KVM: x86: Rename and invert async #PF's send_user_only flag to send_always

Rename send_user_only to avoid "user", because KVM's ABI is to not inject
page faults into CPL0, whereas "user" in x86 is specifically CPL3.  Invert
the polarity to keep the naming simple and unambiguous.  E.g. while KVM
often refers to CPL0 as "kernel", that terminology isn't ubiquitous, and
"send_kernel" could be misconstrued as "send only to kernel".

Link: https://lore.kernel.org/r/20250215010609.1199982-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

Author: sean-jc

arch/x86/include/asm/kvm_host.h

@@ -997,8 +997,8 @@ struct kvm_vcpu_arch {
 		u64 msr_int_val; /* MSR_KVM_ASYNC_PF_INT */
 		u16 vec;
 		u32 id;
-		bool send_user_only;
 		u32 host_apf_flags;
+		bool send_always;
 		bool delivery_as_pf_vmexit;
 		bool pageready_pending;
 	} apf;

arch/x86/kvm/x86.c

@@ -3554,7 +3554,7 @@ static int kvm_pv_enable_async_pf(struct kvm_vcpu *vcpu, u64 data)
 					sizeof(u64)))
 		return 1;
 
-	vcpu->arch.apf.send_user_only = !(data & KVM_ASYNC_PF_SEND_ALWAYS);
+	vcpu->arch.apf.send_always = (data & KVM_ASYNC_PF_SEND_ALWAYS);
 	vcpu->arch.apf.delivery_as_pf_vmexit = data & KVM_ASYNC_PF_DELIVERY_AS_PF_VMEXIT;
 
 	kvm_async_pf_wakeup_all(vcpu);
@@ -13386,7 +13386,7 @@ static bool kvm_can_deliver_async_pf(struct kvm_vcpu *vcpu)
 	if (!kvm_pv_async_pf_enabled(vcpu))
 		return false;
 
-	if (vcpu->arch.apf.send_user_only &&
+	if (!vcpu->arch.apf.send_always &&
 	    (vcpu->arch.guest_state_protected || !kvm_x86_call(get_cpl)(vcpu)))
 		return false;