linux.git/arch/x86/kernel/cpu/resctrl, branch v6.14

Merge tag 'x86_cpu_for_v6.14_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2025-01-21T17:30:59+00:00

Pull x86 cpuid updates from Borislav Petkov:

 - Remove the less generic CPU matching infra around struct x86_cpu_desc
   and use the generic struct x86_cpu_id thing

 - Remove magic naked numbers for CPUID functions and use proper defines
   of the prefix CPUID_LEAF_*. Consolidate some of the crazy use around
   the tree

 - Smaller cleanups and improvements

* tag 'x86_cpu_for_v6.14_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/cpu: Make all all CPUID leaf names consistent
  x86/fpu: Remove unnecessary CPUID level check
  x86/fpu: Move CPUID leaf definitions to common code
  x86/tsc: Remove CPUID "frequency" leaf magic numbers.
  x86/tsc: Move away from TSC leaf magic numbers
  x86/cpu: Move TSC CPUID leaf definition
  x86/cpu: Refresh DCA leaf reading code
  x86/cpu: Remove unnecessary MwAIT leaf checks
  x86/cpu: Use MWAIT leaf definition
  x86/cpu: Move MWAIT leaf definition to common header
  x86/cpu: Remove 'x86_cpu_desc' infrastructure
  x86/cpu: Move AMD erratum 1386 table over to 'x86_cpu_id'
  x86/cpu: Replace PEBS use of 'x86_cpu_desc' use with 'x86_cpu_id'
  x86/cpu: Expose only stepping min/max interface
  x86/cpu: Introduce new microcode matching helper
  x86/cpufeature: Document cpu_feature_enabled() as the default to use
  x86/paravirt: Remove the WBINVD callback
  x86/cpufeatures: Free up unused feature bits

x86/resctrl: Add write option to "mba_MBps_event" file

2024-12-12T10:27:37+00:00

The "mba_MBps" mount option provides an alternate method to control memory
bandwidth. Instead of specifying allowable bandwidth as a percentage of
maximum possible, the user provides a MiB/s limit value.

There is a file in each CTRL_MON group directory that shows the event
currently in use.

Allow writing that file to choose a different event.

A user can choose any of the memory bandwidth monitoring events listed in
/sys/fs/resctrl/info/L3_mon/mon_features independently for each CTRL_MON group
by writing to each of the "mba_MBps_event" files.

Signed-off-by: Tony Luck 
Signed-off-by: Borislav Petkov (AMD) 
Reviewed-by: Reinette Chatre 
Tested-by: Babu Moger 
Link: https://lore.kernel.org/r/20241206163148.83828-8-tony.luck@intel.com

x86/resctrl: Add "mba_MBps_event" file to CTRL_MON directories

2024-12-12T10:27:28+00:00

The "mba_MBps" mount option provides an alternate method to control memory
bandwidth. Instead of specifying allowable bandwidth as a percentage of
maximum possible, the user provides a MiB/s limit value.

In preparation to allow the user to pick the memory bandwidth monitoring event
used as input to the feedback loop, provide a file in each CTRL_MON group
directory that shows the event currently in use. Note that this file is only
visible when the "mba_MBps" mount option is in use.

Suggested-by: Reinette Chatre 
Signed-off-by: Tony Luck 
Signed-off-by: Borislav Petkov (AMD) 
Reviewed-by: Reinette Chatre 
Tested-by: Babu Moger 
Link: https://lore.kernel.org/r/20241206163148.83828-7-tony.luck@intel.com

x86/resctrl: Make mba_sc use total bandwidth if local is not supported

2024-12-10T15:15:14+00:00

The default input measurement to the mba_sc feedback loop for memory bandwidth
control when the user mounts with the "mba_MBps" option is the local bandwidth
event. But some systems may not support a local bandwidth event.

When local bandwidth event is not supported, check for support of total
bandwidth and use that instead.

Relax the mount option check to allow use of the "mba_MBps" option for systems
when only total bandwidth monitoring is supported. Also update the error
message.

Signed-off-by: Tony Luck 
Signed-off-by: Borislav Petkov (AMD) 
Reviewed-by: Reinette Chatre 
Tested-by: Babu Moger 
Link: https://lore.kernel.org/r/20241206163148.83828-6-tony.luck@intel.com

x86/resctrl: Compute memory bandwidth for all supported events

2024-12-10T15:13:48+00:00

Switching between local and total memory bandwidth events as the input
to the mba_sc feedback loop would be cumbersome and take effect slowly
in the current implementation as the bandwidth is only known after two
consecutive readings of the same event.

