From: linlzhan <[email protected]> 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 <[email protected]> --- 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
