From 0fcde5989e8a54b2a155d8bcea21a7f99abb50f9 Mon Sep 17 00:00:00 2001 From: Davidlohr Bueso Date: Tue, 25 Jul 2023 22:19:38 -0700 Subject: [PATCH 1/3] cxl/memdev: Improve sanitize ABI descriptions Be more detailed about the CPU cache management situation. The same goes for both sanitize and secure erase. Signed-off-by: Davidlohr Bueso Link: https://lore.kernel.org/r/20230726051940.3570-2-dave@stgolabs.net Reviewed-by: Dave Jiang Signed-off-by: Vishal Verma --- Documentation/ABI/testing/sysfs-bus-cxl | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl index 6350dd82b9a9..c4c4acb1f3b3 100644 --- a/Documentation/ABI/testing/sysfs-bus-cxl +++ b/Documentation/ABI/testing/sysfs-bus-cxl @@ -82,7 +82,11 @@ Description: whether it resides in persistent capacity, volatile capacity, or the LSA, is made permanently unavailable by whatever means is appropriate for the media type. This functionality requires - the device to be not be actively decoding any HPA ranges. + the device to be disabled, that is, not actively decoding any + HPA ranges. This permits avoiding explicit global CPU cache + management, relying instead for it to be done when a region + transitions between software programmed and hardware committed + states. What /sys/bus/cxl/devices/memX/security/erase @@ -92,7 +96,12 @@ Contact: linux-cxl@vger.kernel.org Description: (WO) Write a boolean 'true' string value to this attribute to secure erase user data by changing the media encryption keys for - all user data areas of the device. + all user data areas of the device. This functionality requires + the device to be disabled, that is, not actively decoding any + HPA ranges. This permits avoiding explicit global CPU cache + management, relying instead for it to be done when a region + transitions between software programmed and hardware committed + states. What: /sys/bus/cxl/devices/memX/firmware/ From 3de8cd2242419fb0adaee629d488acfd6cd93c92 Mon Sep 17 00:00:00 2001 From: Davidlohr Bueso Date: Tue, 25 Jul 2023 22:19:39 -0700 Subject: [PATCH 2/3] cxl/memdev: Document security state in kern-doc ... as is the case with all members of struct cxl_memdev_state. Signed-off-by: Davidlohr Bueso Link: https://lore.kernel.org/r/20230726051940.3570-3-dave@stgolabs.net Reviewed-by: Dave Jiang Signed-off-by: Vishal Verma --- drivers/cxl/cxlmem.h | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h index 499113328586..f3aca828fbec 100644 --- a/drivers/cxl/cxlmem.h +++ b/drivers/cxl/cxlmem.h @@ -434,6 +434,7 @@ struct cxl_dev_state { * @next_persistent_bytes: persistent capacity change pending device reset * @event: event log driver state * @poison: poison driver state info + * @security: security driver state info * @fw: firmware upload / activation state * @mbox_send: @dev specific transport for transmitting mailbox commands * From ad64f5952ce3ea565c7f76ec37ab41df0dde773a Mon Sep 17 00:00:00 2001 From: Davidlohr Bueso Date: Tue, 25 Jul 2023 22:19:40 -0700 Subject: [PATCH 3/3] cxl/memdev: Only show sanitize sysfs files when supported If the device does not support Sanitize or Secure Erase commands, hide the respective sysfs interfaces such that the operation can never be attempted. In order to be generic, keep track of the enabled security commands found in the CEL - the driver does not support Security Passthrough. Signed-off-by: Davidlohr Bueso Link: https://lore.kernel.org/r/20230726051940.3570-4-dave@stgolabs.net Reviewed-by: Dave Jiang Signed-off-by: Vishal Verma --- Documentation/ABI/testing/sysfs-bus-cxl | 6 ++-- drivers/cxl/core/mbox.c | 45 ++++++++++++++++++++++++- drivers/cxl/core/memdev.c | 19 +++++++++++ drivers/cxl/cxlmem.h | 15 +++++++++ 4 files changed, 82 insertions(+), 3 deletions(-) diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl index c4c4acb1f3b3..087f762ebfd5 100644 --- a/Documentation/ABI/testing/sysfs-bus-cxl +++ b/Documentation/ABI/testing/sysfs-bus-cxl @@ -86,7 +86,8 @@ Description: HPA ranges. This permits avoiding explicit global CPU cache management, relying instead for it to be done when a region transitions between software programmed and hardware committed - states. + states. If this file is not present, then there is no hardware + support for the operation. What /sys/bus/cxl/devices/memX/security/erase @@ -101,7 +102,8 @@ Description: HPA ranges. This permits avoiding explicit global CPU cache management, relying instead for it to be done when a region transitions between software programmed and hardware committed - states. + states. If this file is not