On Wed, Jan 08, 2025 at 03:57:49PM -0600, Ben Cheatham wrote:
> Add inject-error command for injecting CXL errors into CXL devices.
> The command currently only has support for injecting CXL protocol
> errors into CXL downstream ports via EINJ.
Hi Ben,
I went through enough to give you some feedback for your v1.
Just ran out of time and didn't want to keep you waiting any longer.
wrt 'currently only has' - what is the grander scope of this that we
might see in the future. Will there only every be one system wide
response to --list-errors or will there be error types per type of
port.
Spec reference?
>
> The command takes an error type and injects an error of that type into the
> specified downstream port. Downstream ports can be specified using the
> port's device name with the -d option. Available error types can be obtained
> by running "cxl inject-error --list-errors".
>
> This command requires the kernel to be built with CONFIG_DEBUGFS and
> CONFIG_ACPI_APEI_EINJ_CXL enabled. It also requires root privileges to
> run due to reading from <debugfs>/cxl/einj_types and writing to
> <debugfs>/cxl/<dport>/einj_inject.
>
> Example usage:
> # cxl inject-error --list-errors
> cxl.mem_correctable
> cxl.mem_fatal
> ...
> # cxl inject-error -d 0000:00:01.1 cxl.mem_correctable
> injected cxl.mem_correctable protocol error
>
I'll probably ask this again later on, but how does user see
list of downstream ports. Does user really think -d dport,
or do they think -d device-name, or ?
Man page will help here.
We don't have cxl-cli support for poison inject, but to future
proof this, let's think about the naming.
Please split the patch up at least into 2 -
libcxl: Add APIs supporting CXL protocol error injection
include updates to Documentation/cxl/lib/libcxl.txt
cxl: add {list,inject}-protocol-error' commands
include man page updates, additiona
The 'list-errors' is the the system level error support, right?
Could that fit in the existing 'cxl list' hierachy?
Would they be a property of the bus?
I don't know that 'protocol' is best name, but seems it needs
another descriptor.
> Signed-off-by: Ben Cheatham <benjamin.cheat...@amd.com>
> ---
> cxl/builtin.h | 1 +
> cxl/cxl.c | 1 +
> cxl/inject-error.c | 188 +++++++++++++++++++++++++++++++++++++++++++++
> cxl/lib/libcxl.c | 53 +++++++++++++
> cxl/lib/libcxl.sym | 2 +
> cxl/libcxl.h | 13 ++++
> cxl/meson.build | 1 +
> 7 files changed, 259 insertions(+)
> create mode 100644 cxl/inject-error.c
>
> diff --git a/cxl/builtin.h b/cxl/builtin.h
> index c483f30..e82fcb5 100644
> --- a/cxl/builtin.h
> +++ b/cxl/builtin.h
> @@ -25,6 +25,7 @@ int cmd_create_region(int argc, const char **argv, struct
> cxl_ctx *ctx);
> int cmd_enable_region(int argc, const char **argv, struct cxl_ctx *ctx);
> int cmd_disable_region(int argc, const char **argv, struct cxl_ctx *ctx);
> int cmd_destroy_region(int argc, const char **argv, struct cxl_ctx *ctx);
> +int cmd_inject_error(int argc, const char **argv, struct cxl_ctx *ctx);
> #ifdef ENABLE_LIBTRACEFS
> int cmd_monitor(int argc, const char **argv, struct cxl_ctx *ctx);
> #else
> diff --git a/cxl/cxl.c b/cxl/cxl.c
> index 1643667..f808926 100644
> --- a/cxl/cxl.c
> +++ b/cxl/cxl.c
> @@ -79,6 +79,7 @@ static struct cmd_struct commands[] = {
> { "enable-region", .c_fn = cmd_enable_region },
> { "disable-region", .c_fn = cmd_disable_region },
> { "destroy-region", .c_fn = cmd_destroy_region },
> + { "inject-error", .c_fn = cmd_inject_error },
> { "monitor", .c_fn = cmd_monitor },
> };
>
> diff --git a/cxl/inject-error.c b/cxl/inject-error.c
> new file mode 100644
Can this fit in an existing file? port.c ?
I didn't review this file yet, so snipping.
> index 0000000..3645934
> --- /dev/null
> +++ b/cxl/inject-error.c
snip
> diff --git a/cxl/lib/libcxl.c b/cxl/lib/libcxl.c
> index 91eedd1..8174c11 100644
> --- a/cxl/lib/libcxl.c
> +++ b/cxl/lib/libcxl.c
> @@ -3179,6 +3179,59 @@ CXL_EXPORT int cxl_dport_get_id(struct cxl_dport
> *dport)
> return dport->id;
> }
>
> +CXL_EXPORT int cxl_dport_inject_proto_err(struct cxl_dport *dport,
> + enum cxl_proto_error_types perr,
> + const char *debugfs)
> +{
> + struct cxl_port *port = cxl_dport_get_port(dport);
> + size_t path_len = strlen(debugfs) + 24;
What's the path_len math, +24 here and +16 in next fcn.
I notice other path calloc's in this file padding more, ie +100 or +50.
