[PATCH v1 01/11] virtio_blk: add inline encryption support
From: Linlin Zhang
Date: Thu Aug 27 2026 - 12:09:37 EST
From: linlzhan <linlzhan@xxxxxxxxxxxxxxxx>
Negotiate VIRTIO_BLK_F_INLINE_ENCRYPTION with the host and wire it into
the block layer's inline-crypto framework to enable inline encryption
on virtio block device.
When the feature is present, the driver reads crypto characteristics from
virtio config space (key-slot count, DUN size, supported key types) and
issues VIRTIO_BLK_T_GET_CRYPTO_MODES to discover supported cipher and
data-unit-size combinations. Encrypted requests use new request types
VIRTIO_BLK_T_CRYPTO_IN/OUT, which append a virtio_blk_crypto_msg
(keyslot index, DUN, data-unit-size-bits) to the standard outhdr.
A new virtio block crypto extension driver (virtio_blk_crypto_ext),
owns the blk_crypto_profile singleton and the blk_crypto_ll_ops dispatch
table. Actual key operations are forwarded to a platform-specific
backend registered via virtblk_set_crypto_ops(); without one,
VIRTIO_BLK_F_INLINE_ENCRYPTION is still negotiated and the
profile is registered, but every keyslot operation returns -EOPNOTSUPP.
The shared profile is a singleton as per blk_crypto_profile is
corresponding to one ICE hardware: the first device to negotiate the
feature initializes it; subsequent devices reuse it only when their
negotiated capabilities (slot count, DUN size, key types) match exactly.
Signed-off-by: linlzhan <linlin.zhang@xxxxxxxxxxxxxxxx>
---
drivers/block/Kconfig | 13 ++
drivers/block/Makefile | 2 +
drivers/block/virtio_blk.c | 199 ++++++++++++++++--
drivers/block/virtio_blk_crypto_ext.c | 283 ++++++++++++++++++++++++++
include/linux/virtio_blk_crypto_ext.h | 78 +++++++
include/uapi/linux/virtio_blk.h | 62 ++++++
6 files changed, 623 insertions(+), 14 deletions(-)
create mode 100644 drivers/block/virtio_blk_crypto_ext.c
create mode 100644 include/linux/virtio_blk_crypto_ext.h
diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig
index 858320b6ebb7..7790ee2c700c 100644
--- a/drivers/block/Kconfig
+++ b/drivers/block/Kconfig
@@ -312,6 +312,19 @@ config VIRTIO_BLK
This is the virtual block driver for virtio. It can be used with
QEMU based VMMs (like KVM or Xen). Say Y or M.
+config VIRTBLK_CRYPTO_VIRTUALIZATION
+ tristate "Virtio block inline encryption virtualization support"
+ depends on VIRTIO_BLK && BLK_INLINE_ENCRYPTION
+ help
+ Say 'Y or M' to enable routing of crypto requests to a different
+ operating system in a virtualized environment. This option by
+ itself does not provide a working backend: enable a
+ platform-specific driver that implements struct
+ virtblk_crypto_variant_ops as well (e.g. QCOM_CRYPTO_VIRT on
+ Qualcomm platforms). Without one, VIRTIO_BLK_F_INLINE_ENCRYPTION is
+ still negotiated and advertised to the block layer, but every
+ inline-crypto operation fails with -EOPNOTSUPP at runtime.
+
config BLK_DEV_RBD
tristate "Rados block device (RBD)"
depends on INET && BLOCK
diff --git a/drivers/block/Makefile b/drivers/block/Makefile
index 2d8096eb8cdf..079c910d5fc9 100644
--- a/drivers/block/Makefile
+++ b/drivers/block/Makefile
@@ -25,6 +25,8 @@ obj-$(CONFIG_SUNVDC) += sunvdc.o
obj-$(CONFIG_BLK_DEV_NBD) += nbd.o
obj-$(CONFIG_VIRTIO_BLK) += virtio_blk.o
+obj-$(CONFIG_VIRTBLK_CRYPTO_VIRTUALIZATION) += virtio_blk_crypto_ext.o
