linux.git/arch/x86/kernel/cpu/resctrl/core.c, branch v6.6

x86/resctrl: Add __init attribute to rdt_get_mon_l3_config()

2023-01-23T16:40:11+00:00

In an upcoming change, rdt_get_mon_l3_config() needs to call rdt_cpu_has() to
query the monitor related features. It cannot be called right now because
rdt_cpu_has() has the __init attribute but rdt_get_mon_l3_config() doesn't.

Add the __init attribute to rdt_get_mon_l3_config() that is only called by
get_rdt_mon_resources() that already has the __init attribute. Also make
rdt_cpu_has() available to by rdt_get_mon_l3_config() via the internal header
file.

Signed-off-by: Babu Moger 
Signed-off-by: Borislav Petkov (AMD) 
Reviewed-by: Reinette Chatre 
Link: https://lore.kernel.org/r/20230113152039.770054-8-babu.moger@amd.com
Signed-off-by: Borislav Petkov (AMD)

x86/resctrl: Detect and configure Slow Memory Bandwidth Allocation

2023-01-23T16:38:44+00:00

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 
Signed-off-by: Borislav Petkov (AMD) 
Reviewed-by: Reinette Chatre 
Link: https://lore.kernel.org/r/20230113152039.770054-7-babu.moger@amd.com

x86/resctrl: Include new features in command line options

2023-01-23T16:38:38+00:00

Add the command line options to enable or disable the new resctrl features:

smba: Slow Memory Bandwidth Allocation
bmec: Bandwidth Monitor Event Configuration.

Signed-off-by: Babu Moger 
Signed-off-by: Borislav Petkov (AMD) 
Reviewed-by: Reinette Chatre 
Link: https://lore.kernel.org/r/20230113152039.770054-6-babu.moger@amd.com

x86/resctrl: Add a new resource type RDT_RESOURCE_SMBA

2023-01-23T16:38:22+00:00

Add a new resource type RDT_RESOURCE_SMBA to handle the QoS enforcement
policies on the external slow memory.

Mostly initialization of the essentials. Setting fflags to RFTYPE_RES_MB
configures the SMBA resource to have the same resctrl files as the
existing MBA resource. The SMBA resource has identical properties to
the existing MBA resource. These properties will be enumerated in an
upcoming change and exposed via resctrl because of this flag.

Signed-off-by: Babu Moger 
Signed-off-by: Borislav Petkov (AMD) 
Reviewed-by: Reinette Chatre 
Link: https://lore.kernel.org/r/20230113152039.770054-4-babu.moger@amd.com

x86/resctrl: Move MSR defines into msr-index.h

2022-11-27T22:00:45+00:00

msr-index.h should contain all MSRs for easier grepping for MSR numbers
when dealing with unchecked MSR access warnings, for example.

Move the resctrl ones. Prefix IA32_PQR_ASSOC with "MSR_" while at it.

No functional changes.

Signed-off-by: Borislav Petkov 
Link: https://lore.kernel.org/r/20221106212923.20699-1-bp@alien8.de

x86/resctrl: Remove arch_has_empty_bitmaps

2022-10-24T08:30:29+00:00

The field arch_has_empty_bitmaps is not required anymore. The field
min_cbm_bits is enough to validate the CBM (capacity bit mask) if the
architecture can support the zero CBM or not.

Suggested-by: Reinette Chatre 
Signed-off-by: Babu Moger 
Signed-off-by: Borislav Petkov 
Reviewed-by: Reinette Chatre 
Reviewed-by: Fenghua Yu 
Link: https://lore.kernel.org/r/166430979654.372014.615622285687642644.stgit@bmoger-ubuntu

x86/resctrl: Fix min_cbm_bits for AMD

2022-10-18T18:25:16+00:00

AMD systems support zero CBM (capacity bit mask) for cache allocation.
That is reflected in rdt_init_res_defs_amd() by:

  r->cache.arch_has_empty_bitmaps = true;

However given the unified code in cbm_validate(), checking for:

  val == 0 && !arch_has_empty_bitmaps

is not enough because of another check in cbm_validate():

  if ((zero_bit - first_bit) < r->cache.min_cbm_bits)

The default value of r->cache.min_cbm_bits = 1.

