KVM: arm64: Unify stage-2 programming behind __load_stage2()

The protected mode relies on a separate helper to load the
S2 context. Move over to the __load_guest_stage2() helper
instead, and rename it to __load_stage2() to present a unified
interface.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Jade Alglave <jade.alglave@arm.com>
Cc: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210806113109.2475-5-will@kernel.org

arch/arm64/include/asm/kvm_mmu.h

@@ -267,9 +267,10 @@ static __always_inline u64 kvm_get_vttbr(struct kvm_s2_mmu *mmu)
  * Must be called from hyp code running at EL2 with an updated VTTBR
  * and interrupts disabled.
  */
-static __always_inline void __load_stage2(struct kvm_s2_mmu *mmu, unsigned long vtcr)
+static __always_inline void __load_stage2(struct kvm_s2_mmu *mmu,
+					  struct kvm_arch *arch)
 {
-	write_sysreg(vtcr, vtcr_el2);
+	write_sysreg(arch->vtcr, vtcr_el2);
 	write_sysreg(kvm_get_vttbr(mmu), vttbr_el2);
 
 	/*
@@ -280,12 +281,6 @@ static __always_inline void __load_stage2(struct kvm_s2_mmu *mmu, unsigned long
 	asm(ALTERNATIVE("nop", "isb", ARM64_WORKAROUND_SPECULATIVE_AT));
 }
 
-static __always_inline void __load_guest_stage2(struct kvm_s2_mmu *mmu,
-						struct kvm_arch *arch)
-{
-	__load_stage2(mmu, arch->vtcr);
-}
-
 static inline struct kvm *kvm_s2_mmu_to_kvm(struct kvm_s2_mmu *mmu)
 {
 	return container_of(mmu->arch, struct kvm, arch);

arch/arm64/kvm/hyp/include/nvhe/mem_protect.h

@@ -29,7 +29,7 @@ void handle_host_mem_abort(struct kvm_cpu_context *host_ctxt);
 static __always_inline void __load_host_stage2(void)
 {
 	if (static_branch_likely(&kvm_protected_mode_initialized))
-		__load_stage2(&host_kvm.arch.mmu, host_kvm.arch.vtcr);
+		__load_stage2(&host_kvm.arch.mmu, &host_kvm.arch);
 	else
 		write_sysreg(0, vttbr_el2);
 }

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

@@ -126,7 +126,7 @@ int __pkvm_prot_finalize(void)
 	kvm_flush_dcache_to_poc(params, sizeof(*params));
 
 	write_sysreg(params->hcr_el2, hcr_el2);
-	__load_stage2(&host_kvm.arch.mmu, host_kvm.arch.vtcr);
+	__load_stage2(&host_kvm.arch.mmu, &host_kvm.arch);
 
 	/*
 	 * Make sure to have an ISB before the TLB maintenance below but only

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

@@ -215,7 +215,7 @@ int __kvm_vcpu_run(struct kvm_vcpu *vcpu)
 	__sysreg_restore_state_nvhe(guest_ctxt);
 
 	mmu = kern_hyp_va(vcpu->arch.hw_mmu);
-	__load_guest_stage2(mmu, kern_hyp_va(mmu->arch));
+	__load_stage2(mmu, kern_hyp_va(mmu->arch));
 	__activate_traps(vcpu);
 
 	__hyp_vgic_restore_state(vcpu);

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

@@ -34,12 +34,12 @@ static void __tlb_switch_to_guest(struct kvm_s2_mmu *mmu,
 	}
 
 	/*
-	 * __load_guest_stage2() includes an ISB only when the AT
+	 * __load_stage2() includes an ISB only when the AT
 	 * workaround is applied. Take care of the opposite condition,
 	 * ensuring that we always have an ISB, but not two ISBs back
 	 * to back.
 	 */
-	__load_guest_stage2(mmu, kern_hyp_va(mmu->arch));
+	__load_stage2(mmu, kern_hyp_va(mmu->arch));
 	asm(ALTERNATIVE("isb", "nop", ARM64_WORKAROUND_SPECULATIVE_AT));
 }
 

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

@@ -124,11 +124,11 @@ static int __kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu)
 	 *
 	 * We have already configured the guest's stage 1 translation in
 	 * kvm_vcpu_load_sysregs_vhe above.  We must now call
-	 * __load_guest_stage2 before __activate_traps, because
-	 * __load_guest_stage2 configures stage 2 translation, and
+	 * __load_stage2 before __activate_traps, because
+	 * __load_stage2 configures stage 2 translation, and
 	 * __activate_traps clear HCR_EL2.TGE (among other things).
 	 */
-	__load_guest_stage2(vcpu->arch.hw_mmu, vcpu->arch.hw_mmu->arch);
+	__load_stage2(vcpu->arch.hw_mmu, vcpu->arch.hw_mmu->arch);
 	__activate_traps(vcpu);
 
 	__kvm_adjust_pc(vcpu);

arch/arm64/kvm/hyp/vhe/tlb.c

@@ -50,10 +50,10 @@ static void __tlb_switch_to_guest(struct kvm_s2_mmu *mmu,
 	 *
 	 * ARM erratum 1165522 requires some special handling (again),
 	 * as we need to make sure both stages of translation are in
-	 * place before clearing TGE. __load_guest_stage2() already
+	 * place before clearing TGE. __load_stage2() already
 	 * has an ISB in order to deal with this.
 	 */
-	__load_guest_stage2(mmu, mmu->arch);
+	__load_stage2(mmu, mmu->arch);
 	val = read_sysreg(hcr_el2);
 	val &= ~HCR_TGE;
 	write_sysreg(val, hcr_el2);