+
obj-$(CONFIG_XEN_BLKDEV_FRONTEND) += xen-blkfront.o
obj-$(CONFIG_XEN_BLKDEV_BACKEND) += xen-blkback/
obj-$(CONFIG_BLK_DEV_DRBD) += drbd/
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 32bf3ba07a9d..61a3967bb4df 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -16,6 +16,8 @@
#include <linux/numa.h>
#include <linux/vmalloc.h>
#include <uapi/linux/virtio_ring.h>
+#include <linux/blk-crypto-profile.h>
+#include <linux/virtio_blk_crypto_ext.h>
#define PART_BITS 4
#define VQ_NAME_LEN 16
@@ -87,7 +89,14 @@ struct virtio_blk {
struct virtblk_req {
/* Out header */
- struct virtio_blk_outhdr out_hdr;
+ union {
+ struct virtio_blk_outhdr base;
+ struct {
+ struct virtio_blk_outhdr base;
+ /* Crypto message (if VIRTIO_BLK_F_INLINE_ENCRYPTION) */
+ struct virtio_blk_crypto_msg msg;
+ } crypto_append;
+ } out_hdr;
/* In header */
union {
@@ -140,12 +149,17 @@ static int virtblk_add_req(struct virtqueue *vq, struct virtblk_req *vbr)
{
struct scatterlist out_hdr, in_hdr, *sgs[3];
unsigned int num_out = 0, num_in = 0;
+ size_t out_hdr_len = sizeof(vbr->out_hdr.base);
+
+ if (vbr->out_hdr.base.type == cpu_to_virtio32(vq->vdev, VIRTIO_BLK_T_CRYPTO_IN) ||
+ vbr->out_hdr.base.type == cpu_to_virtio32(vq->vdev, VIRTIO_BLK_T_CRYPTO_OUT))
+ out_hdr_len = sizeof(vbr->out_hdr.crypto_append);
- sg_init_one(&out_hdr, &vbr->out_hdr, sizeof(vbr->out_hdr));
+ sg_init_one(&out_hdr, &vbr->out_hdr, out_hdr_len);
sgs[num_out++] = &out_hdr;
if (vbr->sg_table.nents) {
- if (vbr->out_hdr.type & cpu_to_virtio32(vq->vdev, VIRTIO_BLK_T_OUT))
+ if (vbr->out_hdr.base.type & cpu_to_virtio32(vq->vdev, VIRTIO_BLK_T_OUT))
sgs[num_out++] = vbr->sg_table.sgl;
else
sgs[num_out + num_in++] = vbr->sg_table.sgl;
@@ -235,6 +249,15 @@ static void virtblk_cleanup_cmd(struct request *req)
kfree(bvec_virt(&req->special_vec));
}
+static bool is_crypto_request(struct virtio_device *vdev, struct request *req)
+{
+ if (!IS_ENABLED(CONFIG_VIRTBLK_CRYPTO_VIRTUALIZATION) ||
+ !virtio_has_feature(vdev, VIRTIO_BLK_F_INLINE_ENCRYPTION))
+ return false;
+
+ return req->crypt_ctx && req->crypt_keyslot;
+}
+
static blk_status_t virtblk_setup_cmd(struct virtio_device *vdev,
struct request *req,
struct virtblk_req *vbr)
@@ -248,15 +271,21 @@ static blk_status_t virtblk_setup_cmd(struct virtio_device *vdev,
return BLK_STS_NOTSUPP;
/* Set fields for all request types */
- vbr->out_hdr.ioprio = cpu_to_virtio32(vdev, req_get_ioprio(req));
+ vbr->out_hdr.base.ioprio = cpu_to_virtio32(vdev, req_get_ioprio(req));
switch (req_op(req)) {
case REQ_OP_READ:
- type = VIRTIO_BLK_T_IN;
+ if (is_crypto_request(vdev, req))
+ type = VIRTIO_BLK_T_CRYPTO_IN;
+ else
+ type = VIRTIO_BLK_T_IN;
sector = blk_rq_pos(req);
break;
case REQ_OP_WRITE:
- type = VIRTIO_BLK_T_OUT;
+ if (is_crypto_request(vdev, req))
+ type = VIRTIO_BLK_T_CRYPTO_OUT;
+ else
+ type = VIRTIO_BLK_T_OUT;
sector = blk_rq_pos(req);
break;
case REQ_OP_FLUSH:
@@ -298,8 +327,9 @@ static blk_status_t virtblk_setup_cmd(struct virtio_device *vdev,
break;
case REQ_OP_DRV_IN:
/*
- * Out header has already been prepared by the caller (virtblk_get_id()
- * or virtblk_submit_zone_report()), nothing to do here.
+ * Out header has already been prepared by the caller (virtblk_get_id(),
+ * virtblk_submit_zone_report() or virtblk_get_crypto_modes()), nothing
+ * to do here.
