[PATCH v2] virtio_blk: add SECURE ERASE command support

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



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 <alvaro.karsz@xxxxxxxxxxxxx>
---
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).
+		 */
+		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).
+		 */
+		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;
+		}
+	}
+
+	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.
+		 */
+		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

_______________________________________________
Virtualization mailing list
Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx
https://lists.linuxfoundation.org/mailman/listinfo/virtualization



[Index of Archives]     [KVM Development]     [Libvirt Development]     [Libvirt Users]     [CentOS Virtualization]     [Netdev]     [Ethernet Bridging]     [Linux Wireless]     [Kernel Newbies]     [Security]     [Linux for Hams]     [Netfilter]     [Bugtraq]     [Yosemite Forum]     [MIPS Linux]     [ARM Linux]     [Linux RAID]     [Linux Admin]     [Samba]

  Powered by Linux