| 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: <dea9cd70b311b6a7e1eb85b1e6087c701bcb488e.1753467772.git.babu.moger@amd.com>
Date: Fri, 25 Jul 2025 13:29:42 -0500
From: Babu Moger <babu.moger@....com>
To: <corbet@....net>, <tony.luck@...el.com>, <reinette.chatre@...el.com>,
<james.morse@....com>, <tglx@...utronix.de>, <mingo@...hat.com>,
<bp@...en8.de>, <dave.hansen@...ux.intel.com>
CC: <Dave.Martin@....com>, <x86@...nel.org>, <hpa@...or.com>,
<akpm@...ux-foundation.org>, <paulmck@...nel.org>, <rostedt@...dmis.org>,
<Neeraj.Upadhyay@....com>, <david@...hat.com>, <arnd@...db.de>,
<fvdl@...gle.com>, <seanjc@...gle.com>, <jpoimboe@...nel.org>,
<pawan.kumar.gupta@...ux.intel.com>, <xin@...or.com>,
<manali.shukla@....com>, <babu.moger@....com>, <tao1.su@...ux.intel.com>,
<sohil.mehta@...el.com>, <kai.huang@...el.com>, <xiaoyao.li@...el.com>,
<peterz@...radead.org>, <xin3.li@...el.com>, <kan.liang@...ux.intel.com>,
<mario.limonciello@....com>, <thomas.lendacky@....com>, <perry.yuan@....com>,
<gautham.shenoy@....com>, <chang.seok.bae@...el.com>,
<linux-doc@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
<peternewman@...gle.com>, <eranian@...gle.com>
Subject: [PATCH v16 23/34] fs/resctrl: Support counter read/reset with mbm_event assignment mode
When "mbm_event" counter assignment mode is enabled, the architecture
requires a counter ID to read the event data.
Introduce an is_mbm_cntr field in struct rmid_read to indicate whether
counter assignment mode is in use.
Update the logic to call resctrl_arch_cntr_read() and
resctrl_arch_reset_cntr() when the assignment mode is active. Report
'Unassigned' in case the user attempts to read the event without assigning
a hardware counter.
Declare mbm_cntr_get() in fs/resctrl/internal.h to make it accessible to
other functions within fs/resctrl.
Suggested-by: Reinette Chatre <reinette.chatre@...el.com>
Signed-off-by: Babu Moger <babu.moger@....com>
---
v16: Squashed two patches here.
https://lore.kernel.org/lkml/df215f02db88cad714755cd5275f20cf0ee4ae26.1752013061.git.babu.moger@amd.com/
https://lore.kernel.org/lkml/296c435e9bf63fc5031114cced00fbb4837ad327.1752013061.git.babu.moger@amd.com/
Changed is_cntr field in struct rmid_read to is_mbm_cntr.
Fixed the memory leak with arch_mon_ctx.
Updated the resctrl.rst user doc.
Updated the changelog.
Report Unassigned only if none of the events in CTRL_MON and MON are assigned.
v15: New patch to add is_cntr in rmid_read as discussed in
https://lore.kernel.org/lkml/b4b14670-9cb0-4f65-abd5-39db996e8da9@intel.com/
---
Documentation/filesystems/resctrl.rst | 6 ++++
fs/resctrl/ctrlmondata.c | 22 +++++++++---
fs/resctrl/internal.h | 5 +++
fs/resctrl/monitor.c | 52 ++++++++++++++++++++-------
4 files changed, 67 insertions(+), 18 deletions(-)
diff --git a/Documentation/filesystems/resctrl.rst b/Documentation/filesystems/resctrl.rst
index 446736dbd97f..4c24c5f3f4c1 100644
--- a/Documentation/filesystems/resctrl.rst
+++ b/Documentation/filesystems/resctrl.rst
@@ -434,6 +434,12 @@ When monitoring is enabled all MON groups will also contain:
for the L3 cache they occupy). These are named "mon_sub_L3_YY"
where "YY" is the node number.
+ When the 'mbm_event' counter assignment mode is enabled, reading
+ an MBM event of a MON group returns 'Unassigned' if no hardware
+ counter is assigned to it. For CTRL_MON groups, 'Unassigned' is
+ returned if the MBM event does not have an assigned counter in the
+ CTRL_MON group nor in any of its associated MON groups.
