Merge tag 'kvm-x86-tdx-6.19' of https://github.com/kvm-x86/linux into HEAD

KVM TDX changes for 6.19:

 - Overhaul the TDX code to address systemic races where KVM (acting on behalf
   of userspace) could inadvertantly trigger lock contention in the TDX-Module,
   which KVM was either working around in weird, ugly ways, or was simply
   oblivious to (as proven by Yan tripping several KVM_BUG_ON()s with clever
   selftests).

 - Fix a bug where KVM could corrupt a vCPU's cpu_list when freeing a vCPU if
   creating said vCPU failed partway through.

 - Fix a few sparse warnings (bad annotation, 0 != NULL).

 - Use struct_size() to simplify copying capabilities to userspace.

virt/kvm/Kconfig

@@ -78,9 +78,6 @@ config HAVE_KVM_IRQ_BYPASS
        tristate
        select IRQ_BYPASS_MANAGER
 
-config HAVE_KVM_VCPU_ASYNC_IOCTL
-       bool
-
 config HAVE_KVM_VCPU_RUN_PID_CHANGE
        bool
 

virt/kvm/kvm_main.c

@@ -4434,10 +4434,10 @@ static long kvm_vcpu_ioctl(struct file *filp,
 		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;