*/
return 0;
default:
@@ -309,8 +339,8 @@ static blk_status_t virtblk_setup_cmd(struct virtio_device *vdev,
/* Set fields for non-REQ_OP_DRV_IN request types */
vbr->in_hdr_len = in_hdr_len;
- vbr->out_hdr.type = cpu_to_virtio32(vdev, type);
- vbr->out_hdr.sector = cpu_to_virtio64(vdev, sector);
+ vbr->out_hdr.base.type = cpu_to_virtio32(vdev, type);
+ vbr->out_hdr.base.sector = cpu_to_virtio64(vdev, sector);
if (type == VIRTIO_BLK_T_DISCARD || type == VIRTIO_BLK_T_WRITE_ZEROES ||
type == VIRTIO_BLK_T_SECURE_ERASE) {
@@ -318,6 +348,17 @@ static blk_status_t virtblk_setup_cmd(struct virtio_device *vdev,
return BLK_STS_RESOURCE;
}
+ if (type == VIRTIO_BLK_T_CRYPTO_IN || type == VIRTIO_BLK_T_CRYPTO_OUT) {
+ unsigned int slot = blk_crypto_keyslot_index(req->crypt_keyslot);
+ unsigned int data_unit_size_bits = req->crypt_ctx->bc_key->data_unit_size_bits;
+ u64 dun = req->crypt_ctx->bc_dun[0];
+
+ vbr->out_hdr.crypto_append.msg.slot = cpu_to_virtio32(vdev, slot);
+ vbr->out_hdr.crypto_append.msg.data_unit_size_bits =
+ cpu_to_virtio32(vdev, data_unit_size_bits);
+ vbr->out_hdr.crypto_append.msg.dun = cpu_to_virtio64(vdev, dun);
+ }
+
return 0;
}
@@ -568,8 +609,8 @@ static int virtblk_submit_zone_report(struct virtio_blk *vblk,
vbr = blk_mq_rq_to_pdu(req);
vbr->in_hdr_len = sizeof(vbr->in_hdr.status);
- vbr->out_hdr.type = cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_ZONE_REPORT);
- vbr->out_hdr.sector = cpu_to_virtio64(vblk->vdev, sector);
+ vbr->out_hdr.base.type = cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_ZONE_REPORT);
+ vbr->out_hdr.base.sector = cpu_to_virtio64(vblk->vdev, sector);
err = blk_rq_map_kern(req, report_buf, report_len, GFP_KERNEL);
if (err)
@@ -817,8 +858,8 @@ static int virtblk_get_id(struct gendisk *disk, char *id_str)
vbr = blk_mq_rq_to_pdu(req);
vbr->in_hdr_len = sizeof(vbr->in_hdr.status);
- vbr->out_hdr.type = cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_GET_ID);
- vbr->out_hdr.sector = 0;
+ vbr->out_hdr.base.type = cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_GET_ID);
+ vbr->out_hdr.base.sector = 0;
err = blk_rq_map_kern(req, id_str, VIRTIO_BLK_ID_BYTES, GFP_KERNEL);
if (err)
@@ -863,6 +904,70 @@ static int virtblk_getgeo(struct gendisk *disk, struct hd_geometry *geo)
return ret;
}
+/* Maps VIRTIO_BLK_CRYPTO_MODE_* values to the kernel's internal enum. */
+static const enum blk_crypto_mode_num
+ virtio_blk_crypto_mode_map[VIRTIO_BLK_CRYPTO_MODE_MAX + 1] = {
+ [VIRTIO_BLK_CRYPTO_MODE_INVALID] = BLK_ENCRYPTION_MODE_INVALID,
+ [VIRTIO_BLK_CRYPTO_MODE_AES_256_XTS] = BLK_ENCRYPTION_MODE_AES_256_XTS,
+};
+
+static int virtblk_get_crypto_modes(struct virtio_blk *vblk,
+ unsigned int *crypto_modes_supported)
+{
+ struct request_queue *q = vblk->disk->queue;
+ unsigned int nr_modes = VIRTIO_BLK_CRYPTO_MODE_MAX + 1;
+ size_t buf_size = sizeof(struct virtio_blk_crypto_modes);
+ struct virtio_blk_crypto_modes *virtblk_cmodes;
+ struct request *req;
+ struct virtblk_req *vbr;
+ unsigned int i;
+ int err;
+
+ virtblk_cmodes = kzalloc(buf_size, GFP_KERNEL);
+ if (!virtblk_cmodes)
+ return -ENOMEM;
+
+ req = blk_mq_alloc_request(q, REQ_OP_DRV_IN, 0);
+ if (IS_ERR(req)) {
+ err = PTR_ERR(req);
+ goto out_free;
+ }
+
+ vbr = blk_mq_rq_to_pdu(req);
+ vbr->in_hdr_len = sizeof(vbr->in_hdr.status);
+ vbr->out_hdr.base.type = cpu_to_virtio32(vblk->vdev,
+ VIRTIO_BLK_T_GET_CRYPTO_MODES);
+ vbr->out_hdr.base.sector = 0;
+
+ err = blk_rq_map_kern(req, virtblk_cmodes, buf_size, GFP_KERNEL);
+ if (err)
+ goto out_req;
+
+ blk_execute_rq(req, false);
+ err = blk_status_to_errno(virtblk_result(vbr->in_hdr.status));
+ if (err)
+ goto out_req;
+
+ for (i = 1; i < nr_modes; i++) {
+ u32 mode_mask = virtio32_to_cpu(vblk->vdev, virtblk_cmodes->modes[i]);
+ enum blk_crypto_mode_num mode = virtio_blk_crypto_mode_map[i];
+
+ if (!mode_mask)
+ continue;
+ if (!mode) {
+ dev_warn(&vblk->vdev->dev,
+ "ignoring unknown crypto mode %u\n", i);
+ continue;
+ }
+ crypto_modes_supported[mode] = mode_mask;
+ }
+out_req:
+ blk_mq_free_request(req);
+out_free:
+ kfree(virtblk_cmodes);
+ return err;
+}
+
static void virtblk_free_disk(struct gendisk *disk)
{
struct virtio_blk *vblk = disk->private_data;
