[RFC PATCH 5/5] target/i386: Access MSR_IA32_RTIT_ADDRn based on guest CPUID configuration

[Xiaoyao Li]

KVM only allows userspace to access legal number of MSR_IA32_RTIT_ADDRn,
which is enumrated by guest's CPUID(0x14,0x1):EAX[2:0], i.e.,
env->features[FEAT_14_1_EAX] & INTEL_PT_ADDR_RANGES_NUM_MASK

Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
---
 target/i386/cpu.c     | 1 -
 target/i386/cpu.h     | 2 ++
 target/i386/kvm/kvm.c | 8 ++++----
 3 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index 2b50ccf79b92..5ff70a8cba54 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -545,7 +545,6 @@ static CPUCacheInfo legacy_l3_cache = {
 
 #define INTEL_PT_MAX_SUBLEAF                0x1
 #define INTEL_PT_DEFAULT_ADDR_RANGES_NUM    0x2
-#define INTEL_PT_ADDR_RANGES_NUM_MASK       0x7
 /* Support ART(0,3,6,9) */
 #define INTEL_PT_DEFAULT_MTC_BITMAP         0x0249
 /* Support 0,2^(0~11) */
diff --git a/target/i386/cpu.h b/target/i386/cpu.h
index e6236c371c4f..20e579f147f8 100644
--- a/target/i386/cpu.h
+++ b/target/i386/cpu.h
@@ -873,6 +873,8 @@ typedef uint64_t FeatureWordArray[FEATURE_WORDS];
 /* Packets which contain IP payload have LIP values */
 #define CPUID_14_0_ECX_LIP                      (1U << 31)
 
+#define INTEL_PT_ADDR_RANGES_NUM_MASK       0x7
+
 /* CLZERO instruction */
 #define CPUID_8000_0008_EBX_CLZERO      (1U << 0)
 /* Always save/restore FP error pointers */
diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index 500d2e0e686f..a90115da9ee5 100644
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -3088,8 +3088,8 @@ static int kvm_put_msrs(X86CPU *cpu, int level)
             }
         }
         if (env->features[FEAT_7_0_EBX] & CPUID_7_0_EBX_INTEL_PT) {
-            int addr_num = kvm_arch_get_supported_cpuid(kvm_state,
-                                                    0x14, 1, R_EAX) & 0x7;
+            int addr_num = env->features[FEAT_14_1_EAX] &
+                           INTEL_PT_ADDR_RANGES_NUM_MASK;
 
             kvm_msr_entry_add(cpu, MSR_IA32_RTIT_CTL,
                             env->msr_rtit_ctrl);
@@ -3433,8 +3433,8 @@ static int kvm_get_msrs(X86CPU *cpu)
     }
 
     if (env->features[FEAT_7_0_EBX] & CPUID_7_0_EBX_INTEL_PT) {
-        int addr_num =
-            kvm_arch_get_supported_cpuid(kvm_state, 0x14, 1, R_EAX) & 0x7;
+        int addr_num = env->features[FEAT_14_1_EAX] &
+                       INTEL_PT_ADDR_RANGES_NUM_MASK;
 
         kvm_msr_entry_add(cpu, MSR_IA32_RTIT_CTL, 0);
         kvm_msr_entry_add(cpu, MSR_IA32_RTIT_STATUS, 0);
-- 
2.27.0