WHPX: vmware cpuid leaf for tsc and apic frequency

Newer versions of WHPX provide the capability to query the tsc
and apic frequency. Expose these through the vmware cpuid leaf.
This patch doesnt support setting the tsc frequency; that will
come as a separate fix.

Signed-off-by: Sunil Muthuswamy <sunilmut@microsoft.com>
Message-Id: <SN4PR2101MB08808DFDDC3F442BBEAADFF4C0710@SN4PR2101MB0880.namprd21.prod.outlook.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

target/i386/whp-dispatch.h

@@ -2,10 +2,11 @@
 #define WHP_DISPATCH_H
 
 #include <windows.h>
-
 #include <WinHvPlatform.h>
 #include <WinHvEmulation.h>
 
+#define WHV_E_UNKNOWN_CAPABILITY 0x80370300L
+
 #define LIST_WINHVPLATFORM_FUNCTIONS(X) \
   X(HRESULT, WHvGetCapability, (WHV_CAPABILITY_CODE CapabilityCode, VOID* CapabilityBuffer, UINT32 CapabilityBufferSizeInBytes, UINT32* WrittenSizeInBytes)) \
   X(HRESULT, WHvCreatePartition, (WHV_PARTITION_HANDLE* Partition)) \

target/i386/whpx-all.c

@@ -27,6 +27,8 @@
 #include <WinHvPlatform.h>
 #include <WinHvEmulation.h>
 
+#define HYPERV_APIC_BUS_FREQUENCY      (200000000ULL)
+
 struct whpx_state {
     uint64_t mem_quota;
     WHV_PARTITION_HANDLE partition;
@@ -1061,6 +1063,18 @@ static int whpx_vcpu_run(CPUState *cpu)
             cpu_x86_cpuid(env, cpuid_fn, 0, (UINT32 *)&rax, (UINT32 *)&rbx,
                 (UINT32 *)&rcx, (UINT32 *)&rdx);
             switch (cpuid_fn) {
+            case 0x40000000:
+                /* Expose the vmware cpu frequency cpuid leaf */
+                rax = 0x40000010;
+                rbx = rcx = rdx = 0;
+                break;
+
+            case 0x40000010:
+                rax = env->tsc_khz;
+                rbx = env->apic_bus_freq / 1000; /* Hz to KHz */
+                rcx = rdx = 0;
+                break;
+
             case 0x80000001:
                 /* Remove any support of OSVW */
                 rcx &= ~CPUID_EXT3_OSVW;
@@ -1191,8 +1205,12 @@ int whpx_init_vcpu(CPUState *cpu)
 {
     HRESULT hr;
     struct whpx_state *whpx = &whpx_global;
-    struct whpx_vcpu *vcpu;
+    struct whpx_vcpu *vcpu = NULL;
     Error *local_error = NULL;
+    struct CPUX86State *env = (CPUArchState *)(cpu->env_ptr);
+    X86CPU *x86_cpu = X86_CPU(cpu);
+    UINT64 freq = 0;
+    int ret;
 
     /* Add migration blockers for all unsupported features of the
      * Windows Hypervisor Platform
@@ -1207,7 +1225,8 @@ int whpx_init_vcpu(CPUState *cpu)
             error_report_err(local_error);
             migrate_del_blocker(whpx_migration_blocker);
             error_free(whpx_migration_blocker);
-            return -EINVAL;
+            ret = -EINVAL;
+            goto error;
         }
     }
 
@@ -1215,7 +1234,8 @@ int whpx_init_vcpu(CPUState *cpu)
 
     if (!vcpu) {
         error_report("WHPX: Failed to allocte VCPU context.");
-        return -ENOMEM;
+        ret = -ENOMEM;
+        goto error;
     }
 
     hr = whp_dispatch.WHvEmulatorCreateEmulator(
@@ -1224,8 +1244,8 @@ int whpx_init_vcpu(CPUState *cpu)
     if (FAILED(hr)) {
         error_report("WHPX: Failed to setup instruction completion support,"
                      " hr=%08lx", hr);
-        g_free(vcpu);
+        ret = -EINVAL;
-        return -EINVAL;
+        goto error;
     }
 
