kernel.git/arch/x86/kernel/cpu/amd.c, branch master

Merge tag 'x86_cleanups_for_v7.0_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2026-02-11T02:43:03Z

Pull x86 cleanups from Borislav Petkov: - The usual set of cleanups and simplifications all over the tree * tag 'x86_cleanups_for_v7.0_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/segment: Use MOVL when reading segment registers selftests/x86: Clean up sysret_rip coding style x86/mm: Hide mm_free_global_asid() definition under CONFIG_BROADCAST_TLB_FLUSH x86/crash: Use set_memory_p() instead of __set_memory_prot() x86/CPU/AMD: Simplify the spectral chicken fix x86/platform/olpc: Replace strcpy() with strscpy() in xo15_sci_add() x86/split_lock: Remove dead string when split_lock_detect=fatal

x86/CPU/AMD: Simplify the spectral chicken fix

2026-01-09T10:36:52Z

msr_set_bit() takes a bit number to set but MSR_ZEN2_SPECTRAL_CHICKEN_BIT is a bit mask. The usual pattern that code uses is a _BIT-named type macro instead of a mask. So convert it to a bit number to reflect that. Also, msr_set_bit() already does the reading and checking whether the bit needs to be set so use that instead of a local variable. Fixup tabbing while at it. No functional changes. Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Nikolay Borisov Link: https://patch.msgid.link/20251230110731.28108-1-bp@kernel.org

x86/cpu: Drop vestigial PBE logic in AMD/Hygon/Centaur/Cyrix

2025-12-14T08:57:13Z

Besides formatting changes, this logic dates back to Linux 2.4.0-test11 in November 2000. Prior to "Massive cleanup of CPU detection and bug handling", c->x86_capability was a single u32 containing cpuid(1).edx, cpuid(0x80000001).edx, or a synthesis thereof. X86_FEATURE_AMD3D was defined as the top bit this single u32. After "Massive cleanup of CPU detection and bug handling", c->x86_capability became an array with AMD's extended feature leaf split away from Intel's basic feature leaf. AMD doc #20734-G states that 3DNow is only enumerated in the extended feature leaf, and that other vendors where using this bit too. i.e. AMD never produced a CPU which set bit 31 in the basic leaf, meaning that there's nothing to clear out in the first place. This logic looks like it was relevant in the pre-"Massive cleanup" world but ought to have been dropped when c->x86_capability was properly split. Signed-off-by: Andrew Cooper Signed-off-by: Ingo Molnar Cc: H. Peter Anvin Cc: Peter Zijlstra (Intel) Cc: Dave Hansen Cc: Pu Wen Link: https://patch.msgid.link/20251126125147.880275-1-andrew.cooper3@citrix.com

x86/cpu/amd: Use ZEN_MODEL_STEP_UCODE() for erratum_1386_microcode[]

2025-12-14T08:55:47Z

... to simplify the result. No functional change. Signed-off-by: Andrew Cooper Signed-off-by: Ingo Molnar Cc: Borislav Petkov Cc: Mario Limonciello Link: https://patch.msgid.link/20251126113442.877024-1-andrew.cooper3@citrix.com

x86/cpu/amd: Correct the microcode table for Zenbleed

2025-12-14T08:54:46Z

The good revisions are tied to exact steppings, meaning it's not valid to match on model number alone, let alone a range. This is probably only a latent issue. From public microcode archives, the following CPUs exist 17-30-00, 17-60-00, 17-70-00 and would be captured by the model ranges. They're likely pre-production steppings, and likely didn't get Zenbleed microcode, but it's still incorrect to compare them to a different steppings revision. Either way, convert the logic to use x86_match_min_microcode_rev(), which is the preferred mechanism. Fixes: 522b1d69219d ("x86/cpu/amd: Add a Zenbleed fix") Signed-off-by: Andrew Cooper Signed-off-by: Ingo Molnar Cc: Borislav Petkov Cc: Mario Limonciello Cc: x86@kernel.org Link: https://patch.msgid.link/20251126130352.880424-1-andrew.cooper3@citrix.com

Merge tag 'x86_misc_for_6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2025-12-02T22:16:42Z

Pull misc x86 updates from Dave Hansen: "The most significant are some changes to ensure that symbols exported for KVM are used only by KVM modules themselves, along with some related cleanups. In true x86/misc fashion, the other patch is completely unrelated and just enhances an existing pr_warn() to make it clear to users how they have tainted their kernel when something is mucking with MSRs. Summary: - Make MSR-induced taint easier for users to track down - Restrict KVM-specific exports to KVM itself" * tag 'x86_misc_for_6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86: Restrict KVM-induced symbol exports to KVM modules where obvious/possible x86/mm: Drop unnecessary export of "ptdump_walk_pgd_level_debugfs" x86/mtrr: Drop unnecessary export of "mtrr_state" x86/bugs: Drop unnecessary export of "x86_spec_ctrl_base" x86/msr: Add CPU_OUT_OF_SPEC taint name to "unrecognized" pr_warn(msg)

x86/CPU/AMD: Add additional fixed RDSEED microcode revisions

2025-11-14T12:02:11Z

Microcode that resolves the RDSEED failure (SB-7055 [1]) has been released for additional Zen5 models to linux-firmware [2]. Update the zen5_rdseed_microcode array to cover these new models. Fixes: 607b9fb2ce24 ("x86/CPU/AMD: Add RDSEED fix for Zen5") Signed-off-by: Mario Limonciello Signed-off-by: Borislav Petkov (AMD) Cc: Link: https://www.amd.com/en/resources/product-security/bulletin/amd-sb-7055.html [1] Link: https://gitlab.com/kernel-firmware/linux-firmware/-/commit/6167e5566900cf236f7a69704e8f4c441bc7212a [2] Link: https://patch.msgid.link/20251113223608.1495655-1-mario.limonciello@amd.com

x86: Restrict KVM-induced symbol exports to KVM modules where obvious/possible

2025-11-12T23:29:38Z

Extend KVM's export macro framework to provide EXPORT_SYMBOL_FOR_KVM(), and use the helper macro to export symbols for KVM throughout x86 if and only if KVM will build one or more modules, and only for those modules. To avoid unnecessary exports when CONFIG_KVM=m but kvm.ko will not be built (because no vendor modules are selected), let arch code #define EXPORT_SYMBOL_FOR_KVM to suppress/override the exports. Note, the set of symbols to restrict to KVM was generated by manual search and audit; any "misses" are due to human error, not some grand plan. Signed-off-by: Sean Christopherson Signed-off-by: Dave Hansen Acked-by: Kai Huang Tested-by: Kai Huang Link: https://patch.msgid.link/20251112173944.1380633-5-seanjc%40google.com

x86/CPU/AMD: Add missing terminator for zen5_rdseed_microcode

2025-11-04T16:16:14Z

Running x86_match_min_microcode_rev() on a Zen5 CPU trips up KASAN for an out of bounds access. Fixes: 607b9fb2ce248 ("x86/CPU/AMD: Add RDSEED fix for Zen5") Signed-off-by: Mario Limonciello Signed-off-by: Borislav Petkov (AMD) Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20251104161007.269885-1-mario.limonciello@amd.com

x86/CPU/AMD: Extend Zen6 model range

2025-10-30T10:33:55Z

Add some more Zen6 models. Signed-off-by: Borislav Petkov (AMD) Signed-off-by: Ingo Molnar Link: https://patch.msgid.link/20251029123056.19987-1-bp@kernel.org