From 9968c9dd568e83f57fdc1f6127f8b369a0594991 Mon Sep 17 00:00:00 2001 From: Davidlohr Bueso Date: Mon, 12 Jun 2023 11:10:33 -0700 Subject: [PATCH] cxl/mem: Introduce security state sysfs file Add a read-only sysfs file to display the security state of a device (currently only pmem): /sys/bus/cxl/devices/memX/security/state This introduces a cxl_security_state structure that is to be the placeholder for common CXL security features. Reviewed-by: Jonathan Cameron Reviewed-by: Fan Ni Signed-off-by: Davidlohr Bueso Reviewed-by: Dave Jiang Link: https://lore.kernel.org/r/20230612181038.14421-3-dave@stgolabs.net Signed-off-by: Dan Williams --- Documentation/ABI/testing/sysfs-bus-cxl | 10 ++++++++ drivers/cxl/core/memdev.c | 33 +++++++++++++++++++++++++ drivers/cxl/cxlmem.h | 10 ++++++++ drivers/cxl/security.c | 3 +++ 4 files changed, 56 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl index 48ac0d911801..721a44d8a482 100644 --- a/Documentation/ABI/testing/sysfs-bus-cxl +++ b/Documentation/ABI/testing/sysfs-bus-cxl @@ -58,6 +58,16 @@ Description: affinity for this device. +What: /sys/bus/cxl/devices/memX/security/state +Date: June, 2023 +KernelVersion: v6.5 +Contact: linux-cxl@vger.kernel.org +Description: + (RO) Reading this file will display the CXL security state for + that device. Such states can be: 'disabled', or those available + only for persistent memory: 'locked', 'unlocked' or 'frozen'. + + What: /sys/bus/cxl/devices/*/devtype Date: June, 2021 KernelVersion: v5.14 diff --git a/drivers/cxl/core/memdev.c b/drivers/cxl/core/memdev.c index 057a43267290..1bbb7e39fc93 100644 --- a/drivers/cxl/core/memdev.c +++ b/drivers/cxl/core/memdev.c @@ -107,6 +107,28 @@ static ssize_t numa_node_show(struct device *dev, struct device_attribute *attr, } static DEVICE_ATTR_RO(numa_node); +static ssize_t security_state_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; + unsigned long state = cxlds->security.state; + + if (!(state & CXL_PMEM_SEC_STATE_USER_PASS_SET)) + return sysfs_emit(buf, "disabled\n"); + if (state & CXL_PMEM_SEC_STATE_FROZEN || + state & CXL_PMEM_SEC_STATE_MASTER_PLIMIT || + state & CXL_PMEM_SEC_STATE_USER_PLIMIT) + return sysfs_emit(buf, "frozen\n"); + if (state & CXL_PMEM_SEC_STATE_LOCKED) + return sysfs_emit(buf, "locked\n"); + else + return sysfs_emit(buf, "unlocked\n"); +} +static struct device_attribute dev_attr_security_state = + __ATTR(state, 0444, security_state_show, NULL); + static int cxl_get_poison_by_memdev(struct cxl_memdev *cxlmd) { struct cxl_dev_state *cxlds = cxlmd->cxlds; @@ -352,6 +374,11 @@ static struct attribute *cxl_memdev_ram_attributes[] = { NULL, }; +static struct attribute *cxl_memdev_security_attributes[] = { + &dev_attr_security_state.attr, + NULL, +}; + static umode_t cxl_memdev_visible(struct kobject *kobj, struct attribute *a, int n) { @@ -375,10 +402,16 @@ static struct attribute_group cxl_memdev_pmem_attribute_group = { .attrs = cxl_memdev_pmem_attributes, }; +static struct attribute_group cxl_memdev_security_attribute_group = { + .name = "security", + .attrs = cxl_memdev_security_attributes, +}; + static const struct attribute_group *cxl_memdev_attribute_groups[] = { &cxl_memdev_attribute_group, &cxl_memdev_ram_attribute_group, &cxl_memdev_pmem_attribute_group, + &cxl_memdev_security_attribute_group, NULL, }; diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h index 1d8e81c87c6a..091f1200736b 100644 --- a/drivers/cxl/cxlmem.h +++ b/drivers/cxl/cxlmem.h @@ -260,6 +260,15 @@ struct cxl_poison_state { struct mutex lock; /* Protect reads of poison list */ }; +/** + * struct cxl_security_state - Device security state + * + * @state: state of last security operation + */ +struct cxl_security_state { + unsigned long state; +}; + /** * struct cxl_dev_state - The driver device state * @@ -336,6 +345,7 @@ struct cxl_dev_state { struct cxl_event_state event; struct cxl_poison_state poison; + struct cxl_security_state security; struct rcuwait mbox_wait; int (*mbox_send)(struct cxl_dev_state *cxlds, struct cxl_mbox_cmd *cmd); diff --git a/drivers/cxl/security.c b/drivers/cxl/security.c index 4ad4bda2d18e..9da6785dfd31 100644 --- a/drivers/cxl/security.c +++ b/drivers/cxl/security.c @@ -34,6 +34,9 @@ static unsigned long cxl_pmem_get_security_flags(struct nvdimm *nvdimm, return 0; sec_out = le32_to_cpu(out.flags); + /* cache security state */ + cxlds->security.state = sec_out; + if (ptype == NVDIMM_MASTER) { if (sec_out & CXL_PMEM_SEC_STATE_MASTER_PASS_SET) set_bit(NVDIMM_SECURITY_UNLOCKED, &security_flags); -- 2.25.1