On Mon, Aug 29, 2022 at 11:23:13AM +0300, Alvaro Karsz wrote:
> Support for the VIRTIO_BLK_F_SECURE_ERASE VirtIO feature.
>
> A device that offers this feature can receive VIRTIO_BLK_T_SECURE_ERASE
> commands.
>
> A device which supports this feature has the following fields in the
> virtio config:
>
> - max_secure_erase_sectors
> - max_secure_erase_seg
> - secure_erase_sector_alignment
>
> max_secure_erase_sectors and secure_erase_sector_alignment are expressed
> in 512-byte units.
>
> Every secure erase command has the following fields:
>
> - sectors: The starting offset in 512-byte units.
> - num_sectors: The number of sectors.
>
> Signed-off-by: Alvaro Karsz <[email protected]>
Review from storage maintainers before I queue this?
Thanks!
> ---
> v2:
> - Set queue max discard segments as the minimum between
> max_secure_erase_seg and max_discard_seg.
> - Set queue discard granularity as the minimum between
> secure_erase_sector_alignment and discard_sector_alignment.
> ---
> drivers/block/virtio_blk.c | 82 +++++++++++++++++++++++++--------
> include/uapi/linux/virtio_blk.h | 19 ++++++++
> 2 files changed, 83 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
> index 30255fcaf18..8a2f00cdf52 100644
> --- a/drivers/block/virtio_blk.c
> +++ b/drivers/block/virtio_blk.c
> @@ -130,7 +130,7 @@ static int virtblk_add_req(struct virtqueue *vq, struct
> virtblk_req *vbr)
> return virtqueue_add_sgs(vq, sgs, num_out, num_in, vbr, GFP_ATOMIC);
> }
>
> -static int virtblk_setup_discard_write_zeroes(struct request *req, bool
> unmap)
> +static int virtblk_setup_discard_write_zeroes_erase(struct request *req,
> bool unmap)
> {
> unsigned short segments = blk_rq_nr_discard_segments(req);
> unsigned short n = 0;
> @@ -240,6 +240,9 @@ static blk_status_t virtblk_setup_cmd(struct
> virtio_device *vdev,
> type = VIRTIO_BLK_T_WRITE_ZEROES;
> unmap = !(req->cmd_flags & REQ_NOUNMAP);
> break;
> + case REQ_OP_SECURE_ERASE:
> + type = VIRTIO_BLK_T_SECURE_ERASE;
> + break;
> case REQ_OP_DRV_IN:
> type = VIRTIO_BLK_T_GET_ID;
> break;
> @@ -251,8 +254,9 @@ static blk_status_t virtblk_setup_cmd(struct
> virtio_device *vdev,
> vbr->out_hdr.type = cpu_to_virtio32(vdev, type);
> vbr->out_hdr.ioprio = cpu_to_virtio32(vdev, req_get_ioprio(req));
>
> - if (type == VIRTIO_BLK_T_DISCARD || type == VIRTIO_BLK_T_WRITE_ZEROES) {
> - if (virtblk_setup_discard_write_zeroes(req, unmap))
> + if (type == VIRTIO_BLK_T_DISCARD || type == VIRTIO_BLK_T_WRITE_ZEROES ||
> + type == VIRTIO_BLK_T_SECURE_ERASE) {
> + if (virtblk_setup_discard_write_zeroes_erase(req, unmap))
> return BLK_STS_RESOURCE;
> }
>
> @@ -889,6 +893,8 @@ static int virtblk_probe(struct virtio_device *vdev)
> int err, index;
>
> u32 v, blk_size, max_size, sg_elems, opt_io_size;
> + u32 max_discard_segs = 0;
> + u32 discard_granularity = 0;
> u16 min_io_size;
> u8 physical_block_exp, alignment_offset;
> unsigned int queue_depth;
> @@ -1046,27 +1052,14 @@ static int virtblk_probe(struct virtio_device *vdev)
>
> if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD)) {
> virtio_cread(vdev, struct virtio_blk_config,
> - discard_sector_alignment, &v);
> - if (v)
> - q->limits.discard_granularity = v << SECTOR_SHIFT;
> - else
> - q->limits.discard_granularity = blk_size;
> + discard_sector_alignment, &discard_granularity);
>
> virtio_cread(vdev, struct virtio_blk_config,
> max_discard_sectors, &v);
> blk_queue_max_discard_sectors(q, v ? v : UINT_MAX);
>
> virtio_cread(vdev, struct virtio_blk_config, max_discard_seg,
> - &v);
> -
> - /*
> - * max_discard_seg == 0 is out of spec but we always
> - * handled it.