@@ -1435,6 +1540,51 @@ static int virtblk_read_limits(struct virtio_blk *vblk,
return 0;
}
+static int virtblk_init_crypto(struct virtio_blk *vblk)
+{
+ struct virtio_device *vdev = vblk->vdev;
+ unsigned int crypto_modes_supported[BLK_ENCRYPTION_MODE_MAX] = { 0 };
+ /* virtio_cread() requires the variable size to match the config field exactly */
+ u16 max_slots;
+ u8 max_dun_bytes, key_types;
+ int err;
+
+ virtio_cread(vdev, struct virtio_blk_config,
+ enc_characteristics.max_slots, &max_slots);
+ virtio_cread(vdev, struct virtio_blk_config,
+ enc_characteristics.max_dun_bytes, &max_dun_bytes);
+ virtio_cread(vdev, struct virtio_blk_config,
+ enc_characteristics.key_types, &key_types);
+
+ dev_dbg(&vdev->dev,
+ "max_slots = %u, max_dun_bytes = %u, key_types = 0x%x\n",
+ max_slots, max_dun_bytes, key_types);
+
+ if (!max_slots)
+ return -EINVAL;
+ if (!(key_types & (VIRTIO_BLK_CRYPTO_KEY_TYPE_RAW |
+ VIRTIO_BLK_CRYPTO_KEY_TYPE_HW_WRAPPED)))
+ return -EINVAL;
+ /*
+ * struct virtio_blk_crypto_msg.dun is a fixed __virtio64, i.e. this
+ * driver can only ever transmit 8 bytes of DUN per request. Refuse
+ * to advertise more than that as supported, or blk-crypto could
+ * negotiate a larger dun_bytes with the filesystem and have the
+ * high-order bytes of req->crypt_ctx->bc_dun silently dropped in
+ * virtblk_setup_cmd(), reusing the same IV across data units that
+ * only differ in those high-order bytes.
+ */
+ if (max_dun_bytes > sizeof(u64))
+ return -EINVAL;
+
+ err = virtblk_get_crypto_modes(vblk, crypto_modes_supported);
+ if (err)
+ return err;
+
+ return virtblk_init_inline_crypto(max_slots, max_dun_bytes, key_types,
+ crypto_modes_supported, &vdev->dev);
+}
+
static int virtblk_probe(struct virtio_device *vdev)
{
struct virtio_blk *vblk;
@@ -1540,6 +1690,26 @@ static int virtblk_probe(struct virtio_device *vdev)
goto out_cleanup_disk;
}
+ if (IS_ENABLED(CONFIG_VIRTBLK_CRYPTO_VIRTUALIZATION) &&
+ virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_INLINE_ENCRYPTION)) {
+ if (virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_ZONED)) {
+ dev_warn(&vdev->dev,
+ "zoned device does not support inline encryption, disabling it\n");
+ } else {
+ /* Initialize supported crypto capabilities */
+ err = virtblk_init_crypto(vblk);
+ if (!err) {
+ if (!virtblk_crypto_register(vblk->disk->queue))
+ dev_warn(&vdev->dev,
+ "failed to register inline crypto profile with the block layer, continuing without inline crypto support\n");
+ } else {
+ dev_warn(&vdev->dev,
+ "inline crypto init failed: %d, continuing without inline crypto support\n",
+ err);
+ }
+ }
+ }
+
err = device_add_disk(&vdev->dev, vblk->disk, virtblk_attr_groups);
if (err)
goto out_cleanup_disk;
@@ -1672,6 +1842,7 @@ static unsigned int features[] = {
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, VIRTIO_BLK_F_ZONED,
+ VIRTIO_BLK_F_INLINE_ENCRYPTION,
};
static struct virtio_driver virtio_blk = {
diff --git a/drivers/block/virtio_blk_crypto_ext.c b/drivers/block/virtio_blk_crypto_ext.c
new file mode 100644
index 000000000000..00b6d410d303
--- /dev/null
+++ b/drivers/block/virtio_blk_crypto_ext.c
@@ -0,0 +1,283 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/export.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/container_of.h>
+#include <linux/blk-crypto.h>
+#include <linux/blk-crypto-profile.h>
+#include <linux/virtio_blk.h>
+#include <linux/virtio_blk_crypto_ext.h>
+
+struct virtblk_crypto_profile {
+ struct blk_crypto_profile profile;
+ struct virtblk_crypto_variant_ops *ops;
+};
+
+static struct virtblk_crypto_profile g_vdcp;
+static bool g_crypto_profile_initialized;
+static struct device *virtblk_profile_owner;
+static unsigned int g_max_slots;
+static unsigned int g_max_dun_bytes;
+static unsigned int g_key_types;
+static DEFINE_MUTEX(virtblk_crypto_init_lock);
+static DEFINE_MUTEX(virtblk_crypto_ops_lock);
+
+bool virtblk_crypto_register(struct request_queue *q)
+{
+ return blk_crypto_register(&g_vdcp.profile, q);
+}
+EXPORT_SYMBOL_GPL(virtblk_crypto_register);
+
+/*
+ * Returns the variant ops registered for @profile's virtblk_crypto_profile
+ * with a module reference held on ops->owner, or NULL if none are
+ * registered. Pairs with virtblk_crypto_ops_put().
