This is a note to let you know that I've just added the patch titled x86/cpu: Add a steppings field to struct x86_cpu_id to the 5.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: x86-cpu-add-a-steppings-field-to-struct-x86_cpu_id.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Wed Oct 5 12:28:43 PM CEST 2022 From: Thadeu Lima de Souza Cascardo <cascardo@xxxxxxxxxxxxx> Date: Mon, 3 Oct 2022 10:10:06 -0300 Subject: x86/cpu: Add a steppings field to struct x86_cpu_id To: stable@xxxxxxxxxxxxxxx Cc: x86@xxxxxxxxxx, kvm@xxxxxxxxxxxxxxx, bp@xxxxxxxxx, pbonzini@xxxxxxxxxx, peterz@xxxxxxxxxxxxx, jpoimboe@xxxxxxxxxx Message-ID: <20221003131038.12645-6-cascardo@xxxxxxxxxxxxx> From: Mark Gross <mgross@xxxxxxxxxxxxxxx> commit e9d7144597b10ff13ff2264c059f7d4a7fbc89ac upstream. Intel uses the same family/model for several CPUs. Sometimes the stepping must be checked to tell them apart. On x86 there can be at most 16 steppings. Add a steppings bitmask to x86_cpu_id and a X86_MATCH_VENDOR_FAMILY_MODEL_STEPPING_FEATURE macro and support for matching against family/model/stepping. [ bp: Massage. ] Signed-off-by: Mark Gross <mgross@xxxxxxxxxxxxxxx> Signed-off-by: Borislav Petkov <bp@xxxxxxx> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Reviewed-by: Tony Luck <tony.luck@xxxxxxxxx> Reviewed-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx> [cascardo: have steppings be the last member as there are initializers that don't use named members] Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/x86/include/asm/cpu_device_id.h | 27 ++++++++++++++++++++++++--- arch/x86/kernel/cpu/match.c | 7 ++++++- include/linux/mod_devicetable.h | 6 ++++++ 3 files changed, 36 insertions(+), 4 deletions(-) --- a/arch/x86/include/asm/cpu_device_id.h +++ b/arch/x86/include/asm/cpu_device_id.h @@ -20,12 +20,14 @@ #define X86_CENTAUR_FAM6_C7_D 0xd #define X86_CENTAUR_FAM6_NANO 0xf +#define X86_STEPPINGS(mins, maxs) GENMASK(maxs, mins) /** - * X86_MATCH_VENDOR_FAM_MODEL_FEATURE - Base macro for CPU matching + * X86_MATCH_VENDOR_FAM_MODEL_STEPPINGS_FEATURE - Base macro for CPU matching * @_vendor: The vendor name, e.g. INTEL, AMD, HYGON, ..., ANY * The name is expanded to X86_VENDOR_@_vendor * @_family: The family number or X86_FAMILY_ANY * @_model: The model number, model constant or X86_MODEL_ANY + * @_steppings: Bitmask for steppings, stepping constant or X86_STEPPING_ANY * @_feature: A X86_FEATURE bit or X86_FEATURE_ANY * @_data: Driver specific data or NULL. The internal storage * format is unsigned long. The supplied value, pointer @@ -37,16 +39,35 @@ * into another macro at the usage site for good reasons, then please * start this local macro with X86_MATCH to allow easy grepping. */ -#define X86_MATCH_VENDOR_FAM_MODEL_FEATURE(_vendor, _family, _model, \ - _feature, _data) { \ +#define X86_MATCH_VENDOR_FAM_MODEL_STEPPINGS_FEATURE(_vendor, _family, _model, \ + _steppings, _feature, _data) { \ .vendor = X86_VENDOR_##_vendor, \ .family = _family, \ .model = _model, \ + .steppings = _steppings, \ .feature = _feature, \ .driver_data = (unsigned long) _data \ } /** + * X86_MATCH_VENDOR_FAM_MODEL_FEATURE - Macro for CPU matching + * @_vendor: The vendor name, e.g. INTEL, AMD, HYGON, ..., ANY + * The name is expanded to X86_VENDOR_@_vendor + * @_family: The family number or X86_FAMILY_ANY + * @_model: The model number, model constant or X86_MODEL_ANY + * @_feature: A X86_FEATURE bit or X86_FEATURE_ANY + * @_data: Driver specific data or NULL. The internal storage + * format is unsigned long. The supplied value, pointer + * etc. is casted to unsigned long internally. + * + * The steppings arguments of X86_MATCH_VENDOR_FAM_MODEL_STEPPINGS_FEATURE() is + * set to wildcards. + */ +#define X86_MATCH_VENDOR_FAM_MODEL_FEATURE(vendor, family, model, feature, data) \ + X86_MATCH_VENDOR_FAM_MODEL_STEPPINGS_FEATURE(vendor, family, model, \ + X86_STEPPING_ANY, feature, data) + +/** * X86_MATCH_VENDOR_FAM_FEATURE - Macro for matching vendor, family and CPU feature * @vendor: The vendor name, e.g. INTEL, AMD, HYGON, ..., ANY * The name is expanded to X86_VENDOR_@vendor --- a/arch/x86/kernel/cpu/match.c +++ b/arch/x86/kernel/cpu/match.c @@ -39,13 +39,18 @@ const struct x86_cpu_id *x86_match_cpu(c const struct x86_cpu_id *m; struct cpuinfo_x86 *c = &boot_cpu_data; - for (m = match; m->vendor | m->family | m->model | m->feature; m++) { + for (m = match; + m->vendor | m->family | m->model | m->steppings | m->feature; + m++) { if (m->vendor != X86_VENDOR_ANY && c->x86_vendor != m->vendor) continue; if (m->family != X86_FAMILY_ANY && c->x86 != m->family) continue; if (m->model != X86_MODEL_ANY && c->x86_model != m->model) continue; + if (m->steppings != X86_STEPPING_ANY && + !