KVM: arm64: Clean up cpu_init_hyp_mode()

Pull bits of code to the only place where it is used. Remove empty function
__cpu_init_stage2(). Remove redundant has_vhe() check since this function is
nVHE-only. No functional changes intended.

Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200515152056.83158-1-dbrazdil@google.com

arch/arm64/include/asm/kvm_asm.h

@@ -70,6 +70,8 @@ extern int kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu);
 
 extern int __kvm_vcpu_run_nvhe(struct kvm_vcpu *vcpu);
 
+extern void __kvm_enable_ssbs(void);
+
 extern u64 __vgic_v3_get_ich_vtr_el2(void);
 extern u64 __vgic_v3_read_vmcr(void);
 extern void __vgic_v3_write_vmcr(u32 vmcr);

arch/arm64/include/asm/kvm_host.h

@@ -533,39 +533,6 @@ static inline void kvm_init_host_cpu_context(struct kvm_cpu_context *cpu_ctxt)
 	cpu_ctxt->sys_regs[MPIDR_EL1] = read_cpuid_mpidr();
 }
 
-void __kvm_enable_ssbs(void);
-
-static inline void __cpu_init_hyp_mode(phys_addr_t pgd_ptr,
-				       unsigned long hyp_stack_ptr,
-				       unsigned long vector_ptr)
-{
-	/*
-	 * Calculate the raw per-cpu offset without a translation from the
-	 * kernel's mapping to the linear mapping, and store it in tpidr_el2
-	 * so that we can use adr_l to access per-cpu variables in EL2.
-	 */
-	u64 tpidr_el2 = ((u64)this_cpu_ptr(&kvm_host_data) -
-			 (u64)kvm_ksym_ref(kvm_host_data));
-
-	/*
-	 * Call initialization code, and switch to the full blown HYP code.
-	 * If the cpucaps haven't been finalized yet, something has gone very
-	 * wrong, and hyp will crash and burn when it uses any
-	 * cpus_have_const_cap() wrapper.
-	 */
-	BUG_ON(!system_capabilities_finalized());
-	__kvm_call_hyp((void *)pgd_ptr, hyp_stack_ptr, vector_ptr, tpidr_el2);
-
-	/*
-	 * Disabling SSBD on a non-VHE system requires us to enable SSBS
-	 * at EL2.
-	 */
-	if (!has_vhe() && this_cpu_has_cap(ARM64_SSBS) &&
-	    arm64_get_ssbd_state() == ARM64_SSBD_FORCE_DISABLE) {
-		kvm_call_hyp(__kvm_enable_ssbs);
-	}
-}
-
 static inline bool kvm_arch_requires_vhe(void)
 {
 	/*
@@ -601,8 +568,6 @@ int kvm_arm_vcpu_arch_get_attr(struct kvm_vcpu *vcpu,
 int kvm_arm_vcpu_arch_has_attr(struct kvm_vcpu *vcpu,
 			       struct kvm_device_attr *attr);
 
-static inline void __cpu_init_stage2(void) {}
-
 /* Guest/host FPSIMD coordination helpers */
 int kvm_arch_vcpu_run_map_fp(struct kvm_vcpu *vcpu);
 void kvm_arch_vcpu_load_fp(struct kvm_vcpu *vcpu);

arch/arm64/kvm/arm.c

@@ -1273,19 +1273,41 @@ static void cpu_init_hyp_mode(void)
 {
 	phys_addr_t pgd_ptr;
 	unsigned long hyp_stack_ptr;
-	unsigned long stack_page;
 	unsigned long vector_ptr;
+	unsigned long tpidr_el2;
 
 	/* Switch from the HYP stub to our own HYP init vector */
 	__hyp_set_vectors(kvm_get_idmap_vector());
 
+	/*
+	 * Calculate the raw per-cpu offset without a translation from the
+	 * kernel's mapping to the linear mapping, and store it in tpidr_el2
+	 * so that we can use adr_l to access per-cpu variables in EL2.
+	 */
+	tpidr_el2 = ((unsigned long)this_cpu_ptr(&kvm_host_data) -
+		     (unsigned long)kvm_ksym_ref(kvm_host_data));
+
 	pgd_ptr = kvm_mmu_get_httbr();
-	stack_page = __this_cpu_read(kvm_arm_hyp_stack_page);
-	hyp_stack_ptr = stack_page + PAGE_SIZE;
+	hyp_stack_ptr = __this_cpu_read(kvm_arm_hyp_stack_page) + PAGE_SIZE;
 	vector_ptr = (unsigned long)kvm_get_hyp_vector();
 
-	__cpu_init_hyp_mode(pgd_ptr, hyp_stack_ptr, vector_ptr);
-	__cpu_init_stage2();
+	/*
+	 * Call initialization code, and switch to the full blown HYP code.
+	 * If the cpucaps haven't been finalized yet, something has gone very
+	 * wrong, and hyp will crash and burn when it uses any
+	 * cpus_have_const_cap() wrapper.
+	 */
+	BUG_ON(!system_capabilities_finalized());
+	__kvm_call_hyp((void *)pgd_ptr, hyp_stack_ptr, vector_ptr, tpidr_el2);
+
+	/*
+	 * Disabling SSBD on a non-VHE system requires us to enable SSBS
+	 * at EL2.
+	 */
+	if (this_cpu_has_cap(ARM64_SSBS) &&
+	    arm64_get_ssbd_state() == ARM64_SSBD_FORCE_DISABLE) {
+		kvm_call_hyp(__kvm_enable_ssbs);
+	}
 }
 
 static void cpu_hyp_reset(void)