present, then there is no hardware + support for the operation. What: /sys/bus/cxl/devices/memX/firmware/ diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c index d6d067fbee97..ca60bb8114f2 100644 --- a/drivers/cxl/core/mbox.c +++ b/drivers/cxl/core/mbox.c @@ -121,6 +121,45 @@ static bool cxl_is_security_command(u16 opcode) return false; } +static void cxl_set_security_cmd_enabled(struct cxl_security_state *security, + u16 opcode) +{ + switch (opcode) { + case CXL_MBOX_OP_SANITIZE: + set_bit(CXL_SEC_ENABLED_SANITIZE, security->enabled_cmds); + break; + case CXL_MBOX_OP_SECURE_ERASE: + set_bit(CXL_SEC_ENABLED_SECURE_ERASE, + security->enabled_cmds); + break; + case CXL_MBOX_OP_GET_SECURITY_STATE: + set_bit(CXL_SEC_ENABLED_GET_SECURITY_STATE, + security->enabled_cmds); + break; + case CXL_MBOX_OP_SET_PASSPHRASE: + set_bit(CXL_SEC_ENABLED_SET_PASSPHRASE, + security->enabled_cmds); + break; + case CXL_MBOX_OP_DISABLE_PASSPHRASE: + set_bit(CXL_SEC_ENABLED_DISABLE_PASSPHRASE, + security->enabled_cmds); + break; + case CXL_MBOX_OP_UNLOCK: + set_bit(CXL_SEC_ENABLED_UNLOCK, security->enabled_cmds); + break; + case CXL_MBOX_OP_FREEZE_SECURITY: + set_bit(CXL_SEC_ENABLED_FREEZE_SECURITY, + security->enabled_cmds); + break; + case CXL_MBOX_OP_PASSPHRASE_SECURE_ERASE: + set_bit(CXL_SEC_ENABLED_PASSPHRASE_SECURE_ERASE, + security->enabled_cmds); + break; + default: + break; + } +} + static bool cxl_is_poison_command(u16 opcode) { #define CXL_MBOX_OP_POISON_CMDS 0x43 @@ -677,7 +716,8 @@ static void cxl_walk_cel(struct cxl_memdev_state *mds, size_t size, u8 *cel) u16 opcode = le16_to_cpu(cel_entry[i].opcode); struct cxl_mem_command *cmd = cxl_mem_find_command(opcode); - if (!cmd && !cxl_is_poison_command(opcode)) { + if (!cmd && (!cxl_is_poison_command(opcode) || + !cxl_is_security_command(opcode))) { dev_dbg(dev, "Opcode 0x%04x unsupported by driver\n", opcode); continue; @@ -689,6 +729,9 @@ static void cxl_walk_cel(struct cxl_memdev_state *mds, size_t size, u8 *cel) if (cxl_is_poison_command(opcode)) cxl_set_poison_cmd_enabled(&mds->poison, opcode); + if (cxl_is_security_command(opcode)) + cxl_set_security_cmd_enabled(&mds->security, opcode); + dev_dbg(dev, "Opcode 0x%04x enabled\n", opcode); } } diff --git a/drivers/cxl/core/memdev.c b/drivers/cxl/core/memdev.c index f99e7ec3cc40..14b547c07f54 100644 --- a/drivers/cxl/core/memdev.c +++ b/drivers/cxl/core/memdev.c @@ -477,9 +477,28 @@ static struct attribute_group cxl_memdev_pmem_attribute_group = { .attrs = cxl_memdev_pmem_attributes, }; +static umode_t cxl_memdev_security_visible(struct kobject *kobj, + struct attribute *a, int n) +{ + struct device *dev = kobj_to_dev(kobj); + struct cxl_memdev *cxlmd = to_cxl_memdev(dev); + struct cxl_memdev_state *mds = to_cxl_memdev_state(cxlmd->cxlds); + + if (a == &dev_attr_security_sanitize.attr && + !test_bit(CXL_SEC_ENABLED_SANITIZE, mds->security.enabled_cmds)) + return 0; + + if (a == &dev_attr_security_erase.attr && + !test_bit(CXL_SEC_ENABLED_SECURE_ERASE, mds->security.enabled_cmds)) + return 0; + + return a->mode; +} + static struct attribute_group cxl_memdev_security_attribute_group = { .name = "security", .attrs = cxl_memdev_security_attributes, + .is_visible = cxl_memdev_security_visible, }; static const struct attribute_group *cxl_memdev_attribute_groups[] = { diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h index f3aca828fbec..706f8a6d1ef4 100644 --- a/drivers/cxl/cxlmem.h +++ b/drivers/cxl/cxlmem.h @@ -244,6 +244,19 @@ enum poison_cmd_enabled_bits { CXL_POISON_ENABLED_MAX }; +/* Device enabled security commands */ +enum security_cmd_enabled_bits { + CXL_SEC_ENABLED_SANITIZE, + CXL_SEC_ENABLED_SECURE_ERASE, + CXL_SEC_ENABLED_GET_SECURITY_STATE, + CXL_SEC_ENABLED_SET_PASSPHRASE, + CXL_SEC_ENABLED_DISABLE_PASSPHRASE, + CXL_SEC_ENABLED_UNLOCK, + CXL_SEC_ENABLED_FREEZE_SECURITY, + CXL_SEC_ENABLED_PASSPHRASE_SECURE_ERASE, + CXL_SEC_ENABLED_MAX +}; + /** * struct cxl_poison_state - Driver poison state info * @@ -346,6 +359,7 @@ struct cxl_fw_state { * struct cxl_security_state - Device security state * * @state: state of last security operation + * @enabled_cmds: All security commands enabled in the CEL * @poll: polling for sanitization is enabled, device has no mbox irq support * @poll_tmo_secs: polling timeout * @poll_dwork: polling work item @@ -353,6 +367,7 @@ struct cxl_fw_state { */ struct cxl_security_state { unsigned long state; + DECLARE_BITMAP(enabled_cmds, CXL_SEC_ENABLED_MAX); bool poll; int poll_tmo_secs; struct delayed_work poll_dwork;