i386: use better matching family/model/stepping for 'qemu64' CPU

The 'qemu64' CPUID currently reports a family/model/stepping that
approximately corresponds to an AMD K7 vintage architecture.
The K7 series predates the introduction of 64-bit support by AMD
in the K8 series. This has been reported to lead to LLVM complaints
about generating 64-bit code for a 32-bit CPU target

  LLVM ERROR: 64-bit code requested on a subtarget that doesn't support it!

It appears LLVM looks at the family/model/stepping, despite qemu64
reporting it is 64-bit capable.

This patch changes 'qemu64' to report a CPUID with the family, model
and stepping taken from a

 AMD Athlon(tm) 64 X2 Dual Core Processor 4000+

which is one of the first 64-bit AMD CPUs.

Closes https://gitlab.com/qemu-project/qemu/-/issues/191

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <20210507133650.645526-2-berrange@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>

diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 8cfaf216e7bebcdbd78816134d37c72a4664e1f5..c6d8d0d84d915caddff88eaa743ad88c1109440b 100644 (file)
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -94,7 +94,11 @@
 #include "trace.h"
 #include CONFIG_DEVICES
 
-GlobalProperty pc_compat_6_0[] = {};
+GlobalProperty pc_compat_6_0[] = {
+    { "qemu64" "-" TYPE_X86_CPU, "family", "6" },
+    { "qemu64" "-" TYPE_X86_CPU, "model", "6" },
+    { "qemu64" "-" TYPE_X86_CPU, "stepping", "3" },
+};
 const size_t pc_compat_6_0_len = G_N_ELEMENTS(pc_compat_6_0);
 
 GlobalProperty pc_compat_5_2[] = {

diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index ff92d924ad9ae943c80296aff30c339fae10e522..078ec9055224c1985ea4ab0e4d048033b8952231 100644 (file)
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -1803,9 +1803,9 @@ static const X86CPUDefinition builtin_x86_defs[] = {
         .name = "qemu64",
         .level = 0xd,
         .vendor = CPUID_VENDOR_AMD,
-        .family = 6,
-        .model = 6,
-        .stepping = 3,
+        .family = 15,
+        .model = 107,
+        .stepping = 1,
         .features[FEAT_1_EDX] =
             PPRO_FEATURES |
             CPUID_MTRR | CPUID_CLFLUSH | CPUID_MCA |