linux-stable.git/arch/x86/kernel/cpu/resctrl/core.c, branch linux-6.6.y Linux kernel stable tree x86/resctrl: Fix memory bandwidth counter width for Hygon 2026-01-30T09:27:28+00:00 Xiaochen Shen shenxiaochen@open-hieco.net 2025-12-09T06:26:50+00:00 b73f2834e1bc6daeb67ef43404149073e7dccadb commit 7517e899e1b87b4c22a92c7e40d8733c48e4ec3c upstream. The memory bandwidth calculation relies on reading the hardware counter and measuring the delta between samples. To ensure accurate measurement, the software reads the counter frequently enough to prevent it from rolling over twice between reads. The default Memory Bandwidth Monitoring (MBM) counter width is 24 bits. Hygon CPUs provide a 32-bit width counter, but they do not support the MBM capability CPUID leaf (0xF.[ECX=1]:EAX) to report the width offset (from 24 bits). Consequently, the kernel falls back to the 24-bit default counter width, which causes incorrect overflow handling on Hygon CPUs. Fix this by explicitly setting the counter width offset to 8 bits (resulting in a 32-bit total counter width) for Hygon CPUs. Fixes: d8df126349da ("x86/cpu/hygon: Add missing resctrl_cpu_detect() in bsp_init helper") Signed-off-by: Xiaochen Shen <shenxiaochen@open-hieco.net> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Tony Luck <tony.luck@intel.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20251209062650.1536952-3-shenxiaochen@open-hieco.net Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 7517e899e1b87b4c22a92c7e40d8733c48e4ec3c upstream.

The memory bandwidth calculation relies on reading the hardware counter
and measuring the delta between samples. To ensure accurate measurement,
the software reads the counter frequently enough to prevent it from
rolling over twice between reads.

The default Memory Bandwidth Monitoring (MBM) counter width is 24 bits.
Hygon CPUs provide a 32-bit width counter, but they do not support the
MBM capability CPUID leaf (0xF.[ECX=1]:EAX) to report the width offset
(from 24 bits).

Consequently, the kernel falls back to the 24-bit default counter width,
which causes incorrect overflow handling on Hygon CPUs.

Fix this by explicitly setting the counter width offset to 8 bits (resulting
in a 32-bit total counter width) for Hygon CPUs.

Fixes: d8df126349da ("x86/cpu/hygon: Add missing resctrl_cpu_detect() in bsp_init helper")
Signed-off-by: Xiaochen Shen <shenxiaochen@open-hieco.net>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20251209062650.1536952-3-shenxiaochen@open-hieco.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
x86/resctrl: Add missing resctrl initialization for Hygon 2026-01-30T09:27:28+00:00 Xiaochen Shen shenxiaochen@open-hieco.net 2025-12-09T06:26:49+00:00 a78dca14fb2b054d7b8b46bda1ea552bd1a88ffe commit 6ee98aabdc700b5705e4f1833e2edc82a826b53b upstream. Hygon CPUs supporting Platform QoS features currently undergo partial resctrl initialization through resctrl_cpu_detect() in the Hygon BSP init helper and AMD/Hygon common initialization code. However, several critical data structures remain uninitialized for Hygon CPUs in the following paths: - get_mem_config()-> __rdt_get_mem_config_amd(): rdt_resource::membw,alloc_capable hw_res::num_closid - rdt_init_res_defs()->rdt_init_res_defs_amd(): rdt_resource::cache hw_res::msr_base,msr_update Add the missing AMD/Hygon common initialization to ensure proper Platform QoS functionality on Hygon CPUs. Fixes: d8df126349da ("x86/cpu/hygon: Add missing resctrl_cpu_detect() in bsp_init helper") Signed-off-by: Xiaochen Shen <shenxiaochen@open-hieco.net> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20251209062650.1536952-2-shenxiaochen@open-hieco.net Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 6ee98aabdc700b5705e4f1833e2edc82a826b53b upstream.

