[Qemu-devel] [PATCH v8 3/8] i386: Add new property to control cache info

[Babu Moger]

The property legacy-cache will be used to control the cache information.
If user passes "-cpu legacy-cache" then older information will
be displayed even if the hardware supports new information. Otherwise
use the statically loaded cache definitions if available.

Signed-off-by: Babu Moger <address@hidden>
Tested-by: Geoffrey McRae <address@hidden>
---
 include/hw/i386/pc.h |  8 ++++
 target/i386/cpu.c    | 97 ++++++++++++++++++++++++++++++++------------
 target/i386/cpu.h    |  5 +++
 3 files changed, 84 insertions(+), 26 deletions(-)

diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
index 2e834e6ded..df15deefca 100644
--- a/include/hw/i386/pc.h
+++ b/include/hw/i386/pc.h
@@ -304,6 +304,14 @@ int e820_add_entry(uint64_t, uint64_t, uint32_t);
 int e820_get_num_entries(void);
 bool e820_get_entry(int, uint32_t, uint64_t *, uint64_t *);
 
+#define PC_COMPAT_2_12 \
+    HW_COMPAT_2_12 \
+    {\
+        .driver   = TYPE_X86_CPU,\
+        .property = "legacy-cache",\
+        .value    = "on",\
+    },
+
 #define PC_COMPAT_2_11 \
     HW_COMPAT_2_11 \
     {\
diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index 3a74c4b1e4..d97b290b08 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -336,10 +336,14 @@ static void encode_cache_cpuid80000006(CPUCacheInfo *l2,
     }
 }
 
-/* Definitions of the hardcoded cache entries we expose: */
+/*
+ * Definitions of the hardcoded cache entries we expose:
+ * These are legacy cache values. If there is a need to change any
+ * of these values please use builtin_x86_defs
+ */
 
 /* L1 data cache: */
-static CPUCacheInfo l1d_cache = {
+static CPUCacheInfo legacy_l1d_cache = {
     .type = DCACHE,
     .level = 1,
     .size = 32 * KiB,
@@ -352,7 +356,7 @@ static CPUCacheInfo l1d_cache = {
 };
 
 /*FIXME: CPUID leaf 0x80000005 is inconsistent with leaves 2 & 4 */
-static CPUCacheInfo l1d_cache_amd = {
+static CPUCacheInfo legacy_l1d_cache_amd = {
     .type = DCACHE,
     .level = 1,
     .size = 64 * KiB,
@@ -366,7 +370,7 @@ static CPUCacheInfo l1d_cache_amd = {
 };
 
 /* L1 instruction cache: */
-static CPUCacheInfo l1i_cache = {
+static CPUCacheInfo legacy_l1i_cache = {
     .type = ICACHE,
     .level = 1,
     .size = 32 * KiB,
@@ -379,7 +383,7 @@ static CPUCacheInfo l1i_cache = {
 };
 
 /*FIXME: CPUID leaf 0x80000005 is inconsistent with leaves 2 & 4 */
-static CPUCacheInfo l1i_cache_amd = {
+static CPUCacheInfo legacy_l1i_cache_amd = {
     .type = ICACHE,
     .level = 1,
     .size = 64 * KiB,
@@ -393,7 +397,7 @@ static CPUCacheInfo l1i_cache_amd = {
 };
 
 /* Level 2 unified cache: */
-static CPUCacheInfo l2_cache = {
+static CPUCacheInfo legacy_l2_cache = {
     .type = UNIFIED_CACHE,
     .level = 2,
     .size = 4 * MiB,
@@ -406,7 +410,7 @@ static CPUCacheInfo l2_cache = {
 };
 
 /*FIXME: CPUID leaf 2 descriptor is inconsistent with CPUID leaf 4 */
-static CPUCacheInfo l2_cache_cpuid2 = {
+static CPUCacheInfo legacy_l2_cache_cpuid2 = {
     .type = UNIFIED_CACHE,
     .level = 2,
     .size = 2 * MiB,
@@ -416,7 +420,7 @@ static CPUCacheInfo l2_cache_cpuid2 = {
 