+ *
+ * Holding a module reference for the duration of each dispatch call (rather
+ * than just dereferencing the raw pointer) is what makes it safe for the
+ * module that implements these ops (e.g. drivers/soc/qcom/crypto_virt.c) to
+ * be rmmod'd: module removal will fail/block until every in-flight dispatch
+ * call has released its reference, instead of racing with a concurrent
+ * virtblk_set_crypto_ops(NULL) and the ops table disappearing mid-call.
+ */
+static struct virtblk_crypto_variant_ops *
+virtblk_crypto_ops_get(struct blk_crypto_profile *profile)
+{
+ struct virtblk_crypto_profile *vdcp =
+ container_of(profile, struct virtblk_crypto_profile, profile);
+ struct virtblk_crypto_variant_ops *ops;
+
+ mutex_lock(&virtblk_crypto_ops_lock);
+ ops = vdcp->ops;
+ if (ops && !try_module_get(ops->owner))
+ ops = NULL;
+ mutex_unlock(&virtblk_crypto_ops_lock);
+
+ return ops;
+}
+
+static void virtblk_crypto_ops_put(struct virtblk_crypto_variant_ops *ops)
+{
+ module_put(ops->owner);
+}
+
+static int virtblk_crypto_keyslot_program(struct blk_crypto_profile *profile,
+ const struct blk_crypto_key *key,
+ unsigned int slot)
+{
+ struct virtblk_crypto_variant_ops *ops = virtblk_crypto_ops_get(profile);
+ int ret;
+
+ if (!ops || !ops->program_key) {
+ if (ops)
+ virtblk_crypto_ops_put(ops);
+ return -EOPNOTSUPP;
+ }
+
+ ret = ops->program_key(key, slot);
+ virtblk_crypto_ops_put(ops);
+ if (ret)
+ pr_err("program hardware wrapped key failed: slot=%u ret=%d\n", slot, ret);
+
+ return ret;
+}
+
+static int virtblk_crypto_keyslot_evict(struct blk_crypto_profile *profile,
+ const struct blk_crypto_key *key,
+ unsigned int slot)
+{
+ struct virtblk_crypto_variant_ops *ops = virtblk_crypto_ops_get(profile);
+ int ret;
+
+ if (!ops || !ops->evict_key) {
+ if (ops)
+ virtblk_crypto_ops_put(ops);
+ return -EOPNOTSUPP;
+ }
+
+ ret = ops->evict_key(slot);
+ virtblk_crypto_ops_put(ops);
+ if (ret)
+ pr_err("evict keyslot %u failed: %d\n", slot, ret);
+
+ return ret;
+}
+
+static int virtblk_crypto_derive_sw_secret(struct blk_crypto_profile *profile,
+ const u8 *eph_key,
+ size_t eph_key_size,
+ u8 sw_secret[BLK_CRYPTO_SW_SECRET_SIZE])
+{
+ struct virtblk_crypto_variant_ops *ops = virtblk_crypto_ops_get(profile);
+ int ret;
+
+ if (!ops || !ops->derive_sw_secret_key) {
+ if (ops)
+ virtblk_crypto_ops_put(ops);
+ return -EOPNOTSUPP;
+ }
+
+ ret = ops->derive_sw_secret_key(eph_key, eph_key_size, sw_secret);
+ virtblk_crypto_ops_put(ops);
+ if (ret)
+ pr_err("derive software secret failed: %d\n", ret);
+
+ return ret;
+}
+
+static int virtblk_crypto_generate_key(struct blk_crypto_profile *profile,
+ u8 lt_key[BLK_CRYPTO_MAX_HW_WRAPPED_KEY_SIZE])
+{
+ struct virtblk_crypto_variant_ops *ops = virtblk_crypto_ops_get(profile);
+ int ret;
+
+ if (!ops || !ops->generate_key) {
+ if (ops)
+ virtblk_crypto_ops_put(ops);
+ return -EOPNOTSUPP;
+ }
+
+ ret = ops->generate_key(lt_key);
+ virtblk_crypto_ops_put(ops);
+ if (ret < 0)
+ pr_err("generate hardware wrapped key failed: %d\n", ret);
+
+ return ret;
+}
+
+static int virtblk_crypto_prepare_key(struct blk_crypto_profile *profile,
+ const u8 *lt_key, size_t lt_key_size,
+ u8 eph_key[BLK_CRYPTO_MAX_HW_WRAPPED_KEY_SIZE])
+{
+ struct virtblk_crypto_variant_ops *ops = virtblk_crypto_ops_get(profile);
+ int ret;
+
+ if (!ops || !ops->prepare_key) {
+ if (ops)
