archdetect: detect Granite Rapids via CPU model when flags match Sapphire Rapids

init/eessi_archdetect.sh

@@ -17,7 +17,7 @@ else
     exit 1
 fi
 
-VERSION="1.2.0"
+VERSION="1.3.0"
 
 # default log level: only emit warnings or errors
 LOG_LEVEL="WARN"
@@ -172,6 +172,28 @@ cpupath(){
         fi
     done
 
+    # Some Intel microarchitectures are flag-indistinguishable from an older one because their
+    # new features are not exposed in /proc/cpuinfo. Granite Rapids (Xeon 6) shows the exact same
+    # visible flags as Sapphire/Emerald Rapids (its extras like amx_fp16 are hidden by the kernel),
+    # so the flag match above lands on 'sapphirerapids'. Refine using the CPU model number - the
+    # only reliable discriminator on Linux. If no dedicated graniterapids subdir is shipped yet,
+    # downstream subdir resolution falls back to the next entry in the chain, so prepending is safe.
+    if [ "${best_arch_match}" == "x86_64/intel/sapphirerapids" ]; then
+        local cpu_family=$(get_cpuinfo "cpu[ _]family")
+        local cpu_model=$(get_cpuinfo "model")
+        log "DEBUG" "cpupath: refining Sapphire Rapids match (family='$cpu_family', model='$cpu_model')"
+        # Intel family 6 model numbers below come from the kernel's authoritative table
+        # arch/x86/include/asm/intel-family.h (what the kernel itself uses for model dispatch):
+        #   INTEL_GRANITERAPIDS_X = IFM(6, 0xAD) -> family 6, model 173 (Granite Rapids-SP/AP)
+        #   INTEL_GRANITERAPIDS_D = IFM(6, 0xAE) -> family 6, model 174 (Granite Rapids-D)
+        # (cf. INTEL_SAPPHIRERAPIDS_X = 0x8F/143, INTEL_EMERALDRAPIDS_X = 0xCF/207)
+        if [ "${cpu_family}" == "6" ] && { [ "${cpu_model}" == "173" ] || [ "${cpu_model}" == "174" ]; }; then
+            best_arch_match="x86_64/intel/graniterapids"
+            all_arch_matches="$best_arch_match:$all_arch_matches"
+            log "DEBUG" "cpupath: model $cpu_model identifies Granite Rapids; best match upgraded to $best_arch_match"
+        fi
+    fi
+
     if [ "allx" == "${CPUPATH_RESULT}x" ]; then
         log "INFO" "cpupath: all matches for host CPU: $all_arch_matches"
         echo "$all_arch_matches"

tests/archdetect/x86_64/intel/graniterapids/Azure-Ubuntu24-6973P-C.all.output

@@ -0,0 +1 @@
+x86_64/intel/graniterapids:x86_64/intel/sapphirerapids:x86_64/intel/icelake:x86_64/intel/cascadelake:x86_64/intel/skylake_avx512:x86_64/intel/haswell:x86_64/generic

tests/archdetect/x86_64/intel/graniterapids/Azure-Ubuntu24-6973P-C.cpuinfo

@@ -0,0 +1,27 @@
+processor	: 0
+vendor_id	: GenuineIntel
+cpu family	: 6
+model		: 173
+model name	: Intel(R) Xeon(R) 6973P-C
+stepping	: 1
+microcode	: 0xffffffff
+cpu MHz		: 4200.428
+cache size	: 491520 KB
+physical id	: 0
+siblings	: 2
+core id		: 0
+cpu cores	: 1
+apicid		: 0
+initial apicid	: 0
+fpu		: yes
+fpu_exception	: yes
+cpuid level	: 36
+wp		: yes
+flags		: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ss ht syscall nx pdpe1gb rdtscp lm constant_tsc rep_good nopl xtopology tsc_reliable nonstop_tsc cpuid aperfmperf tsc_known_freq pni pclmulqdq vmx ssse3 fma cx16 pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm abm 3dnowprefetch tpr_shadow ept vpid ept_ad fsgsbase tsc_adjust bmi1 hle avx2 smep bmi2 erms invpcid rtm avx512f avx512dq rdseed adx smap avx512ifma clflushopt clwb avx512cd sha_ni avx512bw avx512vl xsaveopt xsavec xgetbv1 xsaves user_shstk avx_vnni avx512_bf16 vnmi avx512vbmi umip waitpkg avx512_vbmi2 gfni vaes vpclmulqdq avx512_vnni avx512_bitalg avx512_vpopcntdq la57 rdpid cldemote movdiri movdir64b fsrm serialize tsxldtrk ibt amx_bf16 avx512_fp16 amx_tile amx_int8 arch_capabilities
+vmx flags	: vnmi invvpid ept_x_only ept_ad ept_1gb ept_5level tsc_offset vtpr ept vpid unrestricted_guest ept_mode_based_exec tsc_scaling usr_wait_pause
+bugs		: spectre_v1 spectre_v2 spec_store_bypass swapgs retbleed bhi spectre_v2_user its
+bogomips	: 5199.99
+clflush size	: 64
+cache_alignment	: 64
+address sizes	: 48 bits physical, 57 bits virtual
+power management:

tests/archdetect/x86_64/intel/graniterapids/Azure-Ubuntu24-6973P-C.output

@@ -0,0 +1 @@
+x86_64/intel/graniterapids