 
 /*FIXME: CPUID leaf 0x80000006 is inconsistent with leaves 2 & 4 */
-static CPUCacheInfo l2_cache_amd = {
+static CPUCacheInfo legacy_l2_cache_amd = {
     .type = UNIFIED_CACHE,
     .level = 2,
     .size = 512 * KiB,
@@ -428,7 +432,7 @@ static CPUCacheInfo l2_cache_amd = {
 };
 
 /* Level 3 unified cache: */
-static CPUCacheInfo l3_cache = {
+static CPUCacheInfo legacy_l3_cache = {
     .type = UNIFIED_CACHE,
     .level = 3,
     .size = 16 * MiB,
@@ -3243,6 +3247,10 @@ static void x86_cpu_load_def(X86CPU *cpu, 
X86CPUDefinition *def, Error **errp)
         env->features[w] = def->features[w];
     }
 
+    /* Store Cache information from the X86CPUDefinition if available */
+    env->cache_info = def->cache_info;
+    cpu->legacy_cache = def->cache_info ? 0 : 1;
+
     /* Special cases not set in the X86CPUDefinition structs: */
     /* TODO: in-kernel irqchip for hvf */
     if (kvm_enabled()) {
@@ -3592,11 +3600,21 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, 
uint32_t count,
         if (!cpu->enable_l3_cache) {
             *ecx = 0;
         } else {
-            *ecx = cpuid2_cache_descriptor(&l3_cache);
+            if (env->cache_info && !cpu->legacy_cache) {
+                *ecx = cpuid2_cache_descriptor(&env->cache_info->l3_cache);
+            } else {
+                *ecx = cpuid2_cache_descriptor(&legacy_l3_cache);
+            }
+        }
+        if (env->cache_info && !cpu->legacy_cache) {
+            *edx = (cpuid2_cache_descriptor(&env->cache_info->l1d_cache) << 
16) |
+                   (cpuid2_cache_descriptor(&env->cache_info->l1i_cache) <<  
8) |
+                   (cpuid2_cache_descriptor(&env->cache_info->l2_cache));
+        } else {
+            *edx = (cpuid2_cache_descriptor(&legacy_l1d_cache) << 16) |
+                   (cpuid2_cache_descriptor(&legacy_l1i_cache) <<  8) |
+                   (cpuid2_cache_descriptor(&legacy_l2_cache_cpuid2));
         }
-        *edx = (cpuid2_cache_descriptor(&l1d_cache) << 16) |
-               (cpuid2_cache_descriptor(&l1i_cache) <<  8) |
-               (cpuid2_cache_descriptor(&l2_cache_cpuid2));
         break;
     case 4:
         /* cache info: needed for Core compatibility */
@@ -3609,27 +3627,35 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, 
uint32_t count,
             }
         } else {
             *eax = 0;
+            CPUCacheInfo *l1d, *l1i, *l2, *l3;
+            if (env->cache_info && !cpu->legacy_cache) {
+                l1d = &env->cache_info->l1d_cache;
+                l1i = &env->cache_info->l1i_cache;
+                l2 = &env->cache_info->l2_cache;
+                l3 = &env->cache_info->l3_cache;
+            } else {
+                l1d = &legacy_l1d_cache;
+                l1i = &legacy_l1i_cache;
+                l2 = &legacy_l2_cache;
+                l3 = &legacy_l3_cache;
+            }
             switch (count) {
             case 0: /* L1 dcache info */
-                encode_cache_cpuid4(&l1d_cache,
-                                    1, cs->nr_cores,
+                encode_cache_cpuid4(l1d, 1, cs->nr_cores,
                                     eax, ebx, ecx, edx);
                 break;
             case 1: /* L1 icache info */
-                encode_cache_cpuid4(&l1i_cache,
-                                    1, cs->nr_cores,
+                encode_cache_cpuid4(l1i, 1, cs->nr_cores,
                                     eax, ebx, ecx, edx);
                 break;
             case 2: /* L2 cache info */
-                encode_cache_cpuid4(&l2_cache,
