| Message ID | 20220804045029.2905056-3-dave@stgolabs.net |
|---|---|
| State | Under Review |
| Delegated to: | Vishal Verma |
| Headers | show |
| Series | cxl: BG operations and device sanitation | expand |
On Wed, 3 Aug 2022 21:50:29 -0700 Davidlohr Bueso <dave@stgolabs.net> wrote: > Implement support for the non-pmem exclusive sanitize (aka overwrite) > and secure erase commands, per CXL 3.0 specs. > > To properly support this feature, create a 'security' sysfs file that > when read will list the current pmem security state or overwrite, and > when written to, perform the requested operation. > > As with ndctl-speak, the use cases here would be: > > $> cxl sanitize --erase memX > $> cxl sanitize --overwrite memX > $> cxl sanitize --wait-overwrite memX > > While userspace can implement entirely the wait/query mechanism for > waiting for the sanitize to complete. Unlike persistent memory > equivalents, there is no command to query in CXL, and as such we can > safely just use cxlds->bg. > > Signed-off-by: Davidlohr Bueso <dave@stgolabs.net> > --- > Documentation/ABI/testing/sysfs-bus-cxl | 19 +++++ > drivers/cxl/core/mbox.c | 105 ++++++++++++++++++++++++ > drivers/cxl/core/memdev.c | 58 +++++++++++++ > drivers/cxl/cxlmem.h | 3 + > include/uapi/linux/cxl_mem.h | 2 + > 5 files changed, 187 insertions(+) > > diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl > index 7c2b846521f3..88631b492a11 100644 > --- a/Documentation/ABI/testing/sysfs-bus-cxl > +++ b/Documentation/ABI/testing/sysfs-bus-cxl > @@ -52,6 +52,25 @@ Description: > host PCI device for this memory device, emit the CPU node > affinity for this device. > > +What: /sys/bus/cxl/devices/memX/security > +Date: August, 2022 > +KernelVersion: v5.21 v6.1 > +Contact: linux-cxl@vger.kernel.org > +Description: > + Reading this file will display the security state for that > + device. The following states are available: disabled, frozen, > + locked, unlocked and overwrite. When writing to the file, the > + following commands are supported: > + * overwrite - Sanitize the device to securely re-purpose or > + decommission it. This is done by ensuring that all user data > + and meta-data, whether it resides in persistent capacity, > + volatile capacity, or the label storage area, is made > + permanently unavailable by whatever means is appropriate for > + the media type. This causes all CPU caches to be flushed. > + * erase - Secure Erase user data by changing the media encryption > + keys for all user data areas of the device. This causes all > + CPU caches to be flushed. > + > What: /sys/bus/cxl/devices/*/devtype > Date: June, 2021 > KernelVersion: v5.14 > diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c > index db6e5a4d1f6d..06bbb760b392 100644 > --- a/drivers/cxl/core/mbox.c > +++ b/drivers/cxl/core/mbox.c > @@ -41,6 +41,8 @@ static struct workqueue_struct *cxl_mbox_bgcmd_wq; > #define CXL_BGCMD(_id, sin, sout, _flags, _bgops) \ > __CXL_CMD(_id, sin, sout, _flags | CXL_CMD_FLAG_BACKGROUND, _bgops) > > +static struct cxl_mem_bgcommand_ops sanitize_bgops; > + > #define CXL_VARIABLE_PAYLOAD ~0U > /* > * This table defines the supported mailbox commands for the driver. This table > @@ -71,6 +73,8 @@ static struct cxl_mem_command cxl_mem_commands[CXL_MEM_COMMAND_ID_MAX] = { > CXL_CMD(GET_SCAN_MEDIA_CAPS, 