Hygon CPUs supporting Platform QoS features currently undergo partial resctrl
initialization through resctrl_cpu_detect() in the Hygon BSP init helper and
AMD/Hygon common initialization code. However, several critical data
structures remain uninitialized for Hygon CPUs in the following paths:

 - get_mem_config()-> __rdt_get_mem_config_amd():
     rdt_resource::membw,alloc_capable
     hw_res::num_closid

 - rdt_init_res_defs()->rdt_init_res_defs_amd():
     rdt_resource::cache
     hw_res::msr_base,msr_update

Add the missing AMD/Hygon common initialization to ensure proper Platform QoS
functionality on Hygon CPUs.

Fixes: d8df126349da ("x86/cpu/hygon: Add missing resctrl_cpu_detect() in bsp_init helper")
Signed-off-by: Xiaochen Shen <shenxiaochen@open-hieco.net>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20251209062650.1536952-2-shenxiaochen@open-hieco.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
x86/resctrl: Annotate get_mem_config() functions as __init 2024-10-22T13:46:33+00:00 Nathan Chancellor nathan@kernel.org 2024-09-17T16:02:53+00:00 16d7d35f1c1e2a3a5cb14c91fe0f1922068942c9 commit d5fd042bf4cfb557981d65628e1779a492cd8cfa upstream. After a recent LLVM change [1] that deduces __cold on functions that only call cold code (such as __init functions), there is a section mismatch warning from __get_mem_config_intel(), which got moved to .text.unlikely. as a result of that optimization: WARNING: modpost: vmlinux: section mismatch in reference: \ __get_mem_config_intel+0x77 (section: .text.unlikely.) -> thread_throttle_mode_init (section: .init.text) Mark __get_mem_config_intel() as __init as well since it is only called from __init code, which clears up the warning. While __rdt_get_mem_config_amd() does not exhibit a warning because it does not call any __init code, it is a similar function that is only called from __init code like __get_mem_config_intel(), so mark it __init as well to keep the code symmetrical. CONFIG_SECTION_MISMATCH_WARN_ONLY=n would turn this into a fatal error. Fixes: 05b93417ce5b ("x86/intel_rdt/mba: Add primary support for Memory Bandwidth Allocation (MBA)") Fixes: 4d05bf71f157 ("x86/resctrl: Introduce AMD QOS feature") Signed-off-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Cc: <stable@kernel.org> Link: https://github.com/llvm/llvm-project/commit/6b11573b8c5e3d36beee099dbe7347c2a007bf53 [1] Link: https://lore.kernel.org/r/20240917-x86-restctrl-get_mem_config_intel-init-v3-1-10d521256284@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit d5fd042bf4cfb557981d65628e1779a492cd8cfa upstream.

After a recent LLVM change [1] that deduces __cold on functions that only call
cold code (such as __init functions), there is a section mismatch warning from
__get_mem_config_intel(), which got moved to .text.unlikely. as a result of
that optimization:

  WARNING: modpost: vmlinux: section mismatch in reference: \
  __get_mem_config_intel+0x77 (section: .text.unlikely.) -> thread_throttle_mode_init (section: .init.text)

Mark __get_mem_config_intel() as __init as well since it is only called
from __init code, which clears up the warning.

While __rdt_get_mem_config_amd() does not exhibit a warning because it
does not call any __init code, it is a similar function that is only
called from __init code like __get_mem_config_intel(), so mark it __init
as well to keep the code symmetrical.

CONFIG_SECTION_MISMATCH_WARN_ONLY=n would turn this into a fatal error.

Fixes: 05b93417ce5b ("x86/intel_rdt/mba: Add primary support for Memory Bandwidth Allocation (MBA)")
Fixes: 4d05bf71f157 ("x86/resctrl: Introduce AMD QOS feature")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Cc: <stable@kernel.org>
Link: https://github.com/llvm/llvm-project/commit/6b11573b8c5e3d36beee099dbe7347c2a007bf53 [1]
Link: https://lore.kernel.org/r/20240917-x86-restctrl-get_mem_config_intel-init-v3-1-10d521256284@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
x86/resctrl: Remove hard-coded memory bandwidth limit 2024-03-26T22:19:19+00:00 Babu Moger babu.moger@amd.com 2024-01-15T22:52:27+00:00 655f231bde27f5201b5d35a95bc39f26e34899a3 [ Upstream commit 0976783bb123f30981bc1e7a14d9626a6f63aeac ] The QOS Memory Bandwidth Enforcement Limit is reported by CPUID_Fn80000020_EAX_x01 and CPUID_Fn80000020_EAX_x02: Bits Description 31:0 BW_LEN: Size of the QOS Memory Bandwidth Enforcement Limit. Newer processors can support higher bandwidth limit than the current hard-coded value. Remove latter and detect using CPUID instead. Also, update the register variables eax and edx to match the AMD CPUID definition. 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 below. Fixes: 4d05bf71f157 ("x86/resctrl: Introduce AMD QOS feature") Signed-off-by: Babu Moger <babu.moger@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Link: https://bugzilla.kernel.org/show_bug.cgi?id=206537 Link: https://lore.kernel.org/r/c26a8ca79d399ed076cf8bf2e9fbc58048808289.1705359148.git.babu.moger@amd.com Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 0976783bb123f30981bc1e7a14d9626a6f63aeac ]