-                                    cs->nr_threads, cs->nr_cores,
+                encode_cache_cpuid4(l2, cs->nr_threads, cs->nr_cores,
                                     eax, ebx, ecx, edx);
                 break;
             case 3: /* L3 cache info */
                 pkg_offset = apicid_pkg_offset(cs->nr_cores, cs->nr_threads);
                 if (cpu->enable_l3_cache) {
-                    encode_cache_cpuid4(&l3_cache,
-                                        (1 << pkg_offset), cs->nr_cores,
+                    encode_cache_cpuid4(l3, (1 << pkg_offset), cs->nr_cores,
                                         eax, ebx, ecx, edx);
                     break;
                 }
@@ -3842,8 +3868,13 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, 
uint32_t count,
                (L1_ITLB_2M_ASSOC <<  8) | (L1_ITLB_2M_ENTRIES);
         *ebx = (L1_DTLB_4K_ASSOC << 24) | (L1_DTLB_4K_ENTRIES << 16) | \
                (L1_ITLB_4K_ASSOC <<  8) | (L1_ITLB_4K_ENTRIES);
-        *ecx = encode_cache_cpuid80000005(&l1d_cache_amd);
-        *edx = encode_cache_cpuid80000005(&l1i_cache_amd);
+        if (env->cache_info && !cpu->legacy_cache) {
+            *ecx = encode_cache_cpuid80000005(&env->cache_info->l1d_cache);
+            *edx = encode_cache_cpuid80000005(&env->cache_info->l1i_cache);
+        } else {
+            *ecx = encode_cache_cpuid80000005(&legacy_l1d_cache_amd);
+            *edx = encode_cache_cpuid80000005(&legacy_l1i_cache_amd);
+        }
         break;
     case 0x80000006:
         /* cache info (L2 cache) */
@@ -3859,9 +3890,17 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, 
uint32_t count,
                (L2_DTLB_4K_ENTRIES << 16) | \
                (AMD_ENC_ASSOC(L2_ITLB_4K_ASSOC) << 12) | \
                (L2_ITLB_4K_ENTRIES);
-        encode_cache_cpuid80000006(&l2_cache_amd,
-                                   cpu->enable_l3_cache ? &l3_cache : NULL,
-                                   ecx, edx);
+        if (env->cache_info && !cpu->legacy_cache) {
+            encode_cache_cpuid80000006(&env->cache_info->l2_cache,
+                                       cpu->enable_l3_cache ?
+                                       &env->cache_info->l3_cache : NULL,
+                                       ecx, edx);
+        } else {
+            encode_cache_cpuid80000006(&legacy_l2_cache_amd,
+                                       cpu->enable_l3_cache ?
+                                       &legacy_l3_cache : NULL,
+                                       ecx, edx);
+        }
         break;
     case 0x80000007:
         *eax = 0;
@@ -5039,6 +5078,12 @@ static Property x86_cpu_properties[] = {
                      false),
     DEFINE_PROP_BOOL("vmware-cpuid-freq", X86CPU, vmware_cpuid_freq, true),
     DEFINE_PROP_BOOL("tcg-cpuid", X86CPU, expose_tcg, true),
+    /*
+     * lecacy_cache defaults to CPU model being chosen. This is set in
+     * x86_cpu_load_def based on cache_info which is initialized in
+     * builtin_x86_defs
+     */
+    DEFINE_PROP_BOOL("legacy-cache", X86CPU, legacy_cache, false),
 
     /*
      * From "Requirements for Implementing the Microsoft
diff --git a/target/i386/cpu.h b/target/i386/cpu.h
index 372f8b7ef5..31715d167d 100644
--- a/target/i386/cpu.h
+++ b/target/i386/cpu.h
@@ -1394,6 +1394,11 @@ struct X86CPU {
      */
     bool enable_l3_cache;
 
+    /* Compatibility bits for old machine types.
+     * If true present the old cache topology information
+     */
+    bool legacy_cache;
+
     /* Compatibility bits for old machine types: */
     bool enable_cpuid_0xb;
 
-- 
2.17.0