Compute the bandwidth for all supported events. This doesn't add
significant overhead and will make changing which event is used
simple.

Suggested-by: Reinette Chatre 
Signed-off-by: Tony Luck 
Signed-off-by: Borislav Petkov (AMD) 
Reviewed-by: Reinette Chatre 
Tested-by: Babu Moger 
Link: https://lore.kernel.org/r/20241206163148.83828-5-tony.luck@intel.com

x86/resctrl: Modify update_mba_bw() to use per CTRL_MON group event

2024-12-10T10:15:19+00:00

update_mba_bw() hard codes use of the memory bandwidth local event which
prevents more flexible options from being deployed.

Change this function to use the event specified in the rdtgroup that is
being processed.

Mount time checks for the "mba_MBps" option ensure that local memory
bandwidth is enabled. So drop the redundant is_mbm_local_enabled() check.

Signed-off-by: Tony Luck 
Signed-off-by: Borislav Petkov (AMD) 
Reviewed-by: Reinette Chatre 
Tested-by: Babu Moger 
Link: https://lore.kernel.org/r/20241206163148.83828-4-tony.luck@intel.com

x86/resctrl: Prepare for per-CTRL_MON group mba_MBps control

2024-12-10T10:13:48+00:00

Resctrl uses local memory bandwidth event as input to the feedback loop when
the mba_MBps mount option is used. This means that this mount option cannot be
used on systems that only support monitoring of total bandwidth.

Prepare to allow users to choose the input event independently for each
CTRL_MON group by adding a global variable "mba_mbps_default_event" used to
set the default event for each CTRL_MON group, and a new field
"mba_mbps_event" in struct rdtgroup to track which event is used for each
CTRL_MON group.

Notes:

1) Both of these are only used when the user mounts the filesystem with the
   "mba_MBps" option.
2) Only check for support of local bandwidth event when initializing
   mba_mbps_default_event. Support for total bandwidth event can be added
   after other routines in resctrl have been updated to handle total bandwidth
   event.

  [ bp: Move mba_mbps_default_event extern into the arch header. ]

Signed-off-by: Tony Luck 
Signed-off-by: Borislav Petkov (AMD) 
Reviewed-by: Reinette Chatre 
Tested-by: Babu Moger 
Link: https://lore.kernel.org/r/20241206163148.83828-3-tony.luck@intel.com

x86/resctrl: Introduce resctrl_file_fflags_init() to initialize fflags

2024-12-09T20:37:01+00:00

thread_throttle_mode_init() and mbm_config_rftype_init() both initialize
fflags for resctrl files.

Adding new files will involve adding another function to initialize
the fflags. This can be simplified by adding a new function
resctrl_file_fflags_init() and passing the file name and flags
to be initialized.

Consolidate fflags initialization into resctrl_file_fflags_init() and
remove thread_throttle_mode_init() and mbm_config_rftype_init().

  [ Tony: Drop __init attribute so resctrl_file_fflags_init() can be used at
    run time. ]

Signed-off-by: Babu Moger 
Signed-off-by: Tony Luck 
Signed-off-by: Borislav Petkov (AMD) 
Reviewed-by: Reinette Chatre 
Link: https://lore.kernel.org/r/20241206163148.83828-2-tony.luck@intel.com

x86/resctrl: Use kthread_run_on_cpu()

2024-12-09T19:19:48+00:00

Use the proper API instead of open coding it.

Signed-off-by: Frederic Weisbecker 
Signed-off-by: Borislav Petkov (AMD) 
Acked-by: Reinette Chatre 
Link: https://lore.kernel.org/r/20240807160228.26206-3-frederic@kernel.org

x86/paravirt: Remove the WBINVD callback

2024-12-06T10:01:36+00:00

The pv_ops::cpu.wbinvd paravirt callback is a leftover of lguest times.
Today it is no longer needed, as all users use the native WBINVD
implementation.

Remove the callback and rename native_wbinvd() to wbinvd().

Signed-off-by: Juergen Gross 
Signed-off-by: Ingo Molnar 
Link: https://lore.kernel.org/r/20241203071550.26487-1-jgross@suse.com