0x10, 0x4, 0), > CXL_BGCMD(SCAN_MEDIA, 0x11, 0, 0, NULL), > CXL_CMD(GET_SCAN_MEDIA, 0, CXL_VARIABLE_PAYLOAD, 0), > + CXL_BGCMD(SANITIZE, 0, 0, 0, &sanitize_bgops), > + CXL_CMD(SECURE_ERASE, 0, 0, 0), > CXL_CMD(GET_SECURITY_STATE, 0, 0x4, 0), > CXL_CMD(SET_PASSPHRASE, 0x60, 0, 0), > CXL_CMD(DISABLE_PASSPHRASE, 0x40, 0, 0), > @@ -962,6 +966,107 @@ int cxl_dev_state_identify(struct cxl_dev_state *cxlds) > } > EXPORT_SYMBOL_NS_GPL(cxl_dev_state_identify, CXL); > > +static int sanitize_bgcmd_conflicts(u16 new) > +{ > + /* Forbid anyone but health related commands */ > + if (new == CXL_MBOX_OP_GET_HEALTH_INFO) > + return 0; > + return -EBUSY; > +} > + > +static unsigned long sanitize_bgcmd_delay(struct cxl_dev_state *cxlds) > +{ > + unsigned long secs; > + u64 total_mem; > + > + if (!cxlds) > + return 0; > + > + total_mem = cxlds->total_bytes / CXL_CAPACITY_MULTIPLIER; > + > + if (total_mem <= 16) > + secs = 1; > + else if (total_mem <= 64) > + secs = 10; > + else if (total_mem <= 256) > + secs = 20; > + else if (total_mem <= 512) > + secs = 40; > + else if (total_mem <= 1024) > + secs = 50; > + else > + secs = 60; /* max */ > + return secs; > +} > + > +static void sanitize_bgcmd_post(struct cxl_dev_state *cxlds, bool success) > +{ > + if (success) > + flush_cache_all(); > +} > + > +static struct cxl_mem_bgcommand_ops sanitize_bgops = { > + .conflicts = sanitize_bgcmd_conflicts, > + .delay = sanitize_bgcmd_delay, > + .post = sanitize_bgcmd_post, > +}; blank line here. > +/** > + * cxl_mem_sanitize() - Send sanitation related commands to the device. > + * @cxlds: The device data for the operation > + * @cmd: The command opcode to send > + * > + * Return: 0 if the command was executed successfully, regardless of > + * whether or not the actual security operation is done in the background. > + * Upon error, return the result of the mailbox command or -EINVAL if > + * security requirements are not met. CPU caches are flushed before and > + * after succesful completion of each command. > + * > + * See CXL 2.0 @8.2.9.5.5 Sanitize. > + */ > +int cxl_mem_sanitize(struct cxl_dev_state *cxlds, u16 cmd) > +{ > + int rc; > + bool skip_security; > + u32 sec_out; > + u16 ret_code; /* hw */ > + > + rc = cxl_mbox_send_cmd(cxlds, CXL_MBOX_OP_GET_SECURITY_STATE, > + NULL, 0, &sec_out, sizeof(sec_out), &ret_code); > + /* this may just be plain unsupported, do not error out */ > + skip_security = (ret_code == CXL_MBOX_CMD_RC_UNSUPPORTED); Ah. Now I'm understanding why you had the ret_code. I'd rather see this done using the CEL so we don't send the command if not supported. > + if (rc && !skip_security) > + return rc; > + > + /* > + * Prior to using these commands, any security applied to > + * the user data areas of the device shall be DISABLED (or > + * UNLOCKED for secure erase case). > + */ > + if (!skip_security && (sec_out & CXL_PMEM_SEC_STATE_USER_PASS_SET)) > + return -EINVAL; > + > + if (cmd == CXL_MBOX_OP_SANITIZE) { > + flush_cache_all(); > + > + rc = cxl_mbox_send_cmd(cxlds, cmd, NULL, 0, NULL, 0, &ret_code); > + if (rc == 0 && ret_code != CXL_MBOX_CMD_RC_BACKGROUND) > + flush_cache_all(); > + } else if (cmd == CXL_MBOX_OP_SECURE_ERASE) { > + if (!skip_security && (sec_out & CXL_PMEM_SEC_STATE_LOCKED)) > + return -EINVAL; > + > + flush_cache_all(); > + > + rc = cxl_mbox_send_cmd(cxlds, cmd, NULL, 0, NULL, 0, NULL); > + if (rc == 0) > + flush_cache_all(); > + } else > + rc = -EINVAL; > + > + return rc; > +} > +EXPORT_SYMBOL_NS_GPL(cxl_mem_sanitize, CXL); > + > int cxl_mem_create_range_info(struct cxl_dev_state *cxlds) > { > int rc; > diff --git a/drivers/cxl/core/memdev.c b/drivers/cxl/core/memdev.c > index f7cdcd33504a..db3c5eab7099 100644 > --- a/drivers/cxl/core/memdev.c > +++ b/drivers/cxl/core/memdev.c > @@ -106,12 +106,70 @@ static ssize_t numa_node_show(struct device *dev, struct device_attribute *attr, > } > static DEVICE_ATTR_RO(numa_node); > > +#define CXL_SEC_CMD_SIZE 32 > + > +static ssize_t security_show(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + struct cxl_memdev *cxlmd = to_cxl_memdev(dev); > + struct cxl_dev_state *cxlds = cxlmd->cxlds; > + u32 sec_out = 0; > + u16 ret_code; > + int rc; > + > + if (cxl_mbox_bgcmd_running(cxlds) == CXL_MBOX_OP_SANITIZE) > + return sprintf(buf, "overwrite\n"); > + > + rc = cxl_mbox_send_cmd(cxlds, CXL_MBOX_OP_GET_SECURITY_STATE, > + NULL, 0, &sec_out, sizeof(sec_out), &ret_code); > + if (ret_code == CXL_MBOX_CMD_RC_UNSUPPORTED) As above - if not supported, don't send command. If none of this stuff is supported, hide the sysfs interface via the is_visible callback. > + return sprintf(buf, "disabled\n"); > + if (rc) > + return rc; > + > + if (!(sec_out & CXL_PMEM_SEC_STATE_USER_PASS_SET)) > + return sprintf(buf, "disabled\n"); > + if (sec_out & CXL_PMEM_SEC_STATE_FROZEN) > + return sprintf(buf, "frozen\n"); > + if (sec_out & CXL_PMEM_SEC_STATE_LOCKED) > + return sprintf(buf, "locked\n"); > + else > + return sprintf(buf, "unlocked\n"); > +} > + > +static ssize_t security_store(struct device *dev, > + struct device_attribute *attr, > + const char *buf, size_t len) > +{ > + struct cxl_memdev *cxlmd = to_cxl_memdev(dev); > + struct cxl_dev_state *cxlds = cxlmd->cxlds; > + char cmd[CXL_SEC_CMD_SIZE+1]; > + ssize_t rc; > + > + rc = sscanf(buf, "%"__stringify(CXL_SEC_CMD_SIZE)"s", cmd); > + if (rc < 1) > + return -EINVAL; > + > + if (sysfs_streq(cmd, "overwrite")) > + rc = cxl_mem_sanitize(cxlds, CXL_MBOX_OP_SANITIZE); > + else if (sysfs_streq(cmd, "erase")) > + rc = cxl_mem_sanitize(cxlds, CXL_MBOX_OP_SECURE_ERASE); > + else > + rc = -EINVAL; > + > + if (rc == 0) > + rc = len; > + return rc; > +} > +static DEVICE_ATTR_RW(security); > + > static struct attribute *cxl_memdev_attributes[] = { > &dev_attr_serial.attr, > &dev_attr_firmware_version.attr, > &dev_attr_payload_max.attr, > &dev_attr_label_storage_size.attr, > &dev_attr_numa_node.attr, > + &dev_attr_security.attr, > NULL, > }; > > diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h > index c05dc1b8189a..ee56a4802b34 100644 > --- a/drivers/cxl/cxlmem.h > +++ b/drivers/cxl/cxlmem.h > @@ -256,6 +256,7 @@ enum cxl_opcode { > CXL_MBOX_OP_SCAN_MEDIA = 0x4304, > CXL_MBOX_OP_GET_SCAN_MEDIA = 0x4305, > CXL_MBOX_OP_SANITIZE = 0x4400, This definition should be pulled forwards from previous patch I think. > + CXL_MBOX_OP_SECURE_ERASE = 0x4401, > CXL_MBOX_OP_GET_SECURITY_STATE = 0x4500, > CXL_MBOX_OP_SET_PASSPHRASE = 0x4501, > CXL_MBOX_OP_DISABLE_PASSPHRASE = 0x4502, > @@ -457,6 +458,8 @@ static inline void cxl_mem_active_dec(void) > } > #endif > > +int cxl_mem_sanitize(struct cxl_dev_state *cxlds, u16 cmd); > + > struct cxl_hdm { > struct