Pinning vcpu to cpu to work around a hang issue on Intel.

Author: Taogle2018

gvm-main.c

@@ -29,6 +29,7 @@ static PCALLBACK_OBJECT power_callback;
 static PVOID power_callback_handle;
 static int suspend;
 static atomic_t suspend_wait;
+char CPUString[13];
 
 DRIVER_INITIALIZE DriverEntry;
 
@@ -82,7 +83,6 @@ VOID gvmDriverUnload(PDRIVER_OBJECT pDrvObj)
 	//XXX: Clean up other devices?
 	PDEVICE_OBJECT pDevObj = pDrvObj->DeviceObject;
 	UNICODE_STRING DosDeviceName;
-	char CPUString[13];
 	unsigned int eax = 0;
 
 	if (power_callback_handle)
@@ -379,8 +379,6 @@ NTSTATUS _stdcall DriverEntry(PDRIVER_OBJECT pDrvObj, PUNICODE_STRING pRegPath)
 	struct gvm_device_extension *pDevExt;
 	NTSTATUS rc;
 	int r;
-	char CPUString[13];
-	unsigned int eax = 0;
 
 	rc = NtKrUtilsInit();
 	if (!NT_SUCCESS(rc))
@@ -393,14 +391,9 @@ NTSTATUS _stdcall DriverEntry(PDRIVER_OBJECT pDrvObj, PUNICODE_STRING pRegPath)
 		return STATUS_NO_MEMORY;
 	RtlZeroBytes(pZeroPage, PAGE_SIZE);
 
-	RtlZeroBytes(CPUString, 13);
-	cpuid(0, &eax,
-	      (unsigned int *)&CPUString[0],
-	      (unsigned int *)&CPUString[8],
-	      (unsigned int *)&CPUString[4]);
-	if (strcmp("GenuineIntel", CPUString) == 0)
+	if (is_Intel())
 		r = vmx_init();
-	else if (strcmp("AuthenticAMD", CPUString) == 0)
+	else if (is_AMD())
 		r = svm_init();
 	else {
 		DbgPrint("Processor %s is not supported\n", CPUString);

ntkrutils.c

@@ -48,6 +48,7 @@ struct cpumask __cpu_online_mask;
 struct cpumask *cpu_online_mask = &__cpu_online_mask;
 unsigned int cpu_online_count;
 u64 max_pagen;
+char CPUString[13];
 
 DEFINE_PER_CPU(struct cpu_getput_cxt, cpu_getput_cxt);
 
@@ -536,6 +537,13 @@ NTSTATUS NtKrUtilsInit(void)
 	NTSTATUS rc;
 	int cpu;
 	PROCESSOR_NUMBER cpu_number;
+	unsigned int eax;
+
+	RtlZeroBytes(CPUString, 13);
+	cpuid(0, &eax,
+	      (unsigned int *)&CPUString[0],
+	      (unsigned int *)&CPUString[8],
+	      (unsigned int *)&CPUString[4]);
 
 	cpu_features_init();
 

ntkrutils.h

@@ -1287,5 +1287,20 @@ static inline void xsetbv(u32 index, u64 value)
 	_xsetbv(index, value);
 }
 
+/*
+ * host cpu vendor
+ */
+extern char CPUString[13];
+
+static __inline bool is_Intel()
+{
+	return !strcmp("GenuineIntel", CPUString);
+}
+
+static __inline bool is_AMD()
+{
+	return !strcmp("AuthenticAMD", CPUString);
+}
+
 extern NTSTATUS NtKrUtilsInit(void);
 extern void NtKrUtilsExit(void);

virt/kvm/kvm_main.c

@@ -1871,11 +1871,13 @@ static int kvm_vm_ioctl_create_vcpu(PDEVICE_OBJECT pDevObj, PIRP pIrp, void *arg
 	mutex_unlock(&kvm->lock);
 	kvm_arch_vcpu_postcreate(vcpu);
 
-	Affinity = (KAFFINITY)1 << (
-		cpu_online_count - 1
-		- 2 * vcpu->vcpu_id / cpu_online_count % 2
-		- vcpu->vcpu_id * 2 % cpu_online_count);
-	KeSetSystemAffinityThread(Affinity);
+	if (is_Intel()) {
+		Affinity = (KAFFINITY)1 << (
+			cpu_online_count - 1
+			- 2 * vcpu->vcpu_id / cpu_online_count % 2
+			- vcpu->vcpu_id * 2 % cpu_online_count);
+		KeSetSystemAffinityThread(Affinity);
+	}
 	return r;
 
 unlock_vcpu_destroy:
@@ -1914,6 +1916,7 @@ NTSTATUS kvm_vcpu_fast_ioctl_run(PDEVICE_OBJECT pDevObj)
 	struct kvm_vcpu *vcpu = devext->PrivData;
 	LARGE_INTEGER expire;
 	expire.QuadPart = (u64)-10000000;
+	KAFFINITY Affinity;
 	int r = -EINVAL;
 
 	if (vcpu->kvm->process != IoGetCurrentProcess())
@@ -1928,6 +1931,13 @@ NTSTATUS kvm_vcpu_fast_ioctl_run(PDEVICE_OBJECT pDevObj)
 				NULL,
 				KernelMode,
 				NULL);
+		if (is_Intel()) {
+			Affinity = (KAFFINITY)1 << (
+				cpu_online_count - 1
+				- 2 * vcpu->vcpu_id / cpu_online_count % 2
+				- vcpu->vcpu_id * 2 % cpu_online_count);
+			KeSetSystemAffinityThread(Affinity);
+		}
 	}
 	/* vcpu_run has to return to user space periodically otherwise
 	 * vcpu thread could hang when process terminates.
@@ -1959,26 +1969,7 @@ NTSTATUS kvm_vcpu_ioctl(PDEVICE_OBJECT pDevObj, PIRP pIrp,
 
 	switch (ioctl) {
 	case GVM_RUN:
-		r = -EINVAL;
-		if (vcpu->thread != PsGetCurrentThread()) {
-			vcpu->thread = PsGetCurrentThread();
-			KeInitializeApc(&vcpu->apc, vcpu->thread,
-					OriginalApcEnvironment,
-					gvmWaitSuspend,
-					NULL,
-					NULL,
-					KernelMode,
-					NULL);
-		}
-		/* vcpu_run has to return to user space periodically otherwise
-		 * vcpu thread could hang when process terminates.
-		 */
-		KeSetTimer(&vcpu->run_timer, expire, &vcpu->run_timer_dpc);
-
-		r = kvm_arch_vcpu_ioctl_run(vcpu, vcpu->run);
-
-		KeCancelTimer(&vcpu->run_timer);
-		KeInitializeTimer(&vcpu->run_timer);
+		r = kvm_vcpu_fast_ioctl_run(pDevObj);
 		break;
 	case GVM_VCPU_MMAP:
 		r = -EINVAL;