KVM: Rename kvm_arch_vcpu_async_ioctl() to kvm_arch_vcpu_unlocked_ioctl()

Rename the "async" ioctl API to "unlocked" so that upcoming usage in x86's
TDX code doesn't result in a massive misnomer. To avoid having to retry
SEAMCALLs, TDX needs to acquire kvm->lock *and* all vcpu->mutex locks, and
acquiring all of those locks after/inside the current vCPU's mutex is a
non-starter. However, TDX also needs to acquire the vCPU's mutex and load
the vCPU, i.e. the handling is very much not async to the vCPU.

No functional change intended.

Acked-by: Claudio Imbrenda <[e-mail]>
Reviewed-by: Yan Zhao <[e-mail]>
Tested-by: Yan Zhao <[e-mail]>
Tested-by: Kai Huang <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Sean Christopherson <[e-mail]>

arch/arm64/kvm/arm.c

···
 	return r;
 }
 
-long kvm_arch_vcpu_async_ioctl(struct file *filp, unsigned int ioctl,
-			       unsigned long arg)
+long kvm_arch_vcpu_unlocked_ioctl(struct file *filp, unsigned int ioctl,
+				  unsigned long arg)
 {
 	return -ENOIOCTLCMD;
 }

arch/loongarch/kvm/vcpu.c

···
 	return 0;
 }
 
-long kvm_arch_vcpu_async_ioctl(struct file *filp,
-			       unsigned int ioctl, unsigned long arg)
+long kvm_arch_vcpu_unlocked_ioctl(struct file *filp, unsigned int ioctl,
+				  unsigned long arg)
 {
 	void __user *argp = (void __user *)arg;
 	struct kvm_vcpu *vcpu = filp->private_data;

arch/mips/kvm/mips.c

···
 	return r;
 }
 
-long kvm_arch_vcpu_async_ioctl(struct file *filp, unsigned int ioctl,
-			       unsigned long arg)
+long kvm_arch_vcpu_unlocked_ioctl(struct file *filp, unsigned int ioctl,
+				  unsigned long arg)
 {
 	struct kvm_vcpu *vcpu = filp->private_data;
 	void __user *argp = (void __user *)arg;

arch/powerpc/kvm/powerpc.c

···
 	return -EINVAL;
 }
 
-long kvm_arch_vcpu_async_ioctl(struct file *filp,
-			       unsigned int ioctl, unsigned long arg)
+long kvm_arch_vcpu_unlocked_ioctl(struct file *filp, unsigned int ioctl,
+				  unsigned long arg)
 {
 	struct kvm_vcpu *vcpu = filp->private_data;
 	void __user *argp = (void __user *)arg;

arch/riscv/kvm/vcpu.c

···
 	return VM_FAULT_SIGBUS;
 }
 
-long kvm_arch_vcpu_async_ioctl(struct file *filp,
-			       unsigned int ioctl, unsigned long arg)
+long kvm_arch_vcpu_unlocked_ioctl(struct file *filp, unsigned int ioctl,
+				  unsigned long arg)
 {
 	struct kvm_vcpu *vcpu = filp->private_data;
 	void __user *argp = (void __user *)arg;

arch/s390/kvm/kvm-s390.c

···
 	return r;
 }
 
-long kvm_arch_vcpu_async_ioctl(struct file *filp,
-			       unsigned int ioctl, unsigned long arg)
+long kvm_arch_vcpu_unlocked_ioctl(struct file *filp, unsigned int ioctl,
+				  unsigned long arg)
 {
 	struct kvm_vcpu *vcpu = filp->private_data;
 	void __user *argp = (void __user *)arg;

arch/x86/kvm/x86.c

···
 	return 0;
 }
 
-long kvm_arch_vcpu_async_ioctl(struct file *filp, unsigned int ioctl,
-			       unsigned long arg)
+long kvm_arch_vcpu_unlocked_ioctl(struct file *filp, unsigned int ioctl,
+				  unsigned long arg)
 {
 	return -ENOIOCTLCMD;
 }

include/linux/kvm_host.h

···
 			unsigned int ioctl, unsigned long arg);
 long kvm_arch_vcpu_ioctl(struct file *filp,
 			 unsigned int ioctl, unsigned long arg);
+long kvm_arch_vcpu_unlocked_ioctl(struct file *filp,
+				  unsigned int ioctl, unsigned long arg);
 vm_fault_t kvm_arch_vcpu_fault(struct kvm_vcpu *vcpu, struct vm_fault *vmf);
 
 int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext);
···
 }
 #endif /* CONFIG_HAVE_KVM_NO_POLL */
 
-long kvm_arch_vcpu_async_ioctl(struct file *filp,
-			       unsigned int ioctl, unsigned long arg);
 void kvm_arch_guest_memory_reclaimed(struct kvm *kvm);
 
 #ifdef CONFIG_HAVE_KVM_VCPU_RUN_PID_CHANGE

virt/kvm/kvm_main.c

···
 		return r;
 
 	/*
-	 * Some architectures have vcpu ioctls that are asynchronous to vcpu
-	 * execution; mutex_lock() would break them.
+	 * Let arch code handle select vCPU ioctls without holding vcpu->mutex,
+	 * e.g. to support ioctls that can run asynchronous to vCPU execution.
 	 */
-	r = kvm_arch_vcpu_async_ioctl(filp, ioctl, arg);
+	r = kvm_arch_vcpu_unlocked_ioctl(filp, ioctl, arg);
 	if (r != -ENOIOCTLCMD)
 		return r;