(BIT(c->x86_stepping) & m->steppings)) + continue; if (m->feature != X86_FEATURE_ANY && !cpu_has(c, m->feature)) continue; return m; --- a/include/linux/mod_devicetable.h +++ b/include/linux/mod_devicetable.h @@ -657,6 +657,10 @@ struct mips_cdmm_device_id { /* * MODULE_DEVICE_TABLE expects this struct to be called x86cpu_device_id. * Although gcc seems to ignore this error, clang fails without this define. + * + * Note: The ordering of the struct is different from upstream because the + * static initializers in kernels < 5.7 still use C89 style while upstream + * has been converted to proper C99 initializers. */ #define x86cpu_device_id x86_cpu_id struct x86_cpu_id { @@ -665,12 +669,14 @@ struct x86_cpu_id { __u16 model; __u16 feature; /* bit index */ kernel_ulong_t driver_data; + __u16 steppings; }; /* Wild cards for x86_cpu_id::vendor, family, model and feature */ #define X86_VENDOR_ANY 0xffff #define X86_FAMILY_ANY 0 #define X86_MODEL_ANY 0 +#define X86_STEPPING_ANY 0 #define X86_FEATURE_ANY 0 /* Same as FPU, you can't test for that */ /* Patches currently in stable-queue which might be from cascardo@xxxxxxxxxxxxx are queue-5.4/x86-speculation-disable-rrsba-behavior.patch queue-5.4/kvm-vmx-flatten-__vmx_vcpu_run.patch queue-5.4/x86-kvm-vmx-make-noinstr-clean.patch queue-5.4/revert-x86-speculation-add-rsb-vm-exit-protections.patch queue-5.4/kvm-vmx-fix-ibrs-handling-after-vmexit.patch queue-5.4/kvm-vmx-prevent-guest-rsb-poisoning-attacks-with-eibrs.patch queue-5.4/kvm-nvmx-use-__vmx_vcpu_run-in-nested_vmx_check_vmentry_hw.patch queue-5.4/x86-bugs-keep-a-per-cpu-ia32_spec_ctrl-value.patch queue-5.4/x86-cpu-amd-enumerate-btc_no.patch queue-5.4/x86-speculation-fix-firmware-entry-spec_ctrl-handling.patch queue-5.4/x86-speculation-add-spectre_v2-ibrs-option-to-support-kernel-ibrs.patch queue-5.4/x86-cpu-add-consistent-cpu-match-macros.patch queue-5.4/x86-speculation-remove-x86_spec_ctrl_mask.patch queue-5.4/x86-bugs-add-cannon-lake-to-retbleed-affected-cpu-list.patch queue-5.4/x86-bugs-warn-when-ibrs-mitigation-is-selected-on-enhanced-ibrs-parts.patch queue-5.4/x86-speculation-fill-rsb-on-vmexit-for-ibrs.patch queue-5.4/x86-cpu-add-a-steppings-field-to-struct-x86_cpu_id.patch queue-5.4/kvm-vmx-convert-launched-argument-to-flags.patch queue-5.4/x86-common-stamp-out-the-stepping-madness.patch queue-5.4/x86-bugs-split-spectre_v2_select_mitigation-and-spectre_v2_user_select_mitigation.patch queue-5.4/x86-bugs-report-intel-retbleed-vulnerability.patch queue-5.4/x86-speculation-change-fill_return_buffer-to-work-with-objtool.patch queue-5.4/x86-cpufeatures-move-retpoline-flags-to-word-11.patch queue-5.4/x86-speculation-fix-spec_ctrl-write-on-smt-state-change.patch queue-5.4/kvm-vmx-use-test-reg-reg-instead-of-cmp-0-reg-in-vmenter.s.patch queue-5.4/x86-bugs-optimize-spec_ctrl-msr-writes.patch queue-5.4/x86-bugs-report-amd-retbleed-vulnerability.patch queue-5.4/x86-speculation-fix-rsb-filling-with-config_retpoline-n.patch queue-5.4/intel_idle-disable-ibrs-during-long-idle.patch queue-5.4/x86-speculation-use-declare_per_cpu-for-x86_spec_ctrl_current.patch queue-5.4/x86-entry-remove-skip_r11rcx.patch queue-5.4/x86-speculation-use-cached-host-spec_ctrl-value-for-guest-entry-exit.patch queue-5.4/x86-devicetable-move-x86-specific-macro-out-of-generic-code.patch queue-5.4/x86-bugs-add-amd-retbleed-boot-parameter.patch queue-5.4/x86-entry-add-kernel-ibrs-implementation.patch queue-5.4/revert-x86-cpu-add-a-steppings-field-to-struct-x86_cpu_id.patch queue-5.4/x86-speculation-add-rsb-vm-exit-protections.patch