[PATCH v4] powerpc/papr_scm: Implement initial support for injecting smart errors
Vaibhav Jain
vaibhav at linux.ibm.com
Tue Jan 25 07:22:04 AEDT 2022
Presently PAPR doesn't support injecting smart errors on an
NVDIMM. This makes testing the NVDIMM health reporting functionality
difficult as simulating NVDIMM health related events need a hacked up
qemu version.
To solve this problem this patch proposes simulating certain set of
NVDIMM health related events in papr_scm. Specifically 'fatal' health
state and 'dirty' shutdown state. These error can be injected via the
user-space 'ndctl-inject-smart(1)' command. With the proposed patch and
corresponding ndctl patches following command flow is expected:
$ sudo ndctl list -DH -d nmem0
...
"health_state":"ok",
"shutdown_state":"clean",
...
# inject unsafe shutdown and fatal health error
$ sudo ndctl inject-smart nmem0 -Uf
...
"health_state":"fatal",
"shutdown_state":"dirty",
...
# uninject all errors
$ sudo ndctl inject-smart nmem0 -N
...
"health_state":"ok",
"shutdown_state":"clean",
...
The patch adds a new member 'health_bitmap_inject_mask' inside struct
papr_scm_priv which is then bitwise ANDed to the health bitmap fetched from the
hypervisor. The value for 'health_bitmap_inject_mask' is accessible from sysfs
at nmemX/papr/health_bitmap_inject.
A new PDSM named 'SMART_INJECT' is proposed that accepts newly
introduced 'struct nd_papr_pdsm_smart_inject' as payload thats
exchanged between libndctl and papr_scm to indicate the requested
smart-error states.
When the processing the PDSM 'SMART_INJECT', papr_pdsm_smart_inject()
constructs a pair or 'inject_mask' and 'clear_mask' bitmaps from the payload
and bit-blt it to the 'health_bitmap_inject_mask'. This ensures the after being
fetched from the hypervisor, the health_bitmap reflects requested smart-error
states.
Signed-off-by: Vaibhav Jain <vaibhav at linux.ibm.com>
Signed-off-by: Shivaprasad G Bhat <sbhat at linux.ibm.com>
---
Changelog:
Since v3:
* Renamed the sysfs entry from 'health_bitmap_override' to
'health_bitmap_inject'.
* Simplified the variable names and removed the 'health_bitmap_{mask,override}'
members. Instead replaced them with a single 'health_bitmap_inject_mask'
member. [Aneesh]
* Updated the sysfs documentations and commit description.
* Used READ/WRITE_ONCE macros at places where 'health_bitmap_inject_mask' may be
accessed concurrently.
Since v2:
* Rebased the patch to ppc-next
* Added documentation for newly introduced sysfs attribute 'health_bitmap_override'
Since v1:
* Updated the patch description.
* Removed dependency of a header movement patch.
* Removed '__packed' attribute for 'struct nd_papr_pdsm_smart_inject' [Aneesh]
---
Documentation/ABI/testing/sysfs-bus-papr-pmem | 12 +++
arch/powerpc/include/uapi/asm/papr_pdsm.h | 18 ++++
arch/powerpc/platforms/pseries/papr_scm.c | 90 ++++++++++++++++++-
3 files changed, 117 insertions(+), 3 deletions(-)
diff --git a/Documentation/ABI/testing/sysfs-bus-papr-pmem b/Documentation/ABI/testing/sysfs-bus-papr-pmem
index 95254cec92bf..4ac0673901e7 100644
--- a/Documentation/ABI/testing/sysfs-bus-papr-pmem
+++ b/Documentation/ABI/testing/sysfs-bus-papr-pmem
@@ -61,3 +61,15 @@ Description:
* "CchRHCnt" : Cache Read Hit Count
* "CchWHCnt" : Cache Write Hit Count
* "FastWCnt" : Fast Write Count
+
+What: /sys/bus/nd/devices/nmemX/papr/health_bitmap_inject
+Date: Jan, 2022
+KernelVersion: v5.17
+Contact: linuxppc-dev <linuxppc-dev at lists.ozlabs.org>, nvdimm at lists.linux.dev,
+Description:
+ (RO) Reports the health bitmap inject bitmap that is applied to
+ bitmap received from PowerVM via the H_SCM_HEALTH. This is used
+ to forcibly set specific bits returned from Hcall. These is then
+ used to simulate various health or shutdown states for an nvdimm
+ and are set by user-space tools like ndctl by issuing a PAPR DSM.
