KVM: x86/xen: Move kvm_xen_hvm_config field into kvm_xen

Now that all KVM usage of the Xen HVM config information is buried behind
CONFIG_KVM_XEN=y, move the per-VM kvm_xen_hvm_config field out of kvm_arch
and into kvm_xen.

No functional change intended.

Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>
Link: https://lore.kernel.org/r/20250215011437.1203084-6-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

Author: sean-jc

arch/x86/include/asm/kvm_host.h

@@ -1188,6 +1188,8 @@ struct kvm_xen {
 	struct gfn_to_pfn_cache shinfo_cache;
 	struct idr evtchn_ports;
 	unsigned long poll_mask[BITS_TO_LONGS(KVM_MAX_VCPUS)];
+
+	struct kvm_xen_hvm_config hvm_config;
 };
 #endif
 
@@ -1419,7 +1421,6 @@ struct kvm_arch {
 
 #ifdef CONFIG_KVM_XEN
 	struct kvm_xen xen;
-	struct kvm_xen_hvm_config xen_hvm_config;
 #endif
 
 	bool backwards_tsc_observed;

arch/x86/kvm/x86.c

@@ -3188,7 +3188,7 @@ static int kvm_guest_time_update(struct kvm_vcpu *v)
 	 * problems if they observe PVCLOCK_TSC_STABLE_BIT in the pvclock flags.
 	 */
 	bool xen_pvclock_tsc_unstable =
-		ka->xen_hvm_config.flags & KVM_XEN_HVM_CONFIG_PVCLOCK_TSC_UNSTABLE;
+		ka->xen.hvm_config.flags & KVM_XEN_HVM_CONFIG_PVCLOCK_TSC_UNSTABLE;
 #endif
 
 	kernel_ns = 0;

arch/x86/kvm/xen.c

@@ -1280,10 +1280,10 @@ int kvm_xen_write_hypercall_page(struct kvm_vcpu *vcpu, u64 data)
 		 * Note, truncation is a non-issue as 'lm' is guaranteed to be
 		 * false for a 32-bit kernel, i.e. when hva_t is only 4 bytes.
 		 */
-		hva_t blob_addr = lm ? kvm->arch.xen_hvm_config.blob_addr_64
-				     : kvm->arch.xen_hvm_config.blob_addr_32;
-		u8 blob_size = lm ? kvm->arch.xen_hvm_config.blob_size_64
-				  : kvm->arch.xen_hvm_config.blob_size_32;
+		hva_t blob_addr = lm ? kvm->arch.xen.hvm_config.blob_addr_64
+				     : kvm->arch.xen.hvm_config.blob_addr_32;
+		u8 blob_size = lm ? kvm->arch.xen.hvm_config.blob_size_64
+				  : kvm->arch.xen.hvm_config.blob_size_32;
 		u8 *page;
 		int ret;
 
@@ -1335,13 +1335,13 @@ int kvm_xen_hvm_config(struct kvm *kvm, struct kvm_xen_hvm_config *xhc)
 
 	mutex_lock(&kvm->arch.xen.xen_lock);
 
-	if (xhc->msr && !kvm->arch.xen_hvm_config.msr)
+	if (xhc->msr && !kvm->arch.xen.hvm_config.msr)
 		static_branch_inc(&kvm_xen_enabled.key);
-	else if (!xhc->msr && kvm->arch.xen_hvm_config.msr)
+	else if (!xhc->msr && kvm->arch.xen.hvm_config.msr)
 		static_branch_slow_dec_deferred(&kvm_xen_enabled);
 
-	old_flags = kvm->arch.xen_hvm_config.flags;
-	memcpy(&kvm->arch.xen_hvm_config, xhc, sizeof(*xhc));
+	old_flags = kvm->arch.xen.hvm_config.flags;
+	memcpy(&kvm->arch.xen.hvm_config, xhc, sizeof(*xhc));
 
 	mutex_unlock(&kvm->arch.xen.xen_lock);
 
@@ -1422,7 +1422,7 @@ static bool kvm_xen_schedop_poll(struct kvm_vcpu *vcpu, bool longmode,
 	int i;
 
 	if (!lapic_in_kernel(vcpu) ||
-	    !(vcpu->kvm->arch.xen_hvm_config.flags & KVM_XEN_HVM_CONFIG_EVTCHN_SEND))
+	    !(vcpu->kvm->arch.xen.hvm_config.flags & KVM_XEN_HVM_CONFIG_EVTCHN_SEND))
 		return false;
 
 	if (IS_ENABLED(CONFIG_64BIT) && !longmode) {
@@ -2300,6 +2300,6 @@ void kvm_xen_destroy_vm(struct kvm *kvm)
 	}
 	idr_destroy(&kvm->arch.xen.evtchn_ports);
 
-	if (kvm->arch.xen_hvm_config.msr)
+	if (kvm->arch.xen.hvm_config.msr)
 		static_branch_slow_dec_deferred(&kvm_xen_enabled);
 }

arch/x86/kvm/xen.h

@@ -53,21 +53,21 @@ static inline void kvm_xen_sw_enable_lapic(struct kvm_vcpu *vcpu)
 static inline bool kvm_xen_msr_enabled(struct kvm *kvm)
 {
 	return static_branch_unlikely(&kvm_xen_enabled.key) &&
-		kvm->arch.xen_hvm_config.msr;
+		kvm->arch.xen.hvm_config.msr;
 }
 
 static inline bool kvm_xen_is_hypercall_page_msr(struct kvm *kvm, u32 msr)
 {
 	if (!static_branch_unlikely(&kvm_xen_enabled.key))
 		return false;
 
-	return msr && msr == kvm->arch.xen_hvm_config.msr;
+	return msr && msr == kvm->arch.xen.hvm_config.msr;
 }
 
 static inline bool kvm_xen_hypercall_enabled(struct kvm *kvm)
 {
 	return static_branch_unlikely(&kvm_xen_enabled.key) &&
-		(kvm->arch.xen_hvm_config.flags &
+		(kvm->arch.xen.hvm_config.flags &
 		 KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL);
 }