KVM: x86: Replace growing set of *_in_guest bools with a u64

Store each "disabled exit" boolean in a single bit rather than a byte.

No functional change intended.

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Jim Mattson <jmattson@google.com>
Link: https://lore.kernel.org/r/20250530185239.2335185-2-jmattson@google.com
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Link: https://lore.kernel.org/r/20250626001225.744268-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

Author: jsmattsonjr

arch/x86/include/asm/kvm_host.h

@@ -1392,10 +1392,7 @@ struct kvm_arch {
 
 	gpa_t wall_clock;
 
-	bool mwait_in_guest;
-	bool hlt_in_guest;
-	bool pause_in_guest;
-	bool cstate_in_guest;
+	u64 disabled_exits;
 
 	unsigned long irq_sources_bitmap;
 	s64 kvmclock_offset;

arch/x86/kvm/svm/svm.c

@@ -5012,7 +5012,7 @@ static int svm_vm_init(struct kvm *kvm)
 	}
 
 	if (!pause_filter_count || !pause_filter_thresh)
-		kvm->arch.pause_in_guest = true;
+		kvm_disable_exits(kvm, KVM_X86_DISABLE_EXITS_PAUSE);
 
 	if (enable_apicv) {
 		int ret = avic_vm_init(kvm);

arch/x86/kvm/vmx/vmx.c

@@ -7515,7 +7515,7 @@ int vmx_vcpu_create(struct kvm_vcpu *vcpu)
 int vmx_vm_init(struct kvm *kvm)
 {
 	if (!ple_gap)
-		kvm->arch.pause_in_guest = true;
+		kvm_disable_exits(kvm, KVM_X86_DISABLE_EXITS_PAUSE);
 
 	if (boot_cpu_has(X86_BUG_L1TF) && enable_ept) {
 		switch (l1tf_mitigation) {

arch/x86/kvm/x86.c

@@ -6616,14 +6616,7 @@ int kvm_vm_ioctl_enable_cap(struct kvm *kvm,
 		    (cap->args[0] & ~KVM_X86_DISABLE_EXITS_PAUSE))
 			pr_warn_once(SMT_RSB_MSG);
 
-		if (cap->args[0] & KVM_X86_DISABLE_EXITS_PAUSE)
-			kvm->arch.pause_in_guest = true;
-		if (cap->args[0] & KVM_X86_DISABLE_EXITS_MWAIT)
-			kvm->arch.mwait_in_guest = true;
-		if (cap->args[0] & KVM_X86_DISABLE_EXITS_HLT)
-			kvm->arch.hlt_in_guest = true;
-		if (cap->args[0] & KVM_X86_DISABLE_EXITS_CSTATE)
-			kvm->arch.cstate_in_guest = true;
+		kvm_disable_exits(kvm, cap->args[0]);
 		r = 0;
 disable_exits_unlock:
 		mutex_unlock(&kvm->lock);

arch/x86/kvm/x86.h

@@ -499,24 +499,29 @@ static inline u64 nsec_to_cycles(struct kvm_vcpu *vcpu, u64 nsec)
 	    __rem;						\
 	 })
 
+static inline void kvm_disable_exits(struct kvm *kvm, u64 mask)
+{
+	kvm->arch.disabled_exits |= mask;
+}
+
 static inline bool kvm_mwait_in_guest(struct kvm *kvm)
 {
-	return kvm->arch.mwait_in_guest;
+	return kvm->arch.disabled_exits & KVM_X86_DISABLE_EXITS_MWAIT;
 }
 
 static inline bool kvm_hlt_in_guest(struct kvm *kvm)
 {
-	return kvm->arch.hlt_in_guest;
+	return kvm->arch.disabled_exits & KVM_X86_DISABLE_EXITS_HLT;
 }
 
 static inline bool kvm_pause_in_guest(struct kvm *kvm)
 {
-	return kvm->arch.pause_in_guest;
+	return kvm->arch.disabled_exits & KVM_X86_DISABLE_EXITS_PAUSE;
 }
 
 static inline bool kvm_cstate_in_guest(struct kvm *kvm)
 {
-	return kvm->arch.cstate_in_guest;
+	return kvm->arch.disabled_exits & KVM_X86_DISABLE_EXITS_CSTATE;
 }
 
 static inline bool kvm_notify_vmexit_enabled(struct kvm *kvm)