+
diff --git a/arch/powerpc/include/uapi/asm/papr_pdsm.h b/arch/powerpc/include/uapi/asm/papr_pdsm.h
index 82488b1e7276..17439925045c 100644
--- a/arch/powerpc/include/uapi/asm/papr_pdsm.h
+++ b/arch/powerpc/include/uapi/asm/papr_pdsm.h
@@ -116,6 +116,22 @@ struct nd_papr_pdsm_health {
};
};
+/* Flags for injecting specific smart errors */
+#define PDSM_SMART_INJECT_HEALTH_FATAL (1 << 0)
+#define PDSM_SMART_INJECT_BAD_SHUTDOWN (1 << 1)
+
+struct nd_papr_pdsm_smart_inject {
+ union {
+ struct {
+ /* One or more of PDSM_SMART_INJECT_ */
+ __u32 flags;
+ __u8 fatal_enable;
+ __u8 unsafe_shutdown_enable;
+ };
+ __u8 buf[ND_PDSM_PAYLOAD_MAX_SIZE];
+ };
+};
+
/*
* Methods to be embedded in ND_CMD_CALL request. These are sent to the kernel
* via 'nd_cmd_pkg.nd_command' member of the ioctl struct
@@ -123,12 +139,14 @@ struct nd_papr_pdsm_health {
enum papr_pdsm {
PAPR_PDSM_MIN = 0x0,
PAPR_PDSM_HEALTH,
+ PAPR_PDSM_SMART_INJECT,
PAPR_PDSM_MAX,
};
/* Maximal union that can hold all possible payload types */
union nd_pdsm_payload {
struct nd_papr_pdsm_health health;
+ struct nd_papr_pdsm_smart_inject smart_inject;
__u8 buf[ND_PDSM_PAYLOAD_MAX_SIZE];
} __packed;
diff --git a/arch/powerpc/platforms/pseries/papr_scm.c b/arch/powerpc/platforms/pseries/papr_scm.c
index f48e87ac89c9..20aafd387840 100644
--- a/arch/powerpc/platforms/pseries/papr_scm.c
+++ b/arch/powerpc/platforms/pseries/papr_scm.c
@@ -120,6 +120,10 @@ struct papr_scm_priv {
/* length of the stat buffer as expected by phyp */
size_t stat_buffer_len;
+
+ /* The bits which needs to be overridden */
+ u64 health_bitmap_inject_mask;
+
};
static int papr_scm_pmem_flush(struct nd_region *nd_region,
@@ -347,19 +351,29 @@ static ssize_t drc_pmem_query_stats(struct papr_scm_priv *p,
static int __drc_pmem_query_health(struct papr_scm_priv *p)
{
unsigned long ret[PLPAR_HCALL_BUFSIZE];
+ u64 bitmap = 0;
long rc;
/* issue the hcall */
rc = plpar_hcall(H_SCM_HEALTH, ret, p->drc_index);
- if (rc != H_SUCCESS) {
+ if (rc == H_SUCCESS)
+ bitmap = ret[0] & ret[1];
+ else if (rc == H_FUNCTION)
+ dev_info_once(&p->pdev->dev,
+ "Hcall H_SCM_HEALTH not implemented, assuming empty health bitmap");
+ else {
+
dev_err(&p->pdev->dev,
"Failed to query health information, Err:%ld\n", rc);
return -ENXIO;
}
p->lasthealth_jiffies = jiffies;
- p->health_bitmap = ret[0] & ret[1];
-
+ /* Allow injecting specific health bits via inject mask. */
+ if (p->health_bitmap_inject_mask)
+ bitmap = (bitmap & ~p->health_bitmap_inject_mask) |
+ p->health_bitmap_inject_mask;
+ WRITE_ONCE(p->health_bitmap, bitmap);
dev_dbg(&p->pdev->dev,
"Queried dimm health info. Bitmap:0x%016lx Mask:0x%016lx\n",
ret[0], ret[1]);
@@ -669,6 +683,56 @@ static int papr_pdsm_health(struct papr_scm_priv *p,
return rc;
}
+/* Inject a smart error Add the dirty-shutdown-counter value to the pdsm */