cxl_component_regs regs; > unsigned int decoder_count; > diff --git a/include/uapi/linux/cxl_mem.h b/include/uapi/linux/cxl_mem.h > index 6da25f2e1bf9..2cea8fb33249 100644 > --- a/include/uapi/linux/cxl_mem.h > +++ b/include/uapi/linux/cxl_mem.h > @@ -41,6 +41,8 @@ > ___C(GET_SCAN_MEDIA_CAPS, "Get Scan Media Capabilities"), \ > ___C(SCAN_MEDIA, "Scan Media"), \ > ___C(GET_SCAN_MEDIA, "Get Scan Media Results"), \ > + ___C(SANITIZE, "Sanitize"), \ > + ___C(SECURE_ERASE, "Secure Erase"), \ > ___C(GET_SECURITY_STATE, "Get Security State"), \ > ___C(SET_PASSPHRASE, "Set Passphrase"), \ > ___C(DISABLE_PASSPHRASE, "Disable Passphrase"), \
diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl index 7c2b846521f3..88631b492a11 100644 --- a/Documentation/ABI/testing/sysfs-bus-cxl +++ b/Documentation/ABI/testing/sysfs-bus-cxl @@ -52,6 +52,25 @@ Description: host PCI device for this memory device, emit the CPU node affinity for this device. +What: /sys/bus/cxl/devices/memX/security +Date: August, 2022 +KernelVersion: v5.21 +Contact: linux-cxl@vger.kernel.org +Description: + Reading this file will display the security state for that + device. The following states are available: disabled, frozen, + locked, unlocked and overwrite. When writing to the file, the + following commands are supported: + * overwrite - Sanitize the device to securely re-purpose or + decommission it. This is done by ensuring that all user data + and meta-data, whether it resides in persistent capacity, + volatile capacity, or the label storage area, is made + permanently unavailable by whatever means is appropriate for + the media type. This causes all CPU caches to be flushed. + * erase - Secure Erase user data by changing the media encryption + keys for all user data areas of the device. This causes all + CPU caches to be flushed. + What: /sys/bus/cxl/devices/*/devtype Date: June, 2021 KernelVersion: v5.14 diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c index db6e5a4d1f6d..06bbb760b392 100644 --- a/drivers/cxl/core/mbox.c +++ b/drivers/cxl/core/mbox.c @@ -41,6 +41,8 @@ static struct workqueue_struct *cxl_mbox_bgcmd_wq; #define CXL_BGCMD(_id, sin, sout, _flags, _bgops) \ __CXL_CMD(_id, sin, sout, _flags | CXL_CMD_FLAG_BACKGROUND, _bgops) +static struct cxl_mem_bgcommand_ops sanitize_bgops; + #define CXL_VARIABLE_PAYLOAD ~0U /* * This table defines the supported mailbox commands for the driver. This table @@ -71,6 +73,8 @@ static struct cxl_mem_command cxl_mem_commands[CXL_MEM_COMMAND_ID_MAX] = { CXL_CMD(GET_SCAN_MEDIA_CAPS, 0x10, 0x4, 0), CXL_BGCMD(SCAN_MEDIA, 0x11, 0, 0, NULL), CXL_CMD(GET_SCAN_MEDIA, 0, CXL_VARIABLE_PAYLOAD, 0), + CXL_BGCMD(SANITIZE, 0, 0, 0, &sanitize_bgops), + CXL_CMD(SECURE_ERASE, 0, 0, 0), CXL_CMD(GET_SECURITY_STATE, 0, 0x4, 0), CXL_CMD(SET_PASSPHRASE, 0x60, 0, 0), CXL_CMD(DISABLE_PASSPHRASE, 0x40, 0, 0), @@ -962,6 +966,107 @@ int cxl_dev_state_identify(struct cxl_dev_state *cxlds) } EXPORT_SYMBOL_NS_GPL(cxl_dev_state_identify, CXL); +static int sanitize_bgcmd_conflicts(u16 new) +{ + /* Forbid anyone but health related commands */ + if (new == CXL_MBOX_OP_GET_HEALTH_INFO) + return 0; + return -EBUSY; +} + +static unsigned long sanitize_bgcmd_delay(struct cxl_dev_state *cxlds) +{ + unsigned long secs; + u64 total_mem; + + if (!cxlds) + return 0; + + total_mem = cxlds->total_bytes / CXL_CAPACITY_MULTIPLIER; + + if (total_mem <= 16) + secs = 1; + else if (total_mem <= 64) + secs = 10; + else if (total_mem <= 256) + secs = 20; + else if (total_mem <= 512) + secs = 40; + else if (total_mem <= 1024) + secs = 50; + else + secs = 60; /* max */ + return secs; +} + +static void sanitize_bgcmd_post(struct cxl_dev_state *cxlds, bool success) +{ + if (success) + flush_cache_all(); +} + +static struct cxl_mem_bgcommand_ops sanitize_bgops = { + .conflicts = sanitize_bgcmd_conflicts, + .delay = sanitize_bgcmd_delay, + .post = sanitize_bgcmd_post, +}; +/** + * cxl_mem_sanitize() - Send sanitation related commands to the device. + * @cxlds: The device data for the operation + * @cmd: The command opcode to send + * + * Return: 0 if the command was executed successfully, regardless of + * whether or not the actual security operation is done in the background. + * Upon error, return the result of the mailbox command or -EINVAL if + * security requirements are not met. CPU caches are flushed before and + * after succesful completion of each command. + * + * See CXL 2.0 @8.2.9.5.5 Sanitize. + */ +int cxl_mem_sanitize(struct cxl_dev_state *cxlds, u16 cmd) +{ + int rc; + bool skip_security; + u32 sec_out; + u16 ret_code; /* hw */ + + rc = cxl_mbox_send_cmd(cxlds, CXL_MBOX_OP_GET_SECURITY_STATE, + NULL, 0, &sec_out, sizeof(sec_out), &ret_code); + /* this may just be plain unsupported, do not error out */ + skip_security = (ret_code == CXL_MBOX_CMD_RC_UNSUPPORTED); + if (rc && !skip_security) + return rc; + + /* + * Prior to using these commands, any security applied to + * the user data areas of the device shall be DISABLED (or + * UNLOCKED for secure erase case). + */ + if (!skip_security && (sec_out & CXL_PMEM_SEC_STATE_USER_PASS_SET)) + return -EINVAL; + + if (cmd == CXL_MBOX_OP_SANITIZE) { + flush_cache_all(); + + rc = cxl_mbox_send_cmd(cxlds, cmd, NULL, 0, NULL, 0, &ret_code); + if (rc == 0 && ret_code != CXL_MBOX_CMD_RC_BACKGROUND) + flush_cache_all(); + } else if (cmd == CXL_MBOX_OP_SECURE_ERASE) { + if (!skip_security && (sec_out & CXL_PMEM_SEC_STATE_LOCKED)) + return -EINVAL; + + flush_cache_all(); + + rc = cxl_mbox_send_cmd(cxlds, cmd, NULL, 0, NULL, 0, NULL); + if (rc == 0) + flush_cache_all(); + } else + rc = -EINVAL; + + return rc; +} +EXPORT_SYMBOL_NS_GPL(cxl_mem_sanitize, CXL); + int cxl_mem_create_range_info(struct cxl_dev_state *cxlds) { int rc; diff --git a/drivers/cxl/core/memdev.c b/drivers/cxl/core/memdev.c index f7cdcd33504a..db3c5eab7099 100644 --- a/drivers/cxl/core/memdev.c +++ b/drivers/cxl/core/memdev.c @@ -106,12 +106,70 @@ static ssize_t numa_node_show(struct device *dev, struct device_attribute *attr, } static DEVICE_ATTR_RO(numa_node); +#define CXL_SEC_CMD_SIZE 32 + +static ssize_t security_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct cxl_memdev *cxlmd = to_cxl_memdev(dev); + struct cxl_dev_state *cxlds = cxlmd->cxlds; + u32 sec_out = 0; + u16 ret_code; + int rc; + + if (cxl_mbox_bgcmd_running(cxlds) == CXL_MBOX_OP_SANITIZE) + return sprintf(buf, "overwrite\n"); + + rc = cxl_mbox_send_cmd(cxlds, CXL_MBOX_OP_GET_SECURITY_STATE, + NULL, 0, &sec_out, sizeof(sec_out), &ret_code); + if (ret_code == CXL_MBOX_CMD_RC_UNSUPPORTED) + return sprintf(buf, "disabled\n"); + if (rc) + return rc; + + if (!