Phase R14 (2026-06-07) — CPU bug mitigation. The data +
lookup layer lands now; the kernel-side consumer
(context-switch path) is a follow-up.
Changes:
1. CpuBugFlags (mod.rs:286) with 27 bits, mapping the
22+ X86_BUG_* macros from Linux 7.1
arch/x86/include/asm/cpufeatures.h. Bit positions
match Linux 0-26.
2. CpuId struct (mod.rs:347) with family/model/stepping
fields plus a matches() helper that honours 0xFFFF
as a wildcard on either field.
3. CpuBugQuirkEntry (mod.rs:362) — vendor (0x8086
Intel, 0x1022 AMD, 0xFFFF any) + family + model +
flags. matches() combines vendor + CPUID match.
4. lookup_cpu_bug_flags() (mod.rs:386) — OR-accumulate
the compiled-in CPU_BUG_TABLE entries that match a
given CPUID. Returns empty set if nothing matches.
5. cpu_bug_table.rs — new module with the (currently
empty) compiled-in CPU_BUG_TABLE constant. Runtime
TOML is the data surface (90-cpu-bugs.toml).
6. CPU_BUG_FLAG_NAMES + parse_cpu_bug_toml +
load_cpu_bug_flags (toml_loader.rs) — new
[[cpu_bug_quirk]] TOML table type with vendor +
family + model + flags. Loads from runtime files
and OR-accumulates against the compiled-in table.
7. 1 new unit test: phase_r14_cpuid_matches_respects_wildcards
exercises exact match + 4 wildcard combinations.
125/125 tests pass.
8. quirks.d/90-cpu-bugs.toml (136 lines) — 14 vendor/
family/flag combinations sourced from Linux 7.1
arch/x86/kernel/cpu/bugs.c. Covers:
Intel: Spectre v1/v2/SSBD (any), MDS (Kaby Lake),
TAA / L1TF / MMIO Stale / SRBDS / GDS (any)
AMD: Spectre v1 (any), Spectre v2 (Zen 1/1+),
SSBD (Zen 2/3), RETBLEED (Zen 3+),
AMD_TLB_MMATCH / APIC_C1E (K8/K10),
AMD_E400 (Zen family)
The data is structured as a wide-net baseline; more
specific CPUID matches can be added as concrete
microcode / detection issues are reported.
cargo test: 125/125 (was 124, +1 for the new test).
cargo check: clean (the unused-import warning on
load_cpu_bug_flags is expected — the kernel consumer
is the only caller and lands separately).
The kernel-side mitigation engine will:
1. Read CPUID at boot (vendor + family + model).
2. Call lookup_cpu_bug_flags() + load_cpu_bug_flags().
3. Apply mitigations per bit (KPTI, retpolines,
microcode updates, retpoline_lite, etc.) on the
next context switch.
vasilito
5caab85788