+
"mon_hw_id":
Available only with debug option. The identifier used by hardware
for the monitor group. On x86 this is the RMID.
diff --git a/fs/resctrl/ctrlmondata.c b/fs/resctrl/ctrlmondata.c
index ad7ffc6acf13..31787ce6ec91 100644
--- a/fs/resctrl/ctrlmondata.c
+++ b/fs/resctrl/ctrlmondata.c
@@ -563,10 +563,15 @@ void mon_event_read(struct rmid_read *rr, struct rdt_resource *r,
rr->r = r;
rr->d = d;
rr->first = first;
- rr->arch_mon_ctx = resctrl_arch_mon_ctx_alloc(r, evtid);
- if (IS_ERR(rr->arch_mon_ctx)) {
- rr->err = -EINVAL;
- return;
+ if (resctrl_arch_mbm_cntr_assign_enabled(r) &&
+ resctrl_is_mbm_event(evtid)) {
+ rr->is_mbm_cntr = true;
+ } else {
+ rr->arch_mon_ctx = resctrl_arch_mon_ctx_alloc(r, evtid);
+ if (IS_ERR(rr->arch_mon_ctx)) {
+ rr->err = -EINVAL;
+ return;
+ }
}
cpu = cpumask_any_housekeeping(cpumask, RESCTRL_PICK_ANY_CPU);
@@ -582,7 +587,8 @@ void mon_event_read(struct rmid_read *rr, struct rdt_resource *r,
else
smp_call_on_cpu(cpu, smp_mon_event_count, rr, false);
- resctrl_arch_mon_ctx_free(r, evtid, rr->arch_mon_ctx);
+ if (rr->arch_mon_ctx)
+ resctrl_arch_mon_ctx_free(r, evtid, rr->arch_mon_ctx);
}
int rdtgroup_mondata_show(struct seq_file *m, void *arg)
@@ -653,10 +659,16 @@ int rdtgroup_mondata_show(struct seq_file *m, void *arg)
checkresult:
+ /*
+ * -ENOENT is a special case, set only when "mbm_event" counter assignment
+ * mode is enabled and no counter has been assigned.
+ */
if (rr.err == -EIO)
seq_puts(m, "Error\n");
else if (rr.err == -EINVAL)
seq_puts(m, "Unavailable\n");
+ else if (rr.err == -ENOENT)
+ seq_puts(m, "Unassigned\n");
else
seq_printf(m, "%llu\n", rr.val);
diff --git a/fs/resctrl/internal.h b/fs/resctrl/internal.h
index 216588842444..eeee83a5067a 100644
--- a/fs/resctrl/internal.h
+++ b/fs/resctrl/internal.h
@@ -110,6 +110,8 @@ struct mon_data {
* domains in @r sharing L3 @ci.id
* @evtid: Which monitor event to read.
* @first: Initialize MBM counter when true.
+ * @is_mbm_cntr: Is the counter valid? true if "mbm_event" counter assignment mode is
+ * enabled and it is an MBM event.
* @ci_id: Cacheinfo id for L3. Only set when @d is NULL. Used when summing domains.
* @err: Error encountered when reading counter.
* @val: Returned value of event counter. If @rgrp is a parent resource group,
@@ -124,6 +126,7 @@ struct rmid_read {
struct rdt_mon_domain *d;
enum resctrl_event_id evtid;
bool first;
+ bool is_mbm_cntr;
unsigned int ci_id;
int err;
u64 val;
@@ -391,6 +394,8 @@ int rdtgroup_assign_cntr_event(struct rdt_mon_domain *d, struct rdtgroup *rdtgrp
struct mon_evt *mevt);
void rdtgroup_unassign_cntr_event(struct rdt_mon_domain *d, struct rdtgroup *rdtgrp,
struct mon_evt *mevt);
+int mbm_cntr_get(struct rdt_resource *r, struct rdt_mon_domain *d,
+ struct rdtgroup *rdtgrp, enum resctrl_event_id evtid);
#ifdef CONFIG_RESCTRL_FS_PSEUDO_LOCK
int rdtgroup_locksetup_enter(struct rdtgroup *rdtgrp);
diff --git a/fs/resctrl/monitor.c b/fs/resctrl/monitor.c
index 070965d45770..a8b53b0ad0b7 100644
--- a/fs/resctrl/monitor.c
+++ b/fs/resctrl/monitor.c
@@ -362,13 +362,25 @@ static int __mon_event_count(struct rdtgroup *rdtgrp, struct rmid_read *rr)
u32 closid = rdtgrp->closid;
u32 rmid = rdtgrp->mon.rmid;
struct rdt_mon_domain *d;
+ int cntr_id = -ENOENT;
