On Wed, 21 Sep 2022 08:32:40 -0700
Dave Jiang <dave.ji...@intel.com> wrote:
> Create callback function to support the nvdimm_security_ops() ->erase()
> callback. Translate the operation to send "Passphrase Secure Erase"
> security command for CXL memory device.
>
> When the mem device is secure erased, arch_invalidate_nvdimm_cache() is
> called in order to invalidate all CPU caches before attempting to access
> the mem device again.
>
> See CXL 2.0 spec section 8.2.9.5.6.6 for reference.
Update references now 3.0 is out.
>
> Signed-off-by: Dave Jiang <dave.ji...@intel.com>
A few minor things inline.
> ---
> drivers/cxl/core/mbox.c | 1 +
> drivers/cxl/cxlmem.h | 8 ++++++++
> drivers/cxl/security.c | 29 +++++++++++++++++++++++++++++
> include/uapi/linux/cxl_mem.h | 1 +
> 4 files changed, 39 insertions(+)
>
> diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
> index 243b01e2de85..88538a7ccc83 100644
> --- a/drivers/cxl/core/mbox.c
> +++ b/drivers/cxl/core/mbox.c
> @@ -70,6 +70,7 @@ static struct cxl_mem_command
> cxl_mem_commands[CXL_MEM_COMMAND_ID_MAX] = {
> CXL_CMD(DISABLE_PASSPHRASE, 0x40, 0, 0),
> CXL_CMD(FREEZE_SECURITY, 0, 0, 0),
> CXL_CMD(UNLOCK, 0x20, 0, 0),
> + CXL_CMD(PASSPHRASE_ERASE, 0x40, 0, 0),
> };
>
> /*
> diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
> index 4e6897e8eb7d..1266df3b2d3d 100644
> --- a/drivers/cxl/cxlmem.h
> +++ b/drivers/cxl/cxlmem.h
> @@ -278,6 +278,7 @@ enum cxl_opcode {
> CXL_MBOX_OP_DISABLE_PASSPHRASE = 0x4502,
> CXL_MBOX_OP_UNLOCK = 0x4503,
> CXL_MBOX_OP_FREEZE_SECURITY = 0x4504,
> + CXL_MBOX_OP_PASSPHRASE_ERASE = 0x4505,
Hmm. Name is a bit ambiguous. Is it erasing the passphrase or the data?
Perhaps full
CXL_MBOX_O_PASSPHRASE_SECURE_ERASE is a little better?
> CXL_MBOX_OP_MAX = 0x10000
> };
>
> @@ -400,6 +401,13 @@ struct cxl_disable_pass {
> u8 pass[NVDIMM_PASSPHRASE_LEN];
> } __packed;
>
> +/* passphrase erase payload */
Same here.
> +struct cxl_pass_erase {
> + u8 type;
> + u8 reserved[31];
> + u8 pass[NVDIMM_PASSPHRASE_LEN];
> +} __packed;
> +
> enum {
> CXL_PMEM_SEC_PASS_MASTER = 0,
> CXL_PMEM_SEC_PASS_USER,
> diff --git a/drivers/cxl/security.c b/drivers/cxl/security.c
> index 8bfdcb58d381..df4cf26e366a 100644
> --- a/drivers/cxl/security.c
> +++ b/drivers/cxl/security.c
> @@ -128,12 +128,41 @@ static int cxl_pmem_security_unlock(struct nvdimm
> *nvdimm,
> return 0;
> }
>
> +static int cxl_pmem_security_passphrase_erase(struct nvdimm *nvdimm,
> + const struct nvdimm_key_data *key,
> + enum nvdimm_passphrase_type ptype)
> +{
> + struct cxl_nvdimm *cxl_nvd = nvdimm_provider_data(nvdimm);
> + struct cxl_memdev *cxlmd = cxl_nvd->cxlmd;
> + struct cxl_dev_state *cxlds = cxlmd->cxlds;
> + struct cxl_pass_erase erase;
> + int rc;
> +
> + if (!cpu_cache_has_invalidate_memregion())
> + return -EOPNOTSUPP;
> +
> + erase.type = ptype == NVDIMM_MASTER ?
> + CXL_PMEM_SEC_PASS_MASTER : CXL_PMEM_SEC_PASS_USER;
> + memcpy(erase.pass, key->data, NVDIMM_PASSPHRASE_LEN);
> + /* Flush all cache before we erase mem device */
> + cpu_cache_invalidate_memregion(IORES_DESC_PERSISTENT_MEMORY);
> + rc = cxl_mbox_send_cmd(cxlds, CXL_MBOX_OP_PASSPHRASE_ERASE,
extra space.
> + &erase, sizeof(erase), NULL, 0);
> + if (rc < 0)
> + return rc;
> +
> + /* mem device erased, invalidate all CPU caches before data is read */
> + cpu_cache_invalidate_memregion(IORES_DESC_PERSISTENT_MEMORY);
> + return 0;
> +}
> +
> static const struct nvdimm_security_ops __cxl_security_ops = {
> .get_flags = cxl_pmem_get_security_flags,
> .change_key = cxl_pmem_security_change_key,
> .disable = cxl_pmem_security_disable,
> .freeze = cxl_pmem_security_freeze,
> .unlock = cxl_pmem_security_unlock,
> + .erase = cxl_pmem_security_passphrase_erase,
> };
>
> const struct nvdimm_security_ops *cxl_security_ops = &__cxl_security_ops;
> diff --git a/include/uapi/linux/cxl_mem.h b/include/uapi/linux/cxl_mem.h
> index 95dca8d4584f..6da25f2e1bf9 100644
> --- a/include/uapi/linux/cxl_mem.h
> +++ b/include/uapi/linux/cxl_mem.h
> @@ -46,6 +46,7 @@
> ___C(DISABLE_PASSPHRASE, "Disable Passphrase"), \
> ___C(FREEZE_SECURITY, "Freeze Security"), \
> ___C(UNLOCK, "Unlock"), \
> + ___C(PASSPHRASE_ERASE, "Passphrase Secure Erase"), \
> ___C(MAX, "invalid / last command")
>
> #define ___C(a, b) CXL_MEM_COMMAND_ID_##a
>
>
