KVM: arm64: Make VMID bits accessible outside of allocator

Since we already set the kvm_arm_vmid_bits in the VMID allocator
init function, make it accessible outside as well so that it can
be used in the subsequent patch.
Suggested-by: Will Deacon <will@kernel.org>
Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211122121844.867-3-shameerali.kolothum.thodi@huawei.com

arch/arm64/include/asm/kvm_host.h

@@ -692,6 +692,7 @@ int kvm_arm_pvtime_get_attr(struct kvm_vcpu *vcpu,
 int kvm_arm_pvtime_has_attr(struct kvm_vcpu *vcpu,
 			    struct kvm_device_attr *attr);
 
+extern unsigned int kvm_arm_vmid_bits;
 int kvm_arm_vmid_alloc_init(void);
 void kvm_arm_vmid_alloc_free(void);
 void kvm_arm_vmid_update(struct kvm_vmid *kvm_vmid);

arch/arm64/kernel/image-vars.h

@@ -79,6 +79,9 @@ KVM_NVHE_ALIAS(__hyp_stub_vectors);
 /* Kernel symbol used by icache_is_vpipt(). */
 KVM_NVHE_ALIAS(__icache_flags);
 
+/* VMID bits set by the KVM VMID allocator */
+KVM_NVHE_ALIAS(kvm_arm_vmid_bits);
+
 /* Kernel symbols needed for cpus_have_final/const_caps checks. */
 KVM_NVHE_ALIAS(arm64_const_caps_ready);
 KVM_NVHE_ALIAS(cpu_hwcap_keys);

arch/arm64/kvm/vmid.c

@@ -16,7 +16,7 @@
 #include <asm/kvm_asm.h>
 #include <asm/kvm_mmu.h>
 
-static unsigned int kvm_arm_vmid_bits;
+unsigned int kvm_arm_vmid_bits;
 static DEFINE_RAW_SPINLOCK(cpu_vmid_lock);
 
 static atomic64_t vmid_generation;