struct cacheinfo *ci;
struct mbm_state *m;
int err, ret;
u64 tval = 0;
+ if (rr->is_mbm_cntr) {
+ cntr_id = mbm_cntr_get(rr->r, rr->d, rdtgrp, rr->evtid);
+ if (cntr_id < 0) {
+ rr->err = -ENOENT;
+ return -EINVAL;
+ }
+ }
+
if (rr->first) {
- resctrl_arch_reset_rmid(rr->r, rr->d, closid, rmid, rr->evtid);
+ if (rr->is_mbm_cntr)
+ resctrl_arch_reset_cntr(rr->r, rr->d, closid, rmid, cntr_id, rr->evtid);
+ else
+ resctrl_arch_reset_rmid(rr->r, rr->d, closid, rmid, rr->evtid);
m = get_mbm_state(rr->d, closid, rmid, rr->evtid);
if (m)
memset(m, 0, sizeof(struct mbm_state));
@@ -379,8 +391,12 @@ static int __mon_event_count(struct rdtgroup *rdtgrp, struct rmid_read *rr)
/* Reading a single domain, must be on a CPU in that domain. */
if (!cpumask_test_cpu(cpu, &rr->d->hdr.cpu_mask))
return -EINVAL;
- rr->err = resctrl_arch_rmid_read(rr->r, rr->d, closid, rmid,
- rr->evtid, &tval, rr->arch_mon_ctx);
+ if (rr->is_mbm_cntr)
+ rr->err = resctrl_arch_cntr_read(rr->r, rr->d, closid, rmid, cntr_id,
+ rr->evtid, &tval);
+ else
+ rr->err = resctrl_arch_rmid_read(rr->r, rr->d, closid, rmid,
+ rr->evtid, &tval, rr->arch_mon_ctx);
if (rr->err)
return rr->err;
@@ -405,8 +421,12 @@ static int __mon_event_count(struct rdtgroup *rdtgrp, struct rmid_read *rr)
list_for_each_entry(d, &rr->r->mon_domains, hdr.list) {
if (d->ci_id != rr->ci_id)
continue;
- err = resctrl_arch_rmid_read(rr->r, d, closid, rmid,
- rr->evtid, &tval, rr->arch_mon_ctx);
+ if (rr->is_mbm_cntr)
+ err = resctrl_arch_cntr_read(rr->r, d, closid, rmid, cntr_id,
+ rr->evtid, &tval);
+ else
+ err = resctrl_arch_rmid_read(rr->r, d, closid, rmid,
+ rr->evtid, &tval, rr->arch_mon_ctx);
if (!err) {
rr->val += tval;
ret = 0;
@@ -613,11 +633,16 @@ static void mbm_update_one_event(struct rdt_resource *r, struct rdt_mon_domain *
rr.r = r;
rr.d = d;
rr.evtid = evtid;
- rr.arch_mon_ctx = resctrl_arch_mon_ctx_alloc(rr.r, rr.evtid);
- if (IS_ERR(rr.arch_mon_ctx)) {
- pr_warn_ratelimited("Failed to allocate monitor context: %ld",
- PTR_ERR(rr.arch_mon_ctx));
- return;
+ if (resctrl_arch_mbm_cntr_assign_enabled(r) &&
+ resctrl_arch_mbm_cntr_assign_enabled(r)) {
+ rr.is_mbm_cntr = true;
+ } else {
+ rr.arch_mon_ctx = resctrl_arch_mon_ctx_alloc(rr.r, rr.evtid);
+ if (IS_ERR(rr.arch_mon_ctx)) {
+ pr_warn_ratelimited("Failed to allocate monitor context: %ld",
+ PTR_ERR(rr.arch_mon_ctx));
+ return;
+ }
}
__mon_event_count(rdtgrp, &rr);
@@ -629,7 +654,8 @@ static void mbm_update_one_event(struct rdt_resource *r, struct rdt_mon_domain *
if (is_mba_sc(NULL))
mbm_bw_count(rdtgrp, &rr);
- resctrl_arch_mon_ctx_free(rr.r, rr.evtid, rr.arch_mon_ctx);
+ if (rr.arch_mon_ctx)
+ resctrl_arch_mon_ctx_free(rr.r, rr.evtid, rr.arch_mon_ctx);
}
static void mbm_update(struct rdt_resource *r, struct rdt_mon_domain *d,
@@ -983,8 +1009,8 @@ static void rdtgroup_assign_cntr(struct rdt_resource *r, struct rdt_mon_domain *
* Return:
* Valid counter ID on success, or -ENOENT on failure.
*/
-static int mbm_cntr_get(struct rdt_resource *r, struct rdt_mon_domain *d,
- struct rdtgroup *rdtgrp, enum resctrl_event_id evtid)
+int mbm_cntr_get(struct rdt_resource *r, struct rdt_mon_domain *d,
+ struct rdtgroup *rdtgrp, enum resctrl_event_id evtid)
{
int cntr_id;
--
2.34.1
Powered by blists - more mailing lists