KVM: arm64: Set host stage 2 using kvm_nvhe_init_params

Move the registers relevant to host stage 2 enablement to
kvm_nvhe_init_params to prepare the ground for enabling it in later
patches.
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210319100146.1149909-22-qperret@google.com

arch/arm64/include/asm/kvm_asm.h

@@ -158,6 +158,9 @@ struct kvm_nvhe_init_params {
 	unsigned long tpidr_el2;
 	unsigned long stack_hyp_va;
 	phys_addr_t pgd_pa;
+	unsigned long hcr_el2;
+	unsigned long vttbr;
+	unsigned long vtcr;
 };
 
 /* Translate a kernel address @ptr into its equivalent linear mapping */

arch/arm64/kernel/asm-offsets.c

@@ -120,6 +120,9 @@ int main(void)
   DEFINE(NVHE_INIT_TPIDR_EL2,	offsetof(struct kvm_nvhe_init_params, tpidr_el2));
   DEFINE(NVHE_INIT_STACK_HYP_VA,	offsetof(struct kvm_nvhe_init_params, stack_hyp_va));
   DEFINE(NVHE_INIT_PGD_PA,	offsetof(struct kvm_nvhe_init_params, pgd_pa));
+  DEFINE(NVHE_INIT_HCR_EL2,	offsetof(struct kvm_nvhe_init_params, hcr_el2));
+  DEFINE(NVHE_INIT_VTTBR,	offsetof(struct kvm_nvhe_init_params, vttbr));
+  DEFINE(NVHE_INIT_VTCR,	offsetof(struct kvm_nvhe_init_params, vtcr));
 #endif
 #ifdef CONFIG_CPU_PM
   DEFINE(CPU_CTX_SP,		offsetof(struct cpu_suspend_ctx, sp));

arch/arm64/kvm/arm.c

@@ -1418,6 +1418,11 @@ static void cpu_prepare_hyp_mode(int cpu)
 
 	params->stack_hyp_va = kern_hyp_va(per_cpu(kvm_arm_hyp_stack_page, cpu) + PAGE_SIZE);
 	params->pgd_pa = kvm_mmu_get_httbr();
+	if (is_protected_kvm_enabled())
+		params->hcr_el2 = HCR_HOST_NVHE_PROTECTED_FLAGS;
+	else
+		params->hcr_el2 = HCR_HOST_NVHE_FLAGS;
+	params->vttbr = params->vtcr = 0;
 
 	/*
 	 * Flush the init params from the data cache because the struct will

arch/arm64/kvm/hyp/nvhe/hyp-init.S

@@ -83,11 +83,6 @@ SYM_CODE_END(__kvm_hyp_init)
  * x0: struct kvm_nvhe_init_params PA
  */
 SYM_CODE_START_LOCAL(___kvm_hyp_init)
-alternative_if ARM64_KVM_PROTECTED_MODE
-	mov_q	x1, HCR_HOST_NVHE_PROTECTED_FLAGS
-	msr	hcr_el2, x1
-alternative_else_nop_endif
-
 	ldr	x1, [x0, #NVHE_INIT_TPIDR_EL2]
 	msr	tpidr_el2, x1
 
@@ -97,6 +92,15 @@ alternative_else_nop_endif
 	ldr	x1, [x0, #NVHE_INIT_MAIR_EL2]
 	msr	mair_el2, x1
 
+	ldr	x1, [x0, #NVHE_INIT_HCR_EL2]
+	msr	hcr_el2, x1
+
+	ldr	x1, [x0, #NVHE_INIT_VTTBR]
+	msr	vttbr_el2, x1
+
+	ldr	x1, [x0, #NVHE_INIT_VTCR]
+	msr	vtcr_el2, x1
+
 	ldr	x1, [x0, #NVHE_INIT_PGD_PA]
 	phys_to_ttbr x2, x1
 alternative_if ARM64_HAS_CNP

arch/arm64/kvm/hyp/nvhe/switch.c

@@ -97,10 +97,7 @@ static void __deactivate_traps(struct kvm_vcpu *vcpu)
 	mdcr_el2 |= MDCR_EL2_E2PB_MASK << MDCR_EL2_E2PB_SHIFT;
 
 	write_sysreg(mdcr_el2, mdcr_el2);
-	if (is_protected_kvm_enabled())
-		write_sysreg(HCR_HOST_NVHE_PROTECTED_FLAGS, hcr_el2);
-	else
-		write_sysreg(HCR_HOST_NVHE_FLAGS, hcr_el2);
+	write_sysreg(this_cpu_ptr(&kvm_init_params)->hcr_el2, hcr_el2);
 
 	cptr = CPTR_EL2_DEFAULT;
 	if (vcpu_has_sve(vcpu) && (vcpu->arch.flags & KVM_ARM64_FP_ENABLED))