RE: [PATCH v9 05/13] x86/resctrl: Detect and configure Slow Memory Bandwidth Allocation

From: Moger, Babu
Date: Mon Dec 19 2022 - 10:34:58 EST

[AMD Official Use Only - General]



> -----Original Message-----
> From: Reinette Chatre <reinette.chatre@xxxxxxxxx>
> Sent: Thursday, December 15, 2022 11:14 AM
> To: Moger, Babu <Babu.Moger@xxxxxxx>; corbet@xxxxxxx;
> tglx@xxxxxxxxxxxxx; mingo@xxxxxxxxxx; bp@xxxxxxxxx
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> Subject: Re: [PATCH v9 05/13] x86/resctrl: Detect and configure Slow Memory
> Bandwidth Allocation
>
> Hi Babu,
>
> On 12/1/2022 7:36 AM, Babu Moger wrote:
> > The QoS slow memory configuration details are available via
> > CPUID_Fn80000020_EDX_x02. Detect the available details and initialize
> > the rest to defaults.
> >
> > Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
> > ---
> > arch/x86/include/asm/msr-index.h | 1 +
> > arch/x86/kernel/cpu/resctrl/core.c | 36
> +++++++++++++++++++++++++++--
> > arch/x86/kernel/cpu/resctrl/ctrlmondata.c | 2 +-
> > arch/x86/kernel/cpu/resctrl/rdtgroup.c | 8 ++++--
> > 4 files changed, 41 insertions(+), 6 deletions(-)
> >
> > diff --git a/arch/x86/include/asm/msr-index.h
> > b/arch/x86/include/asm/msr-index.h
> > index 37ff47552bcb..e0a40027aa62 100644
> > --- a/arch/x86/include/asm/msr-index.h
> > +++ b/arch/x86/include/asm/msr-index.h
> > @@ -1061,6 +1061,7 @@
> >
> > /* - AMD: */
> > #define MSR_IA32_MBA_BW_BASE 0xc0000200
> > +#define MSR_IA32_SMBA_BW_BASE 0xc0000280
> >
> > /* MSR_IA32_VMX_MISC bits */
> > #define MSR_IA32_VMX_MISC_INTEL_PT (1ULL << 14)
> > diff --git a/arch/x86/kernel/cpu/resctrl/core.c
> > b/arch/x86/kernel/cpu/resctrl/core.c
> > index 10a8c9d96f32..b4fc851f6489 100644
> > --- a/arch/x86/kernel/cpu/resctrl/core.c
> > +++ b/arch/x86/kernel/cpu/resctrl/core.c
> > @@ -162,6 +162,13 @@ bool is_mba_sc(struct rdt_resource *r)
> > if (!r)
> > return
> rdt_resources_all[RDT_RESOURCE_MBA].r_resctrl.membw.mba_sc;
> >
> > + /*
> > + * The software controller support is only applicable to MBA resource.
> > + * Make sure to check for resource type.
> > + */
> > + if (r->rid != RDT_RESOURCE_MBA)
> > + return false;
> > +
> > return r->membw.mba_sc;
> > }
> >
> > @@ -225,9 +232,15 @@ static bool __rdt_get_mem_config_amd(struct
> rdt_resource *r)
> > struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r);
> > union cpuid_0x10_3_eax eax;
> > union cpuid_0x10_x_edx edx;
> > - u32 ebx, ecx;
> > + u32 ebx, ecx, subleaf;
> >
> > - cpuid_count(0x80000020, 1, &eax.full, &ebx, &ecx, &edx.full);
> > + /*
> > + * Query CPUID_Fn80000020_EDX_x01 for MBA and
> > + * CPUID_Fn80000020_EDX_x02 for SMBA
> > + */
> > + subleaf = (r->rid == RDT_RESOURCE_SMBA) ? 2 : 1;
> > +
> > + cpuid_count(0x80000020, subleaf, &eax.full, &ebx, &ecx, &edx.full);
> > hw_res->num_closid = edx.split.cos_max + 1;
> > r->default_ctrl = MAX_MBA_BW_AMD;
> >
> > @@ -750,6 +763,19 @@ static __init bool get_mem_config(void)
> > return false;
> > }
> >
> > +static __init bool get_slow_mem_config(void) {
