This is a note to let you know that I've just added the patch titled x86/cpufeature: Add facility to check for min microcode revisions to the 4.14-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-cpufeature-add-facility-to-check-for-min-microcode-revisions.patch and it can be found in the queue-4.14 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 Mon Oct 31 07:55:50 AM CET 2022 From: Suraj Jitindar Singh <surajjs@xxxxxxxxxx> Date: Thu, 27 Oct 2022 13:54:28 -0700 Subject: x86/cpufeature: Add facility to check for min microcode revisions To: <stable@xxxxxxxxxxxxxxx> Cc: <surajjs@xxxxxxxxxx>, <sjitindarsingh@xxxxxxxxx>, <cascardo@xxxxxxxxxxxxx>, <kvm@xxxxxxxxxxxxxxx>, <pbonzini@xxxxxxxxxx>, <jpoimboe@xxxxxxxxxx>, <peterz@xxxxxxxxxxxxx>, <x86@xxxxxxxxxx> Message-ID: <20221027205430.17122-2-surajjs@xxxxxxxxxx> From: Kan Liang <kan.liang@xxxxxxxxxxxxxxx> commit 0f42b790c9ba5ec2f25b7da8b0b6d361082d67b0 upstream For bug workarounds or checks, it is useful to check for specific microcode revisions. Add a new generic function to match the CPU with stepping. Add the other function to check the min microcode revisions for the matched CPU. A new table format is introduced to facilitate the quirk to fill the related information. This does not change the existing x86_cpu_id because it's an ABI shared with modules, and also has quite different requirements, as in no wildcards, but everything has to be matched exactly. Originally-by: Andi Kleen <ak@xxxxxxxxxxxxxxx> Suggested-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Signed-off-by: Kan Liang <kan.liang@xxxxxxxxxxxxxxx> Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> Acked-by: Borislav Petkov <bp@xxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: eranian@xxxxxxxxxx Link: https://lkml.kernel.org/r/1549319013-4522-1-git-send-email-kan.liang@xxxxxxxxxxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/x86/include/asm/cpu_device_id.h | 28 ++++++++++++++++++++++++++++ arch/x86/kernel/cpu/match.c | 31 +++++++++++++++++++++++++++++++ 2 files changed, 59 insertions(+) --- a/arch/x86/include/asm/cpu_device_id.h +++ b/arch/x86/include/asm/cpu_device_id.h @@ -11,4 +11,32 @@ extern const struct x86_cpu_id *x86_match_cpu(const struct x86_cpu_id *match); +/* + * Match specific microcode revisions. + * + * vendor/family/model/stepping must be all set. + * + * Only checks against the boot CPU. When mixed-stepping configs are + * valid for a CPU model, add a quirk for every valid stepping and + * do the fine-tuning in the quirk handler. + */ + +struct x86_cpu_desc { + __u8 x86_family; + __u8 x86_vendor; + __u8 x86_model; + __u8 x86_stepping; + __u32 x86_microcode_rev; +}; + +#define INTEL_CPU_DESC(mod, step, rev) { \ + .x86_family = 6, \ + .x86_vendor = X86_VENDOR_INTEL, \ + .x86_model = mod, \ + .x86_stepping = step, \ + .x86_microcode_rev = rev, \ +} + +extern bool x86_cpu_has_min_microcode_rev(const struct x86_cpu_desc *table); + #endif --- a/arch/x86/kernel/cpu/match.c +++ b/arch/x86/kernel/cpu/match.c @@ -48,3 +48,34 @@ const struct x86_cpu_id *x86_match_cpu(c return NULL; } EXPORT_SYMBOL(x86_match_cpu); + +static const