From 735db465b00930c629e8d12898e909a1100efb5e Mon Sep 17 00:00:00 2001
From: Vitaly Kuznetsov <vkuznets@redhat.com>
Date: Thu, 19 Nov 2020 11:32:18 +0100
Subject: [PATCH] i386: move hyperv_interface_id initialization to
 x86_cpu_realizefn()

As a preparation to expanding Hyper-V CPU features early, move
hyperv_interface_id initialization to x86_cpu_realizefn().

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20201119103221.1665171-3-vkuznets@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
---
 target/i386/cpu.c     |  6 ++++++
 target/i386/cpu.h     |  1 +
 target/i386/kvm/kvm.c | 18 ++++++++++++------
 3 files changed, 19 insertions(+), 6 deletions(-)

diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index 599526406a..ab10c0225d 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -6561,6 +6561,12 @@ static void x86_cpu_hyperv_realize(X86CPU *cpu)
         memset(cpu->hyperv_vendor_id, 0, 12);
         memcpy(cpu->hyperv_vendor_id, cpu->hyperv_vendor, len);
     }
+
+    /* 'Hv#1' interface identification*/
+    cpu->hyperv_interface_id[0] = 0x31237648;
+    cpu->hyperv_interface_id[1] = 0;
+    cpu->hyperv_interface_id[2] = 0;
+    cpu->hyperv_interface_id[3] = 0;
 }
 
 static void x86_cpu_realizefn(DeviceState *dev, Error **errp)
diff --git a/target/i386/cpu.h b/target/i386/cpu.h
index ad9ef559fc..fd29afebc9 100644
--- a/target/i386/cpu.h
+++ b/target/i386/cpu.h
@@ -1665,6 +1665,7 @@ struct X86CPU {
     bool hyperv_passthrough;
     OnOffAuto hyperv_no_nonarch_cs;
     uint32_t hyperv_vendor_id[3];
+    uint32_t hyperv_interface_id[4];
 
     bool check_cpuid;
     bool enforce_cpuid;
diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index 6a5d91e39f..d3aa7ca281 100644
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -1171,7 +1171,6 @@ static int hyperv_handle_properties(CPUState *cs,
     CPUX86State *env = &cpu->env;
     struct kvm_cpuid2 *cpuid;
     struct kvm_cpuid_entry2 *c;
-    uint32_t signature[3];
     uint32_t cpuid_i = 0;
     int r;
 
@@ -1215,6 +1214,14 @@ static int hyperv_handle_properties(CPUState *cs,
             cpu->hyperv_vendor_id[2] = c->edx;
         }
 
+        c = cpuid_find_entry(cpuid, HV_CPUID_INTERFACE, 0);
+        if (c) {
+            cpu->hyperv_interface_id[0] = c->eax;
+            cpu->hyperv_interface_id[1] = c->ebx;
+            cpu->hyperv_interface_id[2] = c->ecx;
+            cpu->hyperv_interface_id[3] = c->edx;
+        }
+
         c = cpuid_find_entry(cpuid, HV_CPUID_FEATURES, 0);
         if (c) {
             env->features[FEAT_HYPERV_EAX] = c->eax;
@@ -1297,11 +1304,10 @@ static int hyperv_handle_properties(CPUState *cs,
 
     c = &cpuid_ent[cpuid_i++];
     c->function = HV_CPUID_INTERFACE;
-    memcpy(signature, "Hv#1\0\0\0\0\0\0\0\0", 12);
-    c->eax = signature[0];
-    c->ebx = 0;
-    c->ecx = 0;
-    c->edx = 0;
+    c->eax = cpu->hyperv_interface_id[0];
+    c->ebx = cpu->hyperv_interface_id[1];
+    c->ecx = cpu->hyperv_interface_id[2];
+    c->edx = cpu->hyperv_interface_id[3];
 
     c = &cpuid_ent[cpuid_i++];
     c->function = HV_CPUID_VERSION;