> - */
> - if (!v)
> - v = sg_elems;
> - blk_queue_max_discard_segments(q,
> - min(v, MAX_DISCARD_SEGMENTS));
> + &max_discard_segs);
> }
>
> if (virtio_has_feature(vdev, VIRTIO_BLK_F_WRITE_ZEROES)) {
> @@ -1075,6 +1068,57 @@ static int virtblk_probe(struct virtio_device *vdev)
> blk_queue_max_write_zeroes_sectors(q, v ? v : UINT_MAX);
> }
>
> + if (virtio_has_feature(vdev, VIRTIO_BLK_F_SECURE_ERASE)) {
> + /* The discard alignment value should be the minimum between
> + * secure_erase_sector_alignment and discard_sector_alignment
> + * (if VIRTIO_BLK_F_DISCARD is negotiated).
why minimum?
> + */
> + virtio_cread(vdev, struct virtio_blk_config,
> + secure_erase_sector_alignment, &v);
> + if (v) {
> + if (discard_granularity)
> + discard_granularity = min(discard_granularity,
> v);
> + else
> + discard_granularity = v;
> + }
> +
> + virtio_cread(vdev, struct virtio_blk_config,
> + max_secure_erase_sectors, &v);
> + blk_queue_max_secure_erase_sectors(q, v ? v : UINT_MAX);
> +
> + /* The max discard segments value should be the minimum between
> + * max_secure_erase_seg and max_discard_seg (if
> VIRTIO_BLK_F_DISCARD
> + * is negotiated).
why is that?
> + */
> + virtio_cread(vdev, struct virtio_blk_config,
> + max_secure_erase_seg, &v);
> + if (v) {
> + if (max_discard_segs)
> + max_discard_segs = min(max_discard_segs, v);
> + else
> + max_discard_segs = v;
is this logic repeating code from below?
> + }
> + }
> +
> + if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD) ||
> + virtio_has_feature(vdev, VIRTIO_BLK_F_SECURE_ERASE)) {
> +
> + /* max_discard_seg == 0 or max_secure_erase_seg == 0
> + * are out of spec but we always handled it.
Always? What's going on here?
which versions handled max_secure_erase_seg == 0?
> + */
> + if (!max_discard_segs)
> + max_discard_segs = sg_elems;
> +
> + blk_queue_max_discard_segments(q,
> + min(max_discard_segs,
> MAX_DISCARD_SEGMENTS));
> +
> + /* If alignemnt is 0, use block size alignment */
> + if (discard_granularity)
> + q->limits.discard_granularity = discard_granularity <<
> SECTOR_SHIFT;
> + else
> + q->limits.discard_granularity = blk_size;
> + }
> +
> virtblk_update_capacity(vblk, false);
> virtio_device_ready(vdev);
>
> @@ -1170,6 +1214,7 @@ static unsigned int features_legacy[] = {
> VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE,
> VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE,
> VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES,
> + VIRTIO_BLK_F_SECURE_ERASE,
> }
> ;
> static unsigned int features[] = {
> @@ -1177,6 +1222,7 @@ static unsigned int features[] = {
> VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE,
> VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE,
> VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES,
> + VIRTIO_BLK_F_SECURE_ERASE,
> };
>
> static struct virtio_driver virtio_blk = {
> diff --git a/include/uapi/linux/virtio_blk.h b/include/uapi/linux/virtio_blk.h
> index d888f013d9f..58e70b24b50 100644
> --- a/include/uapi/linux/virtio_blk.h
> +++ b/include/uapi/linux/virtio_blk.h
> @@ -40,6 +40,7 @@
> #define VIRTIO_BLK_F_MQ 12 /* support more than one vq */
> #define VIRTIO_BLK_F_DISCARD 13 /* DISCARD is supported */
> #define VIRTIO_BLK_F_WRITE_ZEROES 14 /* WRITE ZEROES is supported */
> +#define VIRTIO_BLK_F_SECURE_ERASE 16 /* Secure Erase is supported */
>
> /* Legacy feature bits */
> #ifndef VIRTIO_BLK_NO_LEGACY
> @@ -121,6 +122,21 @@ struct virtio_blk_config {
> __u8 write_zeroes_may_unmap;
>
> __u8 unused1[3];
> +
> + /* the next 3 entries are guarded by VIRTIO_BLK_F_SECURE_ERASE */
> + /*
> + * The maximum secure erase sectors (in 512-byte sectors) for
> + * one segment.
> + */
> + __virtio32 max_secure_erase_sectors;
> + /*
> + * The maximum number of secure erase segments in a
> + * secure erase command.
> + */
> + __virtio32 max_secure_erase_seg;
> + /* Secure erase commands must be aligned to this number of sectors. */
> + __virtio32 secure_erase_sector_alignment;
> +
> } __attribute__((packed));
>
> /*
> @@ -155,6 +171,9 @@ struct virtio_blk_config {
> /* Write zeroes command */
> #define VIRTIO_BLK_T_WRITE_ZEROES 13
>
> +/* Secure erase command */
> +#define VIRTIO_BLK_T_SECURE_ERASE 14
> +
> #ifndef VIRTIO_BLK_NO_LEGACY
> /* Barrier before this op. */
> #define VIRTIO_BLK_T_BARRIER 0x80000000
> --
> 2.32.0
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