Leading to:

  $ cd /sys/fs/resctrl
  $ mkdir foo
  $ cd foo
  $ echo L3:0=0 > schemata
    -bash: echo: write error: Invalid argument
  $ cat /sys/fs/resctrl/info/last_cmd_status
    Need at least 1 bits in the mask

Initialize the min_cbm_bits to 0 for AMD. Also, remove the default
setting of min_cbm_bits and initialize it separately.

After the fix:

  $ cd /sys/fs/resctrl
  $ mkdir foo
  $ cd foo
  $ echo L3:0=0 > schemata
  $ cat /sys/fs/resctrl/info/last_cmd_status
    ok

Fixes: 316e7f901f5a ("x86/resctrl: Add struct rdt_cache::arch_has_{sparse, empty}_bitmaps")
Co-developed-by: Stephane Eranian 
Signed-off-by: Stephane Eranian 
Signed-off-by: Babu Moger 
Signed-off-by: Borislav Petkov 
Reviewed-by: Ingo Molnar 
Reviewed-by: James Morse 
Reviewed-by: Reinette Chatre 
Reviewed-by: Fenghua Yu 
Cc: 
Link: https://lore.kernel.org/lkml/20220517001234.3137157-1-eranian@google.com

x86/resctrl: Add per-rmid arch private storage for overflow and chunks

2022-09-22T15:46:09+00:00

A renamed __rmid_read() is intended as the function that an
architecture agnostic resctrl filesystem driver can use to
read a value in bytes from a counter. Currently the function returns
the MBM values in chunks directly from hardware. For bandwidth
counters the resctrl filesystem uses this to calculate the number of
bytes ever seen.

MPAM's scaling of counters can be changed at runtime, reducing the
resolution but increasing the range. When this is changed the prev_msr
values need to be converted by the architecture code.

Add an array for per-rmid private storage. The prev_msr and chunks
values will move here to allow resctrl_arch_rmid_read() to always
return the number of bytes read by this counter without assistance
from the filesystem. The values are moved in later patches when
the overflow and correction calls are moved into __rmid_read().

Signed-off-by: James Morse 
Signed-off-by: Borislav Petkov 
Reviewed-by: Jamie Iles 
Reviewed-by: Shaopeng Tan 
Reviewed-by: Reinette Chatre 
Tested-by: Xin Hao 
Tested-by: Shaopeng Tan 
Tested-by: Cristian Marussi 
Link: https://lore.kernel.org/r/20220902154829.30399-14-james.morse@arm.com

x86/resctrl: Allow update_mba_bw() to update controls directly

2022-09-22T15:43:44+00:00

update_mba_bw() calculates a new control value for the MBA resource
based on the user provided mbps_val and the current measured
bandwidth. Some control values need remapping by delay_bw_map().

It does this by calling wrmsrl() directly. This needs splitting
up to be done by an architecture specific helper, so that the
remainder can eventually be moved to /fs/.

Add resctrl_arch_update_one() to apply one configuration value
to the provided resource and domain. This avoids the staging
and cross-calling that is only needed with changes made by
user-space. delay_bw_map() moves to be part of the arch code,
to maintain the 'percentage control' view of MBA resources
in resctrl.

Signed-off-by: James Morse 
Signed-off-by: Borislav Petkov 
Reviewed-by: Jamie Iles 
Reviewed-by: Shaopeng Tan 
Reviewed-by: Reinette Chatre 
Tested-by: Xin Hao 
Tested-by: Shaopeng Tan 
Tested-by: Cristian Marussi 
Link: https://lore.kernel.org/r/20220902154829.30399-12-james.morse@arm.com

x86/resctrl: Remove architecture copy of mbps_val

2022-09-22T15:37:16+00:00

The resctrl arch code provides a second configuration array mbps_val[]
for the MBA software controller.

Since resctrl switched over to allocating and freeing its own array
when needed, nothing uses the arch code version.

Remove it.

Signed-off-by: James Morse 
Signed-off-by: Borislav Petkov 
Reviewed-by: Jamie Iles 
Reviewed-by: Shaopeng Tan 
Reviewed-by: Reinette Chatre 
Tested-by: Xin Hao 
Tested-by: Shaopeng Tan 
Tested-by: Cristian Marussi 
Link: https://lore.kernel.org/r/20220902154829.30399-11-james.morse@arm.com