The QOS Memory Bandwidth Enforcement Limit is reported by
CPUID_Fn80000020_EAX_x01 and CPUID_Fn80000020_EAX_x02:

  Bits	 Description
  31:0	 BW_LEN: Size of the QOS Memory Bandwidth Enforcement Limit.

Newer processors can support higher bandwidth limit than the current
hard-coded value. Remove latter and detect using CPUID instead. Also,
update the register variables eax and edx to match the AMD CPUID
definition.

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 below.

Fixes: 4d05bf71f157 ("x86/resctrl: Introduce AMD QOS feature")
Signed-off-by: Babu Moger <babu.moger@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206537
Link: https://lore.kernel.org/r/c26a8ca79d399ed076cf8bf2e9fbc58048808289.1705359148.git.babu.moger@amd.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
x86/resctrl: Add __init attribute to rdt_get_mon_l3_config() 2023-01-23T16:40:11+00:00 Babu Moger babu.moger@amd.com 2023-01-13T15:20:33+00:00 bd334c86b5d70e5d1c6169991802e62c828d6f38 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 <babu.moger@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Link: https://lore.kernel.org/r/20230113152039.770054-8-babu.moger@amd.com Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> 
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 <babu.moger@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Link: https://lore.kernel.org/r/20230113152039.770054-8-babu.moger@amd.com
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
x86/resctrl: Detect and configure Slow Memory Bandwidth Allocation 2023-01-23T16:38:44+00:00 Babu Moger babu.moger@amd.com 2023-01-13T15:20:32+00:00 5b6fac3fa44bafee12e0c3d1c5cbae6d058e9c98 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@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Link: https://lore.kernel.org/r/20230113152039.770054-7-babu.moger@amd.com 
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@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
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 Babu Moger babu.moger@amd.com 2023-01-13T15:20:31+00:00 a76f65c89f928b87c49d88b7fd60cb4d7203ffff 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 <babu.moger@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Link: https://lore.kernel.org/r/20230113152039.770054-6-babu.moger@amd.com 
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 <babu.moger@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
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 Babu Moger babu.moger@amd.com 2023-01-13T15:20:29+00:00 a5b699665580725de8c0c01f2163a15af78b6866 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 <babu.moger@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Link: https://lore.kernel.org/r/20230113152039.770054-4-babu.moger@amd.com 
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 <babu.moger@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
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 Borislav Petkov bp@suse.de 2022-11-06T21:24:08+00:00 97fa21f65c3eb5bbab9b4734bed37fd624cddd86 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 <bp@suse.de> Link: https://lore.kernel.org/r/20221106212923.20699-1-bp@alien8.de 
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 <bp@suse.de>
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 Babu Moger babu.moger@amd.com 2022-09-27T20:16:36+00:00 2d4daa549c17b6ba4845a751c7a78d3b2419d78f 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 <reinette.chatre@intel.com> Signed-off-by: Babu Moger <babu.moger@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Reviewed-by: Fenghua Yu <fenghua.yu@intel.com> Link: https://lore.kernel.org/r/166430979654.372014.615622285687642644.stgit@bmoger-ubuntu 
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 <reinette.chatre@intel.com>
Signed-off-by: Babu Moger <babu.moger@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Fenghua Yu <fenghua.yu@intel.com>
Link: https://lore.kernel.org/r/166430979654.372014.615622285687642644.stgit@bmoger-ubuntu