| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <176382651808.498.7055758162897751165.tip-bot2@tip-bot2>
Date: Sat, 22 Nov 2025 15:48:38 -0000
From: "tip-bot2 for Babu Moger" <tip-bot2@...utronix.de>
To: linux-tip-commits@...r.kernel.org
Cc: Babu Moger <babu.moger@....com>, "Borislav Petkov (AMD)" <bp@...en8.de>,
Reinette Chatre <reinette.chatre@...el.com>, x86@...nel.org,
linux-kernel@...r.kernel.org
Subject: [tip: x86/cache] fs/resctrl: Introduce interface to display
"io_alloc" support
The following commit has been merged into the x86/cache branch of tip:
Commit-ID: 48068e565045ee0c77fdb34225ac6dedb5871fc2
Gitweb: https://git.kernel.org/tip/48068e565045ee0c77fdb34225ac6dedb5871fc2
Author: Babu Moger <babu.moger@....com>
AuthorDate: Wed, 12 Nov 2025 18:57:31 -06:00
Committer: Borislav Petkov (AMD) <bp@...en8.de>
CommitterDate: Fri, 21 Nov 2025 22:49:42 +01:00
fs/resctrl: Introduce interface to display "io_alloc" support
Introduce the "io_alloc" resctrl file to the "info" area of a cache resource,
for example /sys/fs/resctrl/info/L3/io_alloc. "io_alloc" indicates support for
the "io_alloc" feature that allows direct insertion of data from I/O
devices into the cache.
Restrict exposing support for "io_alloc" to the L3 resource that is the only
resource where this feature can be backed by AMD's L3 Smart Data Cache
Injection Allocation Enforcement (SDCIAE). With that, the "io_alloc" file is
only visible to user space if the L3 resource supports "io_alloc".
Doing so makes the file visible for all cache resources though, for example
also L2 cache (if it supports cache allocation). As a consequence, add
capability for file to report expected "enabled" and "disabled", as well as
"not supported".
Signed-off-by: Babu Moger <babu.moger@....com>
Signed-off-by: Borislav Petkov (AMD) <bp@...en8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@...el.com>
Link: https://patch.msgid.link/e8b116a8f424128b227734bb1d433c14af478d90.1762995456.git.babu.moger@amd.com
---
Documentation/filesystems/resctrl.rst | 15 +++++++++++++++
fs/resctrl/ctrlmondata.c | 21 +++++++++++++++++++++
fs/resctrl/internal.h | 1 +
fs/resctrl/rdtgroup.c | 22 ++++++++++++++++++++++
4 files changed, 59 insertions(+)
diff --git a/Documentation/filesystems/resctrl.rst b/Documentation/filesystems/resctrl.rst
index d7a51ca..1089956 100644
--- a/Documentation/filesystems/resctrl.rst
+++ b/Documentation/filesystems/resctrl.rst
@@ -137,6 +137,21 @@ related to allocation:
"1":
Non-contiguous 1s value in CBM is supported.
+"io_alloc":
+ "io_alloc" enables system software to configure the portion of
+ the cache allocated for I/O traffic. File may only exist if the
+ system supports this feature on some of its cache resources.
+
+ "disabled":
+ Resource supports "io_alloc" but the feature is disabled.
+ Portions of cache used for allocation of I/O traffic cannot
+ be configured.
+ "enabled":
+ Portions of cache used for allocation of I/O traffic
+ can be configured using "io_alloc_cbm".
+ "not supported":
+ Support not available for this resource.
+
Memory bandwidth(MB) subdirectory contains the following files
with respect to allocation:
diff --git a/fs/resctrl/ctrlmondata.c b/fs/resctrl/ctrlmondata.c
index 0d0ef54..78a8e7b 100644
--- a/fs/resctrl/ctrlmondata.c
+++ b/fs/resctrl/ctrlmondata.c
@@ -676,3 +676,24 @@ out:
rdtgroup_kn_unlock(of->kn);
return ret;
}
+
+int resctrl_io_alloc_show(struct kernfs_open_file *of, struct seq_file *seq, void *v)
+{
+ struct resctrl_schema *s = rdt_kn_parent_priv(of->kn);
+ struct rdt_resource *r = s->res;
+
+ mutex_lock(&rdtgroup_mutex);
+
+ if (r->cache.io_alloc_capable) {
+ if (resctrl_arch_get_io_alloc_enabled(r))
+ seq_puts(seq, "enabled\n");
+ else
+ seq_puts(seq, "disabled\n");
+ } else {
+ seq_puts(seq, "not supported\n");
+ }
+
+ mutex_unlock(&rdtgroup_mutex);
+
+ return 0;
+}
diff --git a/fs/resctrl/internal.h b/fs/resctrl/internal.h
index cf1fd82..a18ed88 100644
--- a/fs/resctrl/internal.h
+++ b/fs/resctrl/internal.h
@@ -426,6 +426,7 @@ int mbm_L3_assignments_show(struct kernfs_open_file *of, struct seq_file *s, voi
ssize_t mbm_L3_assignments_write(struct kernfs_open_file *of, char *buf, size_t nbytes,
loff_t off);
+int resctrl_io_alloc_show(struct kernfs_open_file *of, struct seq_file *seq, void *v);
#ifdef CONFIG_RESCTRL_FS_PSEUDO_LOCK
int rdtgroup_locksetup_enter(struct rdtgroup *rdtgrp);
diff --git a/fs/resctrl/rdtgroup.c b/fs/resctrl/rdtgroup.c
index 41ce4b3..c1a603b 100644
--- a/fs/resctrl/rdtgroup.c
+++ b/fs/resctrl/rdtgroup.c
@@ -1948,6 +1948,12 @@ static struct rftype res_common_files[] = {
.seq_show = rdt_thread_throttle_mode_show,
},
{
+ .name = "io_alloc",
+ .mode = 0444,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .seq_show = resctrl_io_alloc_show,
+ },
+ {
.name = "max_threshold_occupancy",
.mode = 0644,
.kf_ops = &rdtgroup_kf_single_ops,
@@ -2138,6 +2144,20 @@ static void thread_throttle_mode_init(void)
RFTYPE_CTRL_INFO | RFTYPE_RES_MB);
}
+/*
+ * The resctrl file "io_alloc" is added using L3 resource. However, it results
+ * in this file being visible for *all* cache resources (eg. L2 cache),
+ * whether it supports "io_alloc" or not.
+ */
+static void io_alloc_init(void)
+{
+ struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_L3);
+
+ if (r->cache.io_alloc_capable)
+ resctrl_file_fflags_init("io_alloc", RFTYPE_CTRL_INFO |
+ RFTYPE_RES_CACHE);
+}
+
void resctrl_file_fflags_init(const char *config, unsigned long fflags)
{
struct rftype *rft;
@@ -4409,6 +4429,8 @@ int resctrl_init(void)
thread_throttle_mode_init();
+ io_alloc_init();
+
ret = resctrl_mon_resource_init();
if (ret)
return ret;
Powered by blists - more mailing lists