The following commit has been merged into the x86/urgent branch of tip:

Commit-ID: 9fe0450785abbc04b0ed5d3cf61fcdb8ab656b4b Gitweb: https://git.kernel.org/tip/9fe0450785abbc04b0ed5d3cf61fcdb8ab656b4b Author: James Morse james.morse@arm.com AuthorDate: Fri, 21 Feb 2020 16:21:05 Committer: Borislav Petkov bp@suse.de CommitterDate: Fri, 17 Apr 2020 19:35:01 +02:00

x86/resctrl: Preserve CDP enable over CPU hotplug

Resctrl assumes that all CPUs are online when the filesystem is mounted, and that CPUs remember their CDP-enabled state over CPU hotplug.

This goes wrong when resctrl's CDP-enabled state changes while all the CPUs in a domain are offline.

When a domain comes online, enable (or disable!) CDP to match resctrl's current setting.

Fixes: 5ff193fbde20 ("x86/intel_rdt: Add basic resctrl filesystem support") Suggested-by: Reinette Chatre reinette.chatre@intel.com Signed-off-by: James Morse james.morse@arm.com Signed-off-by: Borislav Petkov bp@suse.de Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20200221162105.154163-1-james.morse@arm.com --- arch/x86/kernel/cpu/resctrl/core.c | 2 ++ arch/x86/kernel/cpu/resctrl/internal.h | 1 + arch/x86/kernel/cpu/resctrl/rdtgroup.c | 13 +++++++++++++ 3 files changed, 16 insertions(+)

diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c index 89049b3..d8cc522 100644 --- a/arch/x86/kernel/cpu/resctrl/core.c +++ b/arch/x86/kernel/cpu/resctrl/core.c @@ -578,6 +578,8 @@ static void domain_add_cpu(int cpu, struct rdt_resource *r) d->id = id; cpumask_set_cpu(cpu, &d->cpu_mask);

+ rdt_domain_reconfigure_cdp(r); + if (r->alloc_capable && domain_setup_ctrlval(r, d)) { kfree(d); return; diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h index 181c992..3dd13f3 100644 --- a/arch/x86/kernel/cpu/resctrl/internal.h +++ b/arch/x86/kernel/cpu/resctrl/internal.h @@ -601,5 +601,6 @@ bool has_busy_rmid(struct rdt_resource *r, struct rdt_domain *d); void __check_limbo(struct rdt_domain *d, bool force_free); bool cbm_validate_intel(char *buf, u32 *data, struct rdt_resource *r); bool cbm_validate_amd(char *buf, u32 *data, struct rdt_resource *r); +void rdt_domain_reconfigure_cdp(struct rdt_resource *r);

#endif /* _ASM_X86_RESCTRL_INTERNAL_H */ diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c index 9d4e73a..5a359d9 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -1859,6 +1859,19 @@ static int set_cache_qos_cfg(int level, bool enable) return 0; }

+/* Restore the qos cfg state when a domain comes online */ +void rdt_domain_reconfigure_cdp(struct rdt_resource *r) +{ + if (!r->alloc_capable) + return; + + if (r == &rdt_resources_all[RDT_RESOURCE_L2DATA]) + l2_qos_cfg_update(&r->alloc_enabled); + + if (r == &rdt_resources_all[RDT_RESOURCE_L3DATA]) + l3_qos_cfg_update(&r->alloc_enabled); +} + /* * Enable or disable the MBA software controller * which helps user specify bandwidth in MBps.