+static int papr_pdsm_smart_inject(struct papr_scm_priv *p,
+ union nd_pdsm_payload *payload)
+{
+ int rc;
+ u32 supported_flags = 0;
+ u64 inject_mask = 0, clear_mask = 0;
+ u64 mask;
+
+ /* Check for individual smart error flags and update inject/clear masks */
+ if (payload->smart_inject.flags & PDSM_SMART_INJECT_HEALTH_FATAL) {
+ supported_flags |= PDSM_SMART_INJECT_HEALTH_FATAL;
+ if (payload->smart_inject.fatal_enable)
+ inject_mask |= PAPR_PMEM_HEALTH_FATAL;
+ else
+ clear_mask |= PAPR_PMEM_HEALTH_FATAL;
+ }
+
+ if (payload->smart_inject.flags & PDSM_SMART_INJECT_BAD_SHUTDOWN) {
+ supported_flags |= PDSM_SMART_INJECT_BAD_SHUTDOWN;
+ if (payload->smart_inject.unsafe_shutdown_enable)
+ inject_mask |= PAPR_PMEM_SHUTDOWN_DIRTY;
+ else
+ clear_mask |= PAPR_PMEM_SHUTDOWN_DIRTY;
+ }
+
+ dev_dbg(&p->pdev->dev, "[Smart-inject] inject_mask=%#llx clear_mask=%#llx\n",
+ inject_mask, clear_mask);
+
+ /* Prevent concurrent access to dimm health bitmap related members */
+ rc = mutex_lock_interruptible(&p->health_mutex);
+ if (rc)
+ return rc;
+
+ /* Use inject/clear masks to set health_bitmap_inject_mask */
+ mask = READ_ONCE(p->health_bitmap_inject_mask);
+ mask = (mask & ~clear_mask) | inject_mask;
+ WRITE_ONCE(p->health_bitmap_inject_mask, mask);
+
+ /* Invalidate cached health bitmap */
+ p->lasthealth_jiffies = 0;
+
+ mutex_unlock(&p->health_mutex);
+
+ /* Return the supported flags back to userspace */
+ payload->smart_inject.flags = supported_flags;
+
+ return sizeof(struct nd_papr_pdsm_health);
+}
+
/*
* 'struct pdsm_cmd_desc'
* Identifies supported PDSMs' expected length of in/out payloads
@@ -702,6 +766,12 @@ static const struct pdsm_cmd_desc __pdsm_cmd_descriptors[] = {
.size_out = sizeof(struct nd_papr_pdsm_health),
.service = papr_pdsm_health,
},
+
+ [PAPR_PDSM_SMART_INJECT] = {
+ .size_in = sizeof(struct nd_papr_pdsm_smart_inject),
+ .size_out = sizeof(struct nd_papr_pdsm_smart_inject),
+ .service = papr_pdsm_smart_inject,
+ },
/* Empty */
[PAPR_PDSM_MAX] = {
.size_in = 0,
@@ -838,6 +908,19 @@ static int papr_scm_ndctl(struct nvdimm_bus_descriptor *nd_desc,
return 0;
}
+static ssize_t health_bitmap_inject_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct nvdimm *dimm = to_nvdimm(dev);
+ struct papr_scm_priv *p = nvdimm_provider_data(dimm);
+
+ return sprintf(buf, "%#llx\n",
+ READ_ONCE(p->health_bitmap_inject_mask));
+}
+
+static DEVICE_ATTR_ADMIN_RO(health_bitmap_inject);
+
static ssize_t perf_stats_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
@@ -952,6 +1035,7 @@ static struct attribute *papr_nd_attributes[] = {
&dev_attr_flags.attr,
&dev_attr_perf_stats.attr,
&dev_attr_dirty_shutdown.attr,
+ &dev_attr_health_bitmap_inject.attr,
NULL,
};
--
2.34.1
More information about the Linuxppc-dev
mailing list