KVM: selftests: Add a "struct kvm_mmu_arch arch" member to kvm_mmu

Add an arch structure+field in "struct kvm_mmu" so that architectures can
track arch-specific information for a given MMU.

No functional change intended.

Reviewed-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Link: https://patch.msgid.link/20251230230150.4150236-9-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

Author: sean-jc

tools/testing/selftests/kvm/include/arm64/kvm_util_arch.h

@@ -2,6 +2,8 @@
 #ifndef SELFTEST_KVM_UTIL_ARCH_H
 #define SELFTEST_KVM_UTIL_ARCH_H
 
+struct kvm_mmu_arch {};
+
 struct kvm_vm_arch {
 	bool	has_gic;
 	int	gic_fd;

tools/testing/selftests/kvm/include/kvm_util.h

@@ -92,6 +92,8 @@ struct kvm_mmu {
 	bool pgd_created;
 	uint64_t pgd;
 	int pgtable_levels;
+
+	struct kvm_mmu_arch arch;
 };
 
 struct kvm_vm {

tools/testing/selftests/kvm/include/loongarch/kvm_util_arch.h

@@ -2,6 +2,7 @@
 #ifndef SELFTEST_KVM_UTIL_ARCH_H
 #define SELFTEST_KVM_UTIL_ARCH_H
 
+struct kvm_mmu_arch {};
 struct kvm_vm_arch {};
 
 #endif  // SELFTEST_KVM_UTIL_ARCH_H

tools/testing/selftests/kvm/include/riscv/kvm_util_arch.h

@@ -2,6 +2,7 @@
 #ifndef SELFTEST_KVM_UTIL_ARCH_H
 #define SELFTEST_KVM_UTIL_ARCH_H
 
+struct kvm_mmu_arch {};
 struct kvm_vm_arch {};
 
 #endif  // SELFTEST_KVM_UTIL_ARCH_H

tools/testing/selftests/kvm/include/s390/kvm_util_arch.h

@@ -2,6 +2,7 @@
 #ifndef SELFTEST_KVM_UTIL_ARCH_H
 #define SELFTEST_KVM_UTIL_ARCH_H
 
+struct kvm_mmu_arch {};
 struct kvm_vm_arch {};
 
 #endif  // SELFTEST_KVM_UTIL_ARCH_H

tools/testing/selftests/kvm/include/x86/kvm_util_arch.h

@@ -10,6 +10,8 @@
 
 extern bool is_forced_emulation_enabled;
 
+struct kvm_mmu_arch {};
+
 struct kvm_vm_arch {
 	vm_vaddr_t gdt;
 	vm_vaddr_t tss;