(sec_out & CXL_PMEM_SEC_STATE_USER_PASS_SET)) + return sprintf(buf, "disabled\n"); + if (sec_out & CXL_PMEM_SEC_STATE_FROZEN) + return sprintf(buf, "frozen\n"); + if (sec_out & CXL_PMEM_SEC_STATE_LOCKED) + return sprintf(buf, "locked\n"); + else + return sprintf(buf, "unlocked\n"); +} + +static ssize_t security_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t len) +{ + struct cxl_memdev *cxlmd = to_cxl_memdev(dev); + struct cxl_dev_state *cxlds = cxlmd->cxlds; + char cmd[CXL_SEC_CMD_SIZE+1]; + ssize_t rc; + + rc = sscanf(buf, "%"__stringify(CXL_SEC_CMD_SIZE)"s", cmd); + if (rc < 1) + return -EINVAL; + + if (sysfs_streq(cmd, "overwrite")) + rc = cxl_mem_sanitize(cxlds, CXL_MBOX_OP_SANITIZE); + else if (sysfs_streq(cmd, "erase")) + rc = cxl_mem_sanitize(cxlds, CXL_MBOX_OP_SECURE_ERASE); + else + rc = -EINVAL; + + if (rc == 0) + rc = len; + return rc; +} +static DEVICE_ATTR_RW(security); + static struct attribute *cxl_memdev_attributes[] = { &dev_attr_serial.attr, &dev_attr_firmware_version.attr, &dev_attr_payload_max.attr, &dev_attr_label_storage_size.attr, &dev_attr_numa_node.attr, + &dev_attr_security.attr, NULL, }; diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h index c05dc1b8189a..ee56a4802b34 100644 --- a/drivers/cxl/cxlmem.h +++ b/drivers/cxl/cxlmem.h @@ -256,6 +256,7 @@ enum cxl_opcode { CXL_MBOX_OP_SCAN_MEDIA = 0x4304, CXL_MBOX_OP_GET_SCAN_MEDIA = 0x4305, CXL_MBOX_OP_SANITIZE = 0x4400, + CXL_MBOX_OP_SECURE_ERASE = 0x4401, CXL_MBOX_OP_GET_SECURITY_STATE = 0x4500, CXL_MBOX_OP_SET_PASSPHRASE = 0x4501, CXL_MBOX_OP_DISABLE_PASSPHRASE = 0x4502, @@ -457,6 +458,8 @@ static inline void cxl_mem_active_dec(void) } #endif +int cxl_mem_sanitize(struct cxl_dev_state *cxlds, u16 cmd); + struct cxl_hdm { struct cxl_component_regs regs; unsigned int decoder_count; diff --git a/include/uapi/linux/cxl_mem.h b/include/uapi/linux/cxl_mem.h index 6da25f2e1bf9..2cea8fb33249 100644 --- a/include/uapi/linux/cxl_mem.h +++ b/include/uapi/linux/cxl_mem.h @@ -41,6 +41,8 @@ ___C(GET_SCAN_MEDIA_CAPS, "Get Scan Media Capabilities"), \ ___C(SCAN_MEDIA, "Scan Media"), \ ___C(GET_SCAN_MEDIA, "Get Scan Media Results"), \ + ___C(SANITIZE, "Sanitize"), \ + ___C(SECURE_ERASE, "Secure Erase"), \ ___C(GET_SECURITY_STATE, "Get Security State"), \ ___C(SET_PASSPHRASE, "Set Passphrase"), \ ___C(DISABLE_PASSPHRASE, "Disable Passphrase"), \
Implement support for the non-pmem exclusive sanitize (aka overwrite) and secure erase commands, per CXL 3.0 specs. To properly support this feature, create a 'security' sysfs file that when read will list the current pmem security state or overwrite, and when written to, perform the requested operation. As with ndctl-speak, the use cases here would be: $> cxl sanitize --erase memX $> cxl sanitize --overwrite memX $> cxl sanitize --wait-overwrite memX While userspace can implement entirely the wait/query mechanism for waiting for the sanitize to complete. Unlike persistent memory equivalents, there is no command to query in CXL, and as such we can safely just use cxlds->bg. Signed-off-by: Davidlohr Bueso <dave@stgolabs.net> --- Documentation/ABI/testing/sysfs-bus-cxl | 19 +++++ drivers/cxl/core/mbox.c | 105 ++++++++++++++++++++++++ drivers/cxl/core/memdev.c | 58 +++++++++++++ drivers/cxl/cxlmem.h | 3 + include/uapi/linux/cxl_mem.h | 2 + 5 files changed, 187 insertions(+)