[RFC 1/6] target/i386: Add support for save/load of ACPI thermal MSRs

[Zhao Liu <zhao1.liu@linux.intel.com>]

From: Zhuocheng Ding <zhuocheng.ding@intel.com>

The CPUID_ACPI (CPUID.0x01.edx[bit 22]) feature bit has been
introduced as the TCG feature. Currently, based on KVM's ACPI emulation,
add related ACPI support in QEMU.

From SDM [1], ACPI feature means:

"The ACPI flag (bit 22) of the CPUID feature flags indicates the
presence of the IA32_THERM_STATUS, IA32_THERM_INTERRUPT,
IA32_CLOCK_MODULATION MSRs, and the xAPIC thermal LVT entry."

With the emulation of ACPI in KVM, add the support for save/load of ACPI
thermal MSRs: MSR_IA32_THERM_CONTROL, MSR_IA32_THERM_INTERRUPT and
MSR_IA32_THERM_STATUS.

[1]: SDM, vol. 3B, section 15.8.4.1, Detection of Software Controlled
     Clock Modulation Extension.

Tested-by: Yanting Jiang <yanting.jiang@intel.com>
Signed-off-by: Zhuocheng Ding <zhuocheng.ding@intel.com>
Co-developed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
---
 target/i386/cpu.h     |  9 +++++++++
 target/i386/kvm/kvm.c | 25 +++++++++++++++++++++++++
 2 files changed, 34 insertions(+)

diff --git a/target/i386/cpu.h b/target/i386/cpu.h
index 7f0786e8b98f..e453b3f010e2 100644
--- a/target/i386/cpu.h
+++ b/target/i386/cpu.h
@@ -526,6 +526,10 @@ typedef enum X86Seg {
 #define MSR_IA32_XSS                    0x00000da0
 #define MSR_IA32_UMWAIT_CONTROL         0xe1
 
+#define MSR_IA32_THERM_CONTROL          0x0000019a
+#define MSR_IA32_THERM_INTERRUPT        0x0000019b
+#define MSR_IA32_THERM_STATUS           0x0000019c
+
 #define MSR_IA32_VMX_BASIC              0x00000480
 #define MSR_IA32_VMX_PINBASED_CTLS      0x00000481
 #define MSR_IA32_VMX_PROCBASED_CTLS     0x00000482
@@ -1758,6 +1762,11 @@ typedef struct CPUArchState {
     uint64_t msr_lbr_depth;
     LBREntry lbr_records[ARCH_LBR_NR_ENTRIES];
 
+    /* Per-VCPU thermal MSRs */
+    uint64_t therm_control;
+    uint64_t therm_interrupt;
+    uint64_t therm_status;
+
     /* exception/interrupt handling */
     int error_code;
     int exception_is_int;
diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index 76a66246eb72..3bf57b35bfcd 100644
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -138,6 +138,7 @@ static bool has_msr_ucode_rev;
 static bool has_msr_vmx_procbased_ctls2;
 static bool has_msr_perf_capabs;
 static bool has_msr_pkrs;
+static bool has_msr_therm;
 
 static uint32_t has_architectural_pmu_version;
 static uint32_t num_architectural_pmu_gp_counters;
@@ -2455,6 +2456,11 @@ static int kvm_get_supported_msrs(KVMState *s)
             case MSR_IA32_PKRS:
                 has_msr_pkrs = true;
                 break;
+            case MSR_IA32_THERM_CONTROL:
+            case MSR_IA32_THERM_INTERRUPT:
+            case MSR_IA32_THERM_STATUS:
+                has_msr_therm = true;
+                break;
             }
         }
     }
@@ -3302,6 +3308,11 @@ static int kvm_put_msrs(X86CPU *cpu, int level)
     if (has_msr_virt_ssbd) {
         kvm_msr_entry_add(cpu, MSR_VIRT_SSBD, env->virt_ssbd);
     }
+    if (has_msr_therm) {
+        kvm_msr_entry_add(cpu, MSR_IA32_THERM_CONTROL, env->therm_control);
+        kvm_msr_entry_add(cpu, MSR_IA32_THERM_INTERRUPT, env->therm_interrupt);
+        kvm_msr_entry_add(cpu, MSR_IA32_THERM_STATUS, env->therm_status);
+    }
 
 #ifdef TARGET_X86_64
     if (lm_capable_kernel) {
@@ -3774,6 +3785,11 @@ static int kvm_get_msrs(X86CPU *cpu)
         kvm_msr_entry_add(cpu, MSR_IA32_TSC, 0);
         env->tsc_valid = !runstate_is_running();
     }
+    if (has_msr_therm) {
+        kvm_msr_entry_add(cpu, MSR_IA32_THERM_CONTROL, 0);
+        kvm_msr_entry_add(cpu, MSR_IA32_THERM_INTERRUPT, 0);
+        kvm_msr_entry_add(cpu, MSR_IA32_THERM_STATUS, 0);
+    }
 
 #ifdef TARGET_X86_64
     if (lm_capable_kernel) {
@@ -4255,6 +4271,15 @@ static int kvm_get_msrs(X86CPU *cpu)
         case MSR_ARCH_LBR_INFO_0 ... MSR_ARCH_LBR_INFO_0 + 31:
             env->lbr_records[index - MSR_ARCH_LBR_INFO_0].info = msrs[i].data;
             break;
+        case MSR_IA32_THERM_CONTROL:
+            env->therm_control = msrs[i].data;
+            break;
+        case MSR_IA32_THERM_INTERRUPT:
+            env->therm_interrupt = msrs[i].data;
+            break;
+        case MSR_IA32_THERM_STATUS:
+            env->therm_status = msrs[i].data;
+            break;
         }
     }
 
-- 
2.34.1