struct x86_cpu_desc * +x86_match_cpu_with_stepping(const struct x86_cpu_desc *match) +{ + struct cpuinfo_x86 *c = &boot_cpu_data; + const struct x86_cpu_desc *m; + + for (m = match; m->x86_family | m->x86_model; m++) { + if (c->x86_vendor != m->x86_vendor) + continue; + if (c->x86 != m->x86_family) + continue; + if (c->x86_model != m->x86_model) + continue; + if (c->x86_stepping != m->x86_stepping) + continue; + return m; + } + return NULL; +} + +bool x86_cpu_has_min_microcode_rev(const struct x86_cpu_desc *table) +{ + const struct x86_cpu_desc *res = x86_match_cpu_with_stepping(table); + + if (!res || res->x86_microcode_rev > boot_cpu_data.microcode) + return false; + + return true; +} +EXPORT_SYMBOL_GPL(x86_cpu_has_min_microcode_rev); Patches currently in stable-queue which might be from surajjs@xxxxxxxxxx are queue-4.14/x86-speculation-disable-rrsba-behavior.patch queue-4.14/x86-bugs-report-intel-retbleed-vulnerability.patch queue-4.14/x86-entry-add-kernel-ibrs-implementation.patch queue-4.14/x86-bugs-warn-when-ibrs-mitigation-is-selected-on-enhanced-ibrs-parts.patch queue-4.14/x86-cpu-add-a-steppings-field-to-struct-x86_cpu_id.patch queue-4.14/x86-speculation-fix-spec_ctrl-write-on-smt-state-change.patch queue-4.14/entel_idle-disable-ibrs-during-long-idle.patch queue-4.14/x86-speculation-use-cached-host-spec_ctrl-value-for-guest-entry-exit.patch queue-4.14/x86-speculation-change-fill_return_buffer-to-work-with-objtool.patch queue-4.14/x86-speculation-add-lfence-to-rsb-fill-sequence.patch queue-4.14/x86-bugs-report-amd-retbleed-vulnerability.patch queue-4.14/x86-speculation-add-spectre_v2-ibrs-option-to-support-kernel-ibrs.patch queue-4.14/x86-bugs-keep-a-per-cpu-ia32_spec_ctrl-value.patch queue-4.14/x86-speculation-fill-rsb-on-vmexit-for-ibrs.patch queue-4.14/x86-speculation-fix-rsb-filling-with-config_retpoline-n.patch queue-4.14/x86-speculation-add-rsb-vm-exit-protections.patch queue-4.14/x86-bugs-optimize-spec_ctrl-msr-writes.patch queue-4.14/kvm-vmx-fix-ibrs-handling-after-vmexit.patch queue-4.14/kvm-vmx-prevent-guest-rsb-poisoning-attacks-with-eibrs.patch queue-4.14/x86-speculation-fix-firmware-entry-spec_ctrl-handling.patch queue-4.14/x86-bugs-add-amd-retbleed-boot-parameter.patch queue-4.14/x86-cpu-add-consistent-cpu-match-macros.patch queue-4.14/x86-speculation-remove-x86_spec_ctrl_mask.patch queue-4.14/x86-speculation-use-declare_per_cpu-for-x86_spec_ctrl_current.patch queue-4.14/x86-cpufeature-fix-various-quality-problems-in-the-asm-cpu_device_hd.h-header.patch queue-4.14/x86-entry-remove-skip_r11rcx.patch queue-4.14/revert-x86-cpu-add-a-steppings-field-to-struct-x86_cpu_id.patch queue-4.14/x86-common-stamp-out-the-stepping-madness.patch queue-4.14/x86-cpu-amd-enumerate-btc_no.patch queue-4.14/x86-bugs-add-cannon-lake-to-retbleed-affected-cpu-list.patch queue-4.14/x86-devicetable-move-x86-specific-macro-out-of-generic-code.patch queue-4.14/x86-bugs-split-spectre_v2_select_mitigation-and-spectre_v2_user_select_mitigation.patch queue-4.14/x86-cpufeatures-move-retpoline-flags-to-word-11.patch queue-4.14/x86-cpufeature-add-facility-to-check-for-min-microcode-revisions.patch