This is a note to let you know that I've just added the patch titled
x86/resctrl: Read supported bandwidth sources from CPUID
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
x86-resctrl-read-supported-bandwidth-sources-from-cp.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 1911a030ee3353221ca58c9f14713fdf832abdd1
Author: Babu Moger <babu.moger@xxxxxxx>
Date: Mon Jan 15 16:52:28 2024 -0600
x86/resctrl: Read supported bandwidth sources from CPUID
[ Upstream commit 54e35eb8611cce5550d3d7689679b1a91c864f28 ]
If the BMEC (Bandwidth Monitoring Event Configuration) feature is
supported, the bandwidth events can be configured. The maximum supported
bandwidth bitmask can be read from CPUID:
CPUID_Fn80000020_ECX_x03 [Platform QoS Monitoring Bandwidth Event Configuration]
Bits Description
31:7 Reserved
6:0 Identifies the bandwidth sources that can be tracked.
While at it, move the mask checking to mon_config_write() before
iterating over all the domains. Also, print the valid bitmask when the
user tries to configure invalid event configuration value.
The CPUID details are documented in the Processor Programming Reference
(PPR) Vol 1.1 for AMD Family 19h Model 11h B1 - 55901 Rev 0.25 in the
Link tag.
Fixes: dc2a3e857981 ("x86/resctrl: Add interface to read mbm_total_bytes_config")
Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
Signed-off-by: Borislav Petkov (AMD) <bp@xxxxxxxxx>
Reviewed-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206537
Link: https://lore.kernel.org/r/669896fa512c7451319fa5ca2fdb6f7e015b5635.1705359148.git.babu.moger@xxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
index 81d90f1a8ce58..40b69b3fc8728 100644
--- a/arch/x86/kernel/cpu/resctrl/internal.h
+++ b/arch/x86/kernel/cpu/resctrl/internal.h
@@ -394,6 +394,8 @@ struct rdt_parse_data {
* @msr_update: Function pointer to update QOS MSRs
* @mon_scale: cqm counter * mon_scale = occupancy in bytes
* @mbm_width: Monitor width, to detect and correct for overflow.
+ * @mbm_cfg_mask: Bandwidth sources that can be tracked when Bandwidth
+ * Monitoring Event Configuration (BMEC) is supported.
* @cdp_enabled: CDP state of this resource
*
* Members of this structure are either private to the architecture
@@ -408,6 +410,7 @@ struct rdt_hw_resource {
struct rdt_resource *r);
unsigned int mon_scale;
unsigned int mbm_width;
+ unsigned int mbm_cfg_mask;
bool cdp_enabled;
};
diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c
index f136ac046851c..acca577e2b066 100644
--- a/arch/x86/kernel/cpu/resctrl/monitor.c
+++ b/arch/x86/kernel/cpu/resctrl/monitor.c
@@ -813,6 +813,12 @@ int __init rdt_get_mon_l3_config(struct rdt_resource *r)
return ret;
if (rdt_cpu_has(X86_FEATURE_BMEC)) {
+ u32 eax, ebx, ecx, edx;
+
+ /* Detect list of bandwidth sources that can be tracked */
+ cpuid_count(0x80000020, 3, &eax, &ebx, &ecx, &edx);
+ hw_res->mbm_cfg_mask = ecx & MAX_EVT_CONFIG_BITS;
+
if (rdt_cpu_has(X86_FEATURE_CQM_MBM_TOTAL)) {
mbm_total_event.configurable = true;
mbm_config_rftype_init("mbm_total_bytes_config");
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 725344048f85d..d82d5de183b10 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -1553,12 +1553,6 @@ static int mbm_config_write_domain(struct rdt_resource *r,
struct mon_config_info mon_info = {0};
int ret = 0;
- /* mon_config cannot be more than the supported set of events */
- if (val > MAX_EVT_CONFIG_BITS) {
- rdt_last_cmd_puts("Invalid event configuration\n");
- return -EINVAL;
- }
-
/*
* Read the current config value first. If both are the same then
* no need to write it again.
@@ -1596,6 +1590,7 @@ static int mbm_config_write_domain(struct rdt_resource *r,
static int mon_config_write(struct rdt_resource *r, char *tok, u32 evtid)
{
+ struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r);
char *dom_str = NULL, *id_str;
unsigned long dom_id, val;
struct rdt_domain *d;
@@ -1619,6 +1614,13 @@ static int mon_config_write(struct rdt_resource *r, char *tok, u32 evtid)
return -EINVAL;
}
+ /* Value from user cannot be more than the supported set of events */
+ if ((val & hw_res->mbm_cfg_mask) != val) {
+ rdt_last_cmd_printf("Invalid event configuration: max valid mask is 0x%02x\n",
+ hw_res->mbm_cfg_mask);
+ return -EINVAL;
+ }
+
list_for_each_entry(d, &r->domains, list) {
if (d->id == dom_id) {
ret = mbm_config_write_domain(r, d, evtid, val);