> > + struct rdt_hw_resource *hw_res =
> > +&rdt_resources_all[RDT_RESOURCE_SMBA];
> > +
> > + if (!rdt_cpu_has(X86_FEATURE_SMBA))
> > + return false;
> > +
> > + if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
> > + return __rdt_get_mem_config_amd(&hw_res->r_resctrl);
> > +
> > + return false;
> > +}
> > +
> > static __init bool get_rdt_alloc_resources(void) {
> > struct rdt_resource *r;
> > @@ -780,6 +806,9 @@ static __init bool get_rdt_alloc_resources(void)
> > if (get_mem_config())
> > ret = true;
> >
> > + if (get_slow_mem_config())
> > + ret = true;
> > +
> > return ret;
> > }
> >
> > @@ -869,6 +898,9 @@ static __init void rdt_init_res_defs_amd(void)
> > } else if (r->rid == RDT_RESOURCE_MBA) {
> > hw_res->msr_base = MSR_IA32_MBA_BW_BASE;
> > hw_res->msr_update = mba_wrmsr_amd;
> > + } else if (r->rid == RDT_RESOURCE_SMBA) {
> > + hw_res->msr_base = MSR_IA32_SMBA_BW_BASE;
> > + hw_res->msr_update = mba_wrmsr_amd;
> > }
> > }
> > }
> > diff --git a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
> > b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
> > index 1df0e3262bca..2dd4b8c47f23 100644
> > --- a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
> > +++ b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
> > @@ -209,7 +209,7 @@ static int parse_line(char *line, struct resctrl_schema
> *s,
> > unsigned long dom_id;
> >
> > if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP &&
> > - r->rid == RDT_RESOURCE_MBA) {
> > + (r->rid == RDT_RESOURCE_MBA || r->rid ==
> RDT_RESOURCE_SMBA)) {
> > rdt_last_cmd_puts("Cannot pseudo-lock MBA resource\n");
> > return -EINVAL;
> > }
> > diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> > b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> > index e5a48f05e787..8a3dafc0dbf7 100644
> > --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> > +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> > @@ -1213,7 +1213,7 @@ static bool rdtgroup_mode_test_exclusive(struct
> > rdtgroup *rdtgrp)
> >
> > list_for_each_entry(s, &resctrl_schema_all, list) {
> > r = s->res;
> > - if (r->rid == RDT_RESOURCE_MBA)
> > + if (r->rid == RDT_RESOURCE_MBA || r->rid ==
> RDT_RESOURCE_SMBA)
> > continue;
> > has_cache = true;
> > list_for_each_entry(d, &r->domains, list) { @@ -1402,7
> +1402,8 @@
> > static int rdtgroup_size_show(struct kernfs_open_file *of,
> > ctrl = resctrl_arch_get_config(r, d,
> > closid,
> > type);
> > - if (r->rid == RDT_RESOURCE_MBA)
> > + if (r->rid == RDT_RESOURCE_MBA ||
> > + r->rid == RDT_RESOURCE_SMBA)
> > size = ctrl;
> > else
> > size = rdtgroup_cbm_to_size(r, d, ctrl);
> @@ -2845,7 +2846,8 @@
> > static int rdtgroup_init_alloc(struct rdtgroup *rdtgrp)
> >
> > list_for_each_entry(s, &resctrl_schema_all, list) {
> > r = s->res;
> > - if (r->rid == RDT_RESOURCE_MBA) {
> > + if (r->rid == RDT_RESOURCE_MBA ||
> > + r->rid == RDT_RESOURCE_SMBA) {
> > rdtgroup_init_mba(r, rdtgrp->closid);
> > if (is_mba_sc(r))
> > continue;
> >
> >
>
> Reviewed-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>

Thank you
Babu
>
> Reinette