     hr = whp_dispatch.WHvCreateVirtualProcessor(
@@ -1234,17 +1254,72 @@ int whpx_init_vcpu(CPUState *cpu)
         error_report("WHPX: Failed to create a virtual processor,"
                      " hr=%08lx", hr);
         whp_dispatch.WHvEmulatorDestroyEmulator(vcpu->emulator);
-        g_free(vcpu);
+        ret = -EINVAL;
-        return -EINVAL;
+        goto error;
+    }
+
+    /*
+     * vcpu's TSC frequency is either specified by user, or use the value
+     * provided by Hyper-V if the former is not present. In the latter case, we
+     * query it from Hyper-V and record in env->tsc_khz, so that vcpu's TSC
+     * frequency can be migrated later via this field.
+     */
+    if (!env->tsc_khz) {
+        hr = whp_dispatch.WHvGetCapability(
+            WHvCapabilityCodeProcessorClockFrequency, &freq, sizeof(freq),
+                NULL);
+        if (hr != WHV_E_UNKNOWN_CAPABILITY) {
+            if (FAILED(hr)) {
+                printf("WHPX: Failed to query tsc frequency, hr=0x%08lx\n", hr);
+            } else {
+                env->tsc_khz = freq / 1000; /* Hz to KHz */
+            }
+        }
+    }
+
+    env->apic_bus_freq = HYPERV_APIC_BUS_FREQUENCY;
+    hr = whp_dispatch.WHvGetCapability(
+        WHvCapabilityCodeInterruptClockFrequency, &freq, sizeof(freq), NULL);
+    if (hr != WHV_E_UNKNOWN_CAPABILITY) {
+        if (FAILED(hr)) {
+            printf("WHPX: Failed to query apic bus frequency hr=0x%08lx\n", hr);
+        } else {
+            env->apic_bus_freq = freq;
+        }
+    }
+
+    /*
+     * If the vmware cpuid frequency leaf option is set, and we have a valid
+     * tsc value, trap the corresponding cpuid's.
+     */
+    if (x86_cpu->vmware_cpuid_freq && env->tsc_khz) {
+        UINT32 cpuidExitList[] = {1, 0x80000001, 0x40000000, 0x40000010};
+
+        hr = whp_dispatch.WHvSetPartitionProperty(
+                whpx->partition,
+                WHvPartitionPropertyCodeCpuidExitList,
+                cpuidExitList,
+                RTL_NUMBER_OF(cpuidExitList) * sizeof(UINT32));
+
+        if (FAILED(hr)) {
+            error_report("WHPX: Failed to set partition CpuidExitList hr=%08lx",
+                        hr);
+            ret = -EINVAL;
+            goto error;
+        }
     }
 
     vcpu->interruptable = true;
-
     cpu->vcpu_dirty = true;
     cpu->hax_vcpu = (struct hax_vcpu_state *)vcpu;
     qemu_add_vm_change_state_handler(whpx_cpu_update_state, cpu->env_ptr);
 
     return 0;
+
+error:
+    g_free(vcpu);
+
+    return ret;
 }
 
 int whpx_vcpu_exec(CPUState *cpu)
@@ -1493,6 +1568,7 @@ static int whpx_accel_init(MachineState *ms)
     WHV_CAPABILITY whpx_cap;
     UINT32 whpx_cap_size;
     WHV_PARTITION_PROPERTY prop;
+    UINT32 cpuidExitList[] = {1, 0x80000001};
 
     whpx = &whpx_global;
 
@@ -1551,7 +1627,6 @@ static int whpx_accel_init(MachineState *ms)
         goto error;
     }
 
-    UINT32 cpuidExitList[] = {1, 0x80000001};
     hr = whp_dispatch.WHvSetPartitionProperty(
         whpx->partition,
         WHvPartitionPropertyCodeCpuidExitList,
@@ -1579,14 +1654,13 @@ static int whpx_accel_init(MachineState *ms)
     printf("Windows Hypervisor Platform accelerator is operational\n");
     return 0;
 
-  error:
+error:
 
     if (NULL != whpx->partition) {
         whp_dispatch.WHvDeletePartition(whpx->partition);
         whpx->partition = NULL;
     }
 
-
     return ret;
 }