> + struct cxl_ctx *ctx = port->ctx;
> + char buf[32];
> + char *path;
> + int rc;
> +
> + if (!dport->dev_path) {
> + err(ctx, "no dev_path for dport\n");
> + return -EINVAL;
> + }
> +
> + path_len += strlen(dport->dev_path);
> + path = calloc(1, path_len);
> + if (!path)
> + return -ENOMEM;
> +
> + snprintf(path, path_len, "%s/cxl/%s/einj_inject", debugfs,
> + cxl_dport_get_devname(dport));
> +
> + snprintf(buf, sizeof(buf), "0x%lx\n", (u64) perr);
Here, and in cxl_get_proto_errors(), can we check for the path and
fail with 'unsupported' if it doesn't exist. That'll tell folks
if feature is not configured, or not enabled ?
Are kernel configured and port enabled 2 different levels?
There's an example in this file w "if (access(path, F_OK) != 0)"
> + rc = sysfs_write_attr(ctx, path, buf);
> + if (rc)
> + err(ctx, "could not write to %s: %d\n", path, rc);
for 'sameness' with most err's in this library, do:
err(ctx, "failed write to %s: %s\n", path, strerr(-rc));
> +
> + free(path);
> + return rc;
> +}
> +
> +CXL_EXPORT int cxl_get_proto_errors(struct cxl_ctx *ctx, char *buf,
> + const char *debugfs)
> +{
> + size_t path_len = strlen(debugfs) + 16;
> + char *path;
> + int rc = 0;
> +
> + path = calloc(1, path_len);
> + if (!path)
> + return -ENOMEM;
> +
> + snprintf(path, path_len, "%s/cxl/einj_types", debugfs);
> + rc = sysfs_read_attr(ctx, path, buf);
> + if (rc)
> + err(ctx, "could not read from %s: %d\n", path, rc);
> +
same comments as previous, check path and make err msg similar
> + free(path);
> + return rc;
> +}
> +
> CXL_EXPORT struct cxl_port *cxl_dport_get_port(struct cxl_dport *dport)
> {
> return dport->port;
> diff --git a/cxl/lib/libcxl.sym b/cxl/lib/libcxl.sym
> index 304d7fa..d39a12d 100644
> --- a/cxl/lib/libcxl.sym
> +++ b/cxl/lib/libcxl.sym
> @@ -281,4 +281,6 @@ global:
> cxl_memdev_get_ram_qos_class;
> cxl_region_qos_class_mismatch;
> cxl_port_decoders_committed;
> + cxl_dport_inject_proto_err;
> + cxl_get_proto_errors;
> } LIBCXL_6;
Start a new section above for these new symbols.
Each ndctl release gets a new section - if symbols added.
> diff --git a/cxl/libcxl.h b/cxl/libcxl.h
> index fc6dd00..867daa4 100644
> --- a/cxl/libcxl.h
> +++ b/cxl/libcxl.h
> @@ -160,6 +160,15 @@ struct cxl_port *cxl_port_get_next_all(struct cxl_port
> *port,
> for (port = cxl_port_get_first(top); port != NULL; \
> port = cxl_port_get_next_all(port, top))
>
> +enum cxl_proto_error_types {
> + CXL_CACHE_CORRECTABLE = 1 << 12,
> + CXL_CACHE_UNCORRECTABLE = 1 << 13,
> + CXL_CACHE_FATAL = 1 << 14,
> + CXL_MEM_CORRECTABLE = 1 << 15,
> + CXL_MEM_UNCORRECTABLE = 1 << 16,
> + CXL_MEM_FATAL = 1 << 17,
> +};
Please align like enum util_json_flags
Is there a spec reference to add?
That's all.
-- Alison
> +
> struct cxl_dport;
> struct cxl_dport *cxl_dport_get_first(struct cxl_port *port);
> struct cxl_dport *cxl_dport_get_next(struct cxl_dport *dport);
> @@ -168,6 +177,10 @@ const char *cxl_dport_get_physical_node(struct cxl_dport
> *dport);
> const char *cxl_dport_get_firmware_node(struct cxl_dport *dport);
> struct cxl_port *cxl_dport_get_port(struct cxl_dport *dport);
> int cxl_dport_get_id(struct cxl_dport *dport);
> +int cxl_dport_inject_proto_err(struct cxl_dport *dport,
> + enum cxl_proto_error_types err,
> + const char *debugfs);
> +int cxl_get_proto_errors(struct cxl_ctx *ctx, char *buf, const char
> *debugfs);
> bool cxl_dport_maps_memdev(struct cxl_dport *dport, struct cxl_memdev
> *memdev);
> struct cxl_dport *cxl_port_get_dport_by_memdev(struct cxl_port *port,
> struct cxl_memdev *memdev);
> diff --git a/cxl/meson.build b/cxl/meson.build
> index 61b4d87..79da4e6 100644
> --- a/cxl/meson.build
> +++ b/cxl/meson.build
> @@ -7,6 +7,7 @@ cxl_src = [
> 'memdev.c',
> 'json.c',
> 'filter.c',
> + 'inject-error.c',
> '../daxctl/json.c',
> '../daxctl/filter.c',
> ]
> --
> 2.34.1
>
>
