The src/cpu_map/x86_features.xml file contains the definition
of all x86 CPU features, these definitions specify how we can
decode the feature support fom the CPUID or MSR values.
The helper script sync_qemu_features_i386.py builds the
x86_features.xml file from QEMU source code to be in sync
with supported features in QEMU. This helper script parses
QEMU target/i386/cpu.c file looking for CPU feature definitions
and convert them into x86_features.xml contents.
This is the resulting definition for the vmx-intr-exit feature
encoded in the MSR 0x48d.
<!-- msr 0x0000048d -->
<feature name='vmx-intr-exit'>
<msr index='0x0000048d' edx='0x00000000' eax='0x00000001'/>
</feature>
EAX holds the 32 lower bits of the MSRE 64-bits value and should
not be used to detect the VMX-* features. Indeed, VMX-* bit
position should be parsed from QEMU source code in the 32 higher
bits of the corresponding MSR value.
This commit fixes this issue by using the 32 higher bits (EDX)
to represent VMX-* features.
---
src/cpu_map/sync_qemu_features_i386.py | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)
diff --git a/src/cpu_map/sync_qemu_features_i386.py
b/src/cpu_map/sync_qemu_features_i386.py
index b658b864f2..ed65d9966a 100755
--- a/src/cpu_map/sync_qemu_features_i386.py
+++ b/src/cpu_map/sync_qemu_features_i386.py
@@ -1,6 +1,7 @@
#!/usr/bin/env python3
import argparse
+import enum
import os
import re
@@ -201,6 +202,19 @@ def add_feature_cpuid(eax, ecx, reg, bit, name):
_FEATURES["cpuid"][eax][ecx][reg][bit] = name
+class VmxMsr(enum.Enum):
+ MSR_IA32_VMX_PROCBASED_CTLS2 = 0x0000048b
+ MSR_IA32_VMX_TRUE_PINBASED_CTLS = 0x0000048d
+ MSR_IA32_VMX_TRUE_PROCBASED_CTLS = 0x0000048e
+ MSR_IA32_VMX_TRUE_ENTRY_CTLS = 0x00000490
+ MSR_IA32_VMX_TRUE_EXIT_CTLS = 0x0000048f
+
+def is_vmx_msr(msr):
+ try:
+ VmxMsr(msr)
+ return True
+ except ValueError:
+ return False
# add new msr feature bit
def add_feature_msr(msr, bit, name):
@@ -213,6 +227,11 @@ def add_feature_msr(msr, bit, name):
if msr not in _FEATURES["msr"]:
_FEATURES["msr"][msr] = dict()
+ # VMX-* features are specified in the 32 higher bits
+ # of the MSR value
+ if is_vmx_msr(msr):
+ bit += 32
+
_FEATURES["msr"][msr][bit] = name
--
2.45.2
