qemu-kvm/SOURCES/kvm-target-i386-allow-versioned-CPUs-to-specify-new-cach.patch

From 457e74c076e0fe7b64631dfd4369d167f0762c9a Mon Sep 17 00:00:00 2001
From: Bandan Das <bsd@redhat.com>
Date: Wed, 9 Aug 2023 12:22:41 -0400
Subject: [PATCH 1/7] target/i386: allow versioned CPUs to specify new
 cache_info

RH-Author: Bandan Das <None>
RH-MergeRequest: 198: Add EPYC-Genoa CPU model in qemu
RH-Bugzilla: 2094913
RH-Acked-by: Wei Huang <None>
RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>
RH-Commit: [1/7] 6070e07a4bb070d1c15a811b2bd3195929c18d61 (bdas1/qemu-kvm)

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2094913

commit cca0a000d06f897411a8af4402e5d0522bbe450b
Author: Michael Roth <michael.roth@amd.com>
Date:   Thu May 4 15:53:06 2023 -0500

    target/i386: allow versioned CPUs to specify new cache_info

    New EPYC CPUs versions require small changes to their cache_info's.
    Because current QEMU x86 CPU definition does not support versioned
    cach_info, we would have to declare a new CPU type for each such case.
    To avoid the dup work, add "cache_info" in X86CPUVersionDefinition",
    to allow new cache_info pointers to be specified for a new CPU version.

    Co-developed-by: Wei Huang <wei.huang2@amd.com>
    Signed-off-by: Wei Huang <wei.huang2@amd.com>
    Signed-off-by: Michael Roth <michael.roth@amd.com>
    Signed-off-by: Babu Moger <babu.moger@amd.com>
    Acked-by: Michael S. Tsirkin <mst@redhat.com>
    Message-Id: <20230504205313.225073-2-babu.moger@amd.com>
    Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Signed-off-by: Bandan Das <bsd@redhat.com>
---
 target/i386/cpu.c | 35 ++++++++++++++++++++++++++++++++---
 1 file changed, 32 insertions(+), 3 deletions(-)

diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index 4ac3046313..3558c92ed0 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -1598,6 +1598,7 @@ typedef struct X86CPUVersionDefinition {
     const char *alias;
     const char *note;
     PropValue *props;
+    const CPUCaches *const cache_info;
 } X86CPUVersionDefinition;
 
 /* Base definition for a CPU model */
@@ -5213,6 +5214,31 @@ static void x86_cpu_apply_version_props(X86CPU *cpu, X86CPUModel *model)
     assert(vdef->version == version);
 }
 
+static const CPUCaches *x86_cpu_get_versioned_cache_info(X86CPU *cpu,
+                                                         X86CPUModel *model)
+{
+    const X86CPUVersionDefinition *vdef;
+    X86CPUVersion version = x86_cpu_model_resolve_version(model);
+    const CPUCaches *cache_info = model->cpudef->cache_info;
+
+    if (version == CPU_VERSION_LEGACY) {
+        return cache_info;
+    }
+
+    for (vdef = x86_cpu_def_get_versions(model->cpudef); vdef->version; vdef++) {
+        if (vdef->cache_info) {
+            cache_info = vdef->cache_info;
+        }
+
+        if (vdef->version == version) {
+            break;
+        }
+    }
+
+    assert(vdef->version == version);
+    return cache_info;
+}
+
 /*
  * Load data from X86CPUDefinition into a X86CPU object.
  * Only for builtin_x86_defs models initialized with x86_register_cpudef_types.
@@ -5245,7 +5271,7 @@ static void x86_cpu_load_model(X86CPU *cpu, X86CPUModel *model)
     }
 
     /* legacy-cache defaults to 'off' if CPU model provides cache info */
-    cpu->legacy_cache = !def->cache_info;
+    cpu->legacy_cache = !x86_cpu_get_versioned_cache_info(cpu, model);
 
     env->features[FEAT_1_ECX] |= CPUID_EXT_HYPERVISOR;
 
@@ -6724,14 +6750,17 @@ static void x86_cpu_realizefn(DeviceState *dev, Error **errp)
 
     /* Cache information initialization */
     if (!cpu->legacy_cache) {
-        if (!xcc->model || !xcc->model->cpudef->cache_info) {
+        const CPUCaches *cache_info =
+            x86_cpu_get_versioned_cache_info(cpu, xcc->model);
+
+        if (!xcc->model || !cache_info) {
             g_autofree char *name = x86_cpu_class_get_model_name(xcc);
             error_setg(errp,
                        "CPU model '%s' doesn't support legacy-cache=off", name);
             return;
         }
         env->cache_info_cpuid2 = env->cache_info_cpuid4 = env->cache_info_amd =
-            *xcc->model->cpudef->cache_info;
+            *cache_info;
     } else {
         /* Build legacy cache information */
         env->cache_info_cpuid2.l1d_cache = &legacy_l1d_cache;
-- 
2.39.3