+ virtblk_crypto_ops_put(ops);
+ return -EOPNOTSUPP;
+ }
+
+ ret = ops->prepare_key(lt_key, lt_key_size, eph_key);
+ virtblk_crypto_ops_put(ops);
+ if (ret < 0)
+ pr_err("prepare hardware wrapped key failed: %d\n", ret);
+
+ return ret;
+}
+
+static int virtblk_crypto_import_key(struct blk_crypto_profile *profile,
+ const u8 *raw_key, size_t raw_key_size,
+ u8 lt_key[BLK_CRYPTO_MAX_HW_WRAPPED_KEY_SIZE])
+{
+ struct virtblk_crypto_variant_ops *ops = virtblk_crypto_ops_get(profile);
+ int ret;
+
+ if (!ops || !ops->import_key) {
+ if (ops)
+ virtblk_crypto_ops_put(ops);
+ return -EOPNOTSUPP;
+ }
+
+ ret = ops->import_key(raw_key, raw_key_size, lt_key);
+ virtblk_crypto_ops_put(ops);
+ if (ret < 0)
+ pr_err("import hardware wrapped key failed: %d\n", ret);
+
+ return ret;
+}
+
+static const struct blk_crypto_ll_ops virtblk_crypto_ops = {
+ .keyslot_program = virtblk_crypto_keyslot_program,
+ .keyslot_evict = virtblk_crypto_keyslot_evict,
+ .derive_sw_secret = virtblk_crypto_derive_sw_secret,
+ .generate_key = virtblk_crypto_generate_key,
+ .prepare_key = virtblk_crypto_prepare_key,
+ .import_key = virtblk_crypto_import_key,
+};
+
+int virtblk_init_inline_crypto(unsigned int max_slots, unsigned int max_dun_bytes,
+ unsigned int key_types,
+ const unsigned int crypto_modes_supported[BLK_ENCRYPTION_MODE_MAX],
+ struct device *dev)
+{
+ struct blk_crypto_profile *profile = &g_vdcp.profile;
+ unsigned int key_type_supported = 0;
+ int err = 0;
+
+ dev_info(dev, "probing inline crypto capabilities\n");
+
+ mutex_lock(&virtblk_crypto_init_lock);
+
+ /*
+ * profile is a single, process-wide blk_crypto_profile shared by every
+ * VIRTIO_BLK_F_INLINE_ENCRYPTION device. Only the first device to get
+ * here actually initializes it; any other device just reuses it as-is
+ * if its negotiated capabilities match. A mismatch means this device's
+ * capabilities don't actually correspond to what the shared profile
+ * was set up for (wrong keyslot count, DUN size, or key types), which
+ * is a correctness/security concern, not just a cosmetic one -- fail
+ * instead of silently registering a profile that doesn't match what
+ * this device supports.
+ */
+ if (g_crypto_profile_initialized) {
+ if (max_slots != g_max_slots || max_dun_bytes != g_max_dun_bytes ||
+ key_types != g_key_types) {
+ dev_warn(dev,
+ "inline crypto profile already initialized by %s (max_slots=%u max_dun_bytes=%u key_types=0x%x); "
+ "this device reports max_slots=%u max_dun_bytes=%u key_types=0x%x -- sharing one "
+ "blk_crypto_profile across multiple VIRTIO_BLK_F_INLINE_ENCRYPTION devices with differing "
+ "capabilities is not supported, refusing to enable inline crypto for this device\n",
+ dev_name(virtblk_profile_owner), g_max_slots, g_max_dun_bytes, g_key_types,
+ max_slots, max_dun_bytes, key_types);
+ err = -EINVAL;
+ }
+ goto out_unlock;
+ }
+
+ if (key_types & VIRTIO_BLK_CRYPTO_KEY_TYPE_RAW)
+ key_type_supported |= BLK_CRYPTO_KEY_TYPE_RAW;
+ if (key_types & VIRTIO_BLK_CRYPTO_KEY_TYPE_HW_WRAPPED)
+ key_type_supported |= BLK_CRYPTO_KEY_TYPE_HW_WRAPPED;
+
+ err = blk_crypto_profile_init(profile, max_slots);
+ if (err) {
+ dev_err(dev, "crypto profile initialization failed: %d\n", err);
+ goto out_unlock;
+ }
+
+ profile->ll_ops = virtblk_crypto_ops;
+ profile->max_dun_bytes_supported = max_dun_bytes;
+ profile->key_types_supported = key_type_supported;
