
>

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