+ profile->dev = dev;
+ memcpy(profile->modes_supported, crypto_modes_supported,
+ BLK_ENCRYPTION_MODE_MAX * sizeof(unsigned int));
+
+ virtblk_profile_owner = dev;
+ g_max_slots = max_slots;
+ g_max_dun_bytes = max_dun_bytes;
+ g_key_types = key_types;
+ g_crypto_profile_initialized = true;
+
+ dev_info(dev, "inline crypto profile initialized\n");
+
+out_unlock:
+ mutex_unlock(&virtblk_crypto_init_lock);
+ return err;
+}
+EXPORT_SYMBOL_GPL(virtblk_init_inline_crypto);
+
+void virtblk_set_crypto_ops(struct virtblk_crypto_variant_ops *ops)
+{
+ if (!g_crypto_profile_initialized)
+ pr_warn("virtio blk crypto profile hasn't been initialized\n");
+
+ mutex_lock(&virtblk_crypto_ops_lock);
+ g_vdcp.ops = ops;
+ mutex_unlock(&virtblk_crypto_ops_lock);
+}
+EXPORT_SYMBOL_GPL(virtblk_set_crypto_ops);
+
+MODULE_DESCRIPTION("Virtio block inline crypto extension");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/virtio_blk_crypto_ext.h b/include/linux/virtio_blk_crypto_ext.h
new file mode 100644
index 000000000000..3fe66029ac0d
--- /dev/null
+++ b/include/linux/virtio_blk_crypto_ext.h
@@ -0,0 +1,78 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __LINUX_VIRTIO_BLK_CRYPTO_EXT_H
+#define __LINUX_VIRTIO_BLK_CRYPTO_EXT_H
+
+#include <linux/blk-crypto.h>
+
+struct blk_crypto_profile;
+struct blk_crypto_key;
+struct device;
+struct request_queue;
+
+#if IS_ENABLED(CONFIG_VIRTBLK_CRYPTO_VIRTUALIZATION)
+struct virtblk_crypto_variant_ops {
+ /*
+ * Module providing the function pointers below. virtio_blk_crypto_ext.c
+ * pins it with try_module_get()/module_put() around every call, so that
+ * the module implementing these ops can be safely rmmod'd: the unload
+ * will simply block/fail until no dispatch call is in flight, instead
+ * of racing with one.
+ */
+ struct module *owner;
+ int (*program_key)(const struct blk_crypto_key *key,
+ unsigned int slot);
+ int (*evict_key)(unsigned int slot);
+ int (*derive_sw_secret_key)(const u8 *eph_key, size_t eph_key_size,
+ u8 sw_secret[BLK_CRYPTO_SW_SECRET_SIZE]);
+ int (*generate_key)(u8 lt_key[BLK_CRYPTO_MAX_HW_WRAPPED_KEY_SIZE]);
+ int (*prepare_key)(const u8 *lt_key, size_t lt_key_size,
+ u8 eph_key[BLK_CRYPTO_MAX_HW_WRAPPED_KEY_SIZE]);
+ int (*import_key)(const u8 *raw_key, size_t raw_key_size,
+ u8 lt_key[BLK_CRYPTO_MAX_HW_WRAPPED_KEY_SIZE]);
+};
+
+/*
+ * Probes the platform's inline-encryption capabilities and initializes the
+ * shared blk_crypto_profile singleton (once) with the keyslot/DUN limits,
+ * supported key types, wrapped key size, and supported crypto modes reported
+ * by the device over virtio config space / VIRTIO_BLK_T_GET_CRYPTO_MODES.
+ *
+ * Safe to call from multiple devices, including concurrently: only the
+ * first caller actually initializes the shared profile, every other caller
+ * just validates its own capabilities against what was already negotiated.
+ */
+int virtblk_init_inline_crypto(unsigned int max_slots, unsigned int max_dun_bytes,
+ unsigned int key_types,
+ const unsigned int crypto_modes_supported[BLK_ENCRYPTION_MODE_MAX],
+ struct device *dev);
+
+/*
+ * Registers the (already-initialized) shared blk_crypto_profile with the
+ * given request queue. Returns false (and leaves the queue without inline
+ * crypto) if the queue's block-integrity support conflicts with inline
+ * encryption; see blk_crypto_register().
+ */
+bool virtblk_crypto_register(struct request_queue *q);
+
+void virtblk_set_crypto_ops(struct virtblk_crypto_variant_ops *ops);
+
+#else
+
+static inline int virtblk_init_inline_crypto(unsigned int max_slots,
+ unsigned int max_dun_bytes, unsigned int key_types,
+ const unsigned int crypto_modes_supported[BLK_ENCRYPTION_MODE_MAX],
+ struct device *dev)
+{
+ return -EOPNOTSUPP;
+}
+
+static inline bool virtblk_crypto_register(struct request_queue *q)
+{
+ return false;
+}
+
+
+#endif
+
+#endif /* __LINUX_VIRTIO_BLK_CRYPTO_EXT_H */
diff --git a/include/uapi/linux/virtio_blk.h b/include/uapi/linux/virtio_blk.h
index 3744e4da1b2a..c1941f7fe019 100644
--- a/include/uapi/linux/virtio_blk.h
+++ b/include/uapi/linux/virtio_blk.h
@@ -42,6 +42,7 @@
#define VIRTIO_BLK_F_WRITE_ZEROES 14 /* WRITE ZEROES is supported */
#define VIRTIO_BLK_F_SECURE_ERASE 16 /* Secure Erase is supported */
#define VIRTIO_BLK_F_ZONED 17 /* Zoned block device */
+#define VIRTIO_BLK_F_INLINE_ENCRYPTION 22 /* Inline Encryption is supported */
/* Legacy feature bits */
#ifndef VIRTIO_BLK_NO_LEGACY
@@ -148,6 +149,18 @@ struct virtio_blk_config {
__u8 model;
__u8 unused2[3];
} zoned;
+
+ /* Inline Encryption device characteristics (if VIRTIO_BLK_F_INLINE_ENCRYPTION) */
+ struct virtio_blk_enc_characteristics {
+ __virtio16 max_slots;
+ __u8 max_dun_bytes;
+/* Bitmask values for virtio_blk_enc_characteristics.key_types */
+#define VIRTIO_BLK_CRYPTO_KEY_TYPE_RAW (1 << 0)
+#define VIRTIO_BLK_CRYPTO_KEY_TYPE_HW_WRAPPED (1 << 1)
+ /* Bitmask of supported key types: VIRTIO_BLK_CRYPTO_KEY_TYPE_* */
+ __u8 key_types;
+ __virtio32 unused3;
+ } enc_characteristics;
} __attribute__((packed));
/*
@@ -206,6 +219,15 @@ struct virtio_blk_config {
/* Reset All zones command */
#define VIRTIO_BLK_T_ZONE_RESET_ALL 26
+/* Inline-encrypted write: crypto_msg set in outhdr */
+#define VIRTIO_BLK_T_CRYPTO_OUT 27
+
+/* Inline-encrypted read: crypto_msg set in outhdr */
+#define VIRTIO_BLK_T_CRYPTO_IN 28
+
+/* Get inline crypto modes */
+#define VIRTIO_BLK_T_GET_CRYPTO_MODES 30
+
#ifndef VIRTIO_BLK_NO_LEGACY
/* Barrier before this op. */
#define VIRTIO_BLK_T_BARRIER 0x80000000
@@ -225,6 +247,46 @@ struct virtio_blk_outhdr {
__virtio64 sector;
};
+/*
+ * Crypto message descriptor, appended to the outhdr of a
+ * VIRTIO_BLK_T_CRYPTO_OUT or VIRTIO_BLK_T_CRYPTO_IN request.
+ */
+struct virtio_blk_crypto_msg {
+ /* virtual key slot index */
+ __virtio32 slot;
+ /* log2 of the data unit size in bytes */
+ __virtio32 data_unit_size_bits;
+ /* data unit number (DUN / IV) for this request */
+ __virtio64 dun;
+};
+
+/*
+ * Crypto mode numbers used in VIRTIO_BLK_T_GET_CRYPTO_MODES replies and in
+ * indexing struct virtio_blk_crypto_modes.modes[] below. These numbers are
+ * assigned by the virtio spec and are stable: a number is never reused for
+ * a different crypto mode, and additional crypto modes are assigned new,
+ * higher numbers.
+ */
+enum {
+ VIRTIO_BLK_CRYPTO_MODE_INVALID,
+ VIRTIO_BLK_CRYPTO_MODE_AES_256_XTS,
+ __VIRTIO_BLK_CRYPTO_MODE_MAX, /* sentinel: always one past the last real mode */
+};
+
+/* Highest crypto mode number defined by this version of the header. */
+#define VIRTIO_BLK_CRYPTO_MODE_MAX (__VIRTIO_BLK_CRYPTO_MODE_MAX - 1)
+
+/* Reply to a VIRTIO_BLK_T_GET_CRYPTO_MODES request. */
+struct virtio_blk_crypto_modes {
+ /*
+ * modes[N], for crypto mode number N <= VIRTIO_BLK_CRYPTO_MODE_MAX, is
+ * a bitmask of the data unit sizes with which crypto mode N can be
+ * used: bit i is set if a data unit size of (1 << i) bytes is
+ * supported. modes[0] is reserved and always 0.
+ */
+ __virtio32 modes[__VIRTIO_BLK_CRYPTO_MODE_MAX];
+};
+
/*
